ANZCVS abstracts These abstracts were presented during the feline stream at College Science Week, the annual congress of the Australian and New Zealand College of Veterinary Scientists, in July.
LISTERIAL MESENTERIC LYMPHADENITIS IN THREE CATS
Tommy W Fluen1, Michael Hardcastle2, Randolph M Baral3
1The Veterinary Specialist Group, Auckland, New Zealand
2Gribbles Veterinary Pathology, Auckland, New Zealand
3Paddington Cat Hospital, Sydney, New South Wales, Australia
Email: tommy.fluen@vsg.co.nz
Case series summary: This series describes the presentation, clinical findings and outcome of three cats infected with Listeria monocytogenes. L monocytogenes is a gram-positive bacillus and facultative anaerobe with variable pathogenicity. Listeriosis is a rare disease in cats and only five cases have been reported to date in this species.
The cats included in this case series were between 4 and 6 years of age, and presenting signs included combinations of weight loss, vomiting and anorexia. All three cases had profound abdominal lymphadenomegaly identified by palpation and abdominal ultrasound (2.8 cm, 4 cm and 5 cm on ultrasonographic assessment), and later confirmed at exploratory laparotomy. L monocytogenes infection was confirmed by combinations of culture and immunohistochemistry. In all three cases survival was prolonged, with one case surviving 64 months from diagnosis, and the remaining two cases still alive, at the time of writing, 16 and 21 months from diagnosis. Two of the cats in this case series had been fed a raw meat-based diet prior to the development of clinical illness.
Relevance and novel information: Each of these cases was likely a consequence of gastrointestinal translocation of the bacterium, or haematogenous spread secondary to L monocytogenes septicaemia. The lymphadenitis phenotype of the disease undergoes a protracted time course and is a differential for abdominal lymphadenopathy in middle-aged cats. Feeding of a raw meat-based diet may be a contributing factor for development of listeriosis in cats.
LINKING MACRONUTRIENT INTAKE AND BEHAVIOUR IN DOMESTIC CATS (FELIS CATUS)
Sophia C Little1, Gabriel Machovsky-Capuska1, Kim Kendall2, David Raubenheimer1
1Department of Veterinary Science, The University of Sydney, New South Wales, Australia
2The Cat Palace, Chatswood, New South Wales, Australia
Email: sophia.little7@gmail.com
Background: Given the opportunity, domestic cats naturally self-select their diet based on the macronutrient components. The domestic environment, however, rarely allows for macronutrient selection. Other species of small carnivore are known to change their predation and play behaviour based on their diet; however, the role of macronutrients and their interaction with predation and play behaviour is not yet identified in the domestic cat.
Aim: The aim of this study was to determine whether behavioural links to macronutrient intake exist for domestic cats.
Methods: Seven cats kept in identical enclosures had Fitbark pedometers attached to their collars. Their activity was measured while consuming their usual diet, followed by high protein, high carbohydrate and high fat diets for 3 weeks per diet, with an adjustment period of 1 week. A restricted maximum likelihood (REML) analysis was conducted in GenSTAT 18 (VSNi), with the fixed effect of diet, and a random effect of cat ID. A separate model was run for each outcome variable.
Results: During the high fat diet, cats showed significantly higher activity totals compared with all other diets (P <0.01). During the high protein diet, cats exhibited the lowest activity levels (P <0.01). Diets were not isocaloric; however, BMI was not significantly different across the diets (P = 0.5).
Conclusions: Cats on a high fat diet showed a significant increase in activity compared with the other diets. Conversely, cats on a high protein diet displayed significantly lower total activity, and lower high energy activity levels. The results are suggestive that there may be a behavioural response to macronutrient ingestion. Further studies would improve the reliability of this correlation.
EFFECT OF MELATONIN ON CYCLICITY AND LACTATION OF SEVEN POSTPUBERTAL QUEENS
Mark J Vardanega1, Xavier Schneider2, Philip Thomas2
1Pet Emergency Room, Brisbane, Queensland, Australia
2Queensland Veterinary Specialists, Brisbane, Queensland, Australia
Email: mark.vardanega@uq.net.au
Background: Subcutaneous melatonin implants represent an effective method of suppressing oestrus in queens without causing uterine pathology such as cystic endometrial hyperplasia or pyometra, commonly seen following the use of progestins. Previous studies have demonstrated that 18 mg subcutaneous melatonin implants reliably inhibit oestrus.
Aim: The aim of this study was to add to the limited data describing the duration of suppression, effect on fertility, return to call and effect on lactation of subcutaneous melatonin.
Methods: A retrospective analysis of the medical history of seven postpubertal queens treated
off-label with 18 mg subcutaneous melatonin implants to temporarily suppress oestrus was carried out.
Results: Mean age of all cats was 13 months (range 6–48 months). At the time of suppression, 29% were multiparous, 14% were uniparous and 57% were nulliparous. All cats displayed suppression of oestrus following implantation, with one demonstrating a delay in suppression. Duration of suppression varied between 9 and 17 weeks, with an average of 12.1 weeks. At the time of analysis, 4/7 cats had returned to call following suppression and were mated successfully. Ultrasonographic assessment of the uterus and ovaries revealed no abnormalities or evidence of pathology. One cat was treated postpartum; following this, the mammary glands appeared more distended with milk and the cat continued to produce milk for 2 weeks longer than normal.
Conclusions: The administration of 18 mg subcutaneous melatonin implants represents an effective, safe and reversible method for inducing short-term suppression of oestrus in postpubertal queens, with an added effect on lactation in postpartum queens. Administration postpartum appears safe and effective, and induces a positive effect on lactation.
Mark Vardanega received the Feline Chapter Abstract Prize (see box below).
