Lyme disease can cause heart problems in cats

Although Lyme disease is often asymptomatic in cats, it may cause carditis, just as it does in dogs and humans.   Lyme borreliosis, also known as Lyme disease, is caused by a group of spirochete bacteria transmitted through a tick bite. While the disease is a major cause of morbidity and mortality in humans, dogs and cats rarely develop symptoms. When symptoms do appear, they may occur two to three months after the tick bite. High fever, loss of appetite, and general lethargy can progress to joint inflammation, pain, and stiffness, and may eventually affect the kidneys and heart. However, most cases remain undiagnosed because they are asymptomatic, and thus the description of the disease remains incomplete. For the first time, researchers have identified two suspected cases of Lyme carditis in cats, one of which is the first feline case in which the clinical signs resolved following treatment. Carditis, an inflammation of the heart tissue, is a rare clinical manifestation of Lyme borreliosis in humans, occurring in approximately 1 to 10% of cases. In dogs, suspected cases of Lyme carditis are rare, and the most common presentations are sudden death due to myocarditis and dilated cardiomyopathy. The two cases in cats that tested positive for B. burgdorferi and presented with cardiac abnormalities are therefore consistent with the disease in humans and dogs. The researchers explain that it is likely that new cases of Lyme carditis will emerge in cats, as most practitioners currently do not test for B. burgdorferi in cats with cardiac abnormalities. Further research is needed to fully elucidate the nature of Lyme borreliosis in cats. However, as global warming leads to an increase in the worldwide prevalence of ticks and, consequently, tick-borne infections, new cases are expected.