A study of literature concerning Lyme borreliosis related to animals was done. In the research work the epidemiology, pathogenesis, diagnosis and treatment of horses, cattle and dogs affected with Lyme borreliosis have been discussed. The clinical signs of Lyme borreliosis in horses are: chronic weight loss, sporadic lameness, laminitis, low grade fever, swollen joints, muscle tenderness and anterior uvetitis. In addition to these clinical sings, neurological sings such as depression, behavioral changes, dysphagia and encephalitis can be seen in chronic cases. Cattle affected with acute Lyme borreliosis often show fever, stiffness, swollen joints and decreased milk production. Chronic weight loss, laminitis and abortion are also a possible outcome of borreliosis in cattle. An early infection of Lyme borreliosis in dogs may give evidence of inapetenca, lethargy, lyphadenopathy, and an acute onset of stiffness or pain while a recurrent intermittent nonerosive arthritis is a more advanced manifestation of canine Lyme borreliosis. Glomerulonephritis and tubular damage secondary to Borrelia burgdorferi infection have been reported to occur in normally infected dogs. In an endemic area atrioventricular heart block has also been reported. The underlying pathogenesis of Lyme disease is still unknown. The diagnosis of clinical Lyme borreliosis is difficult and it depends on a successful recognition of clinical signs, a history of possible exposures to the infection and on serologic testings. The therapy of Lyme borreliosis in animals is based upon the principal therapy of this disease in human medicine.