Updated: May 29, 2020
We as people love our four-legged family members,
and want to do what is best for them. We feed them, water them, play with them, love them, and try to keep them as comfortable as possible. One debatable
subject in the dog grooming area is double coated dogs being shaved. Pet parents see their beloved dog
panting and hot with all their hair and don’t want them getting overheated, so they turn to clipping off the coat. Many groomers will say it's fine, while others will tell you it’s a terrible idea for many reasons... But where are the real answers? The PROOF for either side of the argument?
One reason many groomers are against shaving double coated breeds is because of the look and possible issues with how the coat grows back, if it grows back at all. I have personally seen these issues in my 10+ years grooming, many double coated dogs with 'damaged' hair, patches of hair that grows back, and coats that have never grown the same since being clipped. The question is though, why does this happen? Well there are 4 stages of a dogs hair life cycle and two different types of hair.
Anagen or Growth Phase
The anagen phase is the first phase of new hair growth. Dogs that do not shed heavily have a longer anagen phase. Dogs that continuously shed have shorter anagen phases. The amount of time the hair follicle stays in the anagen phase is genetically predetermined. Poodles for example spend almost 98% in the anagen state – their coat basically grows constantly . Breeds with shorter hair spend less time in this phase.
Catagen or Regressing Phase
The catagen phase is the transition phase. The catagen phase starts when the cell creation signals to stop. Hair stops growing during this phase as the outer root sheath attach to the hair.
Telogen or Rest Phase
Telogen is a rest period between the catagen and anagen phases. This period varies depending on the type of coat the dog have – in most breeds this is the longest period in the cycle. Breeds with a “Nordic” type of coat – such as Huskies and Elkhounds can spend several years in this phase. This is natures way of using the nutrition/energy in a good way – in a cold climate you need the energy to keep you warm – not to grow coat.
Exogen or Shedding Phase
The final phase, exogen, is the shedding phase. This phase occurs when the hair falls out and the follicle starts the anagen phase again. The length of the shedding phase depends on the season.
A new phase has been introduced, when we talk about coat growth phases – ‘‘kenogen’’: It applies to hair follicles that have passed the telogen stage, lost their hair fiber (exogen), and remain empty for a certain time before a new anagen phase is starting.
( The Hair Follicle: A Comparative Review of Canine Hair Follicle Anatomy and Physiology . Monika M. Welle and Dominique J. Wiener ,2016 )
A dog's hair follicles are in different stages all over their body at any given time. So, while some follicles are in the anagen stage just starting new growth, others are in the catagen, telogen and exogen phases. This is very practical because creating new hairs demands a lot of nutrition. If all the hairs fell out at the same time there would be a massive amount of nutrition needed to create a full coat again and it's going to be tough to fill that demand. But if some hairs are resting while others are created the nutritionally demand will be much lower.
We would also lose the purpose of the guard hairs if they all fell out at the same time – that would leave the dog without a way to shield themselves from the elements. Which does happen when we clip the coat short (regardless of breed!) And remember now that there is one cycle for the guard hairs and one for the undercoat/wool. In some breeds the guard hairs remain in the resting phase for 4 or 5 years. So when we clip the coat down on these breeds there is the possibility that the coat will not grow back normal for years, it just depends on what phase the hair follicles are in . Senior dogs are more susceptible to having coat issues when being clipped down because their bodies may decide the nutrition needed for growing the coat back is needed for other things. Dogs with underlying issues also run the risk of not growing their coat back because the hair follicles have stopped growing, but we don’t realize this until after we clip the coat and it doesn’t grow back. The undercoat has a much shorter resting phase - roughly 6 months. This is why we notice dogs shedding in the summer and the winter. The undercoat is thicker in the winter and thinner in the summer time because their undercoats are used for both keeping cool and staying warm depending on the season.
