Lyme Disease in Dogs
Definition of Lyme Disease (Borreliosis)
Lyme disease, also called Borreliosis, is one of the most common tick-borne diseases in the United States. It is caused by bacteria called Borrelia burgdorferi. The main reservoir for these bacteria is the white-footed mouse, although they can live in other small mammals, lizards and birds. The bacteria are transmitted to larger animals by tiny, hard-shelled, slow-feeding deer ticks, which carry the bacteria after feeding on the blood of infected reservoir animals. Dogs develop Lyme disease when an infected female tick feeds on them for a prolonged time, although there is some disagreement about just how long that meal must be, ranging somewhere from 5 to 50 hours or more. The actual transfer occurs when the tick regurgitates into bite wound after it finishes feeding, causing local irritation and infection. Over weeks to months, the bacteria migrate throughout the dog’s bloodstream. They tend to lodge in joints, muscles, tendons, skin, heart, lymph nodes and other areas high in collagen. They reproduce vigorously, triggering an immune response and causing lameness and other signs in affected dogs. Many dogs never show signs of Lyme disease.
Lyme disease is caused by a single-celled, spiral-shaped bacterium known as Borrelia burgdorferi. The main reservoir for these bacteria in the United States is the white-footed mouse. The bacteria can also live and replicate inside of other small mammals, lizards and birds. The organisms are transmitted to larger animals by tiny, hard-shelled, slow-feeding ticks. The ticks become infected with the bacteria when they feed on the blood of infected animals – especially the white-footed mouse.
Most dogs with Lyme disease never show signs of illness. When symptoms do occur, they usually involve limping and lameness, which are caused by pain around the dog’s joints. These signs may wax and wane, but they often come back and, if left untreated, progressively worsen with time.Most owners never know that their dogs have been infected by Borrelia burgdorferi. In fact, only about 5% of infected dogs become noticeably ill. Dogs that do develop
Lyme disease in dogs is not easy to diagnose. Most infected dogs are asymptomatic, which means that they have been exposed to and infected by Borrelia burgdorferi but show no outward signs of illness. In addition, dogs with this disease often have other tick-borne ailments, such as ehrlichiosis or babesiosis, which can mimic the signs of Lyme disease. The initial diagnostic focus usually is to rule out other possible causes of lameness and appetite loss
Fortunately, Lyme disease in dogs is usually treatable. Therapeutic goals are to resolve lameness and soreness, relieve fever and pain, eliminate infectious organisms from the blood stream and provide supportive care for dogs with kidney, heart, neurological or other serious complications. Affected dogs should be kept warm, dry and quiet. Their activities should be restricted until their symptoms have been resolved. In most cases, there is no need to change the dog’s diet.Antibiotics are the