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Background: The high doses of radioiodine-131 ( 131 I) and, subsequently, the high radioactive burden for dog and environment warrants optimization of 131 I therapy in dogs with thyroid carcinoma (TC)., Hypothesis/objectives: To evaluate the effect of a revised protocol with recombinant human thyroid stimulating hormone (rhTSH) on tumor radioactive iodine uptake (RAIU) in dogs with TC., Animals: Nine client-owned dogs diagnosed with TC., Methods: A prospective cross-over study in which tumor RAIU was calculated and compared at 8 hours (8h-RAIU) and 24 hours (24h-RAIU) after injection of radioactive iodine-123 ( 123 I), once with and once without rhTSH (ie, 250 μg, IM, 24 and 12 hours before 123 I) in each dog. Simultaneously, serum total thyroxine (TT4) and TSH were measured at baseline (T 0 ), and 6 (T 6 ), 12 (T 12 ), 24 (T 24 ), and 48 hours (T 48 ) after the first rhTSH administration., Results: Tumor RAIU was significantly higher at 24 hours with rhTSH compared to no rhTSH (mean difference = 8.85%, 95% CI of [1.56; 16.14]; P = .03), while this was non-significant at 8 hours (mean difference = 4.54%, 95% CI of [0.35; 8.73]; P = .05). A significant change of serum TT4 (median difference T 24  - T 0  = 35.86 nmol/L, interquartile range [IQR] = 15.74 nmol/L) and TSH (median difference T 24  - T 0  = 1.20 ng/mL, IQR = 1.55 ng/mL) concentrations occurred after administration of rhTSH (P < .001)., Conclusions and Clinical Importance: Recombinant human TSH could optimize 131 I treatment in dogs with TC by increasing tumor RAIU and thus 131 I treatment efficacy., (© 2024 The Author(s). Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.)

Currently, a histological diagnosis of highly vascularized canine (c) thyroid carcinoma (TC) is primarily obtained following excisional biopsy (EB) through thyroidectomy. Non-EBs are contraindicated in unresectable invasive cTCs due to their highly vascularized nature, which subsequently, lack histological diagnosis. We hypothesised ultrasound-guided core needle biopsy (UGCNB) to be a safe biopsy technique to obtain an accurate histological diagnosis in unresectable TCs. Nine client-owned dogs with suspected naturally occurring TC, presented for surgical excision, were included. First, a UGCNB was taken from the cervical tumour, followed by EB. Haemorrhage following UGCNB was evaluated preoperatively and once the tumour was surgically exposed by visual inspection and ultrasonography. Histological analysis, including cell organisation, tumour capsular and vascular invasion, and immunohistochemistry were performed and compared between both biopsy specimens (i.e., UGCNB and EB) of the same dog. Pre- and peroperative visual inspection revealed minor, localised haemorrhage, subsequent to the UGCNB, in 7/9 dogs. Histology of the EBs confirmed TC in 8/9 dogs and was inconclusive in 1/9 dogs. Histology of the UGCNBs revealed neoplastic thyroid tissue in 7/9 UGCNBs and was inconclusive in 1/9 UGCNBs. The remaining UGCNB contained no mass related tissue and was, therefore, excluded. Histological parameters (i.e., cell organisation, tumour capsular and vascular invasion) were not concordant between 6/8 included UGCNBs and their respective EB. Immunolabelling for thyroglobulin and calcitonin was concordant between all eight included UGCNBs and their respective EB. The remaining evaluated immunohistochemical markers (i.e., cyclooxygenase-2 [COX-2], P-glycoprotein and vascular endothelial growth factor [VEGF]) were concordant between the included UGCNBs and the EBs in 6/8 dogs. To conclude, UGCNBs can be safely obtained in suspected cTCs and enable a reliable diagnosis of the thyroid origin, thyroid cell origin and potential therapeutic markers such as COX-2, P-glycoprotein and VEGF. Subsequently, UGCNB enables clinicians to establish an individually tailored treatment plan in dogs with unresectable TC., (© 2023 John Wiley & Sons Ltd.)

