14 May 2018
Alex Gough returns with Research Review, where he runs the rule over the latest studies in companion animal science.
Anorexia is a common response to illness in cats. Malnutrition associated with this can worsen recovery from illness and cause its own problems, such as hepatic lipidosis.
Capromorelin is an appetite stimulant licensed by the US Food and Drug Administration in dogs. Wofford et al1 performed two studies to evaluate the safety of capromorelin in cats.
In one study, cats received placebo or capromorelin – at a variety of doses – once daily for 14 days. In the second study, cats received capromorelin at a single dose, or placebo once daily, for 91 days.
Clinical observations, pathology and postmortem analyses were performed. Clinical signs noted included vomiting, hypersalivation, lethargy and head shaking, which were more frequent in the capromorelin groups.
No important changes between the groups were noted in clinical pathology test results.
Periodontal disease has been linked to various diseases in humans. Trevejo et al2 performed a survival analysis study, with a retrospective cohort design including 169,242 cats, to assess whether an association existed with periodontal disease and chronic kidney disease (CKD) in cats.
Cats with an initial diagnosis of periodontal disease were matched with cats with no history of periodontal disease, by age and date of entry into the study.
Periodontal disease was associated with CKD, while a higher risk of CKD was associated with a higher stage of periodontal disease. Other risk factors included increasing age, general anaesthesia within a year of developing CKD, cystitis at any age and being a pure breed.
Diabetes mellitus and hepatic lipidosis decreased the risk of CKD later in life. The authors noted the importance of maintaining health and preventing periodontal disease in cats.
It is considered desirable to be more open about medical errors and near misses, to reduce their occurrence.
Kogan et al3 performed a cross-sectional study to assess the prevalence of near misses and adverse events, using a survey of members of the Veterinary Information Network.
A total of 606 vets completed the survey – a response rate of 1.3%. Of those, 74% reported they had been involved in at least one near miss or adverse event. Additionally, 68% of respondents reported a short-term negative impact of a near miss on their professional life, and for 36% it had a longer-term negative impact.
Effects on personal lives were similar. For adverse events, 84% reported a short-term – and 56% a long-term – negative impact professionally. Numbers were slightly lower, but similar, for personal impact.
Females were impacted greater by near misses and adverse events than males.
The authors noted medical errors could lead to significant emotional distress, and support should be given to vets to help them and their future patients.
Arrhythmogenic right ventricular cardiomyopathy (ARVC) – noted in humans, boxer dogs and cats – is associated with arrhythmias and sudden death.
Cunningham et al4 performed a retrospective study to describe ARVC in English bulldogs.
Of 31 dogs included in the study, the average age was 9.2 years, with males nearly three times more likely to be affected. At presentation, 5 dogs had subclinical arrhythmia, 10 had clinical signs related to arrhythmia and 16 had congestive heart failure. Ventricular tachycardia existed in 58% of cases, while 16% had supraventricular tachycardia. A total of 4 dogs died suddenly and 2 died from congestive heart failure, while 11 dogs were euthanised for cardiac reasons and 2 euthanised for non-cardiac reasons.
Median survival time was eight months.
Appendicular osteosarcoma is a malignant, aggressive bone cancer with poor prognosis. Different histological grading systems have been proposed, but none universally adopted.
Tumour location and treatment have been shown to correlate with outcome, but these factors were not always taken into account when the grading systems were proposed.
Schott et al5 aimed to compare two histological grading systems in dogs with appendicular osteosarcoma that had received optimal treatment (amputation and chemotherapy). Histological grade was not found to correlate with outcome. The authors concluded the predictive value of histological grading of appendicular osteosarcoma was questionable.
Mast cell tumours are common, with potential for local recurrence and metastasis. However, predicting the behaviour of individual tumours and clinical outcomes is problematic.
Horta et al6 aimed to develop a classification system for mast cell tumours in dogs that would predict mortality based on clinical, histological, immunohistochemical and molecular findings. A total of 149 dogs with a cutaneous or subcutaneous mast cell tumour were included in the study.
Univariate analysis showed metastasis and mortality were significantly related to clinical stage, history of recurrence, Patnaik and Kiupel grades, neoplastic cell organisation, mitotic count, the Ki-67 protein labelling index, KIT receptor pattern and c-KIT mutational status.
However, using multivariate analysis, only an amended World Health Organization staging system and history of tumour recurrence were associated with overall survival, with hazard ratios of 1.82 and 9.25, respectively.
The authors suggested an alternative approach to the clinical and clinicopathological evaluation of dogs with cutaneous mast cell tumours to help predict outcomes.
Hyphaema – the presence of blood in the anterior chamber of the eye – has a number of causes and can be sight-threatening.
Jinks et al7 performed a retrospective study of 99 dogs with hyphaema (120 affected eyes) to try to identify causes and prognostic factors.
A total of 36% of cases were due to systemic disease, 33% due to local ocular disease and 26% due to trauma. Ocular neoplasia, chronic uveitis and trauma were associated with poorer outcomes.
Of the eyes with hyphaema, 55% were blind at the time of their last recheck. Meanwhile, 39.5% of the affected eyes were recommended to be enucleated and 31% had glaucoma.
Absent consensual pupillary light reflex at the time of initial examination led to a 29 times higher risk of blindness. Lack of dazzle reflex, increased intraocular pressure, retinal detachment, unilateral hyphaema and complete hyphaema were all associated with marked increases in risk of blindness. Longer duration of hyphaema increased the risk of glaucoma.
The authors concluded the prognosis for vision in cases of hyphaema varies greatly with the cause and findings at initial examination.
