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Objectives : To determine how general practice veterinarians make weight loss recommendations for dogs and if nutrients become deficient when following these recommendations. Materials and Methods : A questionnaire of general practice veterinarians was conducted to characterise weight loss recommendations made to clients. Using this data, progressive levels of caloric restriction were applied to top‐selling commercial non‐therapeutic adult maintenance diets and non‐therapeutic weight management diets. Nutrient intakes were compared to the National Research Council's Recommended Allowances for metabolic body weight using a theoretical current weight and ideal body weight for an obese dog. Nutrient intakes were also compared to recommendations from the Association of American Feed Control Officials using current body weight. Results : Several nutrients were found at risk of deficiency, including choline, methionine, cysteine, selenium, eicosapentanoic acid, docosahexanoic acid, riboflavin, pantothenic acid and cobalamin in both non‐therapeutic adult maintenance diets and non‐therapeutic weight management diets. Clinical Significance : Caution is warranted when making weight loss recommendations using commercial diets until further research on the nutrient needs of obese dogs undergoing weight loss is undertaken. Restriction of commercial diets to achieve weight loss in dogs may result in nutrient deficiencies. [ABSTRACT FROM AUTHOR]

A grazing experiment was conducted to assess the effects of wild-type endophyte-infected (E+) tall fescue consumption and elevated ambient temperatures on intravaginal temperatures, plasma lipid peroxidation, and glutathione redox of peripheral blood mononuclear cells. Angus heifers (n = 34) were allotted by BW to 4 blocks consisting of E+ and endophyte-free (E- fescue pastures. Monthly, in June, July, and August, temperature loggers were fixed into blank controlled internal drug releasers and inserted into a subsample of heifers (n = 16) for 2 d. After 48 h, heifers were weighed, and blood (30 mL) was collected via jugular venipuncture. Peripheral blood mononuclear cells were isolated for analysis of glutathione peroxidase activity, glutathione reductase activity, and reduced:oxidized glutathione. Plasma malondialdehyde was evaluated as a marker of lipid peroxidation, and whole blood Se concentration was determined. Serum prolactin was assayed after the grazing period. Heifer AIJG was greatest in August and least in July (P < 0.001). In August, heifers grazing E+ fescue exhibited greater (P < 0.05) afternoon intravaginal temperatures and temperature fluctuations than heifers grazing E- fescue. In July and August, all heifers had greater afternoon temperatures (P < 0.02) and less reduced:oxidized glutathione (P < 0.0001) than in June. Glutathione reductase activity of all heifers was greater in June (P = 0.03) than in July. Similarly, all heifers exhibited decreased glutathione peroxidase activity (P < 0.0008) in July, whereas whole blood Se was reduced (P < 0.0001) in July and August. No treatment or date effects were detected for malondi-aldehyde, but serum prolactin was reduced at the end of the grazing period (P = 0.008) in heifers stocked on E+ fescue. Using these markers, differences in oxidative stress were not detected between heifers consuming E+ fescue and those consuming E- fescue. Date effects indicating altered glutathione redox and enzyme activity may have been related to heat stress and nutritional limitations. [ABSTRACT FROM AUTHOR]

Twenty-seven wether lambs were utilized to evaluate select innate immunity and oxidative stress in response to diet and heat stress. Dietary treatments were: (i) control (tall fescue) hay = no TascoTM (tradename for the extract of the brown seaweed, Ascophyllum nodosum, Acadian Sealants Ltd, Nova Scotia, Canada); (ii) pre-harvest Tasco-Forage-treated hay and (iii) control hay + post-harvest Tasco-EX. Tasco-Forage and Tasco-EX are two forms of the TascoTM extract that are either applied to foliage or used for direct feeding, respectively. All lambs were supplemented with soyabean meal and trace mineralized salt. Heat stress was applied for 10 