Experienced and professional animal trainer provide their insights in answering this question :
A. No, dogs’ hair grow back regardless how short you cut it.

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The double coat of an Australian Shepherd also may not grow back right if you cut it too short. Furminator or any other brushes that actually cut the undercoat are terrible for aussies or any other dog with an undercoat. It often causes the topcoat to grow back weirdly which will result in undercoat burn.
While discussing grooming tips for this breed, it`s essential to emphasize that shaving your Miniature Australian Shepherd is definitely not recommended.
When an Australian Shepherd is shaved, its natural oils and protection against mother nature are removed. This may include new problems for your Aussie such as skin irritation, getting sunburnt, and similar. Secondly, shaving their fur tends to yield a more negative impact on the fur`s overall health once grown back.
Most Mini Aussies usually have medium-length coats with fur that can be straight or wavy. There are some short-coated Mini Aussies that have shorter, flatter, less feathery fur, but they are less common than long-haired Aussies.
Skin Problems: When a dog`s coat is cut too short, ingrown hairs can develop that can cause painful bumps or lesions. If the dog is already prone to skin problems such as dryness or sensitivity, shaving will only make those problems worse.
But clipping short ANY double coated breed, even once, can and often does cause serious permanent, irreversible damage to a dog`s beautiful natural coat. Further, using clippers to take off a smooth coat, flat coat or wire coat is also not recommended as it can cause other kinds of problems.
Do NOT shave this breed, as it messes up the delicate balance of the coat, which insulates them from heat and from cold by holding a layer of temperate air close to the body. The coat may never grow back the same if this breed is shaved.
Because of the breed`s extreme intelligence, visual sensitivity, and watchdog traits, Aussie puppies should be socialized in as many different environments and situations as possible.
The quick answer is, no, you shouldn`t shave your dog in summer. And this doesn`t just apply to super-furry Northern breeds, but to other double-coated breeds as well. Herding breeds like Aussie Shepherds, Border Collies and Shelties are double-coated.
Generally, most experts recommend against shaving most pets, though there are exceptions. Veterinarians often advise against shaving cats and dogs for a simple reason: Your pet`s hair isn`t like yours.
To complicate matters, the undercoat grows back fast, but the topcoat does not. It can take the guard hairs a year or two to get to the necessary length to keep your dog clean. Yes, that`s right, you could have to wait two years to undo the damage you wrought by shaving your dog.
Well, this depends on the age. Aussies are cotton ball fluffy when they`re tiny and then they loose all that fluff and have this thin, soft, wispy chicken feather coat for a while during their adolescent phase.
Postclipping alopecia is characterized by lack of hair regrowth after close clipping (surgical procedures, grooming). This disease usually affects Northern breeds such as Siberian Husky, Alaskan Malamute, but can also be seen in Golden retrievers and other breeds.
Pups are somewhat like human babies. Grooming sessions can make them very uncomfortable and even sad! In fact, it`s not at all unusual to see your pup cowering from you or just looking very sad each time you bring him back from a grooming session.
Dogs are happier after grooming due to the many health benefits and overall cleanliness that it provides. Grooming also provides an opportunity to be social with other dogs and groomers. Although some dogs may feel down after grooming, this quickly goes away and they truly appreciate the benefits of grooming.
Dog hair does grow back after shaving in most cases, whether a dog has been fully shaved or has received a fresh haircut. However, diseases such as post-clipping alopecia can result in poor hair growth. Most dogs will never be confronted with shaving (as grooming) at any point in their life.
Interestingly, while small dogs typically have longer life expectancies, mini Australian shepherds, which the AKC recognizes as the miniature American shepherd, have a life expectancy of just 12-13 years.
Australian Shepherd

According to Whistle, which manufactures GPS trackers for pets, Australian Shepherds are the 15th most likely breed to run away, with owners losing this breed an average of . 09 times per month.

Our pets` coats have several layers that are essential to their comfort in the heat. Robbing your dog or cat of this natural cooling system can lead to discomfort, overheating and other serious dangers like sunburn or skin cancer.
The mullet is a hairstyle that we Aussies have claimed as our own. It`s got history, it`s Larkin, it`s wild and these days it comes in endless variations. The hairstyle is more popular today than ever before and we believe that the mullet is truely the most “Australian” hairstyle of all time.
Height: Ideally, males should be 14 to 18 inches tall at the withers; females, 14 to 17 inches. Weight: Approximately 20 to 40 pounds.
Keep in mind the average Australian Shepherd tends to bark a lot, making it a little more challenging to get him to stop barking unless you give him the `speak` command or there is a situation in which he needs to bark to alert you.
A summer haircut may help you feel more comfortable during hot, humid summer weather, but it won`t have the same effect on your pet. In fact, cutting or shaving your pet`s fur can actually compromise your furry friend`s ability to remain cool.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Q. I have been told if I cut my Minnie Aussie Shepard; hair short, it won’t grow back, yes or no, and if true, what’s o too short
ANSWER : A. No, dogs’ hair grow back regardless how short you cut it.

