Collies are one breed of dog that is more likely to have a drug sensitivity. Author Pleple2000 Licensed under the GNU Free Documentation License and Creative Commons Attribution ShareAlike 3.0 LicenseDogs with Drug Sensitivities

Some dog breeds are more sensitive to certain drugs than other breeds. Collies and related breeds, for instance, can have adverse reactions to drugs such as ivermectin and loperamide (Imodium). At Washington State University's College of Veterinary Medicine you can get your dog tested for drug sensitivity and keep up with the latest research.