Pet Tales
by Barry B. Burtis D.V.M.

Cats and dogs can be parasitized by ticks. Ticks are ectoparasites - they live on the outside of their host's body. Ticks are arthropods. Arthropods are invertebrates. An exoskeleton replaces a backbone in arthropods. Ticks are closely related to scorpions, spiders and mites. They feed only on the blood of the animals they parasitize. However, they can transmit other organisms, while feeding, that may be harmful.

There are several different kinds of ticks in North America that can be a threat for pets. In Ontario, there are two tick species that are a problem - the American Dog tick and the Deer tick.

Ticks go through different stages of development as they age. Eggs hatch into larvae, the immature stage in their life cycle. Larvae become nymphs who in turn become adults. Different stages of the parasite may feed from different hosts. The hosts for American dog tick larvae are usually small mammals - most commonly, voles, mice and shrews. Nymphs live on cats, dogs, rabbits, raccoons and opossums. In addition to these animals, adults can infect people. Adults must have a blood meal before laying eggs, to complete the life cycle. They are most commonly found in grassy meadows and in young forests along trails.

Deer tick larvae and nymphs prefer the white-footed mouse, but also parasitize birds, as well as small mammals. Adults feed from the white-tailed deer as well as dogs, coyotes and people. Their preferred habitat is deciduous forests and adjacent brush or grass.

The American Dog tick tends to be most a threat in the spring with a decreasing incidence of problems continuing into the summer. The adult Deer tick tends to be most seasonally active in the fall, September to November or in the spring, April to May. In Ontario, this tick inhabits areas that border the north shores of Lakes Erie and Ontario. This area begins at Point Pelee and Rondeau Provincial Park in south-western Ontario. Turkey Point and Long Point have large tick populations. It appears that another population of Deer ticks has recently established in the Wainfleet Bog area. Endemic sites in our province extend on to include Prince Edward County and the Thousand Islands region in eastern Ontario. It is this species of tick that can transmit the organism that causes Lyme disease. Recent research studies suggest perhaps as many as 10% of dogs in Ontario who encounter ticks may be exposed to that disease. The risk is increased in the preceding listed areas.

Diagnosis of a tick problem is made by finding a tick attached to the skin of a cat or dog. It's thought that cats may be quite efficient at removing ticks, however, it's not unusual to find cats, especially kittens with ticks. Occasionally, pet owners will find a tick feeding cavity on their pet's skin where a tick had previously been attached.

It's important to remove attached ticks, as soon as possible, in an effort to prevent the transmission of tick-borne diseases. Soak the attached tick in alcohol, grasp the head parts, close to the animal's skin with fine-pointed tweezers. Apply firm traction, with a gentle twist, to remove the tick. Wash the affected skin area with soap and water. Application of hot matches, Vaseline or other materials fails to cause detachment of ticks.

Ask your veterinarian about the use of tick collars and other preventives to use for your pet. It's also a good idea to avoid environments with large tick populations. Consideration may need to be given for vaccination against Lyme disease depending on the risk of exposure to Deer ticks. Barry Burtis is a local companion animal veterinarian. Past Pet Tales can be found at www.baycitiesanimalhospital.ca