Heartworm and Tick Borne Diseases

Heartworm Disease

Heartworm disease was once considered a rare condition affecting dogs in Ontario. However, recent changes in climate have led to a significant increase in the numbers of dogs that test positive for this disease in Ontario each year. Another notable change in the incidence of heartworm disease in Ontario occurred after Hurricane Katrina, when many of the pets from the southern US were rescued and brought to shelters in Canada. These pets acted as reservoirs for the disease and this has contributed to the increase in the number of heartworm positive dogs that we now see year after year.

Heartworm disease is spread by mosquitoes. This is why our dogs should be on preventive medication during the late spring, summer, and early fall months when mosquitoes are present. Heartworm disease is easily preventable but expensive to treat and potentially fatal when left untreated. Monthly prevention is the safest and most economical way to deal with this dangerous disease.

Tick Borne Diseases

Ticks hide in grasses and shrubs. Once the outside temperature reaches 4 degrees Celsius, they can attach to pets while they play and walk through our parks. Mild winters lead to expectations that the tick season may not ever cease. Ticks are very small and often missed until they start to feed on pets and grow in size. Unfortunately, once we see them, they have often been feeding long enough to transmit diseases such as Lyme disease and Ehrlichiosis. Over the past three years, we have seen a huge increase in the numbers of ticks affecting neighbourhood pets and as a result tick-borne diseases are rising sharply in Ontario.

Last year our laboratory diagnosed thousands of cases of Lyme disease in Ontario indicating that the disease is here to stay. The use of oral or topical preventatives is the best way to both repel and kill ticks, thus helping prevent the spread of disease. Prevention of ticks should start when the temperature rises above 4 ° Celsius.