Pruritus (Itchiness) in Dogs

If your dog spends a large portion of his time scratching, he may have a condition known as pruritus, or itching, an unpleasant sensation that causes your dog to scratch or bite at himself. It is caused by chemical reactions that occur in the skin and stimulate the nerves, causing the brain to feel the itch. In fact, the act of scratching itself may stimulate these inflammatory reactions in the skin and make the condition worse. Any skin condition that causes inflammation can cause pruritus.

How pruritus affects your dog's health depends on the degree of the pruritus. Mild pruritus may hardly have any effect at all. However, severe pruritus leads to intense scratching, which may result in painful skin lesions that may become infected. Your dog will often whimper or cry out and may have trouble sleeping.

Every dog has a threshold of pruritus or an "itch threshold." This is the point where all of the sources of itching finally add up to enough irritation to cause the irresistible urge to scratch. Scratching begins when the stimulation exceeds that threshold. For example, a dog with a mild allergy to house dust mites may be below the threshold but may begin to scratch severely when he becomes infested with fleas.

Pruritus is associated with other skin diseases, including secondary bacterial skin infections (pyoderma) and secondary yeast infections. But it is the main symptom of skin conditions like allergies and skin parasites.

What To Watch For

Scratching or biting. If this continues beyond one day and leads to lesions such as hair loss, reddening of the skin and obvious pain or discomfort, have your dog evaluated by your veterinarian.

Chronic licking of the feet is also a symptom of pruritus.

Diagnosis

Diagnostic tests may be needed to determine the cause of the pruritus. Your veterinarian will probably do the following:

A complete and thorough medical history

A thorough physical examination

Skin scrapings to rule out mange mites and other parasites

Fungal cultures of hair to rule out dermatophytes (ringworm)

Treatment

The key to relief from pruritus is to identify and treat the underlying cause. Pruritus may be temporarily relieved with medication but the itching often recurs after the medication is finished. Temporary relief may come from the following:

Antihistamines

Fatty acid supplements

Soothing shampoos

Corticosteroids

Home Care

Administer all veterinary prescribed medication as instructed by your veterinarian. Consult with your veterinarian to establish a complete flea control program.

Keep your dog's coat clean and brushed free of mats.