days with measurements obtained at days 0, 4 and 10. A heat × treatment interaction indicated hay with Tasco enhanced monocyte oxidative burst through short duration (p < 0.05) and long duration (p < 0.10) heat stress. Phagocytic activity was influenced by days of heat stress (p < 0.001) and treatment (p = 0.02) with post-harvest TascoTM lambs exhibiting the greatest immune enhancement (p < 0.05). Red and white blood cell glutathione peroxidase increased by heat stress day 10 in Tasco lambs. Superoxide dismutase activity was increased and lipid hydroperoxide metabolites minimized (p < 0.01) through long duration heat stress in the pre-harvest Tasco group. Tasco treatment of tall fescue hay prior to harvest appears to provide residual effects on animal antioxidant availability in short-duration heat stress. Tasco supplementation to post-harvest fescue hay enhances immune function and protects against prolonged heat-induced oxidative stress. [ABSTRACT FROM AUTHOR]

Mammary cancer is the second leading cause of cancer death in women, the second most common neoplasm in dogs and the third leading neoplasm in cats. Mammary tumors are similar in morphology and progression in these species, so cats and dogs are good models for determining treatment or prevention modalities for the human population. Epidemiological, in vitro and rodent studies have demonstrated that polyunsaturated fatty acids (PUFA) can influence the growth, progression and metastasis of mammary cancer. Although a role of PUFA in modulating mammary cancer growth has been shown, the mechanisms by which this occurs remain unclear. Recent studies have demonstrated that PUFA may influence the activity of the epidermal growth factor receptor/mitogen-activated protein kinase pathway, which is involved in regulating several oncogenes (c-myc, c-fos, neu/c-erb-b2) involved in the progression of cancer. We review the potential mechanism by which PUFA may modulate the growth of mammary cancer through regulation of the epidermal growth factor receptor/mitogen-activated protein kinase signal transduction cascade. [ABSTRACT FROM AUTHOR]

Although the early identification of patients with suboptimal nutritional status can allow the implementation of nutritional intervention to enhance the ability of the body to fight infection and disease, currently no definitive test of nutritional status exists. Therefore, this study was conducted to identify possible functional indicators of acute nutritional deprivation. The effects of total nutritional deprivation and subsequent refeeding on lymphocyte functions and subpopulations were examined in 23 healthy cats. Peripheral blood samples were analyzed at various times during food deprivation and refeeding periods. During the food deprivation period, decreases were observed in leukocyte number (P: < 0.05), lymphocyte number (P: < 0.05), percentage of CD4(+) cells [before stimulation with concanavalin-A (Con-A); P: < 0.05] and the CD4/CD8 ratio (before stimulation with Con-A; P: < 0.01) compared with d 0. Increases were observed in the percentage of CD8(+) cells [before (P: < 0.05) and after (P: < 0.01) stimulation with Con-A] and in intracellular calcium (P: < 0.01) during acute starvation. During the refeeding period, increases were observed in the percentage of CD4(+) cells (before and after stimulation with Con-A; P: < 0.01), the percentage of CD8(+) cells (before stimulation with Con-A; P: < 0.05) and lymphocyte number (P: < 0.05) compared with d 7. Lymphocyte proliferative capacity tended to decrease (P: = 0.07) during starvation and increased (P: < 0.01) during the refeeding period. These findings suggest that a 7-d starvation period had immunosuppressive effects on cats and that these effects were not completely normalized during 7 d of refeeding. CD4(+)/CD8(+) subset alterations and CD4/CD8 ratio in conjunction with lymphocyte proliferation may be useful as indices of nutritional status. [ABSTRACT FROM AUTHOR]

Provides information on a study which evaluated immune response and copper status of yearling beef steers as a consequence of grazing tall fescue infected with endophyte fungus Neotyphodium coenophialum. Theoretical background; Materials and methods; Results and discussion.

