Collies are known to be at risk for a genetic mutation that causes a buildup of drugs in the brain. Ivermectin, present in many heartworm medications, is of particular concern. This buildup can cause neurotoxicosis which may be fatal if it is left untreated. If you notice sensitivity symptoms that appear four to 12 hours after exposure to Ivermectin, seek vet treatment immediately.
-
Abnormal Eye Problems
-
One of the first signs of Ivermectin sensitivity is dilated pupils. The pupil (the center black part of an eye) of normal dogs' eyes shrink when exposed to light, but illness or allergic reaction to Ivermectin will cause the collie's pupil to be abnormally large and unresponsive to light. Some dogs may also exhibit blindness as a side effect to the medication.
Digestive Problems
-
The toxicity of Ivermectin may cause collies to lose their appetite. They may show no interest in food they previously had no problems with. Vomiting is also a common digestive issue and can in itself be life threatening as it may lead the dog to dehydration. The lack of food and excessive vomiting may lead to heavy drooling due to infrequent or inefficient swallowing.
Motor Instability
-
Since Ivermectin sensitivity is caused by the buildup of toxins in the brain, motor functions become impaired. The collie may have difficulties rising to its feet, maintaining its balance as it stands and walking. A general lack of energy becomes apparent as the dog struggles to make the slightest movements. Involuntary tremors often accompany this weakness, thus adding to further motor instability.
Seizures
-
The toxic levels of Ivermectin in the brain often causes seizures. The seizures can be characterized by symptoms as subtle as blankness, disorientation and stupor. More severe symptoms include a series of involuntary muscle movements and unconsciousness. Seek veterinary treatment immediately at the first sign of seizures.
-