Lyme Disease Prevention in Washington
At Run Those Dogs we care deeply about the health of your pets. May is Lyme Disease Prevention Month so we’ve put together this helpful post. Although the disease affects many more dogs and people in the eastern coastal United States than in Washington State, being aware of how the disease spreads and how to prevent it could protect you and your pet.
Lyme disease (borreliosis) is an infectious, tick-borne disease first recognized in dogs in 1985. It is caused by a type of bacteria called a spirochete, Borrelia burgdorferi. The Western black-legged tick, Ixodes pacificus, is the primary carrier of the B. burgdorferi bacteria in the western United States. Although Lyme Disease is uncommon in Washington State, it is most common in the Western half of the state. Ticks found in Central and Eastern Washington aren’t likely to cause Lyme disease, but they can rarely transmit Rocky Mountain spotted fever.
History & Occurrence
There is evidence that Lyme disease has existed in wildlife for many years. Research shows that the prevalence of the disease is tied to the tick population and host of those ticks. A boom in deer means more deer ticks available to spread the disease. That means the incidence of Lyme disease is in part tied to geography. In humans, 85% of cases have occurred in the eastern coastal states from Massachusetts to Virginia, 10% of the cases come from Wisconsin and Minnesota and 4% from California. All of the other states including Washington account for less than 1% of the disease.
For a tick nymph to transmit the bacteria, it must be attached to the host for about 48 hours. If the tick dies or is removed before 48 hours, transmission will not occur. Even if a tick is a carrier of B. burgdorferi and it attaches to a dog for more than 48 hours, the dog still may not contract the disease. Only around 10% of dogs that are exposed to B. burgdorferi will contract the disease. There is no evidence to suggest that infected dogs pose a risk to other members of the household except as a reservoir of infected ticks. Once a tick has had a full meal, it will detach and not bite another mammal. The risk comes from ticks that have not gotten a complete meal and are detached.
Dogs are most frequently infected with the Lyme disease bacteria, but infections can also occur in horses, cattle, and cats. But it occurs rarely in them, even in endemic areas.
Symptoms of Exposure
In humans, only zero to three Lyme disease cases per year are reported to be infected in Washington. The first sign of disease is usually an expanding target-shaped or “bull’s-eye”circular rash that starts at the site of the tick bite. Fever, headache, muscle aches, and joint pain may also occur.
Symptoms of Lyme disease in dogs differ from those in people, and usually occur much later after the tick bite. Illness in dogs usually occurs 2 to 5 months after a bite from an infected tick. Dogs show several different forms of the disease, but by far, the most common symptoms are a fever of between 103 and 105°, lameness, swelling in the joints, swollen lymph nodes, lethargy, and loss of appetite. They do not get the circular rash that humans do.
Prevention of Lyme disease in dogs involves the use of vaccination and controlling exposure to ticks.
There are many brands of vaccine available on the market. Some veterinarians have criticized the ineffectiveness and do not recommend their use. Although many dogs have been vaccinated and treated for Lyme disease, some vaccinated animals contract the disease, but it appears that vaccinated animals are less likely to contract the disease than unvaccinated animals. Because of the inherent problems of over-vaccination, it is recommended that only dogs that are exposed to ticks in areas where Lyme disease is a problem be vaccinated. Consult your veterinarian to see if vaccination is right for your pet.
Avoiding Tick Exposure
Avoiding exposure to ticks is the most effective way to prevent Lyme disease. Ticks live in forested or brushy areas of western Washington. They like to hang out in long grass and on the ends of low-hanging branches, where they can casually drop onto animals and people passing through the brush. Some types of ticks perch on the edge of low-lying vegetation and grab onto animals, and people, as they brush past. Other ticks are associated with rodents and their nests and may only come out at night to feed.
When working, camping, or walking in a tick habitat–wooded, brushy, or grassy places–wear long pants and a long-sleeved shirt. Tuck your pant legs into socks or boots and shirt into pants. Check your clothing and your pet’s coat regularly after spending time in these areas. Carefully inspect areas around the head, neck, ears, under arms, between legs, and back of knees. Look for what may appear like a new freckle or speck of dirt. Avoiding areas of high tick infestation during periods when ticks are active is one of the best ways to avoid contact.
Some flea control treatments like Frontline and Andvantix contain pesticides that will kill ticks within 12 hours of attachment.
Removing a Tick
Ticks carrying Lyme disease are very small and most people never see them. If you find a tick on your dog, do not panic. Check out How do I Safely Remove a Tick? Promptly remove the tick using fine-tipped tweezers. Grasp the tick as close to the skin surface as possible and pull upward with steady, even pressure. Avoid removing the tick with bare hands. Don’t twist or jerk the tick — this may cause the mouth parts to break off and remain in the skin. If this happens, remove the mouth parts with tweezers. After removing the tick, disinfect the bite site and wash your hands.
Diagnosis and Treatment
Tests results must always be interpreted by a veterinarian to obtain the correct diagnosis. Animals would have a history of tick exposure, compatible clinical signs, and have a rapid response to antibiotic therapy.
Most veterinarians have an in-house test that takes just a few minutes to run, during your exam, with a few drops of blood. This test tells you if your dog was bitten by a tick carrying one of the organisms. However, a positive on this test does not mean your pet has active disease. Most dogs who test positive have no symptoms. It does not tell you if your pet acquired actual disease from the tick.
Additional tests can be sent out to a lab to help make a more accurate diagnosis. The results take several days, and the tests are a bit expensive. Experts argue about the reliability of some of the additional testing.
Thankfully, Lyme disease is treatable. Dogs and people are treated with a tetracycline or penicillin-based antibiotic like oral doxycycline or amoxicillin for a minimum of 14 days, but 30 days is recommended. Some animals relapse once the antibiotic is discontinued and will need the antibiotic for much longer. Your veterinarian will want to monitor your pet’s kidney, heart, and nervous system function.
At Run Those Dogs we care about pet health. Although rare in Washington State, you can help you and your pet avoid exposure to Lyme disease by being alert and following up on any suspicious ticks, signs, or symptoms.