Consuming diets enriched with either (n-6) or (n-3) fatty acids (FA) will subsequently influence the proportion of cell membrane–associated lipids, arachidonic acid (AA) and eicosapentaenoic acid (EPA). Recent investigations suggest that the mechanism underlying the effectiveness of (n-3) FA supplementation involves the reduction of inflammatory mediators (Vaughn et al. 1994). In addition to reducing levels of inflammatory mediators, (n-3) FA have been associated with altered platelet function. Activation of platelets with high concentrations of (n-6) or (n-3) FA in the cell membrane results in the release of increased amounts of proaggregatory thromboxane A2 (TXA2) or antiaggregatory thromboxane A3 (TXA3) metabolites (Hall 1996), respectively. Studies regarding the possible detrimental effects that may occur from intake of dietary (n-3) FA have yielded conflicting results regarding platelet function (Casali et al. 1986, Kristensen et al. 1989, Landhmore et al. 1986). Currently, pet foods are being formulated to maximize the anti-inflammatory effect of (n-3) FA. Although the benefits of increasing dietary (n-3) FA have been studied, potential adverse effects of feeding diets enriched in (n-3) FA on a long-term basis have not been evaluated. Therefore, the objective of this study was to determine the effects of altering dietary (n-6) to (n-3) FA ratios on platelet aggregation, platelet activation, blood coagulation indices and bleeding time in cats. Materials and methods. Animals and facilities. Twelve domestic short-haired cats, six neutered males and six spayed females, (average age 4 y) were used in this experiment. Cats were housed and fed in individual metal cages in a climate-controlled environment at the Virginia-Maryland Regional College of Veterinary Medicine for the duration of the study. All cats were fed a nutritionally complete dry diet to maintain an optimal body weight and condition score before the start of the study. The prestudy diet contained a (n-6):(n-3) fatty acid ratio of 12:1. The experimental protocol was reviewed and approved by the Virginia Tech Animal Care and Use Committee according to NIH guidelines (NRC 1985). Experimental protocol. Cats were allotted by gender and weight to dietary treatments as follows: enriched (n-6), [(n-6):(n-3) FA ratio 25:1]; control, (12:1); or enriched (n-3), (1.3:1). Experimental diets were formulated by Hill’s Science and Technology Center, Topeka, KS. Fatty acid ratios were manipulated by incorporating specific FA sources into each of the three treatment diets (corn oil, choice white grease or menhaden oil, respectively). During the 16-wk study period, whole blood was collected via jugular venipuncture on d 0, 56 and 112 for evaluation of platelet function, coagulation parameters and fibrinogen concentration. Toenail bleeding time was recorded on d 0 and 112. Platelet isolation. Whole blood was collected via jugular venipuncture into syringes containing 3.8% trisodium citrate (9 parts blood:1 part anticoagulant), and platelet-rich plasma (PRP) was harvested according to the procedure described by Welles et al. (1994). Platelet counts were determined by using a Baker System 9000 Hematology Series Cell Counter (Allentown, PA). Samples of PRP were diluted to 300,000 platelets/ µL with autologous platelet-poor plasma (PPP). Platelet aggregation. Platelet aggregation was performed on diluted PRP stimulated with 50 µmol/L ADP (grade I: Sigma Chemical, St. Louis, MO) using a dual-channel aggregometer (Payton Series 300BD-5, Buffalo, NY). The procedure has been previously described (Welles et al. 1994). Platelet activation. Platelet activation was measured using a modified technique previously reported by Welles et al. (1994). Briefly, PRP stimulated with 50 µmol/L ADP was labeled with fluorescein- conjugated goat F[Ab] monoclonal antibody (Cappel-Organon Teknika, Durham, NC). Fluorescence was measured on the platelets bound with fluorescein-labeled antifibrinogen using a Coulter Epics XL-MCL Flow Cytometer. Determination of bleeding time, coagulation indices, and fibrinogen. Cats were sedated with a combination of acepromazine (0.11 mg/kg, intramuscular) and ketamine HCl (22 mg/kg, intramuscular); one nail was trimmed 2 mm into the capillary bed and gently blotted every 10 s until a clot formed. Time to clot formation was recorded. Whole blood was collected via