Oz: Heartworm concerns heat up with arrival of warm weather
The good news is that the winter is over. The bad news is that we are not the only creatures that are going to enjoy the upcoming spring as mosquitoes are also thriving in the warmer weather.
Beside 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 to 30 centimetres, and in severe cases a dog may be infested with hundreds of worms.
Heartworm 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 heartworm, cats will occasionally become infested as well. Heartworms are spread by mosquitoes as they become active in a warmer temperature environment.
The high-risk areas in Canada are the Okanagan Valley, southern Ontario, southern Quebec and Manitoba. Heartworm is also found in most states in the U.S.
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 mosquito’s saliva in its next bite.
The worm in its immature form travels through the bloodstream and lodge 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 about six to seven 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 series of injections.
While on treatment the dog has to be kept on strict activity to allow the body to absorb the dead worm.
Prevention is the key. Preventive drugs are highly effective.
When regularly administered, they will protect more than 99 per cent 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 to October.
Discuss heartworm prevention with your vet, and get specific recommendation for keeping your beloved pet safe and heart worm free.