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Writer's pictureStephanie Zikmann

Understanding the Importance of a Dog's Skin & Coat: Essential Factors to Consider This Summer for Double-Coated Breeds.

Updated: Jul 3

With a lot of conflicting information available and circulating social media it is no surprise that dog carers are left feeling confused and stressed when thinking about ways to keep their double-coated dog safe during the warmer months. If you are looking for sound advice then read on to learn more about the science of the skin and coat from a scientific, dermatological perspective.


Note: for the purposes of easy reading of this post I will refer to the dog as masculine (he/him/his).

labrador sits in a field in Summer

Table of Contents



Introduction


Much of what I'm about to say in this post is based on the information I have learned during my time studying canine and feline dermatology and cosmetology as per the DAATA Method and through research of various scientific studies accessible online (see Bibliography).


Over the last three years I have really dug into the scientific and biological factors in relation to the anatomy of the skin and coat and have been mind-blown at the many things I didn't know upon completing my Level 3 in Professional Grooming.


For the purposes of this blog post, I want to explain why the skin and coat are very much significant in protecting a dog from extreme weather conditions and the risks involved in clipping double-coated breeds - buckle up, this is a long one!


What is the significance of my dog's skin?



Diagram of the layers of a dog's skin
Photo Credit: MSD Vet Manual

The skin is a dog's largest bodily organ and is much thinner than that of a humans, ranging between 3-5 cells thick vs our 10-15 cells thick.


A dog's skin is covered in nerve endings that are constantly feeling the environment around it and in certain areas, the skin is thinner including the groin, neck, ears, legs and armpits.


When healthy, a dog's skin acts as a defence barrier to mostly all harmful organisms as well as other more physical aggressors such as physical pressure, but it needs the support of the hair/fur to be most effective in its role.


When the skin is exposed and/or damaged whether through trauma, excessive moisture and/or heat or cold, it is significantly more vulnerable to disease caused by exposure to various chemicals and pathogens penetrating through and accessing the bodies vital organs.


Did you know? The skin is also left temporarily more vulnerable after a grooming session as a result of cleaning products, drying methods and vigorous brushing demands, all of which cause friction and trauma to the hair and skin (Doare-Jouglard, 2020).

The skin consists of two layers and a third significant element, as follows:


  1. Epidermis - this layer is superficial with no blood vessels. The purpose of the epidermis is to protect the layers underneath it from external substances that may pose a threat to the dog. This layer is the thinnest of the skin layers and susceptible to damage which makes things like grooming tools quite significant. It's worthwhile noting that in areas where hair grows, the epidermis is at its thinnest (less than one-tenth of a milli-meter) vs in areas where hair does not grow (such as the nose and paw pads). The Epidermis has within it several other layers all of which contribute to it's overall function, but for the purposes of this specific post one that I wish to mention here is Melanocytes: All colours of dogs come from two main pigments of skin - Emelanin (black) and Phaeomelanin (red). When it comes to the relevance of pigmentation in regards to skin exposure, the more pigmented the skin is, the more resistant it is to ultraviolet and the the less pigmented a dog's skin, the more dangerous it is to clip them to expose the skin to direct sunlight - this typically would include all light-coated dogs, or dogs with light skin (Doare-Jouglard, 2020).

  2. Dermis - this layer nourishes the epidermis allowing it to regenerate and keep healthy through blood vessels, as well as aid in regulating the skin and body temperature of the dog. This layer is also responsible for touch sensitivity since there are also sensory nerves present here as well as the hair follicles. The dermis also produces collagen and has a responsibility to fight off potential aggressors in the environment that manage to pass through the epidermis layer. Understandably, this layer plays a really important role in the quality and health of a dog's skin and coat.

  3. Subcutis - though not technically a "layer" the subcutis (or 'hypodermis') forms the base of the two other layers and is there to support their functions. This layer contains the subcutaneous fat that is known for having a few key functions including insulation and shock absorption as well as being the reservoir for storing electrolytes, energy and fluids (Moriello, 2018).


The hair and skin work in conjunction with one another to help ensure that the dog remains cool/warm by not only working to circulate, disperse or retain air across the body (the skin doesn't sweat) but by sending signals to the brain to kickstart the appropriate physiological and behavioural response to aid in temperature control (panting/drooling, moving to a warmer/cooler space in the home, seeking hydration etc.).


Note: The anatomy of the skin is vast and incredibly complex, and so it is worthwhile noting here that while this blog post is focused on eradicating some common misconceptions around the skin and coat, there is simply not enough space to thoroughly explore all aspects relevant in relation to this topic without writing an entire book! Maybe one day...


What is the purpose of my dog's hair and how does it support his skin?



