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Objective: To investigate safety and effectiveness of velagliflozin oral solution as sole therapy in naïve and previously insulin-treated diabetic cats., Animals: 252 client-owned cats receiving ≥ 2 doses of velagliflozin; 214 (85%) naïve diabetics and 38 (15%) insulin-treated diabetics., Procedures: Prospective, baseline-controlled, open-label clinical field trial. Cats received velagliflozin orally, once daily. Physical examinations and blood collections were performed days 0, 3, 7, 30, 60, 120, and 180., Results: Data are median (range). Screening blood glucose (BG) was 436 mg/dL (272 to 676 mg/dL). On days 30, 60, 120, and 180, single BG after receiving velagliflozin was 153 mg/dL (62 to 480 mg/dL), 134 mg/dL (64 to 414 mg/dL), 128 mg/dL (55 to 461 mg/dL), and 125 mg/dL (77 to 384 mg/dL), respectively. Screening fructosamine was 538 µmol/L (375 to 794 µmol/L). On the same recheck days, fructosamine was 310 µmol/L (204 to 609 µmol/L), 286 µmol/L (175 to 531 µmol/L), 269 µmol/L (189 to 575 µmol/L), and 263 µmol/L (203 to 620 µmol/L). At day 180, 81% of 158 cats remaining had BG and/or fructosamine within reference ranges; 88.6% (124 of 140) and 87.7% (121 of 138) showed improvement in polyuria and polydipsia, respectively. Ketonuria developed in 35 cats (13.9%), including 18 (7.1%) that had ketoacidosis. Ketoacidosis was less common in naïve diabetic cats (11 of 214 [5.1%]) compared to insulin-treated diabetic cats (7 of 38 [18.4%]). At ketoacidosis diagnosis, 14 of 18 cats (77.8%) were euglycemic (ie, BG < 250 mg/dL). Most episodes of ketosis or ketoacidosis (30 of 35 [85.7%]) occurred within the first 14 days of treatment. Insulin-treated diabetic cats were less likely to complete the trial. No clinical hypoglycemia occurred., Clinical Relevance: Velagliflozin improved glycemic parameters and clinical signs in diabetic cats. Velagliflozin provides an alternative to insulin as a stand-alone treatment of diabetic cats.

Objective: To determine the sodium correction factor for clinical use in hyperglycemic diabetic dogs., Sample: Retrospective analysis of 76 hospitalization episodes from 67 different dogs presenting to the University of Georgia Veterinary Teaching Hospital between January 1, 2015, and January 1, 2023., Methods: For each hospitalization episode, paired blood sodium and glucose concentration measurements were recorded from the time of presentation until glucose concentration was ≤ 201 mg/dL. Therapies administered, primary diagnosis, and concurrent diseases were also recorded for each episode. A linear mixed model was used to determine the sodium correction factor per 100-mg/dL increase in glucose. Piecewise linear mixed models were also constructed for blood glucose measurements ≤ 400 mg/dL and > 400 mg/dL to explore potential correction factor differences between low and high glucose concentrations., Results: A sodium correction factor of a 1.6-mEq/L (95% CI, 1.3 to 1.9 mEq/L) decrease in sodium concentration per 100-mg/dL increase in blood glucose concentration was calculated. Differences in the correction factor between conditions of low and high glucose concentrations could not be determined due to a small sample size of blood glucose values > 400 mg/dL. Most dogs received similar treatments throughout the study period, including balanced isotonic crystalloids (97% [74/76]), electrolyte supplementation (84% [64/76]), and regular insulin (97% [74/76]). Almost all patients (93% [71/76]) had 1 or more concurrent diseases., Clinical Relevance: A sodium correction factor of 1.6 mEq/L (decrease in sodium per 100-mg/dL increase in glucose) is recommended for clinical use in hyperglycemic diabetic dogs.

Objective: To determine total dietary fiber (TDF) concentration and composition of commercial diets used for management of obesity, diabetes mellitus, and dietary fat-responsive disease in dogs., Design: Cross-sectional study., Sample: Dry (n = 11) and canned (8) canine therapeutic diets., Procedures: Insoluble and soluble dietary fiber (IDF and SDF), high-molecular-weight SDF (HMWSDF), and low-molecular-weight SDF (LMWSDF) concentrations were determined. Variables were compared among diets categorized by product guide indication, formulation (dry vs canned), and regulatory criteria for light and low-fat diets., Results: SDF (HMWSDF and LMWSDF) comprised a median of 30.4% (range, 9.4% to 53.7%) of TDF; LMWSDF contributed a median of 11.5% (range, 2.7% to 33.8%) of TDF. Diets for diabetes management had higher concentrations of IDF and TDF with lower proportions of SDF and LMWSDF contributing to TDF, compared with diets for treatment of fat-responsive disease. Fiber concentrations varied within diet categories and between canned and dry versions of the same diet (same name and manufacturer) for all pairs evaluated. Diets classified as light contained higher TDF and IDF concentrations than did non-light diets. All canned diets were classified as low fat, despite providing up to 38% of calories as fat., Conclusions and Clinical Relevance: Diets provided a range of TDF concentrations and compositions; veterinarians should request TDF data from manufacturers, if not otherwise available. Consistent responses to dry and canned versions of the same diet cannot necessarily be expected, and diets with the same indications may not perform similarly. Many diets may not provide adequate fat restriction for treatment of dietary fat-responsive disease.

Objective: To investigate the effects of insulin detemir in dogs with diabetes mellitus., Design: Prospective, uncontrolled clinical trial., Animals: 10 client-owned dogs with naturally occurring diabetes mellitus., Procedures: Dogs were treated with insulin detemir SC every 12 hours for 6 months. Follow-up evaluations were done at 1, 2, 4, 12, and 24 weeks and included evaluation of clinical signs and measurement of blood glucose concentration curves and serum fructosamine concentrations., Results: Insulin detemir administration resulted in a significant decrease in blood glucose and serum fructosamine concentrations at 6 months, compared with pretreatment values. Median insulin dosage at the end of the study was 0.12 U/kg (0.055 U/lb; range, 0.05 to 0.34 U/kg [0.023 to 0.155 U/lb], SC, q 12 h). Hypoglycemia was identified in 22% (10/45) of the blood glucose concentration curves, and 6 episodes of clinical hypoglycemia in 4 dogs were recorded. A subjective improvement in clinical signs was observed in all dogs during the 6-month study period. On the basis of clinical signs and blood glucose concentration curves, efficacy of insulin detemir at the end of the study was considered good in 5 dogs, moderate in 3, and poor in 2., Conclusions and Clinical Relevance: Results suggested that SC injection of insulin detemir every 12 hours may be a viable treatment for diabetes mellitus in dogs. Insulin detemir dosages were lower than reported dosages of other insulin types needed to maintain glycemic control, suggesting that insulin detemir should be used with caution, especially in small dogs.

Objective: To determine total dietary fiber (TDF) composition of feline diets used for management of obesity and diabetes mellitus., Design: Cross-sectional survey., Sample: Dry veterinary (n = 10), canned veterinary (12), and canned over-the-counter (3) feline diets., Procedures: Percentage of TDF as insoluble dietary fiber (IDF), high-molecular-weight soluble dietary fiber (HMWSDF), and low-molecular-weight soluble dietary fiber (LMWSDF) was determined., Results: Median measured TDF concentration was greater than reported maximum crude fiber content in dry and canned diets. Median TDF (dry-matter) concentration in dry and canned diets was 12.2% (range, 8.11% to 27.16%) and 13.8% (range, 4.7% to 27.9%), respectively. Dry and canned diets, and diets with and without a source of oligosaccharides in the ingredient list, were not different in energy density or concentrations of TDF, IDF, HMWSDF, or LMWSDF. Similarly, loaf-type (n = 11) and gravy-type (4) canned diets differed only in LMWSDF concentration. Disparities in TDF concentrations among products existed despite a lack of differences among groups. Limited differences in TDF concentration and dietary fiber composition were detected when diets were compared on the basis of carbohydrate concentration. Diets labeled for management of obesity were higher in TDF concentration and lower in energy density than diets for management of diabetes mellitus., Conclusions and Clinical Relevance: Diets provided a range of TDF concentrations with variable concentrations of IDF, HMWSDF, and LMWSDF. Crude fiber concentration was not a reliable indicator of TDF concentration or dietary fiber composition. Because carbohydrate content is calculated as a difference, results suggested that use of crude fiber content would cause overestimation of both carbohydrate and energy content of diets.

