A dog losing hair on the top of the head may develop a small bald patch, thinning fur, or a larger area where the skin becomes visible.
The skin underneath may look normal, or it may be red, scaly, crusted, darkened, greasy, or irritated. Some dogs also scratch or rub the area, while others show little or no discomfort.
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Dog Losing Hair on Top of Head: Why It Happens
A dog losing hair on top of the head can be caused by skin irritation, allergies, parasites, fungal or bacterial infections, or repeated scratching and rubbing. Ringworm and mites can produce localized bald patches, while allergies may cause a dog to scratch around the head and face.
Hair loss can also occur after trauma or irritation to the skin.
The appearance of the exposed skin can provide useful clues. Redness, crusts, scaling, small bumps, discharge, or persistent scratching suggest an active skin problem, while smooth hair loss without itching may have a different cause.
If the bald area is spreading, becomes inflamed, or does not begin to improve, a veterinarian should examine the skin to identify the underlying condition.
Dog Losing Hair on Top of Head: Common Causes
Demodectic Mange
Demodicosis, or demodectic mange, is caused by an overgrowth of Demodex mites within the hair follicles.
Localized demodicosis commonly produces small, well-defined areas of hair loss with redness and scaling, and the face is one of the areas that can be affected.
Itching may be mild or absent in localized cases. This can make a small bald patch on the head look relatively harmless even though a skin problem is present. Deep skin scrapings are commonly used to identify the mites.
Related: Dog losing hair with blacks on the skin (Causes and what to do)
Ringworm
Ringworm is a fungal infection that can cause bald, scaly patches with broken hairs.
The face is among the common locations affected in dogs, making it an important consideration when hair loss appears on the head.
The skin may become scaly or crusted, although the appearance can vary. Ringworm can spread between animals and can also infect people, so a suspected infection should be properly diagnosed and managed with veterinary guidance.
Bacterial Skin Infection
A bacterial infection can affect the hair follicles and cause localized hair loss. Redness, bumps, crusting, scabs, tenderness, or discharge may accompany the missing hair.
Bacterial infections can also develop secondarily after another condition has damaged the skin.
For example, allergies, parasites, or repeated scratching can disrupt the skin barrier and allow secondary infection to develop.
Allergies and Itchy Skin Disease
Allergies can cause itching that leads a dog to scratch or rub the head. The resulting self-trauma can break hairs and create areas of thinning or baldness.
Dogs with allergies may have other signs at the same time, such as itchy ears, paws, face, armpits, or abdomen. Recurrent bacterial or yeast infections can make the skin even more irritated.
Hair loss directly over the top of the head is not enough to establish that allergies are responsible, but allergies become more relevant when the dog is persistently itchy or has several affected skin areas.
Related: Dog losing hair in patches and scabs (What it means)
Ear Disease With Scratching and Rubbing
An ear problem can indirectly cause hair loss on the top or side of the head. A dog with an itchy or painful ear may repeatedly scratch around the ear or rub its head against furniture, flooring, or other surfaces.
The resulting friction can break or remove hair. If head hair loss occurs together with frequent head shaking, ear scratching, odor, discharge, or sensitivity around the ears, the ears should be examined as part of the veterinary assessment.
Fleas and Flea Allergy
Flea allergy dermatitis is a common cause of itching and self-trauma in dogs. The classic distribution is around the lower back and tail base, but a dog with significant itching may scratch other areas, including the head and neck.
A lack of visible fleas does not necessarily exclude flea exposure. However, when hair loss is confined specifically to the top of the head, localized causes such as infection, mites, or trauma may deserve particular attention.
Related: Dog losing hair and itching (Here’s why)
Excessive Scratching or Rubbing
Sometimes the hair loss is caused primarily by mechanical damage. A dog may repeatedly scratch the same area because something is irritating or hurting the skin, or it may rub its head against a surface.
This can create a cycle in which the original irritation causes self-trauma, the self-trauma damages the skin and hair, and the damaged skin becomes even more irritated.
Finding the reason for the scratching or rubbing is therefore more important than simply treating the bald area.
Trauma or Local Skin Injury
A localized injury can damage the hair shafts or follicles and cause hair to disappear from one specific area.
The dog may have bumped or scratched its head, rubbed against a rough surface, or sustained another minor injury that was not immediately noticed.
Hair loss associated with a wound, swelling, tenderness, or crusting should be evaluated rather than assumed to be ordinary shedding.
Sebaceous Adenitis
Sebaceous adenitis is an uncommon inflammatory skin disorder affecting the sebaceous glands associated with the hair follicles.
