Heartworm Disease, Treatment, and Prevention

Disease- Canine Vector= mosquito The dog is a natural host for heartworms, Heartworms that live inside the dog mature into adults, mate and produce offspring. Heartworm disease causes lasting damage to the heart, lungs and arteries, and can affect the dog’s health and quality of life long after the parasites are gone.

Disease- Feline Vector= Mosquito The cat is an atypical host for heartworms, and most worms in cats do not survive to the adult stage. Cats with adult heartworms typically have just one to three worms, and many cats affected by heartworms have no adult worms. While this means heartworm disease often goes undiagnosed in cats, it’s important to understand that even immature worms cause real damage in the form of a condition known as heartworm associated respiratory disease (HARD). This is usually fatal.

Heartworm Testing- Canine All patients must undergo heartworm testing annually. All patients must have a current annual heartworm test to be prescribed heartworm prevention. Testing consists of a small blood draw into a lavender top tube for an antigen test conducted either in our own lab or sent to an outside lab (Antech).

Heartworm Testing- Feline Not a routine option Blood is submitted for an antigen/antibody test when disease is being ruled out.

Common Questions and Replies “My dog is always on prevention. Why do I need to test?” – We are glad you give your preventative routinely. We have your dogs best interest in mind when we recommend annual testing. The state of Texas has the second largest population of heartworm disease in the US. Almost all dogs are exposed many times in their lifespan. If your pet does contract the disease we need to know as soon as possible to prevent any damage to the heart. Heartworm prevention is not 100% effective. Some pets will get sick on their prevention and can vomit their dose without you knowing. Sometimes owners try hard to be compliant but can let a few weeks lapse between doses. “My dog is heartworm positive and I was told to just give a preventative and that would treat the heartworms.” This is not an adequate treatment protocol. Preventatives such as Heartgard are not treating the adult heartworms living in the heart and lungs, they only prevent more from developing. Heartworms can live in the dog for 5-7 years and it can take that long for them to test negative. Meanwhile those adult worms are causing heart damage and can migrate to other parts of the body.

Common Questions and Replies “I forgot to give my pet’s preventative this month, do I need to get another test?” If you forgot to give a preventative, always give immediately at the time you realize it has lapsed. Heartworm disease can take 6-9 months to make a test positive. It would be best to restart your preventative and test in 6-9 months unless you are not current on your annual test anyway. “ I accidently gave my pet his preventative twice this month, can I skip next month?” Preventatives only last for 30 days. You still need to give another dose 30 days later. The preventative’s essentially reaching back to deworm for any microfilaria in the pets bloodstream and eliminate the threat of adult heartworms. “My cat is indoors only, he doesn’t need prevention.” It is true that your cats risk for contracting heartworm disease is small, however, there is no treatment for heartworm disease in the cat and it is almost always fatal. Why not prevent something so serious.

Canine Treatment Protocol 1.Pet Diagnosed with heartworms 2.+/- staging for disease by thoracic radiographs and blood work. 3.Pet placed on monthly preventative and doxycycline for at least 30days 4.First immiticide injection. This is a drop off procedure. They will then start the confinement period and likely be on a steroid and pain medication for some of this time. 5.Pet returns 30 days later for a series of 2 immiticide injections 24 hours apart. This is an overnight stay. Pet will then continue another 30 days of confinement and medications. 6.Pet will return in 6-9 months for another heartworm test. **This protocol follows the standard treatment of care based on the American Heartworm Society and is followed by all doctors at WAH.

Feline Treatment Protocol No treatment- supportive care implemented.

Preventatives- Canine Orals Triheart – Heartworm Only Heartgard – Heartworm Only Trifexis – Heartworm and Fleas – Not for seizure patients Topical Advantage Multi Heartworm and Fleas *All are prescription only

Preventatives- Feline Topical Revolution – Heartworm and Fleas Advantage Multi – Heartworm and Fleas Oral Heartgard – Heartworm Only *All are prescription only

Drugs in Westbury Pharmacy PreventativeDrugRouteSpeciesTreatmentsCautions Triheart Ivermectin, Pyrantel Oral- tabletDogHeartworm; hookworms, roundworms Heartgard Ivermectin, pyrantel Oral- chewDog, CatHeartworm; hookworms, roundworms Trifexis Spinosad, Milbemycin oxime Oral- tabletDogHeartworm; hookworms, roundworms, whipworms, Fleas Caution in seizure patients Revolution SelamectinTopicalCatHeartworm, Fleas, ear mites, controls ticks in dogs and intestinal parasites in cats. Advantage Multi Imidacloprid, Moxidectin TopicalDog, CatHeartworms, fleas, intestinal parasites and ear mites in cats. Comfortis SpinosadOral- tabletDog, CatFleasCaution in seizure patients Activyl InoxacarbTopicalDog, CatFleas Nexgard AfoxolanerOral- chewDogFleas and some ticksCaution in seizure patients Scalibor collar DeltamethrincollarDogTicksToxic to Cats