Objective: To determine overall survival time and identify prognostic factors associated with survival time in cats with newly diagnosed diabetes mellitus., Design: Retrospective case series., Animals: 114 cats with newly diagnosed diabetes mellitus., Procedures: Data for analysis included history, signalment, physical examination findings, hematologic and serum biochemical data, presence of ketoacidosis, and diagnosis of concurrent diseases at initial evaluation. The effects of possible predictors on survival time were determined by calculating hazard ratios (HRs) and 95% confidence intervals (CIs)., Results: Median survival time of diabetic cats was 516 days (range, 1 to 3,468 days); 70%, 64%, and 46% lived longer than 3, 6, and 24 months, respectively. Survival time was significantly shorter for cats with higher creatinine concentrations, with a hazard of dying approximately 5% greater for each increase of 10 μg/dL in serum creatinine concentration (adjusted HR, 1.005; 95% CI, 1.003 to 1.007). Ketoacidosis was not significantly associated with survival time (HR, 1.02; 95% CI, 0.590 to 1.78)., Conclusions and Clinical Relevance: Cats with newly diagnosed diabetes mellitus had a fair to good prognosis. High serum creatinine concentration at diagnosis was associated with a poor outcome, likely because of the adverse effects of renal dysfunction. Ketoacidosis apparently was not associated with decreased survival time, suggesting that this complication should not necessarily be regarded as unfavorable.

Case Description: A 7.5-year-old spayed female ferret was evaluated because of weight loss despite a good appetite. Pancreatic insulinoma had been diagnosed at another animal hospital on the basis of detection of low blood glucose concentration on 1 occasion; however, concurrent determination of blood insulin concentration was not performed. The ferret had been treated SC with methylprednisolone acetate (unknown dosage) every 30 days for 2 years. No follow-up data regarding blood glucose concentration were available., Clinical Findings: On physical examination, the ferret was thin (weight, 0.619 kg [1.36 lb]) and bruised easily. Serum biochemical analysis revealed hyperglycemia (blood glucose concentration, 855 mg/dL; reference range, 63 to 134 mg/dL)., Treatment and Outcome: Glucocorticoid injections were discontinued, and the ferret was administered prednisolone (1.13 mg/kg [0.51 mg/lb], q 12 h for 14 days, then 0.56 mg/kg [0.25 mg/lb], q 12 h for 7 days) orally. After prednisolone administration was discontinued, hyperglycemia and weight loss persisted. The ferret was administered insulin glargine (0.5 U) SC; blood glucose concentration was monitored every 2 hours for 24 hours, at which time the value had decreased to nearly within reference range. The owner continued insulin glargine administration at that dose every 12 hours; after 77 days of treatment, the ferret's weight was 0.731 kg (1.61 lb), which was considered normal, and blood glucose concentration was within reference range., Clinical Relevance: Regular SC administration of insulin glargine was successful in the treatment of diabetes mellitus in the ferret of this report and may be effective for other diabetic ferrets.

Objective: To evaluate accuracy of 6 portable blood glucose meters (PBGMs) by comparing results of these meters with results obtained with a reference chemistry analyzer., Design: Evaluation study., Animals: 49 dogs (158 blood samples). Procedures-Venous blood samples were tested with the 6 PBGMs, and results were compared with results of a commercially available analyzer that used a reference method based on the hexokinase reaction., Results: Plasma glucose concentrations obtained with the reference analyzer ranged from 41 to 639 mg/dL. There were significant correlations between blood glucose concentrations obtained with the 6 PBGMs and plasma glucose concentrations obtained with the reference analyzer (r > or = 0.96). However, for all 6 PBGMs, results differed from results for the reference analyzer, with the difference increasing as plasma glucose concentration increased. Significant differences in bias were found among meters. For 142 samples classified as hypoglycemic, euglycemic, or hyperglycemic on the basis of results of the reference analyzer, the percentage of samples that were misclassified on the basis of results of the PBGMs ranged from 2.1% to 38.7%., Conclusions and Clinical Relevance: Results of the present study suggested that there were substantial differences in the accuracy of currently available PBGMs when used to determine blood glucose concentration in dogs.

Case Description: A 21-year-old neutered male captive California sea lion developed chronic polyuria; polydipsia; polyphagia; accelerated development of existing cataracts; and frequent episodes of gastrointestinal upset including anorexia, signs of abdominal discomfort, diarrhea, and vomiting., Clinical Findings: Chronic hypercholesterolemia, hypertriglyceridemia, hyperglycemia, and glucosuria were identified. During episodes of gastrointestinal abnormalities, transient hyperbilirubinemia and increased serum J-glutamyltransferase activities developed. Clinical findings strongly suggested chronic pancreatitis with secondary diabetes mellitus and intermittent cholestasis. Multiple diagnostic tests, including abdominal ultrasonography, serial hematologic and serum biochemical analyses, fecal examinations, urinalyses and bacteriologic culture of urine, measurement of serum fructosamine and insulin concentrations, and evaluation of thyroid and adrenal function, did not reveal any specific parasitic, endocrine, hepatic, or neoplastic etiologies., Treatment and Outcome: For 1.5 years, the sea lion received once-daily administration of glargine insulin, gastrointestinal protectants, and a strict high-protein, low-fat diet. Daily monitoring of glucose regulation was achieved by training the sea lion to submit to blood and urine sampling. Glucose regulation ranged from fair to good, and clinical signs of diabetes mellitus lessened. Episodes of gastrointestinal upset still occurred, although the frequency and severity decreased. Ultimately, a severe episode developed, associated with diabetic ketoacidosis and sepsis, and the sea lion died. Severe fibrosing pancreatitis with exocrine and endocrine atrophy and abscesses arising from ectatic pancreatic ducts were found. Peripancreatic fibrosis caused stricture of the common bile duct, resulting in gallbladder distension without cholecystitis., Clinical Relevance: Diabetes mellitus can occur secondary to chronic pancreatitis in California sea lions and insulin therapy should be considered.

Objective: To examine acid-base and hormonal abnormalities in dogs with diabetes mellitus., Design: Cross-sectional study., Animals: 48 dogs with diabetes mellitus and 17 healthy dogs., Procedures: Blood was collected and serum ketone, glucose, lactate, electrolytes, insulin, glucagon, cortisol, epinephrine, norepinephrine, nonesterified fatty acid, and triglyceride concentrations were measured. Indicators of acid-base status were calculated and compared between groups., Results: Serum ketone and glucose concentrations were significantly higher in diabetic than in healthy dogs, but there was no difference in venous blood pH or base excess between groups. Anion gap and strong ion difference were significantly higher and strong ion gap and serum bicarbonate concentration were significantly lower in the diabetic dogs. There were significant linear relationships between measures of acid-base status and serum ketone concentration, but not between measures of acid-base status and serum lactate concentration. Serum insulin concentration did not differ significantly between groups, but diabetic dogs had a wider range of values. All diabetic dogs with a serum ketone concentration > 1,000 micromol/L had a serum insulin concentration < 5 microU/mL. There were strong relationships between serum ketone concentration and serum glucagon-insulin ratio, serum cortisol concentration, and plasma norepinephrine concentration. Serum beta-hydroxybutyrate concentration, expressed as a percentage of serum ketone concentration, decreased as serum ketone concentration increased., Conclusions and Clinical Relevance: Results suggested that ketosis in diabetic dogs was related to the glucagon-insulin ratio with only low concentrations of insulin required to prevent ketosis. Acidosis in ketotic dogs was attributable largely to high serum ketone concentrations.

