Hyperthyroid cats and their kidneys: a literature review.

Hyperthyroidism and chronic kidney disease (CKD) are common diseases of geriatric cats, and often occur concurrently. Thus, a thorough understanding of the influence of thyroid function on renal function is of significant value for all feline practitioners. Among other effects, hyperthyroidism causes protein catabolism and increases renal blood flow and glomerular filtration rate (GFR). These effects render traditional renal markers insensitive for the detection of CKD in cats with uncontrolled hyperthyroidism. Furthermore, the development of iatrogenic hypothyroidism with over treatment of hyperthyroidism can be detrimental to renal function and may negatively affect long-term survival. This review discusses important diagnostic considerations of feline hyperthyroidism, as well as key treatment modalities, with an emphasis on the use of radioiodine and the importance of post treatment monitoring of thyroid and renal parameters. In Australia, a common curative treatment for cats with benign hyperthyroidism (i.e. thyroid hyperplasia or adenoma) is a fixed dose of orally administered radioiodine, regardless of the serum total thyroxine concentration at the time of diagnosis. This review discusses the long term outcomes of this standard of care in comparison with current, relevant research literature from around the world. Finally, this review explores the use of symmetric dimethylarginine (SDMA) in assessing renal function before and after treatment in hyperthyroid cats. SDMA correlates well with GFR and creatinine in non-hyperthyroid cats, but our understanding of its performance in hyperthyroid cats remains in its infancy.

Clinical safety of percutaneous ultrasound-guided fine-needle aspiration of adrenal gland lesions in 19 dogs.

OBJECTIVE: To evaluate the safety of fine-needle aspiration of adrenal gland lesions in dogs and to characterise the risks in a subset of patients with cytologically or histopathologically diagnosed phaeochromocytoma. MATERIALS AND METHODS: Retrospective review of medical records of dogs that underwent percutaneous ultrasound-guided fine-needle aspiration of adrenal gland lesions between August 2014 and December 2016. Nineteen dogs were identified, with three undergoing bilateral adrenal gland aspiration and one dog undergoing aspiration twice, yielding 23 cytology samples in total. Data collected included signalment, concurrent medical conditions, current medications, blood pressure and heart rate before adrenal fine-needle aspiration, imaging characteristics of the adrenal gland lesions and any clinically apparent procedure-related complications. RESULTS: Phaeochromocytoma was diagnosed in nine of 19 dogs, including one dog with bilateral phaeochromocytoma. One dog developed ventricular tachycardia following aspiration of an adrenal gland lesion cytologically consistent with a phaeochromocytoma. CLINICAL SIGNIFICANCE: Percutaneous ultrasound-guided fine-needle aspiration of adrenal gland lesions appears to be relatively safe, even in phaeochromocytoma, but further data are required to lend more weight to this finding. Minimally invasive aspirates could be considered as part of the diagnostic algorithm in the investigation of an incidentally detected adrenal gland lesion of uncertain clinical significance.

Cricopharyngeal dysphagia and phenobarbitone-responsive sialoadenosis in a Miniature Poodle.

CASE REPORT: An 11-year-old male neutered Miniature Poodle was investigated for ptyalism, weight loss and anorexia. Cricopharyngeal dysphagia was diagnosed using fluoroscopy, and non-inflammatory salivary disease was diagnosed using a combination of cytology and computed tomography. The dog was successfully managed with phenobarbitone. CONCLUSION: To the authors' knowledge this is the first time acquired cricopharyngeal dysphagia and phenobarbitone-responsive sialoadenosis have been described together.