Borreliosis is the most frequently diagnosed tick-borne disease caused by spirochete bacteria
belonging to the genus Borreliae - Borrelia burgdorferi sensu stricto (s.s.), Borrelia afzelii
and Borrelia garinii. Clinical manifestations in dogs include fever, lameness, polyarthritis and
glomerulonephritis. Diagnosis is mainly serological and is based on an immunoenzymatic test
followed by a Western blot confirmatory test. Early treatment with antibiotics such as doxycycline or amoxicillin, for four weeks, usually reduces the risk of chronic disease. Tick control,
including tick repellents, is highly reliable in preventing transmission. Vaccines are available
to reduce transmission and the clinical manifestations of infection in dogs. Bernese Mountain
Dogs are a breed that often test positive for antibodies against B. burgdorferi without showing
any clinical symptoms of the disease. Quantitative determination of the immunoglobulin level
for spirochetes has indicated that Bernese Mountain Dogs may have an increased susceptibility
to Borrelia spp. infections of a hereditary nature.