While most dogs and cats easily tolerate flea treatments, some animals may show sensitivity to the product. Others are allergic to the flea bites. Flea allergies show up typically as red skin and intense itchiness. Dogs lose hair and may develop hot spots where they've scratched themselves raw. These are typically seen from the base of the tail along the back or at the back of the legs.
Cats often show signs of flea allergies by excessive grooming.
Some have skin that appears healthy, but have hair loss on the abdomen, flank and back. Others will have small, crusty sores with hair loss. All flea treatments should be made under the supervision of a veterinarian. If problems persist, the veterinarian should be consulted before changes are made. Recommendations on this web site do not endorse any commercial products or trade names.