Objective: To evaluate day-to-day variability in blood glucose curves (BGCs) generated at home and at the clinic for cats with diabetes mellitus., Design: Prospective study., Animals: 7 cats with diabetes mellitus. Procedures-BGCs generated at home on 2 consecutive days and within 1 week at the clinic were obtained twice. On each occasion, insulin dose, amount of food, and type of food were consistent for all 3 BGCs. Results of curves generated at home were compared with each other and with the corresponding clinic curve., Results: Differences between blood glucose concentration determined after food was withheld (fasting), nadir concentration, time to nadir concentration, maximum concentration, and mean concentration during 12 hours had high coefficients of variation, as did the difference between fasting blood glucose and nadir concentrations and area under the curve of home curves. Differences between home curve variables were not smaller than those between home and clinic curves, indicating large day-to-day variability in both home and clinic curves. Evaluation of the paired home curves led to the same theoretical recommendation for adjustment of insulin dose on 6 of 14 occasions, and evaluation of home and clinic curves resulted in the same recommendation on 14 of 28 occasions. Four of the 6 paired home curves in cats with good glycemic control and 2 of the 8 paired home curves in cats with poor glycemic control led to the same recommendation., Conclusions and Clinical Relevance: Considerable day-to-day variability was detected in BGCs generated at home. Cats with good glycemic control may have more reproducible curves generated during blood collection at home than cats with poorer control.

Objective: To compare incidence of diabetes mellitus in cats that had undergone renal transplantation with incidence in cats with chronic renal failure, compare mortality rates in cats that underwent renal transplantation and did or did not develop diabetes mellitus, and identify potential risk factors for development of posttransplantation diabetes mellitus (PTDM) in cats., Design: Retrospective case series., Animals: 187 cats that underwent renal transplantation., Procedures: Medical records were reviewed., Results: 26 of the 187 (13.9%) cats developed PTDM, with the incidence of PTDM being 66 cases/1,000 cat years at risk. By contrast, the incidence of diabetes mellitus among a comparison population of 178 cats with chronic renal failure that did not undergo renal transplantation was 17.9 cases/1,000 cat years at risk, and cats that underwent renal trans-plantation were 5.45 times as likely to develop diabetes mellitus as were control cats with chronic renal failure. The mortality rate among cats with PTDM was 2.38 times the rate among cats that underwent renal transplantation but did not develop PTDM. Age, sex, body weight, and percentage change in body weight were not found to be significantly associated with development of PTDM., Conclusions and Clinical Relevance: Results suggest that cats that undergo renal transplantation have an increased risk of developing diabetes mellitus, compared with cats with chronic renal failure, and that mortality rate is higher for cats that develop PTDM than for cats that do not.

Objective: To determine whether Scottish Terriers have higher serum alkaline phosphatase (ALP) activities and a higher prevalence of diseases commonly associated with high serum ALP activity than do dogs of other breeds., Design: Retrospective case-control study., Animals: 85 Scottish Terriers and 340 age-matched control dogs that were not Scottish Terriers., Procedure: Medical records were reviewed, and data for year of evaluation, age, sex, breed, serum ALP activity, and final diagnosis were recorded., Results: Scottish Terriers had a significantly higher mean serum ALP activity than did control dogs (1,520 U/L vs 306 U/L). Regardless of breed, dogs that had a disease commonly associated with high serum ALP activity had a significantly higher mean serum ALP activity than did dogs without such diseases (1,304 U/L vs 427 U/L). Scottish Terriers were 2.4 times as likely to have a disease commonly associated with high serum ALP activity than were control dogs, but Scottish Terriers with diseases commonly associated with high serum ALP activity had a significantly higher mean ALP activity than did control dogs with such diseases (2,073 U/L vs 909 U/L), and Scottish Terriers without such diseases had a significantly higher mean serum ALP activity than did control dogs without such diseases (1,349 U/L vs 228 U/L)., Conclusions and Clinical Relevance: Results suggest that Scottish Terriers have higher serum ALP activities than do dogs of other breeds. Although Scottish Terriers also have a higher prevalence of diseases associated with high serum ALP activity, this alone did not explain the higher mean serum ALP activity in the breed.

An 18-year-old Spanish Mustang mare was referred for evaluation of progressive weight loss and persistent hyperglycemia. Clinicopathologic abnormalities included marked hyperglycemia and glycosuria. Serum cortisol concentration was appropriately decreased following administration of dexamethasone, indicating that the horse did not have pituitary pars intermedia dysfunction. Serum insulin and plasma C-peptide concentrations were low, suggesting that hyperglycemia was a result of decreased secretion of insulin by pancreatic beta cells. In addition, glucose concentration did not return to the baseline concentration until 5 hours after i.v. administration of a glucose bolus, suggesting that insulin secretion, insulin effect, or both were reduced. However, i.v. administration of insulin caused only a slight decrease in the plasma glucose concentration, giving the impression that the action of insulin was impaired. Within 5 hours after administration of a combination of glyburide and metformin, which is used to treat diabetes mellitus in humans, the glucose concentration was within reference limits. The horse was euthanized, and a postmortem examination was done. Immunohistochemical staining of sections of the pancreas revealed attenuation of the pancreatic islet beta-cell population, with beta cells that remained generally limited to the periphery of the islets. These findings indicate that, albeit rare, pancreatic beta-cell failure may contribute to the development of diabetes mellitus in horses.

Objective: To determine prevalence of retinal hemorrhages and microaneurysms in dogs with diabetes mellitus following cataract extraction by means of phacoemulsification and identify potential risk factors., Design: Retrospective study., Procedure: Medical records of dogs undergoing phacoemulsification between 1993 and 2003 were reviewed, and information was recorded on signalment, history, physical examination findings, ophthalmic examination findings, results of laboratory testing, electroretinographic findings, and surgical findings. Glycemic control was classified as poor, intermediate, or good on the basis of baseline blood glucose concentration, perioperative body weight loss, daily insulin dosage, and presence of glucosuria and ketonuria. Data from diabetic and nondiabetic dogs were analyzed to determine prevalence and risk factors for development of retinal hemorrhages or microaneurysms following phacoemulsification., Results: 11 of the 52 (21%) dogs with diabetes mellitus developed ophthalmoscopic signs of retinal hemorrhages or microaneurysms, compared with 1 of the 174 (0.6%) nondiabetic dogs. Median time from onset of diabetes mellitus to diagnosis of retinopathy was 1.4 years (range, 0.5 to 3.2 years). No risk factors for development of retinopathy were identified., Conclusions and Clinical Relevance: Results suggest that retinal hemorrhages and microaneurysms may be more common and develop earlier in diabetic dogs than previously reported. This may affect treatment, as diabetic dogs survive longer with improved glycemic control.

Objective: To evaluate owner compliance with longterm home monitoring of blood glucose concentrations in diabetic cats and assess the influence of home monitoring on the frequency of reevaluation of those cats at a veterinary hospital., Design: Retrospective study., Animals: 26 cats with diabetes mellitus., Procedure: Medical records of diabetic cats for which home monitoring was undertaken were reviewed, and owners were contacted by telephone. Signalment, laboratory test results, insulin treatment regimen, details of home monitoring, clinical signs during treatment, frequency of follow-up examinations, and survival times were evaluated., Results: Monitoring of cats commenced within 12 weeks (median, 3 weeks) after initial evaluation; 8 owners were unable to perform home monitoring, and 1 cat was euthanatized after 1 week. In 17 cats, duration of home monitoring was 4.8 to 46.0 months (median, 22.0 months); 6 cats died after 7.0 to 18.0 months (median, 13.0 months). In 11 cats, home monitoring was ongoing at completion of the study (12.0 to 46.0 months' duration). Fourteen owners completed blood glucose curves every 2 to 4 weeks. Cats managed with home monitoring received higher dosages of insulin, compared with cats that were not monitored. Four of 17 cats managed by home monitoring had transient resolution of diabetes mellitus for as long as 1 year. Home monitoring did not affect the frequency of reevaluation at the veterinary hospital., Conclusions and Clinical Relevance: Owner compliance with long-term home monitoring appeared to be satisfactory, and home monitoring did not affect the frequency of reevaluation of patients by veterinarians.

