SARS-CoV-2 infection and heart disease in dogs and cats

ABSTRACT

Since the appearance of COVID-19 in humans, there have been numerous reports of dogs and cats being infected with SARSCoV- 2, with cats appearing to be particularly susceptible. The portal of entry of the virus into the body's cells is a membrane receptor called ACE2 (angiotensin converting enzyme 2) belonging to the renin-angiotensin-aldosterone system. The ACE2 receptor is expressed in airway epithelial cells, myocardium, venous and arterial endothelial cells, kidney, liver, oral cavity, intestine and also adipose tissue, explaining the diversity of clinical expression of the disease, with respiratory manifestations predominating. SARS-CoV-2 causes an imbalance in the renin-angiotensin- aldosterone system. In addition, the virus has a direct action combined with an immune reaction, that is sometimes intense, causing a cascade of lesions, mainly in the lungs but also in the heart. The clinical expression of SARS-CoV-2 infection remains rare in dogs and cats and mainly includes fever, depression, anorexia, digestive, respiratory or ocular disorders. As in humans, various cardiovascular clinical signs are less frequently seen. Several cases of myocarditis, correlated with a positive SARS-CoV-2 test (PCR or serology), have been identified in England and at least one in France. In the latter case, further investigation led to a strong suspicion of hypertrophic cardiomyopathy complicated by myocarditis. It is highly likely that obesity (with significant fat deposition in the pleural and pericardial spaces, tissues with high expression of the ACE2 receptor) may have favoured these complications. SARS-CoV-2 infection should therefore now be included in the differential diagnosis of agents causing myocarditis and pneumonia in both cats and dogs.