Anatomical classification of feline congenital extrahepatic portosystemic shunts based on CT angiography: A SVSTS and VIRIES multi-institutional study in 231 cats.

The prevalence of anatomical-based subtypes of feline congenital extrahepatic portosystemic shunts (EHPSS) has not been completely elucidated. The goal of this study was to use CT angiography to create an anatomical-based nomenclature system for feline congenital EHPSS. Additionally, subjective portal perfusion scores were generated to determine if intrinsic portal vein development was associated with different shunt conformations or patient age at the time of CT. The SVSTS and VIRIES list services were used to recruit cases. Data collected included patient DOB, gender, breed, weight, CT date, and reported diagnosis. Shunts were classified based upon (1) the shunt portal vessel(s) of origin, (2) the shunt systemic vessel(s) of insertion, and (3) any substantial portal vessels contributing to the shunt. Additionally, hepatic portal perfusion was subjectively scored between 1 (poor/none) and 5 (good/normal) based on the caliber of the intrahepatic PVs. A total of 264 CT scans were submitted from 29 institutions. Due to exclusion criteria, 33 (13%) were removed, leaving 231 CT scans to be included. Twenty-five different EHPSS anatomies were identified with five classifications accounting for 78% of all shunts (LGP [53%], LGC-post [11%], LCG [7%], LGC-pre [4%], and PC [4%]). Shunt origin involved the left gastric vein in 75% of the described classifications. Significant differences were identified among the five most common shunt types with respect to age at the time of CT scan (P = .002), breed (P < .001), and subjective portal perfusion score (P < .001). This refined anatomical classification system for feline EHPSS may enable improved understanding, treatment comparisons, and outcome prediction for cats with these anomalies.

A case of canine renal lymphoma of granular lymphocytes with severe polycythemia.

BACKGROUND: Renal lymphoma in dogs is rare and has a poor prognosis. Granular lymphocyte morphology is rarely reported in canine renal lymphoma. Mild to moderate polycythemia is reported in a number of canine renal lymphoma cases. CASE PRESENTATION: A 10-year-old Labrador retriever presented to a university veterinary teaching hospital after a 1-month history of polyuria, polydipsia, and pollakiuria and a 2-week history of abdominal distention, lethargy, and increased respiratory effort. Abdominal ultrasound showed a wedge-shaped to rounded, heterogeneously hypoechoic mass lesion in the left kidney. Cytologic analysis of a percutaneous aspirate of the mass was consistent with lymphoma of granular lymphocytes. Severe polycythemia (hematocrit 0.871) was noted on a complete blood cell count. Clonality analysis identified a clonally rearranged T-cell receptor (TCR) gene and immunohistochemical staining was CD3+, CD79a- and CD11d+, supporting cytotoxic T-cell lymphoma. CONCLUSIONS: To our knowledge, this is the first report of renal cytotoxic T-cell lymphoma with severe polycythemia in a dog. Severe polycythemia and renal cytotoxic T-cell lymphoma are both rare in dogs; this report adds to the body of knowledge on these conditions.

Immediate effect of transmucosal application of corn syrup or 50% dextrose solution on blood glucose concentrations in healthy dogs.

OBJECTIVE: Evaluate and quantify the effects of mucosal corn syrup and 50% dextrose application on blood glucose concentrations in healthy dogs, to assess the effectiveness of a widely used practice for treatment of hypoglycemia. DESIGN: Randomized controlled trial. SETTING: University teaching hospital. ANIMALS: Twelve client-owned dogs that were healthy, >1 year of age, weighing >5 kg, and had normal physical exam and biochemical profiles. INTERVENTIONS: Dogs were fasted overnight for a minimum of 12 hours. Once normal physical exam and biochemical profile were confirmed, an IV catheter was placed in a peripheral vein for serial blood sampling. Each dog served as their own control and received each of 3 treatments, the orders of which were randomized for each dog. Treatments included mucosal application of commercially available corn syrup (Karo light syrup), water (control), and 50% dextrose solution, each at a dose of 1 mL/kg of body weight. Blood glucose was measured using a point-of-care glucometer. Samples were taken immediately prior to each treatment and at 5-, 10-, 15-, 20-, 30-, and 60-minute intervals. RESULTS: All treatments were well tolerated and no adverse events were observed. A statistically significant increase in blood glucose was observed at the 15-, 20-, 30-, and 60-minute time points in the corn syrup and 50% dextrose groups as compared with the control. CONCLUSIONS: A significant effect on the blood glucose concentrations of the treated animals was not observed until 15 minutes after application of concentrated glucose solutions. These findings suggest that, in more severely hypoglycemic patients, parenteral glucose administration may be necessary.

Silicone Pet Tags Associate Tris(1,3-dichloro-2-isopropyl) Phosphate Exposures with Feline Hyperthyroidism.

