The groundhog didn’t see his shadow this year so as we approach an early spring, it is time to reconsider parasite control in your animals. Most veterinarians recommend year round parasite control because ticks and fleas are not just outdoors, they can be in your house as well. While ticks and fleas can be gross, itchy, and annoying to both you and your pets, they also carry various diseases that can cause severe illness to you and your pets. The most common tick-borne diseases include Lyme disease, Ehrlichia, Rocky Mountain Spotted Fever, and Babesia. In addition, the fleas and ticks themselves can actually take enough blood to make your pet anemic. The best way to protect your pet is proper flea and tick control with a monthly spot-on or oral medication.
Lyme disease has become very common in central Virginia in the past ten years. The disease was originally based in New England, but travelers and warmer weather have helped the disease to spread throughout the country. Lyme disease is caused by a bacterium known as Borrelia burgdorferi. It is spread most commonly by the deer tick and western black legged tick. To spread the bacteria, the tick must be on your pet for 2 to 4 days. Therefore products such as Frontline Plus and Advantix provide adequate protection against Lyme disease. If your pet is infected, common clinical signs include fever, lethargy, enlarged lymph nodes, arthritis, and a shifting limb lameness. The most serious form of Lyme disease causes Lyme nephritis. The body attacks the bacteria and antibodies in the blood attach to the bacteria forming complexes. These complexes then become attached to the inside of the kidney. They build up and cause inflammation which can lead to kidney damage and failure. People can also become infected with Lyme disease. The clinical signs are very close to your pets, but a bull’s eye lesion is often noted on people at the site of the tick bite. This bull’s eye lesion is not seen with animals. There is a vaccine available for Lyme disease, but there is some controversy over whether it is effective or predisposes to the more serious Lyme nephritis. If you are interested in the vaccine consult with your veterinarian to see what their recommendations would be. The treatment for Lyme disease is supportive care and more specifically doxycycline, an antibiotic.
Ehrlichia and Anaplasmosis are two rickettsial bacteria that are becoming more common in our area. They are spread by the brown dog tick and lone star tick with infection occurring 24 to 48 hours after attachment. The bacteria infect the white blood cells and platelets. These two bacteria cause a myriad of clinical signs. In an acute infections signs range from lethargy, low platelet count, lameness, weight loss, enlarged spleen, swollen legs, hemorrhage, and even trouble breathing. Signs of chronic infections include fever, weight loss, enlarged lymph nodes, increased drinking, and increased urination. The normal treatment for Ehrlichia is doxycycline, an antibiotic. However, treatment does not always cure this disease and may only reduce it to a subclinical level. Repeated testing is needed to know if your pet has cleared the disease completely.
Rocky Mountain Spotted Fever is caused by a bacteria known as Rickettsia rickettsia. Originally confined to the Rocky Mountains and the Mississippi valley, this disease has spread to include most of the South and is still working its way northward. It is most commonly spread by the brown dog tick and Rocky mountain wood tick. Transmission occurs 4 to 24 hours after attachment of the tick. Like Lyme disease RMSF also affects people. Common signs in both pets and people include fever, lethargy, enlarged lymph nodes, vomiting, seizures, diarrhea, and abdominal pain. Like ehrlichia and lyme disease, RMSF is susceptible to doxycycline. However, a negative test does not always mean that your pet is free from this disease.
The final tick borne disease covered in this article is Babesia. Unlike the first three diseases Babesia is caused by protozoa, not bacteria. It is also less common in our area, but cases are increasing. There are two most common forms, Babesia canis and Babesia gibsoni. Both forms attack the red blood cells directly causing a hemolytic anemia in many cases. Once again the tick must be attached for 24 to 48 hours for infection to occur. However, some forms can be spread by dog bites, shared blood, and in the case of B. gibsoni transmission from mother to offspring. Common signs include lethargy, fever, increased respiratory rate, vomiting, white gums, and an enlarged spleen. In acute cases Babesia can cause kidney failure, heart changes, and even inflammation of the pancreas. Treatment consists of supportive care and medications that depend on which organism is involved. Babesia canis is susceptible to an antiprotozoan treatment known as imidocarb dipropionate. Babesia gibsoni is not as susceptible to imidocarb, and requires a mixture of atovaquone and azithromycin. Both of these treatments are quite expensive. A mix of clindamycin, doxycycline, and metronidazole has been shown to be effective in some studies as well. After treatment many pets remain lifelong subclinical carriers of this disease.
The easiest treatment for all of these diseases is prevention. Proper ectoparasite control is the cheapest, easiest way to prevent your animal from coming down with these diseases. For canine tick control many veterinarians recommend Frontline Plus or Advantix. For felines Frontline spray can be used for tick control. When treating your animals make sure that you read the label and do not apply canine tick control products on your cat. They can be toxic. Always consult your veterinarian to see which products they would recommend for your pet.