Lyme Disease and Pets

Lyme Disease in Dogs

What are the signs and symptoms of Lyme disease in dogs?

Unlike human Lyme disease, which is commonly described in stages, Lyme disease in dogs primarily causes acute or subacute arthritis. The acute form may be temporary and can recur; the severe chronic systemic disease seen in humans is rare in dogs.

Dogs may develop sudden lameness and severe pain. One or more joints may be swollen, warm, and painful when handled. Other signs can include fever, reduced appetite, lethargy, depression, and reluctance to move. Lameness may return after several weeks of recovery. Lameness in dogs occurs an average of two to five months after tick exposure.

The erythema migrans rash common in early human Lyme disease is rarely seen in dogs. Rarely, later-stage symptoms such as heart block, kidney failure, or neurological changes—including seizures, aggression, or other behavior changes—have been reported.

Lyme Disease in Cats

Most cats show few or no symptoms, and Lyme disease is not commonly found in cats. Possible signs are similar to those in dogs and may include fever, fatigue, difficulty breathing, loss of appetite, lethargy, and swelling in muscles or joints. The disease can also affect the kidneys, nervous system, or heart. A veterinarian can advise on diagnosis and treatment; early treatment may improve recovery.

Lyme Disease in Horses

Lyme disease is not common in horses, but infection can have a serious impact. Symptoms may include lameness, arthritis, dermatitis, fever, loss of appetite, fatigue, and sometimes neurological problems. Arthritis may affect one or several joints and can be intermittent or chronic. If left untreated, complications may affect the joints, skin, nervous system, or vision. Diagnosis can be difficult because symptoms overlap with other diseases. Unlike humans or dogs with Lyme disease, horses have not shown heart, liver, or kidney problems as a result of infection.

Lyme Disease in Cattle

Cattle have occasionally been found to have Lyme disease. There is no single established pattern for symptoms, diagnosis, and treatment. Early signs may include fever, stiffness, swollen joints, lameness, and reduced milk production. These signs can resemble other common cattle diseases and vary between animals.