Spring and Mosquitos


Your pet could be their next meal! We wanted to take this time to remind you how important it is to protect them from not only these pests but the diseases they carry, especially Heartworm.

In 2010, The Ontario Veterinary College did a study that showed 564 dogs in Canada tested positive for heartworm. Over 75% (431 dogs) lived in Ontario. These numbers do not include any dogs that were not tested and may have been positive for the disease. These numbers show a 60% increase in heartworm prevalence in Ontario since 2002.

The mosquito plays an essential role in the heartworm life cycle. Adult female heartworms living in an infected dog, fox, coyote, or wolf produce microscopic baby worms called microfilaria that circulate in the bloodstream. When a mosquito bites and takes a blood meal from an infected animal, it picks up these baby worms, which develop and mature into "infective stage" larvae over a period of 10 to 14 days. Then, when the infected mosquito bites another dog, cat, or susceptible wild animal, the infective larvae are deposited onto the surface of the animal's skin and enter the new host through the mosquito's bite wound. Once inside a new host, it takes approximately 6 months for the larvae to mature into adult heartworms. Once mature, heartworms can live for 5 to 7 years in dogs - which is one reason they can potentially be so deadly.

Signs of heartworm disease may include a mild persistent cough, reluctance to exercise, fatigue after moderate activity, decreased appetite, and weight loss. As heartworm disease progresses, pets may develop heart failure and the appearance of a swollen belly due to excess fluid in the abdomen. Dogs with large numbers of heartworms can develop a sudden blockages of blood flow within the heart leading to a life-threatening form of cardiovascular collapse. This is called caval syndrome, and is marked by a sudden onset of laboured breathing, pale gums, and dark bloody or coffee-coloured urine. Without prompt surgical removal of the heartworm blockage, few dogs survive.

Alcona Animal Hospital recommends testing your dog for possible heartworm infection every two years, as long as preventative medication was given for the entire mosquito season prior. If you have a new puppy and they were born in the winter, they will not require a test prior to starting preventative medication as they will not have been exposed to mosquitos. We will need to monitor their weight though as the dose of medication will change as they grow. This simple blood test will detect if your dog has contracted heartworm. There is treatment for heartworm disease but its success depends on how quickly the condition is diagnosed.

There are many types of preventative heartworm medications. They come as tablet or chews or as a topical liquid. They are to be given once a month starting June 1st until November 1st. Only veterinary products have been tested and researched to be safe and effective. Pet store medications can be very harmful to your pet. We would be happy to discuss heartworm and heartworm preventative medication with you! Please contact the clinic with any questions you may have!