Ivermectin is used to treat both demodectic and sarcoptic mange in dogs. Ivermectin used in high dosages is considered to be an off-label use as the drug is not approved by the FDA when used at these dosages. Off-label usage is common and ivermectin is frequently used by veterinarians to treat mange in dogs, but dog owners should be aware that the dosages are much different than those dosages used for monthly heartworm prevention.
While ivermectin is considered to be a reasonably safe drug, even at dosages used for treatment of mange in dogs, side effects can occur. In addition, some dogs may harbor a genetic predisposition to ivermectin sensitivity which places them at further risk, especially when ivermectin is used at higher dosages.
Side effects most commonly seen with ivermectin are:
- lack of appetite
- excessive salivation
Ivermectin should not be used in high dosages with valium or tranquilizers related to valium, amitraz dips, collars or topical treatments, or Comfortis® due to the potential of adverse drug interactions.
Dogs with a Genetic Sensitivity to Ivermectin: Breeds that may possess a genetic sensitivity to ivermectin are Collies, Shetland Sheepdogs and Old English Sheepdogs, although genetic sensitivities have been seen in individuals outside of these breeds as well. A blood test that detects the genetic mutation responsible for the ivermectin sensitivity is available and may be advisable for high-risk dogs before administration of high dosages of ivermectin. Heartworm preventive dosages of ivermectin are normally low enough to be safe for these high-risk dogs.
Symptoms such as uncoordination and dilated pupils are of particular concern and can lead to death if treatment is not sought immediately.
Bill Ormston, DVM, owns and operates Jubilee Animal Health, a mobile mixed animal practice using mostly alternative methods, in the Dallas TX area. jubileeac.com