Ticks and the diseases they carry can have significant impact on both human and animal health. When most people think of tick borne disease, they think of Lyme Disease or Spotted Fever, but there are others out there that can have a significant impact on the health of our beloved pets. Two of these diseases that we screen for on the annual heartworm and tick borne disease test (Idexx 4DX Plus SNAP test) are Ehrlichia and Anaplasma. It is important to keep in mind that nymphal ticks are very small (about the size of a pin head) and are still able to carry and transmit diseases to humans and animals. This is why year round, monthly flea and tick protection is necessary for our beloved furry friends in North Carolina.
Ehrlichia is an intracellular, gram negative bacteria (Rickettisial order) and can take on several forms and infections can range from subclinical (asymptomatic) to severe and life threatening. Incubation time is at least one to three weeks following exposure to the infected tick, and ticks can transmit the disease in as little as 8-12 hours of attached feeding time. Ticks that are capable of spreading Ehrlichia are Lone Star Ticks (Amblyomma americanum) and Brown Dog Ticks (Rhipicephalus sanguineus). Symptoms of Ehrlichia include the following:
• Stiff, stilted gait OR lameness
• Weight loss
• GI signs – vomiting, diarrhea, anorexia/decreased appetite
• Neurological signs – dizziness, tremors, different pupil sizes
• Enlarged lymph nodes
• Edema (excessive fluid build up in the legs or another body part)
• Difficulty breathing
• Discharge from the eyes or nose
• Pale gums or abnormal bleeding
A test to screen for Ehrlichia is the Idexx 4DX test, which is recommended annually to every dog. When a dog tests positive on this test, we recommend checking blood work to see if a subclinical infection is present, as not all dogs will require treatment. For diagnosis of Ehrlichia in sick dogs, we would need to run additional tests to assess other internal organ function and to confirm that an active infection of Ehrlichia is present. These tests would include a CBC, a biochemical profile, a urine analysis, and tick borne disease serology testing. In severe, life-threatening infections, treatment may be started before a diagnosis is confirmed. Antibiotics, pain medications, and other supportive care measures are required for treatment. Prognosis and recovery are highly dependent on how severe the infection is, how much other organ damage is present, and if it has impacted the bone marrow. For infected dogs with clinical signs, we recommend close laboratory monitoring even after recovery to ensure a chronic infection state has not developed.
Cats can develop Ehrlichia, although it is far more common in dogs. Symptoms of Ehrlichiosis are similar between cats and dogs. Testing to confirm a diagnosis is also the same between cats and dogs. Cats can be more sensitive to the antibiotic used to treat these infections, and the medication usually must be compounded into a liquid for safe administration. Cats that do become infected and ill from Ehrlichia have an overall good prognosis, especially if they are otherwise healthy.
Another tick borne disease that is similar to Ehrlichia is Anaplasma. Anaplasmosis is caused by an intracellular, gram negative bacteria (Rickettsial) and is spread by Deer Ticks/Black Legged ticks (Ixodes scapularis). Ticks need to be attached and feed for at least 24 hours for transmission and it takes 1-2 weeks for incubation of the infection within the pet. Signs of Anaplasmosis include:
• Inappetence/reduced appetite
• Lameness or joint pain
• Rarely vomiting, diarrhea, difficulty breathing, or coughing
Screening and confirmatory testing are similar for Anaplasma and Ehrlichia, and not all positive dogs will require treatment. Unlike with Ehrlichia, dogs that do develop signs of Anaplasmosis have a much better chance at a normal recovery and less risk of death. Treatment includes antibiotics for 2-4 weeks and pain medications as needed.
There are no vaccines that can protect your pet against these Rickettsial tick borne infections. Prevention with oral or topical flea/tick medications is the only way to protect your cat or dog from a possible life-threatening infection. Because it never gets cold enough for long enough in this region of North Carolina, our pets are always at risk of contracting these infections from hungry ticks. If you travel out of the state, these infections may be more or less prevalent depending on the tick population of that region. If your pet becomes infected with one of these tick borne infections, it is important to note that many of these infections are zoonotic, meaning that they can be spread from animals to people and vice versa. While your dog or cat will not infect you directly, their positive result means that you are at a higher risk of infection from the same ticks in your shared environment – think of them as your canary in the coal mine! If you suspect that you may have a tick borne disease, you will need to consult with your human medical professional for further advice and diagnosis. Ehrlichia and Anaplasma, while not as popular as Lyme disease, are just as painful and devastating. So make sure your pets are protected! If you have questions, or want more information about these or other tick borne diseases, visit the CDC or CAPC (Companion Animal Parasite Council) websites for more information and links.