01 Seasonal Shedding Often Normal

Many dogs shed heavily in spring and autumn as their coat changes with the season. The amount varies significantly by breed — double-coated breeds such as German Shepherds, Huskies, and Golden Retrievers produce particularly noticeable shedding. This kind of hair loss is general and even across the coat, without bald patches, skin redness, or itching. Regular brushing helps manage it. If shedding seems excessive or is accompanied by skin changes, a vet check is warranted.

02 Allergies Often Itchy

Environmental and food allergies cause itching, and persistent scratching and chewing damages the coat and skin, leading to hair loss. The hair loss in allergy cases is secondary to the scratching and tends to appear in the areas the dog can reach most easily — the base of the tail, the belly, the paws, and the flanks. The skin underneath may be red, thickened, or infected. Addressing the allergy is the key to resolving the hair loss.

03 Flea Allergy Dermatitis Itchy

Dogs with a flea allergy can develop significant hair loss — particularly at the base of the tail and along the lower back — from intense scratching and chewing triggered by flea bites. Even a small number of fleas can cause a severe reaction in a sensitised dog. Consistent flea control, treating all pets and the home environment, is essential for managing this.

04 Sarcoptic Mange Very Itchy Can spread to people

Sarcoptic mange is caused by the mite Sarcoptes scabiei and is highly contagious between dogs — and to people. It causes intense, unrelenting itching, hair loss (particularly around the ears, elbows, belly, and face), and crust formation. Dogs with sarcoptic mange are often obviously miserable from the itch.

05 Demodectic Mange Often Not Itchy

Demodectic mange is caused by Demodex mites, which live in small numbers on all dogs without causing problems. Disease occurs when the immune system fails to keep mite numbers in check — most commonly in puppies whose immune systems are still developing, or in adult dogs with immune suppression from illness or medication.

It causes patchy hair loss — often around the eyes, muzzle, and forelimbs initially — without the intense itching of sarcoptic mange. It's not contagious between dogs in the way sarcoptic mange is. It requires veterinary diagnosis and, depending on severity, specific treatment.

06 Ringworm Can spread to people

Despite the name, ringworm is a fungal infection — not a worm. It causes roughly circular patches of hair loss, often with scaling, crusting, or redness at the edge of the lesion. It's most common in puppies and in dogs living in groups. It can spread between animals and to people, particularly children and immunocompromised individuals.

07 Bacterial Skin Infection (Pyoderma) Itchy

Bacterial infection of the skin — pyoderma — can cause hair loss alongside red bumps, pustules, crusting, and an unpleasant smell. It often occurs as a secondary condition, developing because the skin barrier has been broken by allergy-related scratching or another primary problem. Treating the infection alone without addressing the underlying cause typically leads to recurrence.

08 Hypothyroidism Not Itchy

The thyroid gland regulates metabolism, and when it's underactive (hypothyroidism), the effects show throughout the body — including in the coat. Hair loss in hypothyroid dogs tends to be symmetrical, affecting both flanks or the neck, and the coat becomes dull, dry, and thin. Other signs include weight gain despite no increase in appetite, lethargy, cold intolerance, and a thickened or puffed appearance to the face.

Hypothyroidism is diagnosed by blood test and is typically managed with daily oral medication. Once treated, the coat usually improves significantly over several months.

09 Cushing's Disease (Hyperadrenocorticism) Not Itchy

Cushing's disease occurs when the body produces too much cortisol — most commonly because of a benign tumour in the pituitary gland. It's more common in middle-aged and older dogs. Hair loss in Cushing's tends to be symmetrical and bilateral, often affecting the flanks and abdomen. The skin beneath may become thin, darkened, or visibly changed in texture. Other signs include a pot-bellied appearance, increased thirst and urination, increased appetite, and muscle weakness.

Diagnosis requires specific blood and urine testing. Treatment options depend on the underlying cause and should be discussed with your vet.

10 Post-Clipping Alopecia

Some dogs — particularly double-coated breeds such as Huskies, Samoyeds, and Malamutes — develop delayed or incomplete hair regrowth after being clipped. This is sometimes called post-clipping alopecia. The coat may grow back slowly, in patches, or with a change in texture. Clipping double-coated breeds is therefore generally discouraged by vets and groomers, as the coat may not return to its original condition. If regrowth is absent or very sparse after several months, it's worth a vet check to rule out hormonal causes.