Q. Russian blue mix cat – usually velvet soft coat but hair on back hind qtrs. is thinning, remaining hair seems less velvety than normal
ANSWER : A. Changes in coat appearance can be caused by a number of things. In older cats, hair loss or changes in coat and skin confirmation may indicate a metabolic issue such as thyroid problems. Cats can begin to lose hair and may also show other changes such as weight changes or appetite changes. Blood work is usually done to check for this, and most pets do very well with a daily medication treatment.

Hair loss can also be caused by mites on the skin, external parasites or even skin and fungal infections. These may cause red bumps or sores to appear on the skin in addition to the hair loss and coat changes. Your vet can take a skin scraping of the area to check for mites and infections, and a preventive flea treatment can remove any external parasites. If an infection or mites are present, your vet can also prescribe an antibiotic or topical cream to treat.

After any treatment it may take a month or two for completely bald patches to grow back in. This is normal as the skin and follicles need some time to heal prior to beginning the hair growth cycle again.

Q. I have a border Terrier that I show and someone pulled his mustache hair out two years ago. Do you know of anything I can use to get the hair to grow
ANSWER : A. These hair grown in similar way to other dog’s hair. It takes long time to grow back as they are very long but they should be back as they used to be eventually.

Q. I have a 9 month old Pit Bull. My dog has patches of hair missing and she scratching more than usual how can I stop that and make her hair grow back?
ANSWER : A. You need to establish what is causing the problem and eliminate that first. It could be external parasites, allergies or a dermatitis. Book an appointment with your vet when they open to get appropriate treatment and once treated the hair should grow back

Q. Dachshund has symetrical hair loss since aged 6 mth now 1 treated for mange had testicle removed from abdo still no better what’s next best step ?
ANSWER : A. Has hormonal disease like hypothyroidism been ruled out? That is a hormonal disease that is common causes of symmetrical hair loss, and it can be genetic, so you would see it in a dog that’s very young like yours. I agree that treating for mange was also a good idea, since that can cause hair loss as well and sometimes we can’ actually find the mites on a skin scraping.

Was a biopsy performed on the testicle? Because intra-abdominal testicles frequently turn into Sertoli cell tumors, which also cause symmetrical hair loss. If a biopsy was performed you should know for sure whether that was the cause of the hair loss or not. If the testicle wasn’t cancerous and removing it did not resolve the hair loss then the next step is a skin biopsy, unfortunately. Sounds frustrating – good luck.

Q. My puppy has a bald spot were it looks like his harness rub some of his hair away will the hair come back. Is there any thing I can do
ANSWER : A. As it’s a puppy hopefully the hair should grow back without a problem when the adult comes through. Don’t use the harness unless absolutely necessary.

Q. Cat is 10 years old. She is acting not herself. She is having twitching of the back and ears. She hisses when back is rubbed??? What could be wrong?
ANSWER : A. It is likely she has dermatitis of the skin of her back and or ears; the most likely underlying reasons are bacterial, fungal or parasitic infections. Skin scrapes and hair samples can be used to identify the underlying factors and guide treatment as regards parasite meds, antibiotics and anti-inflammatories. Some anxious cats can also become habitual overgroomers and can cause irritation to the underlying skin (would expect to see short, broken hairs in affected areas)

Q. I have a 17 year old cat and he has been shedding a lot the past 3 years. Is there anything I can do. I brush him but he doesn’t like it.
ANSWER : A. Brushing or providing objects that your cat can use to brush himself on (such as a scratching post with a brush attachment) are often the best ways to remove excess hair. If your cat doesn’t like the particular brush you use, you may want to try a different kind, or even use a warm wet washcloth to wipe your cat down with instead. This will help get rid of some loosened hairs without being as “annoying” to your cat. If he is grooming himself a lot, adding in a hairball paste to his food or placing some on his paw will help keep the hair from forming into a ball or becoming problematic as he removes the excess hair himself.

If you are seeing patches of hair loss, or any other signs of illness in addition to excessive shedding, then scheduling a senior wellness exam with your local vet is always best to check for aging-related issues which may be causing hair loss or other symptoms.