​Why is my dog losing its hair?

A glossy, thick coat is a good indicator that your dog is getting everything they need from their diet, environment and lifestyle—so it can be distressing to see your dog shedding or losing hair, and sometimes difficult to know exactly why it’s happening. 

Hair loss signs in your dog 

The signs of hair loss can include your dog’s hair feeling brittle or dry, shedding more hair than normal and the appearance of bald patches, which can be circular or irregularly shaped. Hair loss might also be focused on a specific region or generalized across your dog’s whole body. 

Common causes of hair loss in dogs 

A very common cause of hair loss in dogs is an infestation by parasites such as mites, lice or fleas. In particular, if your dog is losing hair around its neck and tail, there’s a high chance it’s due to fleas. These tiny parasites can rapidly infest your dog and irritate their skin; this leads to intense scratching, which in turn can cause hair loss. 

Any skin condition your dog has, including eczema or dandruff, can eventually lead to hair loss. If your dog is uncomfortable or their skin is causing them distress, they’ll try to alleviate this by scratching or licking themselves. Over time, this can lead to hair loss as specific areas of skin are weakened and their coat pulled out. 

Hair loss in dogs can also occur due to nutritional deficiencies, the presence of which would otherwise support the development of healthy skin and hair. Keratin, the core component of hair, needs sulfur amino acids to be synthesized properly; without these, your dog might have slow hair growth, their hair may feel brittle and eventually they'll suffer from hair loss. Similarly, biotin is a key nutrient in supporting healthy skin and hair and protecting against complaints, such as hair loss. 

If your dog is experiencing hair loss, it may also be one sign of a more complex problem. Ovarian or testicular tumors, particularly in older dogs, can cause localized hair loss—the tumor secretes hormones that disturb the natural sexual cycle and growth of healthy hair.  Canine Cushing’s disease, where a developing tumor leads to the overproduction of cortisol in your dog’s adrenal gland, can also cause hair loss. Other Canine Cushing's disease symptoms could include obesity, dark patches and several behavioral symptoms. Another condition, hypothyroidism—when your dog’s hormone production is underactive—can have hair loss as one of its signs.

Protecting against hair loss 

Some of the more complex causes of hair loss, such as Cushing’s disease, must be treated by a veterinarian and closely monitored. However, you can also help protect your pet against hair loss at home:

Learning how to identify fleas on your pet may help bring attention to what is going on with your dog’s hair.

Make sure that you follow the recommended guidelines for regular, effective treatment against fleas and their eggs 

Use a dermatologically approved, specialist shampoo for your dog to alleviate any itching and therefore discourage scratching. 

Give your dog food that is enriched with nutrients to support their skin and hair development, including biotin and high-quality, highly digestible proteins 

It’s important to take your dog to your veterinarian once you’ve noticed any hair loss so they can have a thorough check-up and be given the right treatment. You can also ask your veterinarian for advice about caring for your dog’s skin and coat at any time.