A 12-year-old spayed female domestic longhair cat developed fungal cystitis (Candida sp). The cat had a history of chronic diabetes mellitus, hyperadrenocorticism, and bacterial cystitis caused by Escherichia coli. Antifungal agents (itraconazole and fluconazole) were administered orally without noticeable effect on the candiduria. Because of the ineffectiveness of these treatments, intravesicular administration of 1% clotrimazole solution was performed weekly for 3 treatments. Complete resolution of urinary candidiasis was detected after the third infusion. Intravesicular administration of clotrimazole solution appears to be a safe and effective treatment of fungal cystitis in cats.

Objective: To evaluate a continuous glucose monitoring system (CGMS) for use in dogs, cats, and horses., Design: Prospective clinical study. Animals-7 horses, 3 cats, and 4 dogs that were clinically normal and 1 horse, 2 cats, and 3 dogs with diabetes mellitus., Procedure: Interstitial glucose concentrations were monitored and recorded every 5 minutes by use of a CGMS. Interstitial glucose concentrations were compared with whole blood glucose concentrations as determined by a point-of-care glucose meter. Interstitial glucose concentrations were also monitored in 2 clinically normal horses after oral and i.v. administration of glucose., Results: There was a positive correlation between interstitial and whole blood glucose concentrations for clinically normal dogs, cats, and horses and those with diabetes mellitus. Events such as feeding, glucose or insulin administration, restraint, and transport to the clinic were recorded by the owner or clinician and could be identified on the graph and associated with time of occurrence., Conclusions and Clinical Relevance: Our data indicate that use of CGMS is valid for dogs, cats, and horses. This system alleviated the need for multiple blood samples and the stress associated with obtaining those samples. Because hospitalization was not required, information obtained from the CGMS provided a more accurate assessment of the animal's glucose concentrations for an extended period, compared with measurement of blood glucose concentrations. Use of the CGMS will promote the diagnostic and research potential of serial glucose monitoring.

Objective: To determine the prevalence of systemic hypertension in cats with diabetes mellitus and establish ranges for echocardiographic variables in diabetic cats., Design: Prospective study., Animals: 14 cats with diabetes mellitus and 19 healthy control cats., Procedure: Systolic blood pressure was measured indirectly with a noninvasive Doppler technique. Ophthalmic and echocardiographic examinations were performed, and urine protein concentration was measured. Cats were considered to have hypertension if they had systolic blood pressure > 180 mm Hg and at least 1 other clinical abnormality typically associated with hypertension (eg, hypertensive retinopathy, left ventricular hypertrophy, or proteinuria)., Results: None of the diabetic or control cats had systolic blood pressure > 180 mm Hg. One diabetic cat had left ventricular hypertrophy, but systolic blood pressure was 174 mm Hg. None of the cats had evidence of hypertensive retinopathy or proteinuria. Mean values for echocardiographic variables for the diabetic cats were not significantly different from published values for healthy cats., Conclusions and Clinical Relevance: Results suggest that hypertension does not occur or occurs in only a small percentage of cats with diabetes mellitus.

Objective: To evaluate day-to-day variability of serial blood glucose concentration curves in dogs with diabetes mellitus., Design: Prospective clinical study., Animals: 10 dogs with diabetes mellitus., Procedure: Paired 12-hour serial blood glucose concentration curves performed during 2 consecutive days were obtained on 3 occasions from each dog. Dogs received the same dose of insulin and meal every 12 hours on both days. For each pair of curves, comparison was made between the results of days 1 and 2., Results: Mean absolute difference (without regard to sign) between days 1 and 2 for each parameter was significantly > 0, disproving the hypothesis that there is minimal day-to-day variability of serial blood glucose concentration curves when insulin dose and meals are kept constant. Coefficient of variation of the absolute difference between days 1 and 2 for each parameter ranged from 68 to 103%. Evaluation of the paired curves led to an opposite recommendation for adjustment of the insulin dose on day 2, compared with day 1, on 27% of occasions. Disparity between dosage recommendations was more pronounced when glucose concentration nadir was < 180 mg/dL (10 mmol/L) on 1 or both days. In this subset of 20 paired curves, an opposite recommendation for dosage adjustment was made on 40% of occasions., Conclusions and Clinical Relevance: There is large day-to-day variation in parameters of serial blood glucose concentration curves in diabetic dogs. Day-to-day variability of serial blood glucose concentration curves has important clinical implications, particularly in dogs with good glycemic control.

Objective: To compare blood glucose (BG) concentrations measured with a portable blood glucose meter in blood samples obtained with a marginal ear vein (MEV) nick technique, from a peripheral venous catheter, and by direct venipuncture in healthy cats and cats with diabetes mellitus., Design: Prospective study., Animals: 1 0 healthy cats and 11 cats with diabetes mellitus. Procedure-On day 1, blood samples were collected every hour for 10 hours by the MEV nick technique and from a peripheral venous catheter. On day 2, blood samples were collected every hour for 10 hours by the MEV nick technique and by direct venipuncture of the medial saphenous vein., Results: For all cats, mean BG concentration for samples collected by the MEV nick technique was not significantly different from mean concentration for samples obtained from the peripheral venous catheter. For healthy cats, mean BG concentration for samples collected by the MEV nick technique was not significantly different from mean concentration for samples obtained by direct venipuncture. For cats with diabetes mellitus, mean BG concentration for samples collected by the MEV nick technique was significantly different from mean concentration for samples obtained by direct venipuncture; however, for the range of concentrations examined, this difference was not clinically important., Conclusions and Clinical Relevance: Results suggest that for the range of concentrations examined, the MEV nick technique is a reasonable alternative to venous blood collection for serial measurement of BG concentrations in cats.

Objective: To characterize skin lesions and causative infections in diabetic dogs and evaluate other potential causes of dermatologic disorders, including concurrent endocrinopathies, allergic skin disease, and long-term corticosteroid administration., Design: Retrospective study., Animals: 45 dogs with diabetes mellitus (DM) that were examined by dermatologists., Procedure: Medical records were reviewed for signalment; allergic conditions prior to development of DM; prior corticosteroid administration; and results of dermatologic examinations, ear and skin cytologic examinations, skin scrapings for parasites, bacteriologic and fungal culturing of ear and skin specimens, histologic examinations, and endocrine testing., Results: Bacterial skin infection was the most common dermatologic disorder (n = 38 [84%]), followed by otitis (26 [58%]) and Malassezia-induced dermatitis (19 [42%]). Twenty-two (49%) dogs had pruritic skin disease consistent with allergic dermatitis, which preceded diagnosis of DM. Prior corticosteroid administration was reported in 21 (47%) dogs. Concurrent hyperadrenocorticism was diagnosed in 13 (29%) dogs, and concurrent hypothyroidism was diagnosed in 5 (11%) dogs. Iatrogenic hyperadrenocorticism was diagnosed in 1 additional dog. Only 10 (22%) dogs did not have a documented concurrent endocrinopathy or allergic disease that could have caused the dermatitis., Conclusions and Clinical Relevance: Bacterial and yeast-induced dermatitis and otitis develop in dogs with DM. Many diabetic dogs with dermatologic problems have a preexisting allergic condition, history of prior corticosteroid administration, or concurrent endocrinopathy that may be a more likely cause of dermatologic problems than DM alone.

