Frequent scratching, biting, or licking, especially around the neck, back, and base of the tail
Restlessness or discomfort
Small black specks in the fur or on bedding, known as flea dirt
Tiny fast-moving insects in the fur
Hair loss, scabs, or irritated skin
Red or inflamed skin
Excessive grooming
Pale gums in severe infestations
Flea dirt that turns reddish-brown when placed on a damp white paper towel
Signs of flea allergy dermatitis, such as intense itching and skin sores