Dogs of all sizes need Heartworm prevention!
Heartworm Disease is caused by Dirofiliaria immitis, which is transmitted by mosquitoes to both dogs and cats, but is more prevalent in dog These parasites can cause long term lung/heart disease and can even cause sudden death in both dogs and cat. Cats have been shown to be more resistance to infection, but can be infected and have life threatening effect. The up side of heartworm disease is it can be prevented by monthly heartworm prevention in both cats and dogs!
But what happens if your pet gets heartworm disease? In dogs it is treatable by “slow kill method” or adulticide treatment (Immiticide). However, treatments have side effects, can be costly, and require a period of activity restriction. So prevention is the best thing. The recommended treatment currently is using Immiticide to kill the adult heart worms along with concurrent medications to help treat the disease. Treatment and diagnosis in cats can be more difficult. Treatment includes supportive care and surgery in most cases for cats.
What if my pet is mostly indoors? In North Carolina we see a lot of heartworm disease, year round, and in indoor and outdoor pets. Since heartworm is transmitted by mosquitoes, it can be spread even in winter. We recommend testing your dogand cats at least once a year, even if they are on a year round heartworm prevention. If a dog/cat is not on prevention and over 6 months of age, it must be tested before starting prevention too.
What are other reasons to use heartworm prevention?
-Prevents the majority of heartworm disease
-Prevents majority of GI parasites
-Some medications also prevent fleas and ticks too.
-Decrease zoonotic disease (transmitted from animals to people/people to animals) such as roundworms and hookworms
All heartworm prevention options require a prescription from your veterinarian; it is very important that you consult with your veterinarian before starting these products.
But what about herding breeds?
Herding breeds can be affected with a genetic mutation in the MDR-1 (multi-drug resistance) gene. This gene controls the level of certain drugs that can cross in/out of the blood-brain barrier. Other breeds can be affected! Most commonly affected are: Australian Shepherd, Australian Shepherd (Mini), Collie, Long-haired Whippet, McNab, and Silken Windhound The drugs that are most commonly involved include: ivermectin, milbemycin, moxidectin, acepromazine, vincristine, vinblastine, and doxorubicin, etc. Often these drugs can be used at lower doses safely. All heartworm medications are at a lower, safe dose. The toxic levels for MDR-1 gene mutations carriers is 50 times the level of the medications found in heartworm prevention. Effects seen are most often neurologic-salivation, tremors, seizures, etc. Dogs may be tested through Washington State University for the MDR-1 gene mutation.
Learn more about Heartworm Disease at: The American Heartworm Society
Boo Donoho, DVM
Southern Animal Hospital