Dyspnoea is a common presenting sign. No studies have examined the causes of dyspnoea, signalment or outcome. Here, the records of 90 dyspnoeic cats referred to Liverpool University Small Animal Teaching Hospital were retrospectively analysed. The data was extracted concerning their signalment, duration of clinical signs before referral, whether they were emergencies, respiratory rate on admission, length of stay, underlying aetiology and outcome.

In this population, 58% were presented as emergencies and 60% of cats survived to discharge. Aetiology of dyspnoea was categorised into major groups. Thirty four cats had cardiac disease, 19 respiratory, 17 neoplastic, 7 infectious and 7 traumatic causes of dyspnoea. The remaining causes included: 3 developmental abnormalities, one tracheal foreign body, one iatrogenic pneumothorax and one unknown.

The cardiac causes included 4 congenital heart disease, 2 congestive failure and 28 cats had a form of cardiomyopathy (CM): 12 cats with hypertrophic (HCM), 4 hypertrophic obstructive (HOCM), 8 unclassified (UCM), 2 restrictive (RCM) and one each of dilated cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy. Dyspnoea was due to pulmonary oedema, confirmed radiographically in 8 HCM/HOCM cats. Pleural effusions were present in both RCM cats, 2 HCM and five UCM cats (2 chylous). All the HCM/HOCM cats survived to discharge but only 50% of the RCM and 37.5% of the UCM cats survived.

Five of the 19 respiratory cases had asthma, 4 laryngeal paralysis, 4 upper respiratory tract infections and two chronic bronchial disease. These cases had the longest duration of signs before referral (86 days) and the best survival to discharge (84.2%).

Six of 17 cats with neoplasia had lymphoma and in a further 6 cases the exact tumour was not identified. This group had the poorest survival with 23.5% surviving to discharge. However, 77% of the cats that did not survive were euthanized.

Of the 7 cats with infectious causes, 4 were male and 4 had pyothoraces. Three cats had FIP and were all Bengals. Four of the 7 cats suffering trauma were involved in RTAs with a further cat in a suspected RTA. One cat was attacked by a dog and another cat had been shot. Developmental disorders were all British shorthairs including a palatine cyst, diaphragmatic hernia and elongated epiglottis tethered to the floor of the oropharynx.

While this study is a population of cats that were deemed fit to travel by the referring veterinarians, the results will still be of benefit to practitioners.