What Is the Difference Between Hair and Fur?

Seriously, a good question.

February 12, 2026

In This Article:

What’s the Difference Between Hair and Fur?

You pet your dog’s hair and you pet your dog’s fur. We tend to use the two terms interchangeably to describe that thick covering over your dog’s body. It turns out, we may be using one of these terms incorrectly part of the time. Which part? Let’s dive into which dogs have hair and which have fur — not only to use the terms properly but also to wow your next dinner guests.

Main takeaways

At the cellular level, hair and fur are the same. They are both made of the protein keratin, which also makes fingernails (and horns on other animals).
The difference between hair and fur lies in its growth rate, function, and appearance.
Hair and fur have different needs when it comes to maintenance, so knowing which your dog has can come in handy when you groom them.

What’s the difference between hair and fur?

Although the name is used interchangeably, hair and fur are actually different yet the same thing. Confused yet? Don’t worry, here’s what we mean.

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Biological composition

When you view hair and fur under a microscope, they are nearly indistinguishable. There’s no telling whether you’re looking at a strand of hair or a strand of fur without getting some further information. That’s because both are made up of keratin, a protein that is also responsible for making fingernails, feathers, horns, and the outer layer of skin. There’s quite a difference between the hair on your head and the horn of a cow which is basically due to how the keratin is structured. For softer items such as hair, it forms a spiraling helix, for harder structures like horns, it forms sheets.

Functional differences

On the cellular level, hair and fur are the same, so what’s the need for different names? Well, the like structures are functionally and often visually different due to how they are grown than what they are made of.

To dive further, dogs have two types of hair — hair that grows near continually (called underdetermined lengths or UDL) and hair that grows to a predetermined length (PDL). PDL hairs are what’s affectionately known as fur while UDLs are known as hair.

Some dogs have UDL only and some have both. The differences in lengths are due to differences in the hair growth cycle, with PDL hair spending a shorter time in the growth phase and then that hair is lost. Fur also tends to be thicker than hair due to a higher density of hair follicles.

Hair is mainly for protection while fur provides more insulation against both heat and cold.

Differences in species

Now that you may be able to picture the differences of hair and fur, let’s look at which animals have which.

Animals with fur: Double coated dog breeds like Akitas, Huskies, and Borders have fur. Most cats also have fur, as do bears, rodents, raccoons, foxes, otters, and even seals, to name a few.
Animals with hair: Humans (of course), cows, horses, pigs, whales, elephants, and single-coated breeds of dogs like Poodles and Afghan Hounds, and Siamese cats.

Texture and appearance

Keratin can take on many different appearances, even when it comes to hair. Most hair strands are coarser and longer while fur tends to be shorter and more densely packed making it feel softer. However, you’ll see varying textures even among hair and fur.

Think about all the different textures you see in a dog’s hair coat. They can be tightly curled like a Poodle, long and wavy like a Shih Tzu, thin and short like a Boxer, or thick and bushy like a Chow Chow.

Grooming and maintenance

Fur is shed on a regular basis, while hair tends to stick around longer. This means that if you have a thick-coated Husky, you’ll need to brush them regularly to remove those shed hairs, especially during the spring and fall when they’re losing a greater amount of hair. If you have a long and silky Cavalier King Charles Spaniel, you’ll be able to brush less frequently and will be more combing to remove tangles than vigorously pulling out shed hair.

Dogs with fur won’t need regular trimming, while dogs with hair will grow a much longer hair coat that may need frequent clipping to keep it out of the dog’s eyes, mouth, and rear end.

Allergies and sensitivities

Besides grooming, how does your dog having hair versus fur affect you? Well, if you suffer from allergies to dogs there may be a small difference. You see, you’re not actually allergic to your dog’s hair. Instead, you’re allergic to specific proteins in your dog’s skin cells, saliva, and urine. Those skin cells flake off, becoming known as dander, and then spread with your dog’s hair when it’s shed, causing you itchy and watery eyes, sneezing, and general unhappiness.

It doesn’t matter if your dog has hair or fur, they will have dander, but there may be a difference in the amount of dander that’s spread around your home. Because fur is shed more frequently, dogs with it may make your allergies worse due to the sheer amount of dander that it spreads around when shed as compared to dogs with just hair.

As a side note, if you’re unsure what to do with all your dog’s shed hair? Donate it. Really, it’s a thing.

Bottom line

Hair and fur are different terms for the same basic thing, a keratin structure that grows out of your dog’s skin. The difference lies in the type of hair that your dog has, with one type growing longer than the other.

When dogs have the shorter, thicker type, they’re said to have fur. Though cellularly the same, hair and fur can look and behave very different from each other, and knowing these differences can help you better care for your dog as well as your dog allergies if you have them.

Dr. Chyrle Bonk, DVM

Dr. Chyrle Bonk has been a mixed-animal veterinarian since 2010, with a special interest in rehabilitation. When she's not practicing or writing about veterinary medicine, you may find her exploring the outdoors with her family or tending to her cows, horses, chickens, or cats and dogs.