Only a small percentage of these dogs that are infected actually come down with signs of the disease. Therefore in areas where the disease is very prevalent a positive test for Lymes antibodies does not indicate recent infection, only that the dog has had some exposure to the disease. The high incidence of infection with a relatively low rate of signs of the disease suggests that dogs seem to tolerate the organism or possibly defend themselves successfully. The most common sign of Lymes disease in the dog is arthritis affecting more than one joint. Often these are the small joints that are painful, warm and swollen.
Many dogs display only a reluctance to move as their only sign of the disease.
Other signs include fever, loss of appetite and swollen lymph nodes. Dogs do not appear to have any of the long term complications that afflict humans such as degenerative long term arthritis, serious neurological complications and cardiac problems. Less than rarely have these problems been reported. Also, the skin rash that Lymes is associated with in humans is of minor incidence in dogs. The immune response by the dog to the organism is not clearly understood.