Objectives: This study aimed to describe the clinical and diagnostic characteristics, as well as outcomes of radioiodine treatment in dogs with hyperthyroidism caused by a non-resectable ectopic thyroid tumour., Materials and Methods: This retrospective study reviewed the medical records between 2008 and 2018 of dogs diagnosed with hyperthyroidism secondary to a non-resectable ectopic thyroid tumour and treated with radioiodine., Results: Five dogs were included in the study. Three dogs had sublingual ectopic tumours, of which one also had a unilateral cervical thyroid tumour. The remaining two dogs were diagnosed with an ectopic thyroid tumour at the level of the caudal pharynx and the heart base, respectively. All cases were treated with radioiodine. The size of the ectopic masses decreased after radioiodine treatment. Total thyroxine concentrations returned to reference ranges in all dogs. Further, clinical signs of hyperthyroidism disappeared after treatment in all patients. One dog developed myelosuppression secondary to radioiodine treatment. The dog with metastasis had a very short survival compared to the four dogs without metastasis (3 months compared to 7, 36, 50 and 24 months, respectively) and succumbed most likely to thyroid-related problems. In the remaining four dogs, their quality of life improved. They died due to diseases unrelated to the ectopic thyroid tumour., Clinical Significance: Radioiodine therapy should be considered as a treatment option in dogs diagnosed with hyperthyroidism due to a non-resectable ectopic thyroid tumour., (© 2020 British Small Animal Veterinary Association.)

Background: Liver function tests do not always normalize despite successful attenuation of extrahepatic portosystemic shunts (EHPSS)., Objectives: Assess the lidocaine/monoethylglycylxylidide (MEGX) test to determine liver perfusion after EHPSS closure., Animals: Twenty dogs with EHPSS., Methods: A prospective cohort study was performed and all dogs were tested at diagnosis, 1, 3, and 6 months postoperatively. After collecting a baseline blood sample (T0), 1 mg/kg body weight of lidocaine was injected intravenously. Fifteen (T15) and 30 minutes (T30) later, blood was collected. Plasma concentrations of lidocaine and its metabolites MEGX and glycylxylidide (GX) were determined, using a high-performance liquid chromatography with electrospray ionization tandem mass spectrometry method. Three months postoperatively, transsplenic portal scintigraphy was performed to determine EHPSS closure., Results: At T15, median MEGX concentrations were higher in dogs with closed EHPSS compared to diagnosis (33.73 ng/mL [21.11-66.44 ng/mL] vs 13.74 ng/mL [7.25-21.93 ng/mL]; P < .001), but were not different (12.28 ng/mL [10.62-23.17 ng/mL] vs 13.74 ng/mL [7.25-21.93 ng/mL]) in dogs with persistent shunting. Sensitivity to determine shunt closure for MEGX at T15 was 96.2% (95% confidence interval [CI]: 78.4-99.8) and specificity 82.8% (95% CI: 63.5-93.5)., Conclusions and Clinical Importance: The lidocaine/MEGX test is a promising, rapid, and noninvasive blood test that seems helpful to differentiate dogs with closed EHPSS and dogs with persistent shunting after gradual attenuation., (© 2021 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC. on behalf of the American College of Veterinary Internal Medicine.)

Background: Information on scintigraphy findings in dogs with thyroid neoplasia is scarce. The use of single-photon emission computed tomography (SPECT) could improve detection of metastatic disease., Hypothesis/objectives: To describe planar and SPECT imaging findings in dogs with thyroid tumors, and to compare SPECT and thoracic radiography for metastasis detection., Animals: Sixty-eight dogs with thyroid neoplasia., Methods: Retrospective study, search of medical records for dogs with thyroid neoplasia (2008-2018)., Results: Thyroid scintigraphy was available from 68 dogs, of which 6 presented after surgical resection. Radionuclide uptake was increased in 56% of dogs, decreased in 24%, and comparable to that of the salivary glands in 13%. The remainder had multiple masses with variable uptake. A homogeneous uptake pattern was present in 16% and a heterogeneous uptake pattern in 73%. In 11% (all dogs with multiple masses), various uptake patterns were present. Thyroid tumors were well delineated in 55%. There was a significant association between hormone status and uptake pattern (P = .009), with a heterogeneous uptake pattern in the majority of euthyroid dogs, and hormone status and tumor circumscription (P = .003), with well-circumscribed margins in the majority of hypothyroid and hyperthyroid dogs. Thoracic SPECT imaging was available in 39 dogs and identified metastatic lesions in 15 dogs. Thoracic radiographs were performed in 14 of these dogs, and detected metastases in 3 dogs., Conclusions and Clinical Importance: SPECT imaging is a viable imaging technique to screen for thoracic metastasis and wider use of SPECT imaging is recommended in dogs with thyroid neoplasia., (© 2020 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.)

