Lyme disease is an illness caused by an infection with a spirochete bacteria called Borrelia burgdorferi. Lyme disease is very common in the midwestern and northeastern states. Dogs and humans are both susceptible to Lyme disease.
The Borrelia bacteria is transmitted by the bite of the deer tick, Ixodes scapularis. As the tick feeds on blood, it regurgitates the Borrelia burgdorferi bacteria into the host. Deer ticks carrying Lyme disease can be transported into an environment by a variety of hosts including mice, raccoons, fox, and deer. The disease requires a tick to complete its life cycle and cannot spread by direct contact between infected animals or people.
It may take weeks to months after the bite from an infected Ixodes tick before a dog becomes clinically ill. Once symptoms start, the disease can progress rapidly. Owners often report that their pet was fine one day, and unable to walk the next.
Dogs can have the following Lyme disease symptoms:
- Enlarged lymph nodes
- Swollen joints
- Generalized stiffness
Dogs do not develop the characteristic bullseye rash that is common in people infected with Lyme disease.
Chronic Lyme disease can develop into a syndrome called Lyme Nephritis. Infected dogs are harmed by the long-term interactions between the immune system’s antibodies and Borrelia bacteria. The immune system antibody complexes may deposit in the kidney causing severe damage. This condition is usually observed in dogs that have had long standing, untreated, smoldering Lyme infections. The symptoms of Lyme nephritis include extreme lethargy, vomiting, not eating, increased thirst and urination, and weight loss.
A diagnosis of Lyme disease is made by a combination of history, physical signs, and diagnostic tests.
A rapid in clinic blood test called a 4DX confirms the presence of antibodies from exposure to the Borrelia bacteria that cause Lyme disease. The presence of antibodies in combination with physical exam findings can support the diagnosis of Lyme disease. The 4DX test is also used for annual screening to help recognize the disease early in the process.
When a dog is positive on the in clinic 4DX screening test, we may recommend that additional blood work is sent out for a test called a Lyme Quant C6. The Lyme C6 test gives the exact level of antibodies called a titer. The antibody titer helps determine significance of infection, allows for better treatment plan, and assists in monitoring response to treatment.
Additional blood and urine tests to assess kidney health and function may also be recommended to screen for Lyme nephritis.
Dogs that are diagnosed with Lyme disease are treated with antibiotics. The most common oral antibiotic prescribed to adult dogs is Doxycycline. The antibiotic is administered daily for 4 weeks. Doxycycline should be administered with a meal to prevent nausea. Young patients or dogs with sensitive stomachs may need an alternative treatment with the injectable antibiotic, Convenia. Dogs with a high fever and pain may also receive anti-inflammatory medication. Ill pets should improve within the first 2 days of starting treatment. It is very important to complete the full 4 weeks of prescribed treatment.
Only 10% of dogs infected with Lyme disease will have significant symptoms. Most patients that receive antibiotics will make a rapid and complete recovery.
Lyme nephritis is a serious but rare complication of Borrelia burgdorferi infection. Dogs that develop kidney damage secondary to Lyme disease will need lifelong monitoring and therapy. Lyme nephritis has a guarded prognosis and can be fatal.
It is important to remember that Dogs can become reinfected with Lyme disease. Repeated and chronic infections increase the risk of severe disease.
All dogs that are living, playing, or working in areas where they may be exposed to deer ticks are at risk for Lyme disease. Developing a long-term prevention plan is just as important as treatment for acute disease.
The Lyme vaccination is one of the most effective tools to prevent Lyme disease. An initial vaccination is given and then a booster is administered 4 weeks later. After the initial series of vaccination, the vaccine is given annually. Both puppies and adult dogs can receive the Lyme vaccine. Dogs that have been diagnosed with Lyme disease should receive the vaccine because vaccination can help prevent re-infection.
Flea and tick preventatives are another important tool that can be used to prevent Lyme disease. The product recommended most by veterinarians is the oral chewable Nexgard. Nexgard kills the deer tick when they bite the dog, effectively preventing the transmission of Lyme disease. Preventatives should be used monthly year-round in endemic areas.
After walks through the woods or grassy settings, check yourself and your dog for ticks. Remove ticks immediately. The deer tick must be attached for 36 to 48 hours to transmit Borrelia bacteria. The quicker you find and remove ticks, the less likely your dog will be to contract Lyme disease.