Is your dog just shedding its winter coat, or is it something more serious? Perhaps you’ve noticed your dog is itchier than normal and is rubbing up against the furniture. When are bald spots on a dog a cause for concern? Learn more about the various causes of bald spots, and when you should take a trip to your vet.
What Are Bald Spots?
Hair is produced from a follicle within the dermal layer of the skin. It goes through four stages of growth: anagen, catagen, telogen, and exogen. The hair grows in the anagen stage until it reaches its maximal growth and pauses in catagen. From there, the follicle stays dormant in the telogen stage and eventually the hair falls out in the exogen stage (shedding). The cycle then repeats.
A bald spot occurs when there is a thinning or complete loss of hair covering your dog’s skin. Or, it can happen when there is an interruption to the stages of hair growth. While some thinning can be normal with aging or in some breeds, rapid hair loss can be concerning. Bald spots may also not be completely hairless. Instead, you may notice patchy areas of thinner or rough hair that is different from your dog’s usual coat.
Bald spots can also happen from grooming or veterinary procedures where the hair needs to be trimmed. In normal cases, trimmed or treated bald spots will fully grow back within 2-3 months. This ultimately depends on the length of your dog’s coat.
General Signs to Watch Out For
There are many reasons for a bald spot to appear. However, there are some signs to watch out for that warrant a trip to your vet. It may not be normal if your dog is rapidly losing hair out of their normal shedding season. It is also concerning if the hair loss is bilateral, or the same on both sides of your dog’s body.
Dogs that are overly itchy or constantly rub their bodies or snouts on objects may also be signaling an issue. In addition to balding, other signs, like behavioral changes, eating and drinking habits, or bowel habits can signal a problem. Changes to the skin itself, such as wounds, color changes, or texture changes also should be seen by your vet.
Bald Spots on Dogs – Causes
There are many causes, both normal and not, that can lead to bald spots in your dog’s coat:
Normal Hair-free Patches in Certain Breeds
Some dog breeds, such as the Chinese Crested, naturally have bald or hairless patches of fur. Other breeds, such as American Pitbulls, may have spots that are only covered by a very thin line of hair. There may also be normal, thick patches, as well as sparsely haired patches. This pattern can vary from dog to dog, but is not a cause for concern in these breeds. The skin underneath may also vary in color, forming a pattern of pink, black, and gray pigmentation.
Like fully-haired breeds, you should still regularly bathe and care for the skin and coat like normal. As with any short, light-haired, or hairless breed, it is important to take care of the skin showing through. Apply sunscreen on sunny days. Using a dog coat or umbrella and seeking out shade on hot days can help prevent burns and sun-related issues.
Another normal reason for bald spots on the skin includes seasonal shedding. Most dogs, especially double-coated breeds, will shed their coats twice a year, in the spring and fall. This can lead to the appearance of patchy or bald spots as the undercoat fills back in with new growth. However, if the hair loss is extensive or not coinciding with normal seasonal changes, it is not normal. If skin underneath appears irritated or red in addition, something else may be going on.
You can help your dog shed their coat more comfortably with daily brushing. A shedding brush or other grooming tools remove dead hair before it has a chance to mat against the skin. Regular bathing and grooming can also help keep the coat healthy and limit shedding in between seasons.
Allergies, irritation of the skin itself, and even behavioral boredom can lead to excessive rubbing and scratching. This can then lead to hair loss and bald patches. Collars that are too tight or that rub can also cause hair loss from excessive friction. If you notice your dog seems to be rubbing on your furniture or carpeting, look for these issues.
Treatment of friction-related hair loss involves treating the underlying cause. If you can’t find the cause yourself, such as a too-tight collar, or visible parasites, a vet visit to rule out more serious issues is best. Your vet can perform a complete exam of the skin and coat to check for issues.
To prevent friction-related hair loss, make sure your dog’s collar or harness is loose enough. You should be able to comfortably fit two fingers underneath. For behavioral rubbing caused by boredom or anxiety, speak with a local dog trainer. Additionally, providing more enriching activities, such as puzzle toys, can redirect your dog’s energies into something more productive.
Infections From Parasites, Bacteria, Fungi, and Yeast
Skin conditions can lead to bald spots if hair follicles are damaged or irritated. Parasites, such as fleas, ticks, and mange, can lead to widespread hair loss, skin irritation, and flaking and peeling of the skin as they feed and bury into the skin. Fleas also lay eggs at the base of the hairs.
Bacterial infections can lead to visible wounds, irritation, heat, and oozing of debris. Fungal infections, such as ringworm, can create patterns of hair loss as the skin is affected. This is usually in a tell-tale ring or bulls-eye pattern. Yeast between the toes or in the ear canal can also cause patchy hair loss in those areas.
Diagnosis of skin issues involves visual inspection of the hair and coat, as well as taking samples of the affected area. Infections and parasites may be obvious, however, skin scrapings can be used to determine the specific parasite or bacteria. Ringworm infections are usually diagnosed with a Woods Lamp, a UV blacklight that causes the fungus to light up under it. Yeast infections can be diagnosed via skin scraping along with smell (usually “doughy” or smelling like corn chips) and visual inspection.
