top of page

Pruritus - Itching and Scratching in Dogs

One of the most frustrating things to try and diagnose and resolve can be an itchy pet! The fancy name for itching or scratching is pruritus. Pruritus is a sign, like a symptom. It is not a diagnosis or specific disease. Lots of things can cause pruritus, it can be primary or secondary. Pruritus may be well or poorly localized. Mostly likely when dealing with an itchy pet, you are going to need to take a multimodal, chronic approach. Just managing the itch alone will not address the ongoing issue. Things you may notice your pet doing are excessive scratching, licking, biting at the skin, rubbing, or licking of the feet and face.

The most common causes of itching are things like parasites (infestations), infections, and allergies. There are many skin diseases that do not initially cause itching, however, itching may develop afterwards because of secondary bacterial or yeast infections. Excessive scratching, rubbing, or licking of the feet and face are common in animals with concurrent yeast and bacterial infections. One of the things that makes it tricky to determine the root cause of pruritus is that its possible that by the time itching develops the initial cause is long gone.

  • Pruritus is the most common dermatologic problem of animals.

  • Infestation, infection and allergies are the three main causes of itching

  • Parasites ( including Demodex, fleas and ticks, contagious mites, and lice) are the most common cause of pruritus and, often, response to treatment for 3-4 months is the only way to rule out parasite infestations.

  • Infections (Concurrent bacterial and yeast infections are increasingly recognized as a common cause of pruritus in dogs, cats) are common complications of pruritus and should be addressed.

  • Systemic drugs should be used conservatively because the first line of treatment is topical antimicrobial therapy.

  • If parasites and infection are ruled out the next most likely cause of pruritus is allergic causes.

  • The most common causes of allergic pruritus are insect bite hypersensitivity (eg, flea allergy, mosquito bite allergy, fly bite) and atopic dermatitis.

  • Other allergic causes include seasonal allergies (atopy) and contact dermatitis (e.g., soaps and perfumes).

  • Food allergy is less common as a sole cause of pruritus yet we see pet parents often jump there first when treating pruritus before establishing the diagnosis.


With something as tricky to work up as itching in dogs, it’s important to diagnose using a methodical workup performed in a logical sequence in a compact period of time. This is not the time to take a shotgun approach. After addressing the two most common causes, parasites and infections, if the animal’s pruritus is unchanged or only somewhat better, the most likely underlying cause is allergic.

The most common causes of allergic pruritus are insect bite hypersensitivity (eg, flea allergy, mosquito bite allergy, fly bite) and atopic dermatitis. Believe it or not but actually food allergy is less common as a sole cause of pruritus.

One of the big reasons we want to stop the symptoms of pruritus is that things like excessive scratching, licking, or biting at the skin can cause the skin to become red, inflamed, and irritated. In some cases, the skin may become infected or develop scabs. If the pruritus is left untreated, it can lead to more serious health issues. If you notice your dog scratching, licking, or biting at their skin, it is important to take them to the vet for an examination.

Your vet will be able to help you determine the underlying cause of the pruritus and provide the appropriate treatment. Treatment may include medications, topical creams, or changes to the dog’s diet. It is important to follow the vet’s instructions carefully to ensure the best possible outcome for your pet. Pruritus can be a difficult issue to deal with, but with the right treatment, your dog can be comfortable and healthy once again.

What are some of the Diagnostic Tools Vets use in cases of pruritus?

  • Cytology: Cytology is the microscopic examination of cells that have been collected from the body. The initial workup of the pruritic dog should include at least skin and/or ear cytology- taking a look under a microscope at cells from the skin or ears.

  • Skin scrapings: The initial workup of the pruritic dog should also include skin scrapings of affected areas. Superficial skin scrapings may demonstrate many surface and superficial mites; deep skin scrapings may demonstrate Demodex mites.

  • Flea combing and/or surface tape impressions: Examination of debris obtained by flea combing or with surface tape impressions may be helpful for demonstrating surface-dwelling mites, fleas, “flea dirt,” and lice.

  • Flea control: Aggressive flea control is an essential part of the workup and management of the pruritic dog. Flea control should be included in the workup of the pruritic dog even when flea allergy is not considered to be a likely differential because fleas and their bites can produce irritation even in nonallergic patients.

11 views0 comments


bottom of page