jugular venipuncture for determination of activated partial thromboplastin time (APTT), one-stage prothrombin time (OSPT) and fibrinogen concentration with the use of a Sysmex Coagulation Analyzer 1000. Statistical analysis. Data were tested for normality and homogeneity of variance. An ANOVA (SAS/STAT Version 5.0, SAS Institute, Cary, NC) was used to determine dietary treatment effects on platelet count, platelet aggregation, platelet activation, bleeding time, fibrinogen concentration, APTT and OSPT. Tukey’s studentized range test (HSD) was used for means comparisons. The General Linear Models procedure for repeated-measures ANOVA was used to determine within-subject effects and compare response changes over time. Data were considered significant at P < 0.05. Results. Diet analyses are presented in Table 1. Cats fed the enriched (n-3) FA diet for 112 d exhibited an increased (P < 0.05) toenail bleeding time compared with cats fed either the enriched (n-6) FA or control diet (6.1 vs. 3.2 and 3.2 min, respectively). Peak aggregation of platelets from cats fed the enriched (n-3) FA diet was lower (P < 0.05) compared with both the enriched (n-6) FA and control diet on d 112 (Fig. 1). Platelet activation (Fig. 2) tended (P = 0.15) to be higher in the enriched (n-6) FA and control diet groups on d 56 and 112 compared with the enriched (n-3) FA diet group. There was no difference between treatment groups for OSPT, APTT and fibrinogen concentration throughout the study period (data not shown). Discussion. Manipulation of dietary (n-6):(n-3) ratios does not appear to affect coagulation indices such as APTT and OSPT or platelet count in human studies, but platelet function does appear to be altered (Kristensen et al. 1989). The effects of FA supplementation for 4 or 6 wk on bleeding time in dogs have been contradictory (Casali et al. 1986, Landhmore et al. 1986). In this study, bleeding time was significantly increased in cats fed an enriched (n-3) FA diet for 16 wk. Indices of the intrinsic, extrinsic and common coagulation pathways (APTT and OSPT) were not different among cats in the dietary treatment groups throughout the study. Therefore, it is unlikely that alterations in bleeding time were a function of abnormalities in the coagulation cascade. Alterations in bleeding time due to increased dietary (n-3) FA levels may occur in less time than 16 wk; however, that information could not be determined from our study design. The ability of activated platelets to aggregate appeared to be influenced by the ratio of (n-6) to (n-3) FA in the diet as shown in Figure 1. As the level of dietary (n-6) FA decreased, there would be proportionately less AA incorporated into platelet membranes and, therefore, less AA available for conversion to the proaggregatory TXA2. As the concentrations of TXA2 decreased, the ability of platelets to aggregate would diminish. Kristensen et al. (1989) showed a similar effect on human platelet aggregation when fish-based diets were fed. Aggregation of platelets is dependent on or enhanced by fibrinogen binding to platelets. Alteration of platelet membrane glycoprotein complexes, which form a functional receptor for fibrinogen, is an activation- dependent platelet surface change (Welles et al. 1994). The method of measuring platelet activation in this study used an antifibrinogen antibody, which requires the presence of adequate fibrinogen to first bind to the exposed fibrinogen receptors of activated platelets. Our results indicated that platelets derived from cats fed the enriched (n-3) FA diet tended to exhibit decreased activation compared with platelets from cats fed the enriched (n-6) or control diet; fibrinogen concentration did not differ among treatment groups during the study, and values were within the normal range for cats (Duncan and Prasse 1986). This suggested that a decrease in platelet activation resulted in a decrease in aggregatory ability and that this sequence of events was not limited by fibrinogen concentration. Saynor and Gillott (1992) reported that intake by human subjects of diets containing high concentrations of fish oil for over a 7-y period significantly reduced fibrinogen. Possible longer-term effects on fibrinogen concentration of felines fed (n-3) FA-enriched diets may warrant further study with a larger sample size. The results from this study suggest that prolonged (112 d) intake of enriched (n-3) FA diets in cats alters platelet aggregation and bleeding time, such that there were detrimental effects on platelet function. Specific medical conditions in which an enriched (n-3) FA diet or FA supplementation may be indicated would require long-term feeding to confirm the viability of a desired effect. [ABSTRACT FROM AUTHOR]

