Ivermectin is used in dogs primarily to treat and prevent a variety of parasitic infections. Its main uses include:

• Heartworm prevention: Ivermectin is widely used as a monthly oral medication to prevent heartworm disease caused by Dirofilaria immitis , which affects the blood vessels of the lungs

• Treatment of external parasites: It is effective against mites that cause demodectic mange, scabies, and ear mites

• Treatment of internal parasites: Ivermectin treats intestinal parasites such as hookworms, roundworms, and capillaria

Ivermectin works by paralyzing and killing susceptible parasites through neurological disruption, leading to their death

. However, certain dog breeds (especially herding breeds like Collies, Australian Shepherds, and others) may have a genetic mutation (MDR1 gene) that makes them highly sensitive to ivermectin, which can cause severe neurological toxicity

. In summary, ivermectin in dogs is used for:

• Preventing heartworm disease
• Treating mange and scabies mites
• Eliminating intestinal worms such as hookworms and roundworms

All treatments should be under veterinary guidance to ensure proper dosing and safety, especially in sensitive breeds