These abstracts were presented during College Science Week, the annual congress of the Australian and New Zealand College of Veterinary Scientists, in July.
Excess Body Condition Rather than Body Weight Increases the Risk of Urethral Obstruction in Male Castrated Cats
Alison N Jukes1, Megan Lui1, John Morton2, Marcus Gunew1, Rhett Marshall1, Nicholas Yeow1
1The Cat Clinic, Brisbane, Queensland, Australia
2Jemora Pty Ltd, Geelong, Victoria, Australia Email: alison.alick@gmail.com
Background: Urethral obstruction is a serious complication of feline lower urinary tract disease (FLUTD) that occurs most commonly in castrated male cats. Risk factors for FLUTD such as high body weight and obesity have previously been identified; however, limited studies have been performed investigating risk factors specifically for urethral obstruction.
Aim: The primary aim was to assess whether body condition score is a risk factor for urethral obstruction in castrated male cats independently of body weight using a validated body condition scoring method. Secondary aims were to assess whether age, breed, pedigree status and coat length are risk factors for urethral obstruction.
Methods: This retrospective, rate-based, matched case-control study recruited 298 castrated male cats with urethral obstruction and 298 control cats presenting to a feline-only first opinion veterinary practice in Brisbane, Australia.
Results: Body condition score was a risk factor for urethral obstruction independently of body weight. Domestic longhair and non-pedigree breed cats also had an elevated risk of urethral obstruction, and Burmese breed cats were at reduced risk. Cats <1 year old or those >10 years old were at reduced risk.
Conclusions: The increased risk of urethral obstruction in heavy cats is due to excess body condition rather than their higher body weight. Thus, small obese cats are at increased risk of urethral obstruction and heavy cats in ideal body condition are not at increased risk of urethral obstruction. Ensuring castrated male pet cats of all sizes are kept at an ideal body condition may reduce their risk of urethral obstruction.
Feline Hypercalcaemia Caused by Nutritional Hypervitaminosis D: A Case Series of Two Cats
Sarah J Simpson, Wendy Agnew
Veterinary Specialist Services, Underwood, Australia Email: ssimpson@vss.net.au
Case series summary: Two young female spayed Sphynx cats from the same household were treated at Veterinary Specialist Services for hypercalcaemia. The first cat presented for a single episode of vomiting and a 2 week history of progressive lethargy and inappetence. Diagnostic investigation ruled out hyperparathyroidism, hypoadrenocorticism, renal disease and neoplastic disease, and the cat was treated as an idiopathic hypercalcaemia case. Two weeks later, the second cat presented for similar clinical signs and was confirmed to be hypercalcaemic as well. A 25-hydroxyvitamin D level was performed, which returned as markedly elevated (671 nmol/l, reference interval 65–170 nmol/l). An analysis was performed on all eight items the cats had oral exposure to, including multiple diets, toothpastes and supplements. One commercially available food returned with a vitamin D level of 181,720 IU/100 g of dry matter, which is 60 times the maximum allowable limit in accordance with FEDIAF nutritional guidelines. Both cats were treated with intravenous fluids (0.9% NaCl), intravenous esomeprazole and maropitant at 1 mg/kg and were discharged with a strict diet of Hill’s c/d or z/d, which resulted in resolution of their hypercalcaemia.
Relevance and novel information: This is the first report of nutritional hypervitaminosis D in cats in Australia. The food was labelled as ‘complete and balanced’, despite the excessive vitamin D content, and is still available in supermarkets and pet stores. Previous reports of vitamin D intoxication in Australia have involved ingestion of rodenticides. These cases highlight the importance of a thorough investigation of feeding history and measurement of serum 25-hydroxyvitamin D levels in a diagnostic work-up for feline hypercalcaemia.
