This bacterial disease results from the infection of Borrelia burgdorferi, hence it is also called Lyme Borreliosis. Ticks belonging to the genus Ixodes are mainly responsible for transmitting this disease to humans and dogs as well as to other domestic animals. Ixodes pacificus, a very tiny species of tick known as the deer tick is the major contributor to Lyme disease in the US, especially on the west coast. In other places, it is Ixodes scapularis that spreads it.
The tick has different stages in its lifecycle such as the larva that comes out of the egg, a semi adult stage called the nymph, and the final stage as the adult tick. At different stages, this parasite has preference for specific hosts to feed on, such as deer, white-footed mice, or voles. But dogs and humans seem to be its favorites at any stage. If the bacteria Borrelia burgdorferi happen to enter into their body when they feed on an infected person or animal, they play host to the bacteria, and then transmit them to a healthy person or dog on biting them. In spring, when the nymphs emerge looking for hosts to feed on, the risk of infection is the highest. Adult ticks are active in both spring and fall, making both seasons unsafe.
Though Lyme disease in dogs is found everywhere, some areas of the United States have higher risk of the disease because infected ticks are more common there. High risk areas include coastal areas bordering both Atlantic and Pacific oceans besides the upper Midwest area. Even though this disease occurs in many other countries around the world, it was first recognized in Lyme, a Connecticut town, during a widespread outbreak, and thus earned its name.
Among all the domestic animals that are affected by this disease, dogs have the highest chance of contracting it because they are more frequently exposed to ticks. Since proximity to dogs put people at a greater risk of getting infected, Lyme disease is now considered a zoonotic disease.
Many of the symptoms of this affliction are general in nature such as fever, listlessness, lack of appetite and inflammation of lymph nodes. Pain and swelling in the joints and steadily increasing lameness are typical symptoms. The infection can spread to vital organs like the heart, the nervous system and the kidneys, if proper treatment is not given early enough. Kidney damage is the most dreaded outcome of Lyme disease because many dogs die from it. When the brain and the nervous system are infected, seizures and paralysis of the facial muscles may result.
Lyme disease is not easy to diagnose as most of the symptoms are similar to common illnesses. Usual blood tests are not much help because they may not show any abnormality even when the dog is having the disease. When the dog has progressive lameness following a mild fever, the veterinarian may check out whether the dog had been exposed to ticks, and initiate treatment if Lyme disease is suspected. Special antibody tests are required to confirm the disease, but they give positive results about 1 to 1 ½ months after the beginning of the infection.
Lyme disease being the result of a bacterial infection, antibiotic therapy is the main mode of treatment. Immediate relief from the swelling and pain of the joints is experienced in majority of cases, but some dogs may continue to suffer from joint disease due to many structural damages the infection had already caused. In some cases, antibiotic therapy for the usual 2-4 week period fails to eradicate the infection. Targeted treatment of the affected organs, especially in the case of heart, kidney, and nervous system involvement, may give more satisfactory results.
Avoiding exposure to ticks is the first line of defense against Lyme disease. Even though many potent anti-tick medications are easily available, only their consistent use will give the desired results. Dogs can be vaccinated against this bacterial infection, but it should be done before they get exposed to the Borrelia bacteria. To keep the disease at bay, immunity against the bacteria should be built up by repeating booster doses every year.
If the dog is infested with ticks, they should be plucked off and destroyed immediately to prevent the spread of the disease. Care should be taken to avoid squeezing the body of the tick while grabbing it by the head. Careful grooming practices, especially during the high-risk seasons go a long way in avoiding ticks and tick-borne diseases.