Objective: To evaluate effects of protamine zinc insulin (PZI) on control of glycemia in cats with newly diagnosed diabetes mellitus or poorly controlled diabetes., Design: Clinical trial., Animals: 67 diabetic cats., Procedure: 34 cats with newly diagnosed diabetes and 33 cats with poorly controlled diabetes were treated with PZI twice daily for 45 days. Control of glycemia was assessed on days 7, 14, 30, and 45 by evaluation of clinical response, change in body weight, serum fructosamine concentration, blood glucose concentration measured 1, 3, 5, 7, and 9 hours after administration of PZI, lowest blood glucose concentration, and mean blood glucose concentration during the 9-hour period after administration. Adjustments in dosage of PZI were made as needed to attain control of glycemia., Results: For all cats, a significant increase in mean dosage of PZI and significant decreases in 9-hour mean blood glucose concentration, lowest mean blood glucose concentration, and mean serum fructosamine concentration were detected. For cats with poorly controlled diabetes, 9-hour mean blood glucose concentration and mean serum fructosamine concentration were significantly decreased on day 45, compared with day 0. Ninety percent of owners reported improvement or resolution of clinical signs by day 45., Conclusions and Clinical Relevance: Results suggest that PZI was effective for control of glycemia in cats with newly diagnosed or poorly controlled diabetes and may be used as an initial treatment or as an alternative treatment in cats that do not respond to treatment with other types of insulin.

Objective: To characterize concurrent disorders in dogs with diabetes mellitus (DM)., Design: Retrospective study., Animals: 221 dogs with DM., Procedure: Medical records were reviewed, and clinical signs, physical examination findings, and results of clinicopathologic testing, urinalysis, aerobic bacterial culture of urine samples, coagulation testing, endocrine testing, histologic evaluation, diagnostic imaging, and necropsy were recorded., Results: For most dogs, CBC results were normal. Common serum biochemical abnormalities included hypochloremia (127 dogs, 60%) and high alanine aminotransferase (163, 78%), aspartate aminotransferase (78, 71%), and alkaline phosphatase (188, 90%) activities. Venous pH and serum ionized calcium concentration were measured in 121 and 87 dogs, respectively, and were low in 56 (46%) and 41 (47%) dogs. Lipemia was observed in 92 (42%) dogs. Urine samples from 159 (72%) dogs were submitted for aerobic bacterial culture, and 34 (21%) yielded bacterial growth. Escherichia coli was the most commonly isolated organism. Thirty-six (16%) dogs had dermatitis or otitis. Hyperadrenocorticism was diagnosed in 51 (23%) dogs on the basis of clinical signs and results of a low-dose dexamethasone suppression test (41 dogs), an adrenocorticotropic hormone stimulation test (5), both tests (4), or histologic evaluation of necropsy specimens (1). Acute pancreatitis was diagnosed in 28 (13%) dogs. Eleven (5%) dogs had tumors for which a histologic diagnosis was obtained. Eight (4%) dogs were hypothyroid., Conclusions and Clinical Relevance: Results suggest that dogs with diabetes mellitus may have many concurrent disorders. The most commonly identified concurrent disorders included hyperadrenocorticism, urinary tract infection, dermatitis, otitis, acute pancreatitis, neoplasia, and hypothyroidism.

Objective: To determine prevalence of pituitary tumors, detectable by means of computed tomography or magnetic resonance imaging, in cats with insulin resistance suspected to have acromegaly or hyperadrenocorticism versus cats with well-controlled diabetes mellitus., Design: Case series., Animals: 16 cats with insulin resistance that were also suspected to have acromegaly (n = 12) or pituitary-dependent hyperadrenocorticism (4) and 8 cats with well-controlled diabetes mellitus., Procedure: Computed tomography was performed on all 16 cats with insulin resistance and 2 cats in which diabetes mellitus was well-controlled. The remaining 6 cats in which diabetes mellitus was well-controlled underwent magnetic resonance imaging. Images were obtained before and immediately after i.v. administration of contrast medium., Results: Computed tomography revealed a mass in the region of the pituitary gland in all 16 cats with insulin resistance. Maximum width of the masses ranged from 4.4 to 12.7 mm; maximum height ranged from 3.1 to 12.6 mm. Results of computed tomography performed on 2 cats with well-controlled diabetes and magnetic resonance imaging performed on the remaining 6 cats were considered normal., Conclusions and Clinical Relevance: Results suggest that cats with insulin resistance suspected to have acromegaly or pituitary-dependent hyperadrenocorticism are likely to have a pituitary mass detectable by means of computed tomography or magnetic resonance imaging.

Objective: To determine which dog breeds are at low and high risk for developing diabetes mellitus (DM)., Design: Cohort study., Animals: Hospital population of 221 dogs with DM and 42,882 dogs without DM during 5.5 years., Procedure: 165 breeds (including a mixed-breed category) were represented in the hospital population. Breed-specific expected numbers of dogs with DM were calculated by multiplying the proportion of all dogs admitted to the hospital that were determined to have DM during the study period by the breed-specific totals during the study period. Breeds or breed groups evaluated in the analysis (n = 20) were restricted to those that had a combined observed and expected count > 5 to document breeds at low and high risk for developing DM. Proportionate changes in the risk of developing DM by breed were calculated and presented using exact odds ratios, 95% confidence intervals, and P values. Mixed-breed dogs were chosen as the reference breed., Results: Samoyeds, Miniature Schnauzers, Miniature Poodles, Pugs, and Toy Poodles were at high risk for developing DM. Dog breeds found to be at low risk for developing DM were German Shepherd Dog, Golden Retriever, and American Pit Bull Terrier., Conclusion and Clinical Relevance: The finding that certain dog breeds are at low or high risk for developing DM suggests that some genetic defects may predispose dogs to development of DM, whereas other genetic factors may protect dogs from development of DM.

Objective: To evaluate effect of acarbose on control of glycemia in dogs with diabetes mellitus., Design: Prospective randomized crossover controlled trial., Animals: 5 dogs with naturally acquired diabetes mellitus., Procedure: Dogs were treated with acarbose and placebo for 2 months each: in 1 of 2 randomly assigned treatment sequences. Dogs that weighed < or = 10 kg (22 lb; n = 3) or > 10 kg (2) were given 25 or 50 mg of acarbose, respectively, at each meal for 2 weeks, then 50 or 100 mg of acarbose, respectively, at each meal for 6 weeks, with a 1-month interval between treatments. Caloric intake, type of insulin, and frequency of insulin administration were kept constant, and insulin dosage was adjusted as needed to maintain control of glycemia. Serum glucose concentrations, blood glycosylated hemoglobin concentration, and serum fructosamine concentration were determined., Results: Significant differences in mean body weight and daily insulin dosage among dogs treated with acarbose and placebo were not found. Mean preprandial serum glucose concentration, 8-hour mean serum glucose concentration, and blood glycosylated hemoglobin concentration were significantly lower in dogs treated with insulin and acarbose, compared with insulin and placebo. Semisoft to watery feces developed in 3 dogs treated with acarbose., Conclusions and Clinical Relevance: Acarbose may be useful as an adjunctive treatment in diabetic dogs in which cause for poor glycemic control cannot be identified, and insulin treatment alone is ineffective.