Mammary cancer, a devastating disease in both humans and companion animals, has been associated with numerous factors including diet. Polyphenolic antioxidants found in pomegranate fruits have been shown to reduce tumor burden and inhibit angiogenesis and cell growth.(Kim et al., 2002; Afaq et al., 2005; Malik et al., 2005) Feline mammary carcinomas (FMC) are known to have similar invasive behavior, histologic appearance, and overall poor prognosis to estrogen receptor negative (ER-) invasive human mammary cancer.(Porrello et al., 2004; Zappulli et al., 2005) In this study, supplementation with an antioxidant-rich whole food (pomegranate) was evaluated for anti-cancer properties in an ER- human breast cancer cell line (MDA-MB-231) as a model for FMC. Antioxidant capacity and polyphenolic content of pomegranate juices (PJ) were characterized by reportable methods. ER- cells were exposed to PJ at various concentrations (0.5%, 1%, 5%) and to Cisplatin (5 ug/ml, 10 ug/ml, 15 ug/ml) doses for 48 and 72 h. MTT assays were performed to evaluate the ability of PJ to inhibit tumor cell growth. Statistical significance was determined using PROC GLM (SAS 9.1) with alpha = 0.05. Cell proliferation of the ER- cancer cells was inhibited by pomegranate juice in a dose- and time-dependent manner (p < 0.0001). Maximal inhibition was seen for pomegranate juice formulations at the 5% dose, and the response was comparable to that of high-dose Cisplatin. This first phase study shows that PJ may be a useful nutrient-based, non-chemotherapeutic treatment alternative for the inhibition of ER- breast cancer cell proliferation. [ABSTRACT FROM AUTHOR]

A practical alternative to traditional central line delivery of parenteral admixtures (PA) for small animal patients is utilization of a peripheral route. Admixtures delivered via this route should be a lower osmolarity to prevent complications; to attain this goal a high lipid:low dextrose (HL:LD) is formulated. Lipid peroxidation is a common sequella of PA containing high lipid content. This in vitro peroxidation can lead to oxidative injury of biological membranes in vivo. Despite this concern, peripheral PA have many benefits and continue to be utilized. Therefore, the objectives of this study were to measure lipid hydroperoxides in HL:LD PA; and to determine the optimal dose of d-α-tocopherol to minimize peroxidation in the PA during a 24 h hang time. This in vitro experiment included three identical blocks consisting of 14 bags ( n = 7 control; n = 7 treatment) filled aseptically with 109 ml of HL:LD PA. Total lipid content per bag was 8 g as soybean oil (Intralipid®). Natural d-α-tocopherol (Vital E-300™) was added to the treatment bags as 8, 12, 16, 24, 32, 48, 64 IU/g of lipid. Control bags contained Vital E-300™ equivalent amounts of ethanol and benzyl alcohol. Bags were hung for 24 h at room temperature under fluorescent light exposure. Hydroperoxides were measured by FOX assay and tocopherols by HPLC at times 0 and 24 h. The level of hydroperoxides was expressed as μM equivalents tert-butyl hydroperoxide (μM = TBH). A Repeated Measures anova was used for data analysis, with p < 0.05 considered significant. Detectable levels of hydroperoxides were found in all PA at time 0 and 24. Mean TBH concentrations in control bags were 380 and 383 μM at time 0 and 24 respectively. A 3-way interaction (time x treatment x α-toc) was observed, p = 0.0018. d-α-tocpherol supplementation at 24–64 IU/g lipid decreased (p < 0.0001) TBH production from controls at time 0. By time 24 h, significant reduction in TBH was observed with Vit E concentrations of 48 and 64 IU/g lipid of d-α-tocopherol. In conclusion: lipid peroxidation of HL:LD PA occurs immediately following lipid administration, and d-α-tocopherol, as Vital E-300™, appears to significantly minimize this peroxidation process in vitro based on concentration and time of exposure to lipid. This has clinical implications for parenteral feeding in critically ill patients. [ABSTRACT FROM AUTHOR]