Pruritus (Itching) In Dogs

Written by Shula Berg BVSc CertAVP(GSAS) GPAdvCert(SASTS) MRCVS
Clinically reviewed by Elizabeth McLennan-Green BVM&S CertAVP(SAM) MRCVS

- Overview
- Diagnosis
- Treatment
- Outlook

What is Pruritus?

Pruritus, the medical term for itching, is very common in dogs. Some pets will quite obviously scratch continuously, while others deal with the itch by chewing their feet, licking excessively, or rubbing themselves along the carpet. Pruritus is a symptom, not a condition in its own right, and there are lots of possible causes. Some skin diseases cause intense itching as a primary symptom. Other conditions cause changes in the skin that make it prone to secondary infection; it is this that then causes itching. If the underlying condition isn't treated, then the infection and subsequent itching will rapidly return. Several tests may be required to identify the underlying issue, but this is important to determine effective treatment and stop the problem recurring.

The most common causes of pruritus are:

Allergies/atopic dermatitis
Parasites
Infection with bacteria or yeast

Which tests are used to diagnose Pruritus?

At the initial consultation, your vet will take a thorough history and examine your pet. This is the first step in identifying the cause of the itching. Your pet's age and breed may make some problems more likely. Sometimes, the time or pattern of onset can identify a likely cause. Examination of the skin and ears will help your vet gather more information. Your vet may then advise any or all of the following investigations:

Skin scrapes, hair plucks and tape strips

These samples are examined under the microscope to identify parasites. Lots of visible bacteria or yeasts suggests that an infection is present.

Culture and sensitivity

In severe infections, it may be advised to take a sample from the skin for analysis, allowing identification of the exact bacteria and the most appropriate antibiotic.

General blood tests

Blood tests are a general screen and can identify underlying diseases, particularly endocrine disorders (hormone imbalances) that can cause skin changes. Checking organ function may be recommended before starting some treatments.

Allergy blood tests

Specific blood tests can identify which environmental allergens an individual is particularly sensitive to. It is more useful for treatment planning than as a diagnostic tool, and is most reliable in animals over a year old.

Diet trial

This is the only way to definitively rule a food allergy in or out. A prescription diet must be fed for 6-8 weeks with no other food, also excluding treats and titbits.

Biopsy

Some less common conditions can only be diagnosed on a biopsy sample, such as autoimmune disease and skin cancers.

How is Pruritus treated?

There are many possible treatments for skin disease, and often a combination of treatments is used to manage symptoms successfully. Some conditions can be cured, however, problems such as allergies and atopic dermatitis need lifelong management. If skin disease is not successfully controlled, long term changes occur which make things worse - this is especially true of ear disease.

Parasite treatment

Some parasites, such as demodex mites, may need specific treatment with repeat testing to ensure that the infection has cleared. It is essential for any pet with skin disease to have regular parasite control with a reliable product, as fleas are a common source of irritation.

Antibiotics

If infection is present, it will need treating. Mild infection can be managed topically with ointment, shampoos or wipes. Deep infection will need oral antibiotics for a minimum of 6 weeks. Treatment needs to continue 14 days after the symptoms have cleared up, to ensure no bacteria remains in the deeper layers of the skin.

Anti-pruritic

Several drugs can be used to prevent itching, given either as tablets or as monthly injections. These work well for environmental allergens, but it's important to rule out underlying problems first.

Immunosuppressants

Allergies are essentially an over-reaction of the immune system, so suppressing the immune system can reduce symptoms. Steroids are commonly used as they are cost effective. However, given over long time periods, they can have side effects. Other immunosuppressants with fewer side effects are available, but can be more costly.

Immunotherapy

Giving regular, low doses of allergens can eventually stop the body over-reacting to them. Immunotherapy requires allergy bloods to be taken first, and is administered by injection every month. It is extremely safe and is effective in 50-80% of dogs.

Skin barrier support

Various products are available to help support the skin barrier and reduce the irritation of allergies. These include essential fatty acids, medicated shampoos, sprays and foams.

Diet

If a food trial successfully diagnoses a food allergy, symptoms can often be managed long-term with dietary management. This may be the same prescription food as used for the trial, or an alternative product.

What is the outlook for dogs with Pruritus?

The prognosis for pets with skin disease is good, however, managing skin disease is not always about cure. Conditions such as allergies are permanent, and long-term treatment is required. Although one treatment may prove particularly effective for an individual, usually several of the above components are needed together to manage symptoms. Sometimes, it can take time to learn the most effective combination for an individual.

Most pets have a threshold of what they can tolerate before the itching, secondary skin trauma and infection starts. By having good parasite prevention and giving additional skin barrier support, we can sometimes stop them reaching the "itch threshold" even though we may not be able to remove the environmental allergens.

Disclaimer

Please note that the content made available on this webpage is for general information purposes only. Whilst we try to ensure that at the time of writing all material is up to date and reflects industry standards, we make no representation, warranties or guarantees that the information made available is up to date, accurate or complete. Any reliance placed by yourselves is done so at your own risk.

Page last reviewed: 25^th March 2024

Next review due: 25^th March 2026