Hair Loss in Dogs – Symptoms, Causes & Treatment

Understanding Hair Loss in Dogs

Hair loss in dogs can be a concerning issue for pet owners. It can affect dogs of any age or breed, with severity ranging from mild to serious, depending on the cause. There are numerous conditions that could result in this symptom, so you should seek veterinary advice from your local Greencross Vets team as soon as you notice your dog losing hair.

Common Symptoms of Hair Loss in Dogs

If your dog is losing hair in focal patches, has inflamed skin, rashes, sores, or scabs forming on exposed skin, is experiencing general thinning of their haircoat or is prone to excessive scratching, it’s important to speak to your vet. Hair loss can be seen in combination with itchy skin, but there are also many causes of hair loss for dogs not associated with being itchy. It’s important to take note of all these symptoms, and any others you spot, so your vet can make an informed diagnosis.

What Causes Hair Loss in Dogs?

There are a number of causes of dog hair loss, which range in severity. Aside from seasonal shedding – which impacts some dog breeds throughout the entire year – hair loss can be attributed to the following causes:

Fleas, mites (mange) and other parasites

Fleas are a common culprit. Their bites often drive dogs to scratch and gnaw to the point of hair loss, particularly in dogs that are allergic to flea bites. Similarly, microscopic mites that live on the surface of your dog’s skin or in their hair follicles can result in seriously itchy skin. As with fleas, mites can affect humans, too.

Bacterial, yeast or fungal infection

Bacteria and yeast occur naturally on your dog’s skin, but they can be at risk of growing out of control and becoming infected under the right conditions, resulting in itching, hair loss and malodour. Ringworm (dermatophytes) is a fungal infection that results in hair loss, often in circular patches, dry flaky skin and brittle, snapped hairs. They are sometimes itchy and can lead to secondary bacterial infections if scratched. Ringworm is contagious to humans and people who get it usually present with pink to red coloured, circular skin lesions, which can be itchy, but not always. 

Allergies – Contact, food and/or environmental allergies

Allergies cause itchy skin that is often inflamed and fragile, being more susceptible to secondary infection. Food allergies are triggered by specific foods eaten, environmental allergies by being in close proximity to specific triggers and contact allergies results from direct contact with an irritating trigger. Hair loss from allergies is caused by irritants such as pollen, mould, fleas or dust mites, as well as the food they eat (which can also cause a sensitive stomach) causing itchiness and then chewing, scratching and rubbing of the skin, that causes the hair to be damaged or fall out. This broad range of potential allergens highlights the importance of checking in with your vet if you suspect an allergy is responsible for your dog’s hair loss so it can be properly diagnosed and treated. 

Trauma

Grazes, scratches and other injuries to the skin can result in hair +/- the top layers of skin being removed.

Friction from a harness or collar

Ill-fitting accessories can rub in the wrong places (especially if your dog pulls on their lead or gets moisture trapped under the fabric) and may need to be replaced.

Nervous licking or chewing

Stress and anxiety – or even boredom – can cause compulsive behaviours such as licking to the point of hair loss.

Genetic conditions

Your dog may be predisposed to hair loss from birth due to a congenital condition – which may or may not be hereditary. A lack of hair follicle development may be clear when they’re born, or shortly after, or when they develop into a young adult.

Hormonal/Metabolic conditions

There are a few metabolic and hormonal diseases that can cause dogs to have thin, patchy hair loss or a thin haircoat in general. Examples include hypothyroidism, hyperadrenocorticism (Cushing’s disease) and growth hormone disorders.

Cancer

While this is the result that no owner wishes to see, skin cancer can be a cause of hair loss in dogs. If this is the case, the hair loss will likely be centred around a lump on your dog’s skin.

Diagnosing The Cause of Hair Loss in Dogs

The causes of dog hair loss comprise of a range of conditions with varying treatments, which is why visiting your local Greencross Vets team for diagnosis is essential. When you visit, be sure to share any notes on the physical and behavioural symptoms you’ve noticed in your dog. Some or all of the following diagnostic approaches may be used to reach a diagnosis: 

Physical Examination

Your vet will perform a thorough physical exam in all cases, where they’ll review the site/s of hair loss as well as your dog’s overall health and condition. Patterns of hair loss can help narrow down the list of possible causes, for example, hair loss targeted around the tail area is often caused by a flea allergy/fleas, while paw and face hair loss can be triggered by environmental or contact allergies. If your vet suspects ringworm, they may use an ultraviolet light to ascertain whether it glows green or, if they’re looking for mites, they may take a scraping of hair follicles to review under a microscope.

Skin impression smears

Your vet may go a step further and press a slide on the affected area to look for bacteria, yeast or inflammatory cells under the microscope so they can diagnose or eliminate certain infections.

Blood testing

If your dog’s hair loss and related symptoms require further investigation, your vet will perform a blood test. This will help diagnose immune system conditions, hormonal issues, thyroid and pituitary gland disorders and diabetes mellitus. This may be supported with urine and stool samples. 

Biopsy

A biopsy will be an essential step if your vet suspects cancer is the culprit of your dog’s hair loss. By taking a sample of the affected area and sending it to the lab, they’ll likely have a clearer picture of your dog’s prognosis and treatment options.

Allergen trials

In some cases, dog hair loss from allergies will require a longer-term diagnostic plan, which may involve a new hypoallergenic diet or the elimination of certain shampoos or medications, or a treatment trial with specific allergy medications. Your vet may refer you to a dermatologist vet specialist in some cases, where testing can be done to check for specific environmental allergy triggers.

How to Treat Hair Loss in Dogs

Treatment for dog hair loss is as varied as the causes. Some conditions, like bacterial, fungal and yeast infections, require topical and/or oral treatments, while parasite treatments can treat mange and fleas (along with long term preventative treatments and supportive topical therapy as needed). Dog hair loss from allergies may require a change of diet or the prescription of allergy specific medications (E.g., Cytopoint or Apoquel) to manage environmental allergies long term. If your dog’s hair loss is linked to anxiety, your vet may prescribe behavioural medications and/or discuss training, supplements, etc, to help manage anxiety issues. If cancer is the cause of your dog’s hair loss, they may require surgery and ongoing care based on their condition. But rest assured, whatever course of action is needed, your local Greencross Vets team will tailor the ideal treatment plan to your dog’s needs.

Preventative Tips for Maintaining a Healthy Coat

Coat condition can clearly indicate your dog’s overall health. Frequent grooming sessions are a good chance to do a general health check and spot any problems in their early stages. Regular brushing stops your dog’s fur getting matted and spreads natural oils through their hair for lustre and strength. And, if you live in a tick-prone area, you’ll be able to keep an eye out for these. Grooming sessions are beneficial for bonding and ensuring your dog is used to these interactions, which will make monthly (or otherwise) application of topical parasite treatments as seamless as possible and allow early detection of any problems. 

Nutrition is also an important part of your dog’s overall health and, as a result, will impact their coat. Choosing the right dog food for your dog’s specific needs will go a long way in ensuring they are as healthy as possible and their coat is shiny, too. Supplements containing Omega 6s and probiotics can also help support a stronger, healthy skin barrier and improved coat quality.

If you need any more information on treating dog hair loss or keeping your dog healthy, touch base with your local Greencross Vets team.