In some dogs, particularly long-haired breeds, lesions can begin on top of the head and along the spine.
Hair loss may be symmetrical and accompanied by a dull or brittle coat and adherent white scales. More severe cases can develop secondary bacterial infection.
Because several other disorders can produce similar hair and skin changes, a skin biopsy may be needed to confirm sebaceous adenitis.
Seborrhea
Seborrhea can cause flaky, greasy, scaly, or irritated skin and commonly affects areas such as the face, back, and flanks.
Hair loss is not necessarily the primary feature, but persistent inflammation, scratching, or secondary infection can contribute to thinning hair.
Seborrhea may also occur as a secondary problem associated with another underlying skin disorder.
Hormonal or Systemic Disorders
Hormonal disorders such as hypothyroidism and Cushing disease can interfere with normal hair growth.
These conditions generally produce broader or more characteristic patterns of hair loss rather than a single small bald spot on the top of the head.
They become more relevant when the dog is losing hair in multiple areas or has other changes involving weight, energy, thirst, urination, appetite, or skin quality.
Hair loss can result from disorders that interfere with the normal growth cycle of the hair follicle.
Hereditary or Follicular Hair Disorders
Some dogs develop inherited or follicular disorders that affect how hair grows. These conditions can produce patterned or localized hair loss and may occur without significant itching or inflammation.
A veterinarian generally rules out more common causes such as parasites and infections before considering a hereditary or follicular disorder.
Some cases require a skin biopsy to evaluate the hair follicles directly.
Related: Dog Losing Near Eyes (Causes and treatment)
Dog Losing Hair on Top of Head but Not Itching
A dog losing hair on the top of the head without itching may have a noninflammatory hair-growth disorder, a localized follicular problem, or an infection that is producing little obvious discomfort.
The absence of itching is useful information, but it does not rule out conditions such as localized demodicosis or ringworm. The appearance of the skin and the pattern of the missing hair are still important.
A smooth, stable patch with normal-looking skin is different from a bald area that is red, scaly, crusted, or rapidly expanding.
Dog Losing Hair on Top of Head and Scratching
When a dog is repeatedly scratching the top of its head, self-trauma may be contributing to the hair loss.
Possible underlying triggers include allergies, parasites, infection, ear disease, or another source of skin irritation.
Continued scratching can break hairs and further inflame the skin, so the cause of the itching needs to be investigated rather than assuming that the bald patch itself is the primary disease.
Dog Losing Hair on Top of Head With Scabs or Crusts
Scabs and crusting suggest that the skin is being affected in addition to the hair follicles. Infection, parasites, fungal disease, scratching, and trauma can all produce these changes.
Ringworm, for example, can cause bald, scaly patches with broken hairs, while demodicosis can cause hair loss with redness and scaling.
A crusted or rapidly enlarging bald area should be examined, especially if it is painful, moist, or producing discharge.
When to Call or Visit the Vet
Veterinary evaluation is appropriate when hair loss on the head persists, spreads, or is accompanied by abnormal skin changes.
Contact a veterinarian if your dog has:
Hair loss that is rapidly spreading
Persistent scratching, rubbing, or pawing at the head
Redness, swelling, pain, or warmth
Scabs, crusts, sores, or discharge
Circular or sharply defined bald patches
Significant scaling or greasy skin
Hair loss around the eyes, ears, or muzzle
Recurrent skin or ear problems
Hair loss in several other areas of the body
Changes in skin color or texture
Low energy, appetite changes, weight changes, or other signs of illness
A bald area that continues to enlarge or does not improve
Immediate veterinary assessment is particularly important if the skin is painful, ulcerated, infected-looking, or rapidly deteriorating.
Dog Losing Hair on Top of Head: Treatment
Treatment is then directed at the diagnosis, such as appropriate parasite control, treatment of bacterial or fungal infection, management of allergies, or treatment of an underlying systemic or follicular disorder.
Key Takeaway
A dog losing hair on the top of the head can have a localized skin problem such as demodicosis, ringworm, infection, irritation, or trauma, particularly when the area is red, scaly, crusted, or itchy.
Less commonly, disorders affecting the hair follicles themselves can cause hair loss without much inflammation.
The location and appearance of the bald area are useful clues, but they cannot reliably identify the cause on their own.
If the hair loss persists, spreads, becomes inflamed, or is accompanied by scratching, sores, or other changes in your dog’s health, veterinary examination can help determine what is preventing normal hair growth and whether treatment is needed.