What is Heartworm Disease?
- Heartworm disease is caused by long slender worms that can reach up to 12 inches in length and can infect dogs and cats in Singapore. The worms live in the right side of the heart and large blood vessels of infected pets and are capable of causing significant damage before the pets show any sign of disease.
- These worms can live for up to 2-3 years inside the cat and between 5-7 years inside the dog.
- Transmitted from one pet to another by infected mosquitoes when they are feeding.
- When a pet gets bitten by mosquito-carrying microfilariae (heartworm larvae), the microfilariae gets injected under the skin of the pet which eventually ends up in the blood vessels. The microfilariae then moult into juvenile adults and move into the heart and lung of the pet. Adult heartworms then breed and release microfilariae into the bloodstream 6-9 months after infection.
- Both indoor and outdoor pets are at risk for heartworm disease. Some mosquitoes prefer indoor environments.
Clinical Signs Associated with Heartworm Disease
In the initial stages of the disease, clinical symptoms may not be evident. As the disease progresses in dogs, you may notice coughing, exercise intolerance, lethargy and weight loss. For cats, signs are similar and include coughing, wheezing, occasional vomiting, inappetence and weight loss.
Heartworm Prevention
* Heartworm preventatives should be given for life
If the animal is less than 6 months of age, do start on heartworm preventatives.
Heartworm preventatives for dogs available include monthly oral Heartgard, monthly topical revolution spot on or yearly injectable Pro-heart injection. The only available product for cats is revolution spot-on.
If the animal is greater than 6 months old, a Heartworm test should be done first prior to initiating heartworm preventatives.
Heartworm tests involve taking a small blood sample from your pet to check for the presence of heartworm antigens. Results will be ready in 10-15 mins.
Heartworm Treatment if Tested Positive
Cats – There are currently no approved products available to treat heartworm in cats.
Dogs – We follow the treatment protocol of the American Heartworm Society. It involves oral medication as well as a total of 3 immiticide injections to kill adult heartworms.
There are potential risks even with treatment. Dead heartworms may break off from the heart and form embolus which may cause life-threatening conditions.
Strict rest/exercise restriction post-immiticide treatment helps to reduce the possibility of complications. Treatment outcomes can vary depending on the damage caused by heartworm disease.