Treatment depends on the underlying cause. Fleas, ticks, and parasites like mange can be treated with medicated shampoos and flea medications. Bacterial infections are usually cleaned, and a course of antibiotics prescribed. Fungal and yeast infections tend to be treated with medicated dips and shampoos. However, oral medications can be given for widely affected areas.
Prevention typically involves monthly flea treatments, as well as regular bathing and grooming. Early treatment of wounds or skin irritation can also help. In the case of ringworm, careful isolation of affected animals (and people) is best. Ringworm is highly contagious to other pets and people.
Skin Trauma (Burns, Wounds)
Trauma to the skin through burns or wounds can also cause bald spots. The hair can be lost due to damage to either the skin or hair follicle. Signs of skin traumas include visible wounds, redness, swelling, irritation, and general hair loss. Treatment depends on the underlying cause of the skin injury. Wounds are usually treated by careful clipping of any remaining fur, cleaning, and draining of infection under the skin. It can then be kept clean, sutured if very large, or treated with antibiotics and pain meds.
Using an Elizabethan (cone) collar to prevent licking and chewing will also help the skin to heal. For burns, medicated creams may help with healing along with traditional wound care. In the case of burns covering a large portion of the body, hospitalization and IV fluids and long-term palliative care may be needed. Antibiotic creams and oral medications can also help with burn-caused skin infections
In most cases, once the skin is repaired, the hair will begin to grow back in two to three months. However, if the hair follicle was badly damaged in the injury, the bald spot can be permanent. Prevention involves treating any minor wounds early on by keeping them clean and dry. You can also prevent burns by keeping dogs away from hot surfaces such as hot asphalt or open fires.
Allergies and Inflammation
Food and environmental allergens can cause a response both internally, via digestive upset, and externally, via irritation of the skin. Irritated skin may become very red and inflamed, itchy, and bothersome. As your dog scratches or rubs the irritated spot, bald spots can appear as the hair falls out. In some cases, the allergic reaction itself may lead to hair loss.
Allergies are generally diagnosed by ruling out other issues such as infections of the skin. Your vet will also take a history of potential environmental or food triggers. If your vet suspects a food-based allergen from ingredients like wheat, corn, beef, or chicken, they may suggest a food trial. Food trials involve switching your dog’s meals to a bland diet or hypoallergenic food for 6-8 weeks to see if there is an improvement. From there, your vet may have you add in potentially allergenic ingredients to see if they cause a reaction. Or, they may keep your dog on the new diet long term.
For environmental allergies, keeping the environment dust-free and your dog away from triggers can help. Your vet may also treat with a daily over the counter or prescription medication such as Zyrtec or Apoquel. In more severe cases, your vet may refer you to an allergist that can test for specific allergies. They can then provide more tailored allergy medications or even allergy shots to reduce irritation.
Prevention of allergies is hard. They usually don’t appear until a dog’s adolescence, and it may be hard to pin down the cause. Usually, trial and error over a period of weeks to months can help figure out triggers.
Physical and Emotional Stress
Changes in life circumstances can cause hair loss and bald spots. This is often due to a stress response to the new situation. External stressors like a move, or internal stressors like changes in health, lead to physical changes. Often, nutritional needs will change in these stressful periods.
Diagnosis of nutritional changes involves checking for underlying illnesses through blood work and examination. A complete history of any lifestyle changes can also narrow down causes. In many cases, supplementing the diet with extra nutrition, such as higher fat or protein diets may help. Treating underlying illness can also sometimes reverse the issue. In the cases of external stress, supplements that help with calming, as well as establishing a routine can reduce stress and support the body.
If you’re starting your dog on a sports program that can increase physical stress, plan ahead by increasing protein and fats in the diet. This can help support the body as it adjusts. Take precautions if you’re expecting a big lifestyle change. Purchasing calming supplements, establishing routines, and speaking with a trainer can help reduce stress.
Nutritional deficiencies can arise from changes in nutritional needs, such as with pregnancy and lactation. Underfeeding or poor health can also cause deficiencies and coat changes. Protein is one of the most important macronutrients needed for healthy hair growth and production. Zinc deficiency, sometimes caused by underlying illness, can also lead to hair loss and bald spots.
Nutritional deficiencies can be determined by blood work, as well as a work-up of your dog’s health history. In most cases, problems can be reversed through a change in diet or an increase in total food volume. Supplementation of protein during times of higher nutritional needs or stress can help prevent issues. Other nutrients, such as vitamin E, omega-3 fish oils, and other coat and immune health supplements may help.
Hormonal Imbalances (Hypothyroidism, Cushing’s Disease)
In older dogs, metabolic diseases may lead to changes throughout the body. A major symptom of these issues is hair loss, usually in one of two places. In the case of hypothyroidism, or low thyroid, hair loss and balding are typically along the chest and front legs. Your dog may also become more lethargic, gain weight, or have changes in appetite.