Diagram of the different hairs of a dog
Photo Credit: Canine Design Academy

A dog's coat has a natural growth cycle that protects it from all climates depending on the time of year - in colder months the undercoat (secondary hair) is retained and remains thick to help trap heat and keep the skin warm, while in warmer months it begins to thin and fall out to allow for more oxygen and air to circulate the skin thus helping the dog to cool down.


Each hair follicle on a dog consists of:


  • Primary Hairs - the umbrella that protects the next two hairs from rain thus helping the skin retain its heat but they are also responsible for protecting the skin from ultraviolet rays. These hairs have their own pores with sebaceous glands, sweat glands and arrector pili muscles.

  • Primary Lateral Hairs - these hairs are known as "guard hairs" and they help support the undercoat with thermal insulation. These hairs also have sebaceous glands. Additionally, they help to support the primary hairs by preventing knots and tangles, allowing more air to pass through and cool the skin down in warmer months.

  • Secondary Hairs - these are typically referred to as the "undercoat" amongst groomers. The purpose of the undercoat is to stabilise body temperature in a dog, they can be referred to as a heated blanket to keep the skin warm during Winter months. These hairs will shed and renew as per the dog's specific hair growth cycle (though manual intervention may also be required depending on other factors such as health, lifestyle, hormones and diet).


Should I clip my dog's coat to help keep him cool in Summer?


Generally speaking, unless for medical or significant behavioural reasons, the answer is NO.


In comparison to humans, dogs are covered almost entirely of hair/fur (with exception to rare hairless breeds) to compensate for having a thinner skin.


As mentioned already, the purpose of a dog's fur/hair is to protect the skin from the external environment around it, including:

  • extreme temperatures

  • foreign substances/chemicals

  • parasites

Without hair a dog's skin is subsequently exposed and vulnerable to various conditions, some more serious than others.


The most concerning risk to a dog's skin when exposed to the environment around it is of course cancer caused by overexposure to UV Rays (Madewell et al., 2008).

In the diagram below, you can see the comparisons between a coat that is well maintained and coats that are either compacted/matted or clipped short.


diagram of the risks in sunburn of a dog's hair and skin
Credit: Unknown. Please contact me to claim.

Clipping of double coated breeds is also known to cause short and long-term coat changes including 'post clipping alopecia'. More on this later.


In the below diagram posted by Vets4Pets, you can see how the coat works at protecting the skin in different climates - it acts as an insulator for both Summer and Winter temperatures:


Diagram of the purpose of a dog's coat in warm and cold weather
Photo Credit: Vets4Pets, Newton

The hair also has a significant communication purpose, 'piloerection' is a distinctive, yet reflexive defence signal that communicates stress, anxiety, fear but also excitement (Knowles, 2023). Piloerection also helps aid in heat retention by trapping insulated air between the standing hair strands on a dog's body (Protexin, 2023), without hair this process obviously cannot occur.

An illustration of a dog exhibiting 'piloerection' when faced with a rustling plastic bag
This illustration shows 'piloerection' in action.

Much like other specialised hairs, a dog uses his whiskers (known as 'vibrissae') to express how he is feeling (Grucsa & Flowers, 2022) while they also help with proprioception.

Since removing whiskers tends to be a common theme amongst groomers, I should also mention that science shows that 40% of a dog's brain sensors are directly linked to his whiskers, suggesting that they are more important than we might initially believe (Llera & Buzhardt, Unknown).

What is the difference between fur and hair?


First of all, "fur" and "hair" are technically the same thing - when looked at through a microscopic lens, they are the same.


In the grooming world however, the term "fur" is often used to describe dogs with double-coats that are thick and have two seasonal sheds each year, while the term "hair" is used to describe dogs with single coats that do not have undercoats that release during seasonal sheds throughout the year.


The difference between the two types of coat are basically in how they shed, how they look, how they feel and how much they grow.


Fur-coated breeds (as in double-coated breeds) can have long hair like Tibetan Mastiffs, medium hair or short hair like Shiba Inu's but they tend to have a maximum hair growth point in terms of length.


Double-coated breeds are able to stay warmer more successfully in Winter months than single-coated dogs because of their undercoats while single-coated breeds often struggle more in colder climates since they don't have the insulation from an undercoat to help retain their heat.


In many hair-coated breeds (as in single-coated breeds), regular trimming is required to maintain the coat to a reasonable length and they will also need protection against UV Rays in the Summer months..


As mentioned, single-coated breeds do not have two seasonal shedding cycles each year since they are without an undercoat, but that doesn't mean that they do not cast.


This blog post is focusing more on protecting double-coated breeds in Summer.


What dogs are at higher risk of sun burn and heat stroke?


