It's distressing to notice your dog continually biting herself. While it's a natural way for her to cope with an itch every once in a while, if it's ongoing, she probably has chronic itchiness or irritation. Examine the areas being bitten and schedule an appointment with your veterinarian. If your dog continues biting excessively, not only is there an underlying problem, she may also injure herself or develop sores or an infection.
External parasites—and fleas in particular—commonly cause excessive itchiness and are a likely reason your dog keeps biting herself. Ticks are another possibility. Check your pet for signs of infestation. Run a flea comb through her coat and inspect the teeth for insects or nits. Also, look for deposits of small, black specks on her skin; "flea dirt," or flea droppings, are a sure sign of an infestation. Consult your vet about an appropriate flea treatment. If you see a small, hard arachnid adhered to your dog, it's a tick. Use tweezers or a tick-removing implement to extract it. If you don't know the proper technique, ask your vet. Prompt removal is important not only to stop your dog from biting herself, but to limit the chances of disease transmission. Some ticks spread Lyme disease, Rocky Mountain spotted fever and other illnesses.
A variety of allergic conditions affect the skin and cause mild to severe itching, often chronic. Seeing your vet is the best way to identify whether an allergic disorder is causing problems. Contact dermatitis results from exposure to an environmental irritant and may leave your dog biting and chewing herself. Plants in the yard, cleaning products you use in your home and grooming products are likely culprits. Food allergies also cause itching. Your vet can help you design an exclusion diet to get to the bottom of possible food hypersensitivities. Seborrhea and other skin conditions are other causes of biting. Again, your vet can best advise you on managing the condition. He'll usually recommend a specialty shampoo, fatty acid supplements and other remedies.
Dogs often bite themselves out of boredom, anxiety, stress, depression or other emotional or psychological upset. It's not unlike a person who bites her nails, twirls her hair, picks at her skin or has other compulsive behaviors. Providing your pet with more physical and mental stimulation may resolve the problem. Spend more time with her, especially walking and playing outdoors, and give her some new toys. Talk to your vet about managing stress or emotional problems, too. He may also want to pursue testing to determine whether a medical condition is causing depression or a mood disorder.
Thyroid dysfunction, nutritional deficiencies and other health problems can cause itchy skin, and other skin and coat problems may prompt excessive biting or chewing. Sometimes a minor irritant, such as a thorn or an insect bite or sting, is just driving your pet crazy. Remove anything stuck in your dog's skin and ask your vet about an appropriate topical antibiotic and anti-itch product. Dogs with bone, ligament or joint problems sometimes react to the pain by biting themselves. A small fracture or tear may be to blame, or your dog may have arthritis, hip dysplasia or another degenerative condition. Dry skin is another possible explanation, and it's generally easily manageable with a moisturizing product recommended by your vet. The vast number of possible causes of your dog's biting—some of which can be serious—mean you must consult your vet for a diagnosis.
Eric Mohrman has been a freelance writer since 2007, focusing on travel, food and lifestyle stories. His creative writing is also widely published. He lives in Orlando, Florida.