Why are some Australian shepherd puppies born fluffy and others born with short hair?

My dog is 3 months old and has mostly black hair on his back and spots on his stomach, but the hair is really short it is like the length of a chihuahuas hair. He is pure breed Australian shepherd. Will his hair grow longer? I see that black hair looks shorter than the white hair. When will he start shedding into his adult coat? Thanks in advance.

Yes it will grow longer,and the pup is young,not yet into adult hood.And around a year he will.

He's got an improper coat. He won't get a fluffy coat. Are you sure he's purebred? Might just be poorly bred.

The litter may be registered but it sounds extremely likely that the puppies were sired by two different fathers. Your dog may be HALF Australian shepherd. Registration papers are not proof that a dog is purebred.

It is just like when a mom gives birth to a few kids they dont always look they same. They may never get long fluffy hair they may always have short hair. U just wont know until they get a older. by 4 months u will start to have a pretty good idea of what the fur will look like.

If your puppy has very short hair that lays flat and not a normal puppy coat that is fluffy, then I would suspect your puppy is mixed with something else. Maybe Australian Cattle dog. Some herding dog breeders who don't register their dogs or don't care, will cross herding breeds and some do the ACD cross to get more drive into the Australian Shepherds. If your puppy has papers, I would send in a DNA to the registry and make sure the sire and dam are the ones that are on the papers. I have a 4 month old Border Collie pup and she has a fluffy coat although it isn't full length like an adult. I got her at nine weeks and she had a fluffy, stand off coat even then. BCs have less coat than Australian Shepherds and the 7 week old Australian Shepherds at the herding kennel I was at when I got her, all had longer, fluffier coats than she did. So, I definitely think your pup, if it has a chihuahua length coat, is not purebred.