Itching and Scratching (Pruritus) in Dogs

Occasional scratching is a normal behavior for dogs. Sustained or repeated scratching, pawing at the face or ears, dragging or rubbing parts of the body against surfaces, or biting/chewing/“worrying” at an area with teeth is more likely to indicate a problem and cause injury. Seek veterinary care if a dog is scratching continuously or repeatedly, or shows signs of hair loss or injury.

Pruritus as a single symptom doesn’t indicate an emergency, but when it’s severe it can be hard for both the dog and the people in the house with the dog. Severely itchy dogs are uncomfortable and benefit from veterinary care as quickly as possible.

Pruritus may be a localized (e.g insect bites) or a full-body sensation (e.g. allergic reaction due to food).

A dog may be able to relieve more minor itches by scratching or rubbing, but continuous scratching and self-injury indicate a more serious problem.

Pruritus is a symptom of many skin conditions and disorders.

The most common cause of pruritus in dogs is flea allergy dermatitis, or FAD. Lack of visible flea infestation does not rule out FAD.

A variety of skin disorders can become itchy, especially when secondary bacterial or fungal infections set in.

Rarely, a dog may have a neurological disorder such as sensory neuropathy, cauda equina syndrome, or syringomyelia/Chiari-like malformation. Neurological dysfunction causes itching sensations or scratching action not due to problems with the skin itself.

Pruritus is a common symptom of a variety of disorders and/or exposure to parasites, allergens or irritants. Itching may be a secondary symptom of infection.

Veterinary care is warranted for severely itchy dogs who scratch a lot, especially if they also shows signs of:

• Bleeding, wounds or scabs
• Inflamed and/or thickened skin
• Crusty, draining sores
• A foul smell to the skin
• Excessively flaky or greasy skin
• Hair loss
• Hives or swelling

Many skin disorders appear alike upon physical examination and are difficult to differentiate. Diagnosis requires tests or trials to eliminate potential causes and find treatments which relieve the dog’s discomfort.

Diagnostic tools include:

• examination for fleas or visible parasites
• skin scraping and cytology
• fungal culture
• allergy tests (intradermal test, blood test)
• elimination dietary trials
• medication trial (e.g. antibiotics if infection is suspected)
• skin biopsy

Treatments vary depending on the diagnosed or suspected causes. These include:

• external parasite control
• medications (allergy and/or steroid and/or microbials, depending on diagnosis)
• limited ingredient or hydrolyzed diets
• bathing, medicated shampoo

Similar symptoms to pruritus include normal scratching or grooming, normal shedding, scrapes or other injuries, boredom, anxiety.