Every dog requires parasite prevention to safeguard against heartworms and intestinal worms. Ivermectin (Heartgard, Stromectol) has been widely acknowledged as a safe and effective parasite preventative for dogs, making it a common ingredient in various monthly preventatives.
In addition to its role as a preventative measure, ivermectin is also utilized for treating parasitic infections in dogs. Veterinarians often prescribe ivermectin to address conditions such as mange and other parasitic infestations in dogs.
Ivermectin is a prevalent anti-parasitic medication for dogs, used to prevent heartworm and certain intestinal worm infections when administered monthly. Veterinarians may also prescribe ivermectin to address other parasitic infestations.
Once ivermectin enters a dog's body, it circulates through the bloodstream. Parasites residing within the dog are exposed to the ivermectin carried by the bloodstream. Vulnerable parasites experience paralysis, leading to their eventual demise.
Ivermectin is a key component in numerous monthly oral heartworm preventatives, providing protection against:
1. Heartworms: Transmitted through mosquito bites, heartworm infection can lead to the growth of spaghetti-like worms that obstruct blood flow in a dog's heart and lungs, causing symptoms like cough, weakness, and potential sudden death.
2. Hookworms: Common intestinal parasites in dogs, hookworms spread through contact with infected dog feces or contaminated soil. They attach to the intestinal wall, extracting a dog's blood and causing symptoms such as vomiting, diarrhea, and anemia.
3. Roundworms: Another prevalent intestinal parasite, roundworms are transmitted through contaminated dog feces and soil. They reside in the intestine, depriving the host dog of nutrients and manifesting symptoms like vomiting, diarrhea, and coughing.
Ivermectin-based heartworm preventatives effectively guard against these infections. Some products combine ivermectin with another anti-parasitic medication to broaden protection against various parasites.
Veterinarians also prescribe oral or injectable ivermectin to treat the following parasitic diseases:
- Demodex
- Scabies
- Nasal mites
- "Walking dandruff" (Cheyletiellosis)
In these cases, ivermectin is used "off-label," administered at higher doses than recommended for heartworm prevention and potentially more frequently than once a month.
Heartworm preventatives containing ivermectin typically come in the form of chewable, flavored tablets. The monthly dosage for your dog is determined by their body weight. Administer one tablet orally once a month, consistently on the same day — or as directed by your veterinarian.
For off-label uses of ivermectin, a tailored treatment plan is necessary. Your dog's dosage may range from once daily to once monthly, and both oral and injectable forms are available. The frequency and form of ivermectin administration will be determined by your dog's specific diagnosis under the guidance of your veterinarian.
Heartworm preventatives typically contain a minimal amount of ivermectin, and associated side effects are extremely rare.
However, higher doses of ivermectin may lead to neurological side effects, especially in dogs with the MDR1 mutation. Breeds with this genetic mutation, such as collies and Australian shepherds, are more sensitive to various medications, including ivermectin. Genetic testing is used to diagnose the MDR1 mutation.
Dogs exposed to high doses of ivermectin may experience neurological side effects, including:
- Dilated pupils
- Incoordination
- Stumbling or a drunken gait
- Seizures
These severe side effects are exceptionally rare in dogs receiving ivermectin heartworm preventatives and are primarily a concern when dogs are exposed to elevated doses, particularly if they have the MDR1 mutation.
Another serious risk arises from overdosing, often occurring when owners administer horse or cattle ivermectin to their dogs. It is crucial never to give large-animal formulations of ivermectin to dogs.
If your dog displays neurological side effects, cease administering ivermectin immediately and promptly contact your veterinarian.
While interactions between ivermectin and other dog medications are uncommon, they may occur, especially in dogs receiving high doses of ivermectin. Interactions are more prevalent in dogs with the MDR1 mutation. Your veterinarian will inform you if your dog is at risk for such interactions.
It's important to inform your veterinarian about any other medications your dog is taking, including prescription medications, over-the-counter drugs, and vitamins/supplements. This practice helps minimize the risk of potential adverse interactions.
If you forget to administer a dose of ivermectin to your dog, give the missed dose as soon as you remember. Following that, continue with the regular schedule as advised by your veterinarian. Avoid giving your dog a double dose of ivermectin.
