Ticks are one of the most common ectoparasites (on the skin) found on pets.
They are of particular concern because they can transmit potentially serious diseases to both humans and their pets. While it is fortunately very unlikely for a tick to transmit a particular disease directly from a dog to a human, or vice versa, our pets can act as important sentinels of disease in our environment — i.e. if a dog has tested positive for exposure to the causative organism of Lyme disease, it indicates an environmental risk to the human parents as well.
The four most common ticks found in this part of the U.S. and the diseases they can carry and transmit are:
- the Lone Star tick (Amblyomma americanum) – Ehrlichiosis, Cytauxzoonosis – cats, and Rocky Mountain Spotted Fever (RMSF)
- the American dog tick (Dermacentor variabilis) – RMSF, Ehrlichia, Babesia and possiblyCytauxzoonosis
- the deer tick/black-legged tick (Ixodes scapularis) – Lyme and Anaplasma
- the brown dog tick (Rhipicephalus sanguineus) – RMSF, Ehrlichia, and Babesia
According to the Companion Animal Parasite Council, 1 in 35 dogs in Arlington County has tested positive for exposure to Ehrlichia species, 1 in 18 has tested positive for exposure to the organism that causes Lyme disease (Borrelia burdgorferi), and 1 in 458 has tested positive for exposure to Anaplasma.
Many of the tick-borne diseases, including Lyme, Ehrlichiosis, Anaplasmosis, and RMSF, can cause abnormalities in the white blood cells, red blood cells, and/or platelets, as well as fever, enlarged lymph nodes, enlarged spleen, joint pain, and/or general malaise.
Tick paralysis is a potentially serious condition caused by a neurotoxin from the saliva of certain ticks, typically after they have been attached for at least several days. Symptoms start with weakness and can progress to paralysis and even death if the dog is unable to breath. Removal or death/detachment of the tick will result in a quick improvement of symptoms, often within hours.
Cats seem to be uniquely resistant to many of the tick-borne diseases, with the exception of Cytauxzoonosis, and Mycoplasma haemofelis. Cytauxzoonosis a severe and typically life-threatening disease transmitted by the Lone Star tick. This condition is more common in southeastern and south-central states, but fortunately quite rare in northern Virginia.
Mycoplasma haemofelis is a cause of feline infectious anemia – and is an organism that lives within red blood cells, causing them to be destroyed, leading to a an often severe decrease in red blood cell numbers (anemia). It can be transmitted by any blood-sucking arthropod (mostly fleas but ticks can and do transmit it) – and we do see it in this geographic region. Ehrlichiosis and Anaplasmosis have been poorly characterized in cats but few reports do exist and generally the symptoms are nonspecific and general-malaise in nature. And while Borrelia is capable of infecting cats, Lyme has not been reported in a cat outside of a laboratory setting.
Of all the diseases described above, there is only a vaccination available for the prevention of Lyme disease. In many cases, ticks need to be attached for 12-48 hours to transmit diseases which means that the most effective way to prevent tick borne diseases is to prevent tick exposure, remove ticks when they are found and the use of year-round tick prevention (to quickly kill them when they do get on your pet). When choosing a tick prevention medication recognize that many products that are safe to use in dogs are NOT safe to use in cats and that many of the “over the counter” flea/tick medications do not carry the same safety and efficacy profiles and guarantees that prescription medications do.
Talk to your veterinarian about tick prevention strategies that best suit you and your pets to keep all your fur-kids happy, healthy and tick-free.