Lyme disease (Lyme borreliosis) is one of the most common tick-born infectious diseases in the world. Caused by single-celled, spiral-shaped bacterium known as Borrelia burgdorfer, the infection affects multiple systems in the body, producing a range of symptoms. The white-footed mouse is the principal reservoir for the spirochete(bacteria) but birds, lizards and other animals can also carry the causative bacteria. Transmission of the bacteria from host to the dogs takes place through a bite by ticks that carry these spirochetes.
The disease in dogs is most commonly characterized by the sudden onset of lameness. In fact, lameness is often the only sign of infection. One or more joints may become swollen and painful to touch. Other symptoms, if develop, include fever, weakness, poor appetite and weight loss.
The lameness is of different types in different dogs. Some dogs develop recurrent lameness while others develop acute lameness which lasts for only three to four days but reappears in the same or other limb, days to weeks later. "Shifting-leg lameness", as this condition is called, is characterized by lameness in one leg, disappearence, then returning in the other leg.
Kidney problems are the next most common sign of this condition. Inflammation and accompanying dysfunction sets in glomeruli (essentially, a blood filter). This condition is known as glomerulonephritis and can lead to complete kidney failure if left untreated. Vomiting, diarrhea, lack of appetite, weight loss, increased urination and thirst, fluid buildup in the abdomen and fluid buildup in the tissues are the accompanying signs of kidney infection. Acute cardiac syndrome or damage to nervous system may also occur in rare cases.
Other symptoms associated with Lyme disease include:
Stiff walk with an arched back
Sensitive to touch
Fever, lack of appetite, and depression may accompany inflammation of the joints
Superficial lymph nodes close to the site of the infecting tick bite may be swollen
Heart abnormalities are reported, but rare; they include complete heart block
Nervous system complications (rare)