What Are the Causes of Hair Loss & Spots on a Dog's Neck?

Updated November 21, 2016

You may have noticed that your dog has lost some of the hair on its neck and you may also see spots that didn't used to be there. Several illnesses or conditions in dogs can result in hair loss as well as the development of spots and sores. Consult your veterinarian for diagnosis and treatment for your pet.

Alopecia Areata and Pattern Alopecia

Alopecia areata is believed to be an autoimmune disorder that causes hair loss. When it occurs in a dog, the hair loss is usually on the neck, head and body. Dogs generally recover from this condition on their own without intervention.

Pattern baldness or pattern alopecia can cause hair loss on the neck, the ears of dachshunds and the tails of Portuguese water dogs and American water spaniels. If a Chihuahua, whippet, dachshund or greyhound has this type of alopecia, it will lose hair on the back of its thighs and abdomen.


Young male dogs such as chows, Samoyeds and Pomeranians may suffer from sex hormonal-responsive dermatosis, where hair loss occurs on the neck, the back of the dog's thighs, his tail and then travels to the trunk. The dog's skin will darken. Castration is usually the treatment.

Hormone Problems

When a dog has a decrease of adrenal hormones or an enzyme deficiency, it can lead to loss of hair on the neck, the back of the thighs and the tail, as well as darkening of the skin. This condition usually occurs when a dog is less than 2 years old. The veterinarian may prescribe hormone supplements.


When a dog suffers from a sluggish thyroid -- hypothyroidism -- it may lose hair on the neck under the chin, as well as on the backs of the thighs, the top of the tail and the sides of the body.


Basal cell tumours result in nodules on the neck, head or shoulders of a dog. The nodules are usually on a narrow stalk or base. Small nodules may resemble spots.


An ill-fitting collar can cause hair loss on your dog's neck and create spots and sore areas.

Hot Spots

"Hot spots" can occur on your dog's neck and elsewhere. These are skin irritations called moist eczema. A hot spot can be caused by a collar or by scratching or licking. The moist spot can be infected by bacteria and may ooze. The veterinarian will probably treat the condition with an antibiotic.

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About the Author

Cindi Pearce is a graduate of Ohio University, where she received her bachelor’s degree in journalism. She completed both the undergraduate and graduate courses offered by the Institute of Children’s Literature. Pearce has been writing professionally for over 30 years.