What Causes a Dog to Want to Lick or Bite at His Haunches?

If your pooch spends much of his time licking and biting at his haunches -- his hindquarters, a number of causes could be to blame, including external parasites, skin infections and allergies. Some dogs even bite their legs because they are dealing with anxiety or arthritis. Because this behavior can lead to painful open sores, it's best to get your dog to the vet for a proper diagnosis and a treatment plan.

Fleas are among the most common causes of itchy skin in dogs. These pesky parasites bite dogs to feed on their blood; pups sensitive to their saliva will experience extreme bouts of itching all over their bodies, including their legs.

Other types of skin parasites, including lice, ticks and mites, may also cause itchy skin on the legs. Fortunately, your vet can treat most skin parasites; she may prescribe a topical medication, shampoo or cream to get rid of them.

Your pup may have a skin allergy that causes his back legs to itch at the site of contact with an irritant. Contact allergies and other skin allergies have many causes, including pollen and dust mites.

Two forms of skin allergies that can affect the legs are acute pyotraumatic dermatitis and acral lick dermatitis. Both cause a dog to lick and bite at one particularly itchy area, lead to bacterial infections and scarring. Your vet can determine the exact cause of your pup's allergic reaction through skin tests.

Food allergies can cause skin irritation that may extend to the haunches. To determine whether your pup is suffering from a food allergy, your vet will put him on a hypoallergenic diet. The diet will contain a limited number of ingredients he's never eaten. If your pup's condition improves after eating this food for two to three months, your vet will slowly add the ingredients he was eating before back into his diet. The ingredients your pup reacts to are the culprits of his allergy, and you can avoid them henceforth.

Fungal and bacterial skin infections can cause your pup's skin to become painfully irritated and itchy. These can occur on their own or in conjunction with parasites or allergies. Your vet will prescribe a topical medication to treat the infection and determine the main cause, if applicable, of any itchy skin.

Another cause of itching is dry skin. If your pup's skin becomes dry, it could lead to itching. Your vet may prescribe fatty acid supplements, a topical cream or a gentle, moisturizing shampoo to treat this condition.

Dogs lick and bite at their hind legs for many reasons, which your vet will help to determine.

• A simple mosquito bite can cause itchy skin in the area that your dog is biting and licking.    
  
• If your pup has injured his back legs or is experiencing pain from arthritis, he may lick at the area.
  
• Sometimes, dogs who are bored or anxious may bite and lick at their skin as a way to relieve stress. After ruling out other causes, your vet may recommend that you give your dog more attention, toys and exercise to help stop this behavior.