Canine Lyme Disease What is Lyme disease?
Lyme disease is a set of clinical symptoms caused by the infectious bacterial organism Borrelia burgdorferi ( B. burgdorferi). It's named after the city of Lyme in Connecticut, where the disease was first identified. Both humans and dogs can get Lyme disease, but the symptoms and timeline for the onset of disease are quite different. People cannot contract Lyme disease directly from animals or vice versa.
How does my dog get it?
Lyme disease is a vector-borne disease: it requires a tick to transmit B. burgdorferi into its host (ex. a dog). The bacterial organism is spread in the saliva from infected ticks that are actively feeding on your dog. Deer ticks(black-legged ticks) are the primary carrier(vector) for the bacteria. They must be attached approximately 48 hours for the bacterial organism to be transmitted from the tick to the dog. The deer tick life-cycle primarily utilizes mice and deer, but canines and humans often share environments with these primary hosts. This makes outdoor dogs and people who frequent wooded areas or tall vegetation areas at higher risk for contracting Lyme disease as well as other tick-borne diseases. Tick species are regionally specific (have a habitat preference) as well as host preference which they feed on. Lyme disease is predominantly diagnosed in 3 geographic locations of the U.S. based on where the deer tick life cycle is completed- the northeast coastal states, the upper part of the midwest, and the northwest coastal states.
What are the symptoms?
The majority of dogs (about 90%) infected with B. burgdorferi do not become clinically ill and will clear the infection on their own without treatment. Though the mechanism is not completely understood, some dogs develop an overzealous immune response when attempting to clear B. burgdorferi from their body. These dogs go on to develop clinical symptoms of Lyme disease several months after the initial tick bite. Symptoms of Lyme disease are recurring joint pain and lameness (sometimes changing which leg is lame), fever, lethargy, enlarged lymph nodes, and anorexia. Severe cases can also develop chronic arthritis, kidney disease, and heart related issues.
How is it detected?
A simple blood test is utilized to detect if your dog has antibodies to B. burgdorferi. This test is recommended as a screening test at your dog's annual exam(at least in at risk parts of the U.S.). If you dog tests positive on a screening test, it does not mean that your dog has Lyme disease- it simply means that your dog has been exposed to infected ticks and has responded to infection by producing antibodies. Your dog will not test positive for B. burgdorferi antibodies until about a month after the infected tick was attached. If you find and remove an engorged tick from your dog, your vet will likely recommend waiting to screen your dog at a later date. Dogs remain positive for antibodies on blood screening tests for about one year after initial inoculation with the bacteria.
How is it treated?
If your dog has symptoms of Lyme disease, has a history of potential tick exposure, and tests positive for antibodies to the bacteria, your veterinarian will likely recommend a course of treatment with antibiotics. It is important to complete the full course of antibiotics to ensure the disease is completely eliminated. Sometimes additional testing is warranted to confirm the diagnosis or to check the overall health status of the dog if complications arrive. Dogs with severe lameness or joint pain may also be placed on anti-inflammatory medications or remedies if there are no contraindications.
How do I protect my dog?
- Quality tick protection on all pets year round is key to preventing Lyme disease. (No current tick products claim prevention of disease transmission, but if the ticks can't effectively feed on your pets, it makes disease transmission unlikely.)
- Annual blood testing to screen for tick-borne diseases
- Lyme vaccinations are available- discuss this option with your veterinarian to decide if this vaccine is right for your pets.
- Check pets over daily for attached ticks- remove all ticks
- Minimize environmental exposure to ticks where feasible- treat your yard for bugs, keep lawns and shrubs trimmed short, keep invasive wildlife off the property
Lyme disease is a human health issue! If your dog has been exposed to ticks, it is likely that you or family members have been too. Be vigilant with tick checks of pets and people after outdoor activities and remove all ticks promptly. For more information on Lyme disease and other tick-borne diseases in humans, please contact your physician.
### Amanda Burow, D.V.M. (Dr. B), is a graduate of Iowa State University's College of Veterinary Medicine. Dr. Burow's patient list includes hunting dogs of all varieties, as well as several field trial dogs and full time sporting guide dogs. In addition to practicing general veterinary medicine, she has special interest in the areas of preventive care, emergency medicine, and dermatology. In her spare time, she enjoys being outdoors and on the lake, staying active, reading, and spending time with family and friends. Mud River is proud to share these tips from Dr. B with our customers. Keep in mind it is best to work with your local veterinarian to determine the needs for your animals.