Heartworm prevalent in Okanagan

The good news is that the winter is almost over. The bad news is that we are not the only creatures that are going to enjoy the upcoming spring.  Mosquitoes are also thrive in the warm weather. Besides being a nuisance to people, mosquitoes have the capability of transmitting a dangerous disease to our pets known as Heartworm.  

Heartworms (Dirofilaria immitis) are large roundworms that live in the right side of the heart and the blood vessels that supply blood to the lungs. The mature form of the worm can grow to a length of 23-30 cm, and in severe cases a dog may be infested with hundreds of worms.

Heart worm infestation can potentially cause damage to the heart, lungs and liver as well as obstruction of blood flow and eventually, death due to respiratory and heart failure.

Although dogs are the natural hosts for heartworms, cats will occasionally become infested as well.

Heartworms are spread by mosquitoes. Mosquitoes are active in warm temperature environments. The high-risk areas in Canada are the Okanagan Valley in British Columbia, southern Ontario, southern Quebec and Manitoba. Heartworm is also found in most states in the US.

A mosquito bites an infected dog and sucks its blood. The worm develops in the mosquito’s body, and passes to an uninfected dog with the mosquito’s saliva in its next bite. The worm in its immature form travels through the bloodstream and lodges in the right side of the heart and the blood vessels that supply the lungs, where it matures and multiplies.

There are no symptoms at all until the disease is very advanced. Then, the symptoms are those of congestive heart failure:  dull coat, lack of energy, coughing, difficulty breathing, perhaps fainting spells and an enlarged abdomen.

A blood test is available and is the most common method of diagnosis. It takes approximately 6 – 7 months from the time of infection until the test becomes positive. The dead worm poses a lot of potential damage by breaking loose, obstructing blood vessels and causing respiratory failure and death.

Treatment for heartworm disease is available. However, treatment is costly and not without risks. The treatment consists of a series of injections. While on treatment the dog has to be kept to strict activity to allow the body to absorb the dead worm.  

Prevention is the key.  Preventive drugs are highly effective and when regularly administered will protect more than 99 percent of dogs and cats from heartworm.

There are few different types of preventative medications. The medications differ in their administration route, spectrum of activity and cost.

In general, I recommend to my clients to administer the preventative medications throughout the warm months of the year, in the active period of the mosquitoes. Here in our beautiful warm Okanagan Valley the medications should be administered between April and October.

Discuss heartworm prevention with your vet, and get specific recommendations for keeping your beloved pet safe and heartworm free.

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About the Author

Dr. Moshe Oz owns Rose Valley Veterinary Hospital, a small animal veterinary practice in West Kelowna.

Dr. Oz has deep love and affection for animals. It was his childhood dream to become a veterinarian, a dream that he has fulfilled when he graduated with honours from KUVM,on 2006. Dr. Oz's special interest is internal medicine and surgery.

In his free time Dr. Oz enjoys training and racing triathlons, including the legendary Penticton's Ironman.

Dr. Oz can be contacted through his website: www.KelownaVet.ca

The views expressed are strictly those of the author and not necessarily those of Castanet. Castanet does not warrant the contents.

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