Boredom
If a dog is bored, they will try to find anything that will help them kill time, and most of the time, these activities are not very wise. That may become a habit if not receiving enough activity and entertainment, and that’s when you have a problem. One of the most common ways dogs fight boredom is by eating their own or human hair.
Both are bad news. When your dog is bored, this is usually due to a lot of pent-up physical energy with nowhere to go. This is probably happening because of a lack of exercise for the mind and body. In other words, you are not playing and training enough with your dog.
Pica
When you eliminate the causes mentioned above as possibilities for hair-eating behavior, there are several involuntary causes of this action. First, one being the pica condition. It is a behavioral issue. Dogs affected by pica tend to consume non-food items. Eating human hair is one of the most common symptoms of pica, and the causes behind it can be quite complex.
It could be some kind of learned behavior or even an indirect way to avoid punishment. In many cases, a rescue dog or rehomed dogs have at least some manifestation of pica due to some kind of previous trauma and bad habits formed in the past.
Development
It is common knowledge amongst dog owners that puppies explore the world with their mouth. Given that, most puppies will try eating their own fur coat at some point as a way to explore it and understand it better. Not only that but hair will also feel interesting to eat. It moves around and gives some sort of feedback when they chew on it.
Parasites
Fleas, ticks, and other parasites can be a reason for your dog’s weird diet choices. If you notice that your pet is not only eating their hair but is also aggressively itching compulsively, then parasites can be the cause. Hair loss, redness, scabs, and sores in the area of chewing are common symptoms of parasites.
Allergies
Another environmental reason behind hair eating can be various allergies. Something in a dog’s food or surroundings can cause allergies and therefore cause itching. This will cause your pet to lick and eat hair in the area of irritation.