Ticks cause a host of illnesses, including Lyme disease, which affects dogs and people alike. A bite from an infected tick can mean tiredness, fever, joint pain, and loss of appetite. Antibiotics generally provide relief from Lyme disease, but relapses can occur. Spot-on tick-control products can kill or repel ticks that carry Lyme disease, as can some tick collars. There is a Lyme disease vaccine for dogs, but it’s not always part of a dog’s routine vaccination protocol.
Lyme disease is one of a number of frustratingly common tick-borne diseases that are regarded by both veterinarians and human physicians as stubborn, insidious, and just plain problematic in a number of ways.
An infection caused by the Borrelia burgdorferi bacterium, Lyme disease is transmitted through the bite of an infected tick and can affect many species, including dogs and humans.
Ticks of the Ixodes species (called deer ticks) are known to transmit Lyme disease when they attach to a host and feed. Because the tick must be attached for at least 50 hours to transmit Lyme disease, frequent inspection for ticks (and quick removal) can reduce the risk of disease transmission.
Lyme disease is more common in certain areas of the United States, including the Northeast, Mid-Atlantic, and upper Midwest.
Symptoms and Identification
Clinical signs may not appear for several months after a dog is infected with Lyme disease. In fact, many dogs fail to display any obvious clinical signs at all. When signs of infection are noted, they may include the following:
- Lethargy (manifested as tiredness or exercise intolerance)
- Painful joints
- Loss of appetite
Signs may seem to resolve on their own only to reappear later. Lyme disease has also been linked to long-term complications involving the joints, kidneys, heart, and nervous system.
Lyme disease is usually diagnosed based on a medical history that includes the possibility of tick exposure, suspicious clinical signs, and results of diagnostic testing.
Several tests can identify the Borrelia burgdorferi organism in blood or tissues. In addition, a test (called a quantitative C6 antibody test or QC6 antibody test) can measure the level of antibodies to help veterinarians determine whether treatment is recommended. However, many veterinarians test for Lyme disease using an in-hospital SNAP test. SNAP tests are a group of quick, convenient, blood tests that can be performed at your veterinarian’s office. There are various SNAP tests for different purposes:
- SNAP Heartworm RT Test: screens for heartworm infection
- SNAP 3Dx Test: simultaneously screens for heartworm disease, Lyme disease, and ehrlichiosis (another tick-borne disease that can affect dogs)
- SNAP 4Dx Test: simultaneously screens for heartworm disease, Lyme disease, ehrlichiosis, and anaplasmosis (also a tick-borne disease that can cause illness in dogs)
SNAP testing is very accurate and is a good way to identify dogs that may be infected with one or more of these diseases. SNAP testing is also very convenient because it uses a very small amount of blood and takes only a few minutes to perform. However, sending blood to an outside laboratory for testing can be every bit as reliable as an in-hospital SNAP test.
In some cases, veterinarians may recommend additional testing to follow up a test result or look for other evidence of illness related to heartworm disease or one of the tick-borne infections. Testing may involve sending additional blood samples to a laboratory for further analysis or performing other diagnostic tests to obtain more information about a dog’s condition.
All breeds of dogs are equally susceptible to this infectious disease, though dogs used for hunting or other outdoor sporting activities are at higher risk for exposure to ticks.
Treatment of Lyme disease generally consists of administration of antibiotics and (if necessary) other medications to temporarily help control joint pain and other clinical signs. Some dogs show dramatic improvement after only a few days of receiving antibiotics, but most veterinarians now recommend a 28- to 30-day course of treatment. Relapses are not uncommon, so pet owners are advised to monitor their dogs carefully for signs of illness.
Tick-borne diseases such as Lyme disease pose a risk to dogs in many areas of the country. Because clinical signs are not always apparent, periodic testing is a good way to identify dogs that have been infected. Even dogs that receive year-round tick control products and don’t spend a lot of time outside are at risk for exposure to tick-borne diseases. Testing helps identify dogs that need treatment for one of these infections or an adjustment in the type of tick control being used.
Tick-borne diseases like Lyme disease, ehrlichiosis, Rocky Mountain spotted fever, babesiosis, and anaplasmosis (among others) may or may not be prevalent in your area. However, travel habits of owners and their dogs, and changing patterns of tick migration may drive veterinarians to recommend testing for tick-borne diseases.
Several vaccines are available to help prevent disease caused by Borrelia burgdorferi, the Lyme disease organism. An initial vaccination is followed by a booster vaccine two to four weeks later (in accordance with label recommendations) and annual boosters, as long as the risk for disease exposure remains.
The Lyme vaccine is not necessarily recommended for all dogs. Ask your veterinarian about the risk of Lyme disease where you live and whether the Lyme vaccine is recommended for your dog.
There are currently no vaccines to protect dogs from other tick-borne diseases, such as ehrlichiosis and anaplasmosis. Appropriate tick-control methods combined with periodic testing may be the best ways to help protect dogs from these diseases. Being “tick savvy” can also help protect dogs from Lyme disease exposure. Here are some tips:
- Check dogs (and humans) frequently for ticks. They should be removed promptly.
- Use a reliable method of tick control (several spot-on products kill and repel ticks).
- If possible, avoid tall grass or wooded areas where ticks are likely to hide.
- If owners routinely take dogs camping or walking in wooded areas, they should apprise their veterinarians of this possible means of exposure.
This article has been reviewed by a Veterinarian.