Heartworm medicine is critical to preventing your animal from contracting heartworm, particularly in areas rife with mosquitoes, the insects responsible for carrying the disease. To find out more about heartworm prevention drugs, including how to administer them and possible side effects, read on.
Types of Heartworm Drugs
The pills approved for heartworm prevention in the U.S. are milbemycin (sold under the brand Interceptor and Sentinel), ivermectin (sold as Heartgard and as a generic drug), and moxidectin (sold as ProHeart). All these are typically sold in chewable or pill form.
In countries like Australia, Canada, Japan and Korea, pet owners can buy ProHeart 6 or ProHeart 12 – these are injections that are administered by a veterinarian and will last for 6 to 12 months. The injectable form of moxidectin is not approved for use in the U.S.
Feline owners can turn to products like selamectin, a topical cream which is typically known as Revolution for Feline; ivermectin, also known as Heartgard, but for cats; and milbemycin, also known as Interceptor.
How Effective is Heartworm Medicine?
If it’s administered properly and on a regular schedule, heartworm prevention drugs are over 99% effective in protecting dogs and cats from heartworm infections.
Most failures are caused by irregular or incorrect administration of the drug. However, the monthly versions of heartworm prevention drugs typically have a long margin for error. For example, if a pet owner misses a month’s dose, the dog is typically protected for at least another month as long as the next two doses are administered on schedule. It’s also important to maintain heartworm medication before, throughout and after mosquito season.
How to Administer Heartworm Drugs
Monthly drugs for heartworm prevention should be given to your pet beginning a month before the start of your local mosquito season. The treatment should then continue for a month after the end of typical mosquito activity.
In tropical and sub-tropical climates with year-round mosquito activity, most veterinarians recommend that animals take heartworm prevention drugs throughout the entire year. Some also recommend it for colder regions, but it’s not typically necessary unless you plan to travel with your pet.
Because most heartworm prevention medications are available in pill form, many pet owners have a hard time getting their pets to take the drug. Try hiding it in their foot or crushing it up in peanut butter.
Possible Side Effects
Side effects for heartworm prevention medications are rare, but this is partly because it’s difficult to spot those that aren’t blatant. For example, a dog can’t let you or your veterinarian know that his tummy is sore or he’s slightly nauseous.
Despite a lack of apparent side effects, overdoses of heartworm medicine can be very dangerous and should be treated immediately. Signs of overdose include tremors, vomiting, diarrhea and lack of coordination.
Despite the small risks, veterinarians almost universally recommend heartworm medication for dogs and cats, as the risks associated with not taking it far exceed the reverse, and the onslaught of heartworms is a painful experience for any beloved pet.