In Cushing’s Disease, hair loss occurs in a bilateral pattern along the flank and hind legs. The skin beneath the thinning hair can also change, creating a velvety texture. Dogs with Cushing’s can also exhibit symptoms such as increased thirst and urination, and changes to appetite and bowel habits.
Diagnosis of metabolic disease involves general blood work to rule out more common issues. Specific blood panels will check for these, such as TSH and Free T4 for thyroid disease, and ACTH stim and low-dexamethasone suppression tests for Cushing’s. If the diseases are present, medications to adjust thyroid and corticosteroid levels can help reverse symptoms. In most cases, the skin and hair will return to normal as the condition is treated. However, hair loss can be permanent if the disease was present for a long time, or the hair follicles were damaged.
Congenital Hair Loss
Congenital hair loss is a condition that occurs from birth, or shows up in early adulthood. This is due to a defect in the hair follicles themselves. The defect leads to bald spots that never fill in or that eventually thin over time. In most cases, the hair loss is also symmetrical. Follicles are affected the same way on both sides of the body. Underneath, the skin will be normal. It should not show any signs of inflammation or irritation present with other conditions like allergies or infections.
While it isn’t known if congenital hair loss is hereditary, many breeds, such as Dobermans, Dachshunds, Chihuahuas, and more are prone. Congenital hair loss and balding can also be linked to dogs with blue or gray colored coats. As the condition is congenital, there isn’t much that can be done in the way of treatment. That said, keeping the skin underneath clean, healthy, and free of sun damage can help. Supplements such as vitamin E and omega-3 fish oils may also help. They work by keeping the remaining hair, skin, and follicles in good condition.
A cyst is a fluid-filled growth that sits underneath the upper skin layer. Follicular cysts are cysts that affect hair follicles in particular, usually when the hair follicle is not formed properly. As they grow, they fill with sebum and other skin secretions. Since they affect the hair follicle, this leads to loss of hair and can create a bald spot. A cyst can be diagnosed through a fine-needle aspirate. Material within the cyst is studied under a microscope to rule out other issues such as infection or cancerous growths.
Cysts can be drained, but may reappear and refill with liquid over time. Surgical removal and drainage may also help, but if the follicle is completely damaged, it may not recover. Keep the area clean and dry. Preventing your dog from licking and chewing at the spot may allow the cyst to naturally recover and return to normal on its own.
Canine Ichthyosiform Dermatosis
A rare disease of Dobermans, Rottweilers, Collies, Setters, Retrievers, and Spaniels, Canine Ichthyosiform Dermatosis leads to whole-body bald spots and skin scaling. It’s unsure if the disease is hereditary in all breeds. However, there has been a connection found in some such as Golden Retrievers and Terriers. As the disease progresses, more of the skin becomes affected. It begins to lose hair and flake away, leading to large plaques of patchy, thickening skin that are painful.
Treatment is difficult as the disease is progressive and there is little that can be done to help. Medicated shampoos have helped in reducing pain and spread. However, keeping your dog comfortable is usually the best, and only, course of action at this time. Treating secondary issues, such as infections due to the large-scale skin changes, can also keep your dog more comfortable. Since there is research that the condition is hereditary, affected dogs or dogs with affected litters should not be bred.
Hair Follicle Deformities (Vitiligo, Albinism)
Deformities of the hair follicle can lead to loss of pigmentation in odd patterns. Hereditary conditions, like albinism, can also cause changes in hair pigmentation. Both Vitiligo and Albinism do not cause actual bald spots. However, the patches of white or gray hair may appear to be thinner or balding compared to the surrounding normal coat. Some breeds are more affected than others in both cases, namely Collies, Dalmatians, Belgian Tervurens, and Rottweilers.
In Vitiligo, a dog’s coat will start as a normal color and gradually lose pigmentation over time. This can occur anywhere, but is usually over the face and limbs. With Albinism, the entire coat is affected. The iris of the eye and skin on the nose and paw pads can also be affected. True Albinism is rare, but some coat colors, such as piebald coats, may actually be a form of albino expression. There is no treatment needed for these conditions. However, care should be taken to prevent sunburns in light or white-pigmented sections.
Hereditary Pattern Baldness
Mostly affecting the outer ear, Hereditary Pattern Baldness can occur in many breeds including Dachshunds, Chihuahuas, Whippets, and Greyhounds. Balding is gradual. It usually starts when the dog is still young, increasing by the senior years. In some dogs, the balding may spread down the neck and over the shoulders and chest. There is usually no treatment needed for this, however, there has been some success with experimental drugs currently being tested.
As with other breeds that experience hair loss or natural bald spots, care should be taken to prevent sunburn. Affected areas can be protected through the use of sunscreen, hats, clothing, and shade.
Bald Spots on a Dog – Wrap Up
Bald spots can be an unsightly, worrisome problem. However, knowing the signs to look out for, and providing the right treatment for any underlying conditions can help. Additional skin supplements such as omega-3 fish oils and vitamin E, as well as keeping your dog’s coat clean and brushed can keep it shiny and strong. When in doubt, a trip to your vet is always best.