Background: The aims of this study were to determine if extrahepatic portosystemic shunt (EHPSS) postoperative closure could be predicted based on preoperative blood analyses and to determine the accuracy of blood variables to evaluate persistence of portosystemic shunting postoperatively (multiple acquired portosystemic shunts (MAPSS) or persistent EHPSS)., Methods: Retrospectively, 62 dogs treated surgically for congenital EHPSS that underwent postoperative trans-splenic portal scintigraphy or CT angiography three to six months postoperatively were included., Results: None of the studied preoperative blood variables could unambiguously predict surgical outcome. Elevated postoperative fasting venous ammonia (FA) concentration always indicated surgical failure (persistent shunting or MAPSS), but normal FA did not provide any information on the postoperative shunting status. Paired serum bile acids (SBA) were not reliable enough to confirm or exclude postoperative shunting. In the presence of low normal postoperative FA levels, elevated preprandial SBA was more likely in dogs with persistent shunting (sensitivity of 0.79, specificity of 0.83), whereas postprandial SBA below reference limit was more often observed in case of surgical success (sensitivity of 0.93, specificity of 0.67)., Conclusion: Blood variables, and more specifically the combination of FA and SBA, are not a valuable alternative to advanced medical imaging to reliably assess the surgical outcome after EHPSS surgery., Competing Interests: Competing interests: None declared., (© British Veterinary Association 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

OBJECTIVE To compare ammonia concentrations in arterial blood, venous blood, and CSF samples of dogs with and without extrahepatic portosystemic shunts (EHPSS). ANIMALS 19 dogs with congenital EHPSS and 6 healthy control dogs. PROCEDURES All dogs underwent a physical examination and then were anesthetized for transsplenic portal scintigraphy to confirm the presence or absence of EHPSS. While dogs were anesthetized, arterial and venous blood samples and a CSF sample were simultaneously collected for determination of ammonia concentration, which was measured by use of a portable blood ammonia analyzer (device A) and a nonportable biochemical analyzer (device B). Results were compared between dogs with EHPSS and control dogs. RESULTS Arterial, venous, and CSF ammonia concentrations for dogs with EHPSS were significantly greater than those for control dogs. For dogs with EHPSS, ammonia concentrations in both arterial and venous blood samples were markedly increased from the reference range. There was a strong positive correlation between arterial and venous ammonia concentrations and between blood (arterial or venous) and CSF ammonia concentrations. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that blood and CSF ammonia concentrations in dogs with EHPSS were greater than those for healthy dogs and were strongly and positively correlated, albeit in a nonlinear manner. This suggested that the permeability of the blood-brain barrier to ammonia may be abnormally increased in dogs with EHPSS, but further investigation of the relationship between blood or CSF ammonia concentration and clinical signs of hepatic encephalopathy or the surgical outcome for dogs with EHPSS is warranted.

Regional cerebral blood flow (rCBF) in eight dogs with congenital portosystemic shunt (PSS) and hepatic encephalopathy (HE) was compared with rCBF in eight healthy control dogs using single photon emission computed tomography (SPECT) with a 99m technetium-hexamethylpropylene amine oxime ( 99m Tc-HMPAO) tracer. SPECT scans were abnormal in all PSS dogs. Compared to the control group, rCBF in PSS dogs was significantly decreased in the temporal lobes and increased in the subcortical (thalamic and striatal) area. Brain perfusion imaging alterations observed in the dogs with PSS and HE are similar to those in human patients with HE. These findings suggest that dogs with HE and PSS have altered perfusion of mainly the subcortical and the temporal regions of the brain., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Scintigraphy is an extremely sensitive tool for the detection of early changes in bone metabolism. Sixty-eight lame dogs underwent a scintigraphic examination. For each elbow lateromedial (LM), caudomedial (CdM) flexed and caudomedial (CdM) extended scintigraphic views were obtained. Semi-quantitative analysis was performed to determine radiopharmaceutical uptake at the medial coronoid process (MCP) and at the attachment of the flexor muscles at the medial humeral epicondyle, normalised to activity registered in either the total elbow joint or the radius/ulna. MCP pathology/flexor enthesopathies were divided into simple (containing one abnormality) or complex (containing more than one abnormality) lesions. The influence of different views or normalisation procedures on sensitivity and specificity was evaluated. MCP lesions were detected on radiography, ultrasound, computed tomography, magnetic resonance imaging and/or arthroscopy in 49 elbows, with 13 simple and 36 complex lesions. Flexor enthesopathy was diagnosed in 54 elbows, with 14 simple and 40 complex lesions. In seven elbows only degenerative changes were present, whereas in 50 elbows no abnormalities could be detected. MCP lesions were best detected with the CdM extended view, whereas for flexor enthesopathy the CdM flexed view offered the best result. To detect simple lesions, the normalisation procedure to the elbow gave the best result, whereas normalisation to the radius/ulna was the best choice for complex lesions. This study suggests that semi-quantification is a valuable method in case of simple pathology, especially when MCP lesions are considered. For elbows with complex lesions, the quantification procedure is less reliable., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