Objective: To evaluate glycemic response to insulin treatment in dogs with diabetes mellitus., Design: Retrospective study., Animals: 221 dogs with diabetes mellitus., Procedure: Type and dosage of insulin used, minimum and maximum blood glucose concentrations, time of blood glucose concentration nadir, and optimal duration of action of insulin were determined on the basis of data obtained prior to initial examination at the teaching hospital (127 dogs), at the time of initial examination (212 dogs), at the time a second follow-up blood glucose curve was performed (59 dogs), and at the time of clinical control of diabetes mellitus (83 dogs)., Results: Prior to examination, 69 of 127 dogs (54%) received 1 s.c. insulin injection daily. Thirty-one dogs (24%) received a high dose of insulin (i.e., > 1.5 U/kg [0.7 U/lb] of body weight); 27 of these dogs (87%) received 1 injection/d. Eleven of 16 dogs (69%) that were hypoglycemic (blood glucose concentration < 80 mg/dl) also received 1 injection/d. However, optimal duration of action of insulin was > 12 hours in only 5 of 83 dogs (6%) evaluated at the time diabetes mellitus was clinically controlled. At that time, only 1 dog (1%) received a high dose of insulin, and the dog received 2 injections/d. Moreover, 8 of 10 dogs (80%) with hypoglycemia received 1 injection/d., Conclusions and Clinical Relevance: Most dogs with diabetes mellitus are clinically regulated with 2 daily insulin injections. Administration of a high dose of insulin or development of hypoglycemia may be more common in diabetic dogs that receive insulin once daily, compared with dogs that receive insulin twice daily.

Objective: To compare blood glucose concentrations obtained using a point-of-care (POC) analyzer, 5 portable blood glucose meters (PBGM), and a color reagent test strip with concentrations obtained using a reference method, and to compare glucose concentrations obtained using fresh blood samples in the PBGM with concentrations obtained using blood anticoagulated with lithium heparin., Design: Case series., Sample Population: 110 blood samples from 34 dogs; glucose concentration of the samples ranged from 41 to 596 mg/dl., Procedure: Logistic regression was used to compare blood glucose concentrations obtained with the various devices with reference method concentrations. Ease of use was evaluated subjectively. Percentage of times a clinical decision would have been altered if results of each of these methods had been used, rather than results of the reference method, was calculated., Results: For 3 of the PBGM, blood glucose concentrations obtained with fresh blood were not significantly different from concentrations obtained with blood samples anticoagulated with lithium heparin. None of the devices provided results statistically equivalent to results of the reference method, but the POC analyzer was more accurate than the others. For some samples, reliance on results of the PBGM or the color test strip would have resulted in erroneous clinical decisions., Conclusions and Clinical Relevance: Although commercially available PBGM and color test strips provided blood glucose concentrations reasonably close to those obtained with reference methods, some devices were more accurate than others. Use of results from these devices could lead to erroneous clinical decisions in some cases.

Objective: To determine magnesium (Mg) status in cats with naturally acquired diabetes mellitus (DM) and diabetic ketoacidosis (DKA), evaluate changes in Mg status after treatment for DKA, and correlate Mg status with systemic blood pressure and degree of glycemic control., Design: Case series and cohort study., Animals: 12 healthy cats (controls), 21 cats with DM, and 7 cats with DKA., Procedure: Serum total magnesium (tMg) and ionized magnesium (iMg) concentrations and spot urinary fractional excretion of magnesium (FEmg) were determined, using serum and urine samples obtained from all cats when they were entered in the study and from cats with DKA 12, 24, and 48 hours after initiating treatment. Indirect blood pressure and degree of glycemic control were determined in 10 and 21 cats with DM, respectively., Results: Initially, 2 and 13 cats with DM and 1 and 4 cats with DKA had serum tMg and iMg concentrations, respectively, less than the low reference limit (mean-2 SD) determined for controls. In cats with DKA, serum tMg concentration decreased significantly over time after initiating treatment. Urinary FEmg was significantly higher in cats with DM or DKA, compared with controls. Systemic hypertension was not detected nor was there a correlation between Mg status and degree of glycemic control in cats with DM., Conclusions and Clinical Relevance: Hypomagnesemia was a common finding in cats with DM and DKA and was more readily identified by measuring serum iMg concentration than tMg concentration. The clinical ramifications of hypomagnesemia in such cats remain to be determined.

Objective: To determine the effect of hyperthyroidism on serum fructosamine concentration in cats., Design: Cohort study., Animals: 22 cats with overt hyperthyroidism., Procedure: Hyperthyroidism was diagnosed on the basis of clinical signs, detection of a palpable thyroid gland, and high total serum thyroxine (T4) concentrations. Hyperthyroid cats with abnormal serum albumin, total protein, and glucose concentrations were excluded from the study. Samples for determination of serum fructosamine concentration were obtained prior to initiating treatment. Results were compared with fructosamine concentrations in healthy cats, cats in which diabetes had recently been diagnosed, and cats with hypoproteinemia. In 6 cats, follow-up measurements were obtained 2 and 6 weeks after initiating treatment with carbimazole., Results: Serum fructosamine concentrations ranged from 154 to 267 mumol/L (median, 198 mumol/L) and were significantly lower than values in healthy cats. Eleven (50%) of the hyperthyroid cats had serum fructosamine concentrations less than the reference range. Serum fructosamine concentrations in hyperthyroid, normoproteinemic cats did not differ from values in hypoproteinemic cats. During treatment, an increase in serum fructosamine concentration was detected., Conclusions and Clinical Relevance: In hyperthyroid cats, concentration of serum fructosamine may be low because of accelerated protein turnover, independent of blood glucose concentration. Serum fructosamine concentrations should not be evaluated in cats with overt hyperthyroidism and diabetes mellitus. Additionally, concentration of serum fructosamine in hyperthyroid cats should not be used to differentiate between diabetes mellitus and transitory stress-related hyperglycemia.

Objective: To correlate serum fructosamine concentrations with established measures of glycemic control and to compare serum fructosamine and blood glycosylated hemoglobin (GHb) concentrations as a means for assessing glycemic control in diabetic cats., Design: Longitudinal cohort study., Animals: 26 healthy cats, 5 cats with stress-induced hyperglycemia, 15 untreated diabetic cats, and 36 treated diabetic cats., Procedure: Control of glycemia was classified and monitored and serum fructosamine and blood GHb concentrations were measured for 12 poorly controlled diabetic cats before and after improving glycemic control, 8 well-controlled treated diabetic cats before and after glycemic control deteriorated, and 5 cats with diabetes mellitus before and after onset of stress-induced hyperglycemia., Results: Mean serum fructosamine and blood GHb concentrations were significantly higher in untreated diabetic cats, compared with healthy cats, and in 24 poorly controlled diabetic cats, compared with 12 well-controlled diabetic cats. Mean serum fructosamine and blood GHb concentrations decreased significantly in 12 poorly controlled diabetic cats after improving glycemic control and increased significantly in 8 well-controlled diabetic cats after glycemic control deteriorated. A significant stress-induced increase in mean blood glucose concentration was evident 12 hours after insulin administration, but not in 5 docile diabetic cats that became fractious., Clinical Implications: Serum fructosamine and blood GHb concentrations are clinically useful tools for monitoring control of glycemia in cats with diabetes mellitus.

Objective: To identify risk factors associated with fatal acute pancreatitis in dogs., Design: Case-control study., Animals: 70 case dogs with clinical evidence and histopathologic confirmation of fatal acute pancreatitis and 104 control dogs that had trauma, underwent necropsy, and did not have histologic evidence of acute pancreatitis., Procedure: Information on signalment, weight, body condition, medical history, concurrent disease, and results of histopathologic examination was obtained by reviewing medical records. Logistic regression analysis included calculation of univariate and multivariate (adjusted) odds ratios and 95% confidence intervals. RESULTS AND CLINICAL IMPLICATIONS: Dogs with fatal acute pancreatitis were largely middle- to older-aged dogs. Risk of developing fatal acute pancreatitis was increased by overweight body condition, diabetes mellitus, hyperadrenocorticism, hypothyroidism, prior gastrointestinal tract disease, and epilepsy. Additionally, Yorkshire Terriers were at increased risk, and Labrador Retrievers and Miniature Poodles were at decreased risk, of developing fatal acute pancreatitis. Males and neutered females appeared to have an increased risk of developing fatal acute pancreatitis, compared with sexually intact females. Thrombus formation was more likely in dogs that developed fatal acute pancreatitis than in control dogs.

