Heartworm prevention is a key part of keeping our small animal patients healthy. As a vet tech, you will play an important role in educating clients about heartworm prevention and helping them choose the best product for their pets.

 

The number of preventives can be overwhelming for many clients, so you will need to develop a strategy to narrow down the options and help each client choose the prevention that best fits their needs. 

 

Each practice stocks different heartworm preventatives, based on the preferences of the practice management and the practice’s clients. After spending twelve years in small animal general practice, working in a number of different clinics, I’ve developed three “go-to” favorites for heartworm prevention in dogs. Most practices stock some or all of these products. 

 

 

I love Trifexis^® (spinosad + milbemycin oxime) because it’s the closest thing we have to an all-in-one parasite prevention in pill form. Trifexis^® is a tablet, given once monthly, that protects dogs against fleas, heartworms, hookworms, roundworms, and whipworms. It can be started in puppies as young as 8 weeks old and as small as 5 pounds. The convenience of preventing so many parasites with a single tablet is a huge benefit to clients and patients. 

 

The primary drawback to Trifexis^® is that it doesn’t protect against ticks. If your patient is at risk of tick exposure, you will either need to add tick prevention (such as a Preventic^® collar) or consider a different heartworm prevention that can be combined with flea/tick prevention. 

Interceptor^® (milbemycin oxime) is a once-monthly tablet that protects against heartworms, hookworms, roundworms, and whipworms. Basically, it’s Trifexis^® without the flea prevention. Interceptor^® can be used in puppies as young as 4 weeks old and as small as 2 pounds. It’s a great option for dogs that are already on another flea/tick prevention and dogs whose owners decline flea/tick prevention. Because it doesn’t contain flea prevention, it’s less expensive than Trifexis^® and therefore a good choice for cost-conscious owners. 

 

I typically recommend Interceptor^® over other monthly heartworm preventatives, because it offers protection against whipworms. (Ivermectin-based heartworm preventatives, such as Heartgard^®, do not.) Although whipworms are not extremely common, I do see them in practice and they can cause significant illness. If an owner is going to give monthly heartworm prevention, it makes sense to use a product that protects against whipworms. 

Proheart^® 6 (moxidectin) is a great option for clients who skip or forget doses of heartworm prevention, as well as for pets that are difficult to pill. It is an injectable heartworm preventative, administered every six months in the veterinary clinic. The client doesn’t give any heartworm prevention at home; their only responsibility is to schedule and attend vet visits every six months. (In many practices, clients are already bringing their dogs in every six months for wellness visits. The injection can be given during that wellness visit.)  Proheart^® 6 can be used in any dog over 6 months of age.

 

The primary drawback of Proheart^® 6, when compared to monthly preventatives, is decreased protection against intestinal parasites. First, Proheart 6^® has no activity against roundworm or whipworm infections. Second, it functions as an every-six-months intestinal dewormer, versus monthly deworming in dogs receiving oral heartworm prevention. Given its decreased protection against intestinal worms, I typically only recommend Proheart^® 6 in dogs that may not otherwise receive heartworm prevention. Still, it can be a great option in that subset of dogs! 

 

While there is no single “best” heartworm prevention, these options cover the most common client scenarios you are likely to encounter as a vet tech. Learn which products are available in your practice, learn the pros and cons of each product, and be prepared to help clients make informed decisions regarding heartworm prevention.