There's a rising belief that dogs with excessive and/or thick coats are at higher risk of heatstroke, particularly double-coated breeds, but that's not strictly true.


While it is true that some dogs may be more susceptible to heatstroke than others, it is more to do with the condition of the coat and skin, rather than how long/short the coat is.


To recap: the purpose of the hair is to protect a dog's skin irrespective of weather and it is only when other factors obstruct the role of the hair that the skin is left more vulnerable, and at higher risk of heatstroke.


There is just as high a risk of heatstroke in a dog who has had his coat shaved short since it exposes the skin to ultraviolet rays, significantly increasing their chances of getting sunburnt.


Factors that may increase a dog's chances of heatstroke include:


  • dog's who are geriatric and unable to withstand regular grooming sessions to maintain a healthy skin and coat.

  • dog's who have an underlying or known medical condition that has a negative impact on the skin and coat and/or prevents a dog from being able to withstand regular grooming appointments.

  • dog's who share their homes with dog carers who are unfit to groom their dogs regularly or are unaware of how to groom their dogs effectively.

  • dog's who have experienced a significant coat change - a disrupted hair cycle thus resulting in an inconsistent coat growth.

  • dog's who are victim of severe neglect and are faced with extensive matting in need of immediate removal (this procedure is often recommended under the supervision of a Registered Vet), and will hopefully be an isolated occurrence.

  • dog's who have significant behavioural issues - a clip off may be necessary to help support a family while a dog undergoes a behaviour modification program to help relieve/resolve the problem. A clip off can remove the pressure of grooming for as long as possible giving dog carer and professional breathing space.


In the below image, a severely matted Newfoundland that was rescued by the RSPCA will need to be shaved down to prevent further suffering.

a severely matted Newfoundland dog is rescued by the RSPCA
Photo Credit: RSPCA

Successful thermoregulation relies on a coat being free from obstruction caused by knots, tangles and matting as well as having skin that is well hydrated and free from trauma and/or disease.


In all cases, it is simply not enough to solely rely on a regular grooming session to guarantee a healthy skin and coat since everything is connected.


The skin also relies on healthy nutrition with ample evidence to show the link between this and skin disease (Ward & Hunter, Unknown).


What issues might hinder successful thermoregulation in my dog?


There are various factors that contribute to the overall condition of the skin and coat as mentioned including diet, lifestyle, hormones, breed-type and even genetics. There are also external events that can have a detrimental impact on the future growth of the hair such as 'post-clipping alopecia' and 'hypothyroidism' resulting in hair thinning or 'hormonal alopecia'.


There is some evidence to suggest that castrating/dressing either a female or male dog triples their chances of developing hypothyroidism (amongst other risks) - a condition that is directly linked to coat changes and substantial hair loss (Sanborn & Katz, 2007).


And in one interesting experiment involving a three-year-old retriever, researchers embarked on melatonin therapy in an attempt to reverse 'post-clipping alopecia' caused by prior Summer shave-downs. Thankfully, treatment was successful after some time and the hair seemed to revert back to a normal hair growth cycle, but how many more dogs out there are suffering with post-clipping alopecia, unaware that there is a therapy that may help them?


Several dog carers have reported a significant change in the texture and growth of their dog's coats post-neutering to further support the above theory, and I have personally observed this myself through my work as a professional dog groomer and experience caring for my own Tibetan Mastiff's post-neutering .


Ultimately, when a dog's coat and skin is not well-maintained or is generally unhealthy he will struggle to regulate his temperature without human intervention.


If a dog's coat is unhealthy the coat will:


  • knot and become matted easily

  • appear dull, dry and brittle

  • it may begin to show unusual patterns

  • have different textures to it

  • be flaky/have dandruff

  • not shed as it should and become compacted

  • become fluffy and hard to manage


These factors will absolutely cause a dog to overheat in Summer and/or lose heat in Winter, and so it is the responsibility of the dog carer to take the necessary steps to help support their dog going forward to prevent heat stroke and get the skin/coat back to good health.


How do I prevent heatstroke and sunburn if my dog's coat is an issue?


If you are unfortunate to have a dog with an unmanageable coat/skin, then manual intervention is the next best thing, there are two ways a dog carer can help a dog with thermoregulation:


  1. Regular grooming sessions using the right tools - Regular, positive grooming sessions are paramount to ensure any dead undercoat is removed from the dog to allow air to flow through the body freely. Understanding what tools to use and which to avoid will further help to support the condition of the skin and it's worthwhile getting to know the facts about some of our most common "go-to" tools when it comes to shedding. For example, shedding tools like FURminators and/or even slicker brushes may not be the best tools to use since they risk damaging the outer, tender layer of the skin (the epidermis). While some tools may appear effective at removing excess coat, they can damage the guard hairs and surface