The case records of 106 cats with idiopathic cardiomyopathy that presented to the Feline Centre of the University of Bristol between September 1994 and September 2001 were reviewed retrospectively. Hypertrophic cardiomyopathy (HCM) was the most common form seen (57.5%), followed by restrictive cardiomyopathy (RCM) (20.7%), dilated cardiomyopathy (DCM) (10.4%) and unclassified cardiomyopathy (UCM) (10.4%). One cat showed echocardiographic changes compatible with a moderator band cardiomyopathy (MBCM). Most affected cats were domestic short hairs (DSH) (57.5%). The mean (±SD, range) age of cats with cardiomyopathy at presentation was 6.8 (4.3, 0.5–16) years, with an equal distribution of males and females. Clinical findings, electrocardiographic changes and radiographic abnormalities were also reviewed. The median survival time for 73 cats for which follow-up data was available was 300 days. A greater survival time was observed for cats with UCM (925 days) when compared with those with HCM (492 days), RCM (132 days) or DCM (11 days).

Background: Domestic pets can contract severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection; however, it is unknown whether the UK B.1.1.7 variant can more easily infect certain animal species or increase the possibility of human‐to‐animal transmission. Methods: This is a descriptive case series reporting SARS‐CoV‐2 B.1.1.7 variant infections in a group of dogs and cats with suspected myocarditis. Results: The study describes the infection of domestic cats and dogs by the B.1.1.7 variant. Two cats and one dog were positive to SARS‐CoV‐2 PCR on rectal swab, and two cats and one dog were found to have SARS‐CoV‐2 antibodies 2–6 weeks after they developed signs of cardiac disease. Many owners of these pets had developed respiratory symptoms 3–6 weeks before their pets became ill and had also tested positive for COVID‐19. Interestingly, all these pets were referred for acute onset of cardiac disease, including severe myocardial disorders of suspected inflammatory origin but without primary respiratory signs. Conclusions: These findings demonstrate, for the first time, the ability for pets to be infected by the B.1.1.7 variant and question its possible pathogenicity in these animals.

Practical relevance Myocardial disease (cardiomyopathy, CM) is the most common cardiac disorder observed in cats. The disease usually leads to the development of congestive heart failure, which is the major cause of cardiac mortality. Arterial thromboembolism is another severe outcome often associated with feline CM. Patient group The median age of cats when diagnosed with a form of CM is 5.5 years (range 4 months to 16 years). The disease appears to be equally distributed between males and females and among different breeds, although a genetic predisposition of some pedigrees should be taken into consideration (ie, Maine Coons, Ragdolls, Norwegian Forest cats). Audience General practitioners, as well as specialists in small animal medicine, cardiology and pathology, have to deal with CM on a regular basis. Clinical challenges The diagnosis and clinical management of myocardial disease in cats represents one of the greatest challenges in veterinary cardiology. Although several attempts have been made to standardise the classification of CM, both in humans and cats, some disagreement still exists among cardiologists. Classification criteria are continuously evolving as the aetiology of myocardial disease becomes better understood. It is now widely appreciated that, for a given aetiology, there may be a spectrum of phenotypes ranging from restrictive to dilated. Diagnostics The diagnosis and classification of CM is primarily based on echocardiographic criteria. However, phenotypic variability is substantial, even within a single form of CM, and this often causes subjective interpretations of echocardiographic diagnosis, especially by inexperienced echocardiographers. Post-mortem examination is an alternative approach to diagnosis. Evidence base The clinical management of feline myocardial disease is even more controversial, especially in the light of recent clinical studies. This two-part article reviews the literature to date, discusses various manifestations of the disease in cats and offers a critical, and often controversial, approach to diagnosis and management.