Tick-Borne Diseases Lyme Disease Lyme disease, caused by the bacterium Borrelia burgdorferi,  is transmitted by deer ticks. Signs can come and go, vary in intensity, and mimic many other conditions. Renal failure can occur in severe cases. The signs  may not appear for several months after infection, or not appear at all. Signs and symptoms include:     headache     swollen lymph nodes     recurrent arthritis     joints that are swollen and warm to the touch     lameness lasting for three or four days     stiff, painful gait     reluctance to move     loss of appetite     depression     pain in the legs or throughout the body     fever     fatigue Anaplasmosis Anaplasmosis, caused by Anaplasma marginale and sometimes Anaplasma centrale, is transmitted by deer ticks. Signs of infection can come and go, or not be present at all. Signs and symptoms include:     fever     loss of appetite     joints that are swollen and warm to the touch     lameness lasting for three or four days      pain in the legs or throughout the body     fatigue       swollen lymph nodes     recurrent arthritis     stiff, painful gait     reluctance to move     depression     thrombocytopenia (look for nose bleeds, bruising, and or bleeding gums) Ehrliciosis  Ehrliciosis is an infectious disease that can be transmitted to dogs by several types of ticks. This disease is caused by ehrlichiosis canis. A wide variety of symptoms may appear, some mimicking other diseases. The most common signs of ehrlichia infection usually remain hidden. If untreated, this disease can cause autoimmune diseases, blindness, bleeding complications, or death. Signs and symptoms include:     loss of appetite     depression     fever     joints that are swollen and warm to the touch     pain in the legs or throughout the body   See how big of a threat each tick-borne disease is in your area from Idexx (click here). Interactive maps require Flash version 8 or above.