Why Do Older Dogs Shed Big Clumps of Hair?

Your dog's diet may cause patchy hair loss.
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While some amount of shedding is natural in dogs of any age, senior pets may experience psychological and physical changes that lead to major hair loss. If you notice big clumps of hair around the home, look for context clues that may help narrow down the cause of fur loss.

Medical Conditions

Medical conditions including hypothyroidism and canine Cushing's disease may cause significant hair loss in dogs. Hypothyroidism may often cause hair loss around the tail or collar area. Other symptoms include skin infection, smelly odor, lethargy, obesity and dryness. Canine Cushing's disease symptoms include increased water consumption and increased urination, increased appetite and loss of hair on the elbows, legs, belly and back. Hair loss from canine Cushing's disease can be so dramatic that your dog may only have hair on his tail and head. If you notice these patterns of shedding, talk to your vet to diagnose and treat your pet.


Not only do older dogs have different nutritional needs than young pups, they're more likely to experience difficulty when eating. For example, an aging dog may lose teeth and struggle to chew dry dog food. Senior dog foods are formulated to be easily digestible, so switching to this food may help your dog receive adequate nutrients and reverse hair loss. Talk to your vet about what type of dog food to offer your senior pet.

Behavioral Causes

Stress may play a role in your senior dog's excessive shedding. New pets, guests, family members or seasonal changes can stress out an older pet. Additional signs that your dog is experiencing stress include snapping or other moody behavior and weight loss or gain. Your vet can help determine whether your dog's shedding has behavioral causes and suggest ways for you to help alleviate some of his stress.


Regular grooming of your older dog will help you notice sudden changes to his fur and coat, such as loss of clumps of fur. For older dogs, fish oil may help reduce some shedding. Fish oil also helps with canine arthritis and brain function in older dogs. Offer a dog 100 to 150 milligrams of fish oil per 10 pounds of body weight daily.