Objective: To determine prevalence and severity of systemic arterial hypertension and proteinuria in dogs with naturally developing diabetes mellitus (DM) and to determine whether these abnormalities were related to age, sex, duration of DM, or degree of control of glycemia., Design: Case series and cohort study., Animals: Fifty dogs with naturally developing DM., Procedures: Blood pressure was measured in all 50 dogs. Thirty-eight dogs were evaluated once, and 12 were evaluated sequentially. Thirty-five were evaluated for proteinuria by determining protein-to-creatinine ratio in urine (n = 35) or by electrophoresis of urine (33)., Results: Hypertension was detected in 23 on the basis of a systolic pressure > 160 mm HG (12 dogs), a diastolic pressure > 100 mm HG (21), or a mean pressure > 120 mm HG (23). All dogs with systolic hypertension had concurrent diastolic and mean hypertension, and 19 of 21 dogs with diastolic hypertension had concurrent high mean pressure. Ten of 12 dogs reevaluated at subsequent visits had no change in blood pressure. Blood pressure remained consistent in 3 dogs tested at different times during the day on a single visit. Duration of DM and presence of proteinuria were significant predictors of hypertension. Seven of 35 (20%) dogs had an increased protein-to-creatinine ratio in their urine. Albumin concentration and albumin-to-creatinine ratio were significantly higher in urine from diabetic dogs, compared with healthy, nondiabetic dogs. Hypertension was associated with an increased albumin-to-creatinine ratio., Clinical Implications: Systemic hypertension and proteinuria may be common in diabetic dogs, but the clinical importance of these findings are, as yet, unknown.

Objective: To determine the reference range for glucose tolerance, using a simplified glucose tolerance test (GTT), and to evaluate glucose tolerance status in cats., Design: Prospective study., Animals: 57 clinically normal cats., Procedure: 2 catheters were placed in the cephalic veins of nonsedated cats at least 3 hours before the test. Blood samples were obtained before (0 minutes) and 2, 5, 10, 15, 30, 45, 60, 90, and 120 minutes after glucose (0.5 g/kg [0.23 g/lb] of body weight) was injected i.v. Blood glucose concentration was measured by a glucose meter. Glucose half-life (t1/2) and disappearance of glucose (Kglucose) were calculated., Results: Glucose tolerance in cats was considered normal when upper limits for glucose concentration were < or = 159 mg/dl at 0 minutes, < or = 322 mg/dl at 60 minutes, < or = 238 mg/dl at 90 minutes, or < or = 171 mg/dl at 120 minutes and glucose t1/2 was < or = 94.7 minutes or Kglucose was > or = 0.41%/min. Impaired glucose tolerance in cats was defined as a glucose concentration > or = 160 mg/dl at 0 minutes, > or = 323 mg/dl at 60 minutes, > or = 239 mg/dl at 90 minutes, or > or = 172 mg/dl at 120 minutes. The frequency of impaired glucose tolerance was 2%. Five cats had stress-affected GTT. Significant differences in glucose t1/2 or Kglucose between cats < 7 and > or = 7 years old were not found., Clinical Implications: The simplified GTT and measurement of glucose concentration by a glucose meter provides a simple and low-cost method of assessing glucose tolerance status in cats that are normoglycemic after food is withheld. Use of absolute glucose concentrations overcomes the need to calculate glucose t1/2 values. The high glucose concentration at 0 minutes found in this study may reflect a more realistic concentration to use in assessing client-owned cats in a hospital environment.

Acromegaly was diagnosed in 3 cats with insulin-resistant diabetes mellitus (DM) on the basis of history and physical examination findings, which ruled out other causes of insulin-resistant DM, and by documenting high plasma concentrations of growth hormone. Computed tomography revealed a mass in the area of the pituitary gland in each cat. Pituitary gland tumors were irradiated with cobalt 60, and none of the cats developed complications to radiotherapy. Each cat received a total dose of 48 Gy of cobalt 60 during 12 treatments. After completion of radiotherapy, insulin requirements were less for all cats, although in 1 cat, this improvement was transient. Diabetes mellitus resolved in 2 of 3 cats. After treatment, decreases in insulin requirements correlated with decreases in plasma growth hormone concentrations in 2 of 3 cats in which DM resolved. On the basis of these findings, irradiation of pituitary gland tumors appears to be a treatment option for cats with acromegaly.

Objective: To determine the association between body condition and disease in cats., Design: Prospective study., Sample Population: Information on 1,457 cats without major illnesses from 27 veterinary hospitals in the northeastern United States., Procedure: Cats that had body conditions determined from 1991 to 1992, using a set of 6 body condition silhouettes, had their health experiences and body conditions assessed for the subsequent 4.5 years. Cats were described by the following 6 body conditions: cachectic, lean, optimally lean, optimal weight, heavy, and obese. Data obtained from medical records and owner interviews were collected, using standard forms. Associations between body condition and specific diseases were analyzed. Findings in cats with body conditions other than optimal were compared with findings in cats with optimal body condition., Results: Compared with optimal weight cats, heavy cats were 2.9 times as likely to be taken to veterinarians because of lameness not associated with cat bite abscesses. Obese cats were also 3.9 times as likely to develop diabetes mellitus, 2.3 times as likely to develop nonallergic skin conditions, and 4.9 times as likely to develop lameness requiring veterinary care. Cats considered thin (cachectic and lean) were 1.7 times as likely to be presented to veterinary hospitals for diarrhea., Clinical Implications: Results of this study substantiate reports of health risks associated with excess body weight in cats. Efforts to reduce weight in heavy and obese cats can lead to reduced risks of diabetes mellitus, lameness (presumably related to osteoarthritis and soft-tissue injuries), and skin problems unrelated to allergies. Cachectic and lean cats are more likely to have diarrhea that is not associated with a definitive diagnosis.

Objective: To characterize glycosylated hemoglobin (GHb) concentrations in the blood of dogs with disorders that may affect serum glucose or blood GHb concentrations, and to determine whether changes in GHb concentration correlate with changes in control of diabetes in dogs., Design: Prospective study., Animals: 63 healthy dogs, 9 dogs with anemia, 24 dogs with untreated hyperadrenocorticism, 12 dogs with pancreatic beta-cell neoplasia, 23 dogs with newly diagnosed diabetes mellitus, and 77 diabetic dogs treated with insulin., Procedure: Control of diabetes in dogs treated with insulin was classified as good or poor on the basis of history, physical examination findings, changes in body weight, and measurement of serum glucose concentrations Sequential evaluations of control were performed and GHb concentration in blood was measured, by means of affinity chromatography, for 5 untreated diabetic dogs before and after initiating insulin treatment, for 10 poorly controlled diabetic dogs before and after increasing insulin dosage, and for 5 diabetic dogs before and after pancreatic islet cell transplantation., Results: Mean (+/-SD) GHb concentration was 3.3 +/- 0.8% in the blood of healthy dogs. Compared with results from healthy dogs, mean GHb concentration was significantly lower in the blood of dogs with anemia and pancreatic beta-cell neoplasia and significantly higher in the blood of untreated diabetic dogs. Mean GHb concentration was significantly higher in the blood of 46 poorly controlled diabetic dogs, compared with 31 well-controlled diabetic dogs (7.3 +/- 1.8 vs 5.7 +/- 1.7%, respectively). Mean GHb concentration in blood decreased significantly in 5 untreated diabetic dogs after treatment (8.7 +/- 1.9 vs 5.3 +/- 1.9%). Mean GHb concentration in blood also decreased significantly in 10 poorly controlled diabetic dogs after control was improved and in 5 diabetic dogs after they had received a pancreatic islet cell transplant., Clinical Implications: Measurement of GHb concentration in blood may assist in monitoring control of diabetes in dogs.

