Ivermectin is a widely used antiparasitic drug effective against nematodes and ectoparasites in animals. While generally safe, certain dog breeds with a mutation in the MDR1 (ABCB1) gene are highly susceptible to ivermectin neurotoxicity due to impaired blood-brain barrier protection. The toxic effects regardless of administration route?include ataxia, lethargy, tremors, seizures, and coma, especially in genetically sensitive breeds such as Collies and Australian Shepherds. Toxicity arises from the action of Ivermectin on glutamate- and GABAgated chloride channels, causing inhibition of neural and muscular activity leading to paralysis and death of the parasite. Diagnosis is based on clinical signs, exposure history, and ruling out other toxicants. There is no antidote; treatment is supportive, including decontamination, IV fluids, respiratory support, and close monitoring. With prompt care, prognosis is good, though severe cases may require extended treatment.