In this study the use of the high resolution Micro-Single Photon Emission Tomography (HiSPECT) system with a radioactive bonemarker, (99m)Tc-oxidronate, was evaluated in dogs with coronoid pathology and/or flexor enthesopathy. Sixty-five elbows of 34 dogs were included. CT and HiSPECT were performed on all elbows, arthroscopy on 59. Tracer uptake in 8 anatomical regions was graded according to two models. Increased activity in the medial epicondylar region was associated with flexor pathology on CT (P=0.0002) and arthroscopy (P<0.0001) and increased uptake in the medial coronoid (P<0.0001) and the medial condylar area (P<0.013) with coronoid pathology. Uptake in the remaining areas was not associated with both pathologies. In conclusion, the improved resolution of the HiSPECT system allows identification of increased tracer uptake in the anatomical regions involved in coronoid pathology and flexor enthesopathy. This modality may improve the diagnostic potential of the bone scan in canine elbow disease., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Objective: To investigate the possibilities and limitations of planar bone scintigraphy and high resolution single photon emission computed tomography (HiSPECT) to diagnose flexor enthesopathy and to distinguish primary flexor enthesopathy from the concomitant form., Materials and Methods: A prospective study of 46 dogs with primary flexor enthesopathy, concomitant flexor enthesopathy, medial coronoid disease, and normal elbows was performed. All dogs underwent planar bone scintigraphy and HiSPECT imaging. The obtained images were visually scored for increased radiopharmaceutical uptake in the medial humeral epicondylar and medial coronoid process region using a score from 1-3., Results: Planar bone scintigraphy demonstrated increased radiopharmaceutical uptake in all diseased elbow joints, except for one. HiSPECT demonstrated increased radiopharmaceutical uptake of the medial humeral epicondyle in nearly all clinically affected joints with primary and concomitant flexor enthesopathy. Additional uptake of the medial coronoid process was recorded in all clinically affected joints with concomitant flexor enthesopathy and in six out of 18 with primary flexor enthesopathy. No difference in intensity of the uptake was noticed., Clinical Significance: Planar bone scintigraphy allows the attribution of lameness to the elbow joint in cases of primary flexor enthesopathy with minimal or even absent radiographic changes. The more detailed HiSPECT enables the localization of pathology within the elbow joint and is a sensitive technique to detect flexor enthesopathy. However HiSPECT is insufficient to distinguish primary from concomitant flexor enthesopathy.

[123I]-iodo-L-phenylalanine was successfully evaluated for gamma camera imaging in vivo in tumor-bearing athymic mice and in humans with brain tumors. Here, we report the use of this tracer in two dogs with synovial cell sarcoma of the tarsus. [123I]-iodo-L-phenylalanine was quantitatively prepared as a kit formulation using the Cu(1+) +-assisted nucleophilic exchange. Rapid [123I]-2-iodo-L-phenylalanine tumor accumulation was observed with good tumor to background contrast and rapid clearance in these two dogs. This radiopharmaceutical is a promising alternative tumor tracer to overcome the known limitations of 18F-fluorodeoxyglucose and, when labelled with radioiodine-131, has the potential to be used for therapeutic purposes.

Secreted phospholipase A2 inhibitor (sPLA2i) has been reported to have an anti-inflammatory function by blocking the production of inflammatory mediators. Obesity is characterized by low-grade inflammation and oxidative stress. The aim of this study was to investigate the effects of dietary supplementation of sPLA2i on inflammation, oxidative stress and serum fatty acid profile in dogs. Seven obese and seven lean Beagle dogs were used in a 28-day double blind cross-over design. Dogs were fed a control diet without supplemental sPLA2i or an sPLA2i supplemented diet. The sPLA2i diet decreased plasma fibrinogen levels and increased the protein:fibrinogen ratio in obese dogs to levels similar to those of lean dogs fed the same diet. Obese dogs had a higher plasma concentration of the lipophilic vitamin A with potential antioxidative capacity and a lower ratio of retinol binding protein 4:vitamin A compared to lean dogs, independent of the diets. A higher proportion of myristic acid (C14:0) and a lower proportion of linoleic acid (C18:2n-6) were observed in the dogs fed with the sPLA2i diet compared to dogs fed with the control diet. Furthermore, a higher ratio of n-6 to n-3, a lower proportion of n-3 polyunsaturated fatty acids and lower omega-3 index were observed in obese compared to lean dogs. The results indicate that obese dogs are characterized by a more ‘proinflammatory’ serum fatty acid profile and that diet inclusion of sPLA2i may reduce inflammation and alter fatty acid profile. [ABSTRACT FROM AUTHOR]