Objective: To characterize the frequency, medical history, clinical signs, methods of treatment, and outcome of insulin-induced hypoglycemia and to identify predisposing factors., Design: Retrospective study., Animals: 8 dogs and 20 cats with diabetes mellitus that developed hypoglycemia because of insulin overdose., Procedure: Medical records of dogs and cats receiving insulin for treatment of diabetes mellitus were reviewed. Medical records of dogs and cats that had an episode of hypoglycemia were reviewed in detail., Results: Overdosing of insulin was more common in cats than in dogs. Median weight of diabetic cats that became hypoglycemic was significantly greater than that of the hospital population of diabetic cats at diagnosis. Eighty percent of cats that became hypoglycemic were receiving insulin doses > 6 U/injection, administered once or twice daily. Dose and type of insulin did not correlate with duration or severity of hypoglycemia. In 7 of 8 dogs and 10 of 20 cats, management factors or concurrent medical problems were considered to be predisposing causes for insulin overdose. Two dogs and 2 cats did not have clinical signs of hypoglycemia, despite documented low concentrations of glucose in their blood., Clinical Implications: Diabetic cats, especially if obese, are at greater risk of insulin overdose than are diabetic dogs. The reason for overdose may not be evident. Diabetic dogs and cats may become hypoglycemic without developing autonomic warning signs of hypoglycemia, or these signs may not be recognized (hypoglycemia unawareness).

Objective: To assess pretreatment clinical and laboratory findings in cats with diabetes mellitus and to determine the influence of ketoacidosis on pretreatment findings., Design: Retrospective case series., Animals: 104 cats with diabetes mellitus, 38 of which had ketoacidosis., Procedure: Medical records of cats with diabetes mellitus examined over a 20-month period were reviewed. Cats that had received previous treatment for diabetes mellitus, or for which medical records were incomplete, were excluded from this study., Results: Cats ranged in age from 1 to 19 years (median, 11 years). Male cats were twice as likely to develop diabetes as females. The most common historical signs were polyuria, polydipsia, weight loss, and diminished activity. Anorexia or poor appetite was reported more commonly than polyphagia, especially in cats with ketoacidosis. Diminished activity, anorexia, weakness, and vomiting were all significantly more common in ketoacidotic cats than in nonketoacidotic cats. Forty-four cats were considered thin, and 34 were considered obese. All cats had hyperglycemia and most had hypercholesterolemia and high activities of 1 or more hepatic enzymes. Compared with nonketoacidotic cats, ketoacidotic cats were more likely to have had low serum electrolyte values. All cats had glucosuria and 42 (40.4%) had ketonuria. Baseline serum insulin concentrations were measured in 18 cats and were low or at the low end of the reference range in 14 (77.8%) cats. Serum fructosamine concentration, determined in 22 cats, was high in 20 (90.9%) cats. Twenty-three of the 104 (22.1%) cats had concurrent disease, the most common of which were hyperthyroidism, inflammatory bowel disease, and eosinophilic granuloma complex., Clinical Implications: In more than a third of cats, diabetes mellitus is complicated by development of ketoacidosis, which increases the severity of clinical and laboratory abnormalities. Diagnosis of diabetes mellitus is made on the basis of signalment (e.g., middle-aged to old male cats), owner complaints (e.g., polyuria, polydipsia, and weight loss), physical examination findings (e.g., lethargy or muscle wasting), and laboratory findings (e.g., hyperglycemia and glucosuria).

Four dogs with thrombosis were referred for diagnostic testing and were subsequently treated by the use of streptokinase. The range of duration of clinical signs associated with thrombosis was 6 to 120 days. Causes of thrombosis were heart disease (1 dog), protein-losing nephropathy and hyperadrenocorticism (1), hyperadrenocorticism (1), and idiopathic (1). Possible factors that predisposed dogs to hypercoagulability included hypertension (2 dogs) and diabetes mellitus (1). All dogs were treated for underlying disease by use of supportive care. The first dog was treated with a loading dose of 250,000 U of streptokinase, i.v., with a subsequent maintenance dosage of 100,000 U/h, i.v., and also was treated with anticoagulant. The subsequent 3 dogs were treated with a loading dose of 90,000 U of streptokinase, i.v., and maintenance dosage of 45,000 U/ h, i.v., at various intervals. These dogs also were treated with anticoagulant. Three dogs had minor hemorrhage as an adverse effect to streptokinase infusion, but they did not require treatment for the hemorrhage. Complete resolution of the thrombus was observed in 3 dogs, and partial resolution of the thrombus was observed in the other dog. In all dogs, partial or complete resolution of clinical signs associated with thrombosis was seen. Streptokinase may be an effective treatment for dogs with thrombosis.

Ultralente insulin has replaced protamine zinc insulin as the treatment of choice in treatment of diabetes mellitus in cats. There is variability in effectiveness of ultralente insulin and problems with glycemic control develop in some cats. Alternative insulin preparations are sought when ultralente insulin is ineffective. Twelve cats with insulin-dependent diabetes mellitus were treated with lente insulin. Clinical signs improved in 8 cats given lente insulin every 12 hours. Lente insulin was ineffective in 4 cats. Three of these cats were subsequently found to have an insulin resistant disorder. In 1 cat, lente insulin was ineffective because of short duration of action. Lente insulin is a viable treatment alternative when ultralente insulin is ineffective in achieving glycemic control. Ultralente insulin is still the insulin of choice for the initial treatment of diabetes in cats, because of the potential to establish glycemic control with once-a-day treatment.

Data were collected from the medical records of 123 nondiabetic dogs (182 eyes) and 30 diabetic dogs (57 eyes) in which phacoemulsification surgery was performed. Pre- and postoperative comparisons, including signalment, initial ophthalmic examination findings, surgical variables, and postoperative findings for the short-term follow-up period (mean, 5.75 weeks), between nondiabetic and diabetic dogs revealed that the complication rate was not greater in the diabetic group. Postoperative uveitis was evident with nearly equal frequency (in nondiabetic dogs, 90% or 164 of 182 eyes and in diabetic dogs, 88% or 50 of 57 eyes). In nondiabetic dogs, 1% prednisolone ophthalmic solution and prednisone were administered pre- and postoperatively, and amoxicillin and dichlorphenamide postoperatively. In diabetic dogs, the same treatment regimen, except for treatment with flunixin meglumine IV at surgery and substitution of aspirin for prednisone, was used. When nondiabetic and diabetic dogs were treated according to their respective pre- and postoperative medical regimens, clinical differences in postoperative findings were not apparent.

An 8-year-old ovariohysterectomized Chow Chow was referred because of dermatologic lesions diagnosed as pemphigus foliaceus. Intolerance to orally administered corticosteroids necessitated the use of methylprednisolone pulse therapy. One week after treatment, diabetes mellitus was diagnosed on the basis of blood and urine test results. For 3 years after treatment, the dog has remained a well-regulated diabetic. Complete remission of pemphigus foliaceus is maintained by alternate-day, orally administered prednisone (0.5 mg/kg of body weight).

A newly recognized disease in dogs, ulcerative dermatosis associated with diabetes mellitus (diabetic dermatopathy), was diagnosed in 2 dogs with pancreatic endocrine tumors that had immunohistologic evidence of glucagon production. Dogs developed diabetes mellitus in the later stages of the illness, months after the skin disease was first observed. Liver disease was identified and characterized by high serum alkaline phosphatase and alanine transaminase activities. Clinically, erythema and crusting involved the footpads, the face, perioral and genital skin, and ventrum. Histologically, skin lesions were intercellular and intracellular edema and necrosis of the upper half of the epidermis and diffuse parakeratosis. Clinically and histologically, skin lesions closely resembled necrolytic migratory erythema of people, a skin disease that usually is associated with a glucagon-secreting pancreatic endocrine tumor and diabetes mellitus (glucagonoma syndrome): The morphologically descriptive term, superficial necrolytic dermatitis, was preferred over the previously proposed names hepatocutaneous syndrome and diabetic dermatopathy, which each connote only a single feature of the disease.