About Patches of Hair Loss in Dogs

Excessive scratching can lead to hair loss.
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When men start going bald, it’s probably no cause for celebration, but it’s not harmful or abnormal, either. Not so with dogs. They are not supposed to go bald. If your dog is losing hair in patches, called alopecia, do not ignore the situation; speak with your vet.

Many Possible Causes

The appearance of your dog’s skin and coat is an indication of whether he is in good health. Hair loss and bald patches are signs there is a problem. The condition can be attributed to many causes: parasites, bacterial or fungal infection, allergies, disease, pregnancy, medications, excessive licking, sunburn and contact with an irritant. A veterinarian can diagnose the problem.


Mange, caused by mites that burrow under the skin, is the leading cause of patches of hair loss in dogs and is seen mostly in puppies, but adult dogs can have it, too. Besides the hair loss, you probably will notice red bumps and that your dog is constantly scratching. Mange in puppies might heal by itself in six to eight weeks. If not, your vet might prescribe a lime-sulfur dip and a medicated shampoo that you apply for one to six months.


Ringworm, a fungus, can be transferred to dogs from humans and vice versa. The fungus lives in the hair follicles, which causes the hair loss. With ringworm, you would typically see hair loss on the head, ears, belly, front paws and tail. The hair loss forms a circle. Treat ringworm by using an anti-fungal lotion or pet shampoo for mild cases or with a lime-sulfur dip for severe cases. You should see improvement within two weeks. If not, see your vet.


Allergies are the most common causes of skin conditions in dogs, and they sometimes cause hair loss when dogs continually scratch or chew itchy areas, causing them to lose some hair. Chewing can also cause an infection, which can cause hair loss. Flea, environmental and food allergies are the most common types. Treatment depends on the type of allergy the dog has. Your vet can help you determine the cause and the treatment.

Hot Spots

Some dogs lick their skin, which leads to what is called a “hot spot.” The skin becomes irritated and red. The hot spots cause the dog to lick the spot even more, which worsens the condition. Your vet can help you determine why this is happening. Your dog could be bored by not getting enough exercise or your dog might need to be groomed more regularly.

Always check with your veterinarian before changing your pet’s diet, medication, or physical activity routines. This information is not a substitute for a vet’s opinion.

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