Side Effects of Ivermectin and Doramectin in Canines

Ivermectin and doramectin are both anti-parasitic medications; however, ivermectin is used in dogs and cats while doramectin is recommended for use in sheep, cattle and elephants. In dogs, ivermectin has a variety of uses including treating ear mites, mange mites, hookworms and roundworms. It can also be used as a heartworm preventive. Meanwhile, doramectin is still undergoing various testing and trials for use in dogs, so little information is currently available on the safety and effectiveness of doramectin in canines.

  1. Allergic Reactions

    • Allergic reactions are a potential side effect and can occur either due to the medication itself or due to the dying parasites. Symptoms of an allergic reaction include cold limbs, diarrhea, facial swelling, pale gums, vomiting, scratching, seizures and coma.

    Vomiting and Diarrhea

    • Vomiting and diarrhea are common side effects of various medications, including ivermectin. While a single episode of vomiting or diarrhea is usually not a cause for concern, veterinary care should be sought if the vomiting or diarrhea progresses. Excessive vomiting or diarrhea can cause dehydration and even death, if left untreated.

    Drooling

    • Drooling is not uncommon following the administration of medication and excessive drooling may occur.

    Changes in Behavior

    • A variety of behavioral changes may be noted by the owner in their canine. This can vary from dog to dog: some dogs may become unresponsive or lethargic, while other dogs may appear to depressed or have a loss of appetite.

    Weakness

    • In dogs, weakness may be noted in the hours following the administration of ivermectin. The severity of weakness may vary from dog to dog and some dogs may be unable to get up or move, while other dogs may suffer from paralysis of the limbs.

    Respiration

    • Respiratory changes may occur, such as a slowed respiratory rate in the affected canine.

    Neurological Side Effects

    • In severe cases, various neurological side effects can occur in a dog. These can include muscle tremors, seizures or coma. If any of these occur, the owner should seek immediate emergency veterinary care.

    Overdose

    • If levels above the recommended dosage are given, an overdose can occur. In dogs, symptoms of an ivermectin overdose include weakness, disorientation, tremors, stumbling and blindness.

    Ivermectin Warning

    • Ivermectin is not recommended for use in various herding breeds such as Collies, Shetland Sheepdogs, Border Collies or Old English Sheepdogs. Ivermectin toxicity is common due to a genetic sensitivity present in these breeds. Reactions in herding breeds can vary from dog to dog and can be mild to severe in nature.

    Doramectin

    • In an article compiled by Kathy Tater, DVM and Adam Patterson, DVM, doramectin has not yet proven to be effective in either preventing, treating or controlling parasites in canines. Pfizer Animal Health also notes that doramectin simply should not be used in canines, as it can result in an untimely death.