Feline hyperthyroidism is the most commonly diagnosed endocrine-related disease among senior and geriatric housecats, but the causes remain unknown. Exposure to endocrine-disrupting compounds with thyroid targets, such as flame retardants (FRs), may contribute to disease development. Silicone passive sampling devices, or pet tags, quantitatively assessed the bioavailable FR exposures of 78 cats (≥7 y) in New York and Oregon using gas chromatography-mass spectrometry. Pet tags were analyzed for 36 polybrominated diphenyl ethers, six organophosphate esters (OPEs), and two alternative brominated FRs. In nonhyperthyroid cats, serum free thyroxine (fT4), total T4 (TT4), total triiodothyronine, and thyroid-stimulating hormone concentrations were compared with FR concentrations. Tris(1,3-dichloro-2-isopropyl) phosphate (TDCIPP) concentrations were higher in hyperthyroid pet tags in comparison to nonhyperthyroid pet tags (adjusted odds ratio, p < 0.07; Mantel-Cox, p < 0.02). Higher TDCIPP concentrations were associated with air freshener use in comparison to no use (p < 0.01), residences built since 2005 compared to those pre-1989 (p < 0.002), and cats preferring to spend time on upholstered furniture in comparison to no preference (p < 0.05). Higher TDCIPP concentrations were associated with higher fT4 and TT4 concentrations (p < 0.05). This study provides proof-of-concept data for the use of silicone pet tags with companion animals and further indicates that bioavailable TDCIPP exposures are associated with feline hyperthyroidism.

Clinical evaluation of a benchtop dry chemistry analyzer for measurement of ammonium concentrations in canine plasma samples.

OBJECTIVE To evaluate the clinical performance of a veterinary benchtop dry chemistry analyzer for measurement of plasma ammonium concentrations in dogs by comparing results with those obtained by a reference standard test method. DESIGN Prospective evaluation study. SAMPLE 32 blood samples from 30 dogs (16 with and 14 without suspected hepatobiliary disease). PROCEDURES Blood samples were collected by jugular venipuncture. A veterinary benchtop dry chemistry analyzer and a reference standard (enzymatic) test method were used to measure ammonium concentrations in plasma collected from heparinized whole blood. Bland-Altman plots were used to assess intermethod agreement. Results were compared by linear regression, and correlation was calculated by the Pearson method. Samples were classified as having high or normal ammonium concentrations on the basis of cutoff data for the relevant test method; results were compared between methods to evaluate diagnostic agreement. RESULTS 31 of 32 (97%) samples were classified correctly with the benchtop analyzer; 1 sample with a high ammonium concentration was classified as having a normal value (ie, false-negative result) by this method. A strong positive correlation (r2 = 0.989) was found between methods, with constant, proportional, negative bias for benchtop analyzer results. The interassay coefficient of variation (ie, precision) for measurement of an internal standard with the benchtop analyzer was 2.74% (n = 20 repetitions). CONCLUSIONS AND CLINICAL RELEVANCE The dry chemistry analyzer used in the study had acceptable clinical performance for detection of high versus normal ammonium concentrations in canine plasma, indicating the method can be used to aid diagnosis in dogs with suspected hepatobiliary disease.

COMPUTED TOMOGRAPHIC CHARACTERISTICS OF THE THYROID GLANDS IN EIGHT HYPERTHYROID CATS PRE- AND POSTMETHIMAZOLE TREATMENT COMPARED WITH SEVEN EUTHYROID CATS.

Hyperthyroidism is the most common feline endocrinopathy; thyroid computed tomography (CT) may improve disease detection and methimazole dose selection. Objectives of this experimental pre-post with historical case-control study were to perform thyroid CT imaging in awake or mildly sedated hyperthyroid cats, compare thyroid gland CT appearance in euthyroid and hyperthyroid cats pre- and postmethimazole treatment, and determine whether thyroid size or attenuation correlate with methimazole dose needed for euthyroidism. Premethimazole treatment, eight hyperthyroid cats received CT scans from the head to heart, which were compared to CT of seven euthyroid cats. Total thyroxine levels were monitored every 3-4 weeks. Postmethimazole CT was performed 30 days after achieving euthyroid status. Computed tomography parameters recorded included thyroid length, width, height, attenuation, and heterogeneity. Median time between CT was 70 days (53-213 days). Mild sedation was needed in five hyperthyroid cats premethimazole, and none postmethimazole. Thyroid volume was significantly larger in hyperthyroid cats compared to euthyroid cats (785.0 mm3 vs. 154.9 mm3 ; P = 0.002) and remained unchanged by methimazole treatment (-4.5 mm3; P = 0.50). Thyroid attenuation and heterogeneity decreased with methimazole treatment (96.1 HU vs. 85.9 HU; P = 0.02. 12.4 HU vs. 8.1 HU; P = 0.009). Methimazole dose ranged from 2.5 to 10 mg daily with a positive correlation between pretreatment thyroid gland volume and dose needed to achieve euthyroidism (P = 0.03). Euthyroid and hyperthyroid cats are easily imaged awake or mildly sedated with CT. Methimazole in hyperthyroid cats significantly lowers thyroid attenuation and heterogeneity, but not size.

Juvenile hyperthyroidism in a cat.

An 8-month-old, male domestic shorthaired cat presented for chronic weight loss, intermittent dyspnea, chronic diarrhea, hyperactivity, and weakness. The cat had a palpable thyroid nodule and increased serum total thyroxine and 3,5,3' triiodothyronine levels. The cat was diagnosed with hyperthyroidism, and a unilateral thyroidectomy was performed followed by radioactive iodine at a later date. The clinical signs resolved following radioactive iodine, and the cat subsequently developed clinical hypothyroidism.