It is spring in Manitoba and the ticks have arrived. Ticks are not only pests to people and dogs, they also affect our horses.
There are several common ticks in Manitoba. There are wood ticks (aka American dog tick), which are large ticks with white markings on their backs and there are deer ticks (blacklegged tick) which are small and don’t have white markings on their back.
A tick has several stages in its life cycle and the various stages (from a very small larva through small nymph before progressing to adult) can also cause disease, depending on the type of tick.
Lyme disease is the most infamous infectious condition ticks can carry. Lyme disease is generally not carried by wood ticks, so it is important to recognize the difference between the wood tick and deer tick, as deer ticks do carry the bacteria.
Lyme disease bacteria is spread by deer ticks when feeding on their hosts. It generally takes about 24 hours of attachment to a host for a sufficient bacterial infection to occur.
In horses, Lyme disease will manifest with varying symptoms including depression, lethargy, joint swelling and pain, skin conditions and blood changes such as anemia and depression of white blood cells.
Since these aberrations are often difficult to put together under a single cause, the diagnosis of Lyme disease in horses (as in humans) can be difficult to confirm.
The test for Lyme disease is based on antibodies; isolation of the bacteria is ideal but it is rarely possible.
Treatment for Lyme disease involves long term use of antibiotics (typically oxytetracycline). The prognosis is varied depending on the degree of damage already done.
Both deer and dog ticks can cause another syndrome called Tick Paralysis. In this condition, a massive tick infestation of the animal is necessary to cause disease. If ticks are not removed in a timely manner, the paralysis can result in death and permanent neurological damage. Treatment involves removing the offending ticks.
Prevention of infection is the best medicine for ticks. Prompt removal of ticks is still best and medications such as Ivermectin can help in decreasing the ticks that will bite and feed on the horse.
Ticks generally hide in the mane and tail but may also be found between the front and hind legs as well as along the midline of the horse. Removal by pulling the entire tick with feeding parts attached is ideal and a credit card or similar surface corner can be effective in ensuring the entire tick is removed.
Chris Bell is an equine veterinarian and surgical specialist who operates Elders Equine Veterinary Service, with clinics in Cartier and Winnipeg. See www.eldersequineclinic.com