All dogs shed. Double coated breeds shed enormously twice a year and it can look alarming while being entirely normal. The distinction that matters is between even shedding from healthy skin and patchy loss from skin that is not healthy.

Normal shedding

Most dogs moult in spring and autumn, triggered mainly by changing day length. Dogs living mostly indoors under artificial light often shed moderately year round instead.

Double coated breeds such as German Shepherds, Huskies, Golden Retrievers and Akitas “blow” their undercoat in large quantities over a few weeks. It comes out in clumps of soft woolly fur while the outer coat stays put.

Normal shedding is even, the skin underneath looks healthy, and the dog is not itchy.

Shedding that is a problem

Bald patches or thinning worse in some places than others. Red, scaly, crusty or thickened skin. Constant scratching, licking or chewing. Black specks in the coat, which are flea dirt. A dull, greasy or foul smelling coat. Hair that comes out with the skin looking inflamed underneath.

Common causes

Fleas, still the most common cause of skin disease, and many dogs are allergic to flea saliva, so a few bites cause a large reaction along the back and tail base.

Allergy, environmental or food related, typically causing itching at the paws, ears, armpits, belly and face. Recurrent ear infections in a dog that also licks its paws is a classic allergy picture.

Mange mites, both sarcoptic, which is intensely itchy and transmits to people, and demodectic, which usually is not itchy.

Ringworm, a fungal infection causing circular patches, which also transmits to people.

Hypothyroidism, causing symmetrical hair loss, weight gain, lethargy and a dull coat, most often in middle aged dogs.

Cushing’s disease, causing thin skin, a pot bellied appearance, increased thirst and hair loss.

Poor nutrition, which shows in the coat before anywhere else.

What helps

Brush regularly, and more often during a moult. For double coated breeds an undercoat rake removes far more than a standard brush.

Do not clip a double coated breed to the skin. The coat insulates against heat as well as cold, clipping removes that protection, and in some dogs the coat never grows back correctly. Removing the dead undercoat is what actually cools the dog.

Keep flea treatment current all year, treating every animal in the household. Feed a complete diet appropriate to age. Bathe only as often as needed, with a shampoo made for dogs; frequent washing with the wrong product strips the skin.

When to come in

Bald patches or asymmetric thinning. Red, scabby, thickened or smelly skin. Constant scratching or licking. Recurrent ear infections. Circular lesions, particularly if anyone at home has a rash. Or shedding with weight change, increased thirst or lethargy, which points at a hormonal cause.