The dog's body can also decide to put the hair follicles in a permanent resting phase when we clip them short. This is mostly common in the ”nordic type” of breeds – but it can sometimes occur in other breeds as well. The cause of this is still unknown – one theory is that the cooling of the skin when the hair is gone gives a signal to the body to reduce the blood flow to the skin to keep the core heat and that affects the hair follicles growth cycle. Another theory is that hormones is disrupting the growth cycle. (A Colour Handbook of Skin Diseases of the Dog and Cat UK Version, Second Edition,Patrick J. McKeever, Tim Nuttall, Richard G. Harvey)
So it's not that the coat is damaged or destroyed from being clipped, it simply depends on what phase the follicles are in, and any underlying issues that cause the coat to not immediately grow back just as it was before being clipped. This may leave the dog with an ugly coat, so it is very important to educate pet parents on how the hair follicle phases work and the risks that come with shaving their dog, especially “Nordic” breeds as their guard hairs stay in the resting phase for so long.
Now that we have a better understanding of the hair follicle stages, we can discuss dog's thermal regulation.
The thermoregulation system is basically the same for all warm-blooded creatures. The body have an advanced system that is in charge 24/7 to keep the body temperature –core temperature – at the correct level. It works like a thermostat in a home, if the temperature goes too high or too low, the system kicks on to bring the temperature back to normal. Dogs’ have protoplasm, which is a vital liquid within the cells that contains proteins and vital nutrients, enzymes, and hormones necessary for life function. If the temperature gets too low or high the chemical reactions happening within the cells are altered causing damage to the cells and even death.
The coating of the body with hair is to insulate and prevent heat loss and to protect the skin. The hair insulates and prevents the heat from leaving the body. An example of that is dogs that are from colder environments because they have thick coats and small ears that are very hairy, while on the opposite dogs from hot environments have thinner coats and large smooth haired ears to make it easier for heat to evaporate from the skin. Dogs have also been altered by humans through generations of breeding with the purpose of picking characteristic in the dogs they want to carry on to the offspring. This has created much different coats than these breeds originally had many generations ago. While humans changed dogs' coats, nature left dogs with the same thermoregulation system, so now there are issues with thermoregulation because it's trying to do more work than it used to.
The ways that dogs cool off are laying on something cool, such as tile floors and dirt they have dug into, or getting airflow into the coat such as sitting in front of a fan. Dogs coats are generally thinner on their belly so when they do lay on a cool surface it helps to lower their temperature. A groomer may even do what is known as tunneling or shelling out the belly, which is where we shave the dog's whole underneath, in order to help the dog cool down without exposing the majority of the dog's body to the elements. A layer of air is trapped between the surface of the skin and the outer surface of the coat. Air has a low heat capacity and is a poor conductor of heat, therefore it serves as an insulator. The degree of insulation can be altered by increasing or decreasing the thickness of the air layer (brushing). Dogs have muscles that control their hair follicles allowing them to lift or lower their hair to allow air into the coat or to keep it out. The only problem with these cooling mechanisms is that the outside temperature must be cooler than the dogs internal temperature. If the temperature is higher outside the dog is left with panting and sweating to cool off. The main mechanism of heat loss during panting is by water evaporation from the moist soft tissue in the nose.
Heat is radiating out from the dog's body and if the dog has a dense coat, it is going to trap the warm air against the body making it harder for the dog to cool down. So if a dense coated dog is kept in full coat, regular brushing is needed to remove lose undercoat in order to help keep them cool.
The final factor to consider when shaving a dog is its environment, does it stay predominately inside or outside? Does it have shade if it is outside? A dog who spends most of its time indoors can be clipped down low without having to consider much other than the possibility of the coat not growing back for years or at all. If the dog is an outside dog then the environmental factors need to be considered before choosing to completely shave down the dog. If you live in a northern area it is not likely you will have to worry about heat stroke due to lack of shade. Whereas those located in southern states must make sure their dog has constant access to shade if it will be shaved. It is also a good Idea to keep the dog well brushed during summer time and not clip the coat too short so that they have protection from the sun.
In conclusion, there is no simple yes or no when it comes to the question, should double coated dogs be shaved? The pet parent must factor in everything,: environment, does the dog have any illnesses or skin issues, how old is the new dog, and are they willing to risk the coat not growing back quickly or at all? Once the pet parent considers all these factors they can make an educated decision on what best suits their dogs needs.