Lyme disease is caused by a spirochete, Borrelia burgdorferi. A spirochete is a type of bacterium. It is transmitted to dogs through the bite of a tick. Once in the blood stream, the Lyme disease organism is carried to many parts of the body and is likely to localize in joints. It was first thought that only a few types of ticks could transmit this disease, but now it appears that several common species may be involved. The most common type of tick to carry Lyme disease is the Deer Tick.
Can Lyme disease also affect people?
Yes, but people do not get it directly from dogs. They get it from being bitten by the same ticks that transmit it to dogs. Therefore, preventing exposure to ticks is important for you and your dog.
What are the clinical signs?
Many people with Lyme disease develop a characteristic bull's-eye rash at the site of the bite within three to thirty days. For these people, the disease can be easily diagnosed at an early stage. However, symptoms of Lyme disease are more difficult to detect in animals than in people.
The characteristic rash does not develop in dogs or cats. Because the other symptoms of the disease may be delayed or go unrecognized and because the symptoms are similar to those of many other diseases, Lyme disease in animals is often not considered until other diseases have been eliminated.
Many dogs affected with Lyme disease are taken to a veterinarian because they seem to be experiencing generalized pain and have stopped eating. Affected dogs have been described as if they were "walking on eggshells." Often these pets have high fevers. Dogs may also begin limping. This painful lameness often appears suddenly and may shift from one leg to another. If untreated, it may eventually disappear, only to recur weeks or months later.
Recently, evidence is surfacing that a Lyme infection can affect the kidneys causing a syndrome known as Lyme Nephritis. This disease can progress to eventual kidney failure.
Some pets are affected with the Lyme disease organism for over a year before they finally show symptoms. Other dogs can have infections and never develop symptoms. In fact, this may happen more frequently than we once thought. It is thought that less than 10% of dogs that are infected actually develop symptoms.
How is Lyme disease diagnosed?
Dogs with lameness, swollen joints, and fever are suspected of having Lyme disease. However, other diseases may also cause these symptoms. As part of your dog's annual wellness exam, your vet may check for Lyme disease. If you live in a Lyme endemic area, your dog may have a positive test. This does not mean they have Lyme disease! It only indicates exposure to the ticks carrying the parasite. Your vet may or may not recommend treatment. However, if your dog is exhibiting clinical symptoms treatment is warranted. All dogs with a positive test should be screened for underlying and early kidney disease. This can be done with a urine sample.
How is Lyme disease treated?
Because the Lyme spirochete is a bacterium, it can be controlled by antibiotics. Doxycycline is the drug of choice. However, a lengthy course of treatment is necessary and total eradication of the organism is not likely. Occasionally, the initial infection will recur, or the pet will become re-infected after being bitten by another infected tick.
How can I prevent my dog from getting Lyme disease?
The key to prevention is keeping your dog from being exposed to ticks. Ticks are found in grassy, wooded, and sandy areas. They find their way onto an animal by climbing to the top of a leaf, blade of grass, or short trees and shrubs. Here they wait until their sensors detect a close-by animal on which to crawl or drop. Keeping animals from thick underbrush reduces their exposure to ticks. Dogs should be kept on trails when walked near wooded or tall grass areas. Total prevention is multi-faceted and includes immediate removal of the tick, (It takes time for an infected tick to transmit Borrelia to a dog, this typically can happen no sooner than 18-24 hours from the beginning of the blood meal), application of a tick repellent and vaccination. Prevention options should be discussed in detail with your veterinarian and tailored to your pets risk of exposure.
How do I remove a tick from my dog?
Check your pet immediately after it has been in a tick-infected area. The Deer Tick is a small tick and only about pinhead size in juvenile stage, but a little more obvious in adult phase and after feeding. If you find a tick moving on your pet, the tick has not fed. Remove the tick promptly and place it in rubbing alcohol or crush it between two solid surfaces. If you find a tick attached to your pet, grasp the tick with fine tweezers or your finger nails near the dog's skin and firmly pull it straight out. You may need another person to help restrain your dog. Removing the tick quickly is important since the disease is not transmitted until the tick has fed for approximately twelve hours. If you crush the tick, do not get the tick's contents, including blood, on your skin. The spirochete that causes Lyme disease can pass through a wound or cut in your skin.