Signs of Fleas on Dogs

Flea bites are itchy and irritating, and a dog infested with fleas will scratch frequently. Methods of scratching include using the nails on his hind legs, or his teeth. If you observe your dog sharply curving his body to bite or nibble a particular area, check to see whether feeding or migrating fleas are the cause of his discomfort. Dogs with severe infestations are often in constant motion, trying to scratch, itch and bite their skin.

Flea droppings, known as "flea dirt," are small, black pepper-like flecks. After fleas eat, they expel waste on your dog's skin. Flea dirt can appear anywhere, but is often most visible behind the dog's ears, around his genital area, and at the base of his tail. Depending on his coat, you might have to comb through his hair to see the dirt at the base of his hair. Flea larvae are approximately 1/4 inch long, but their pale grey color makes them difficult to see except on a completely white dog.

Despite their small size, each flea eats up to 15 times their body weight in blood twice a day. This blood loss adds up quickly and can eventually cause anemia. The most obvious visible sign of anemia is white or gray gums. Puppies and smaller dogs, who stand only a few inches off the ground, are especially at risk of significant blood loss caused by flea infestation. Always consult an experienced veterinarian regarding the health and treatment of your pet.

Like mosquito bites, flea bites can cause small red spots to develop on your dog's skin. The size and visibility of these spots increases after he starts scratching and chewing the affected areas. Over time, the scratching can break open the skin, which can lead to secondary bacterial infections known as "hot spots." For some dogs, these red spots mean the dog is allergic to the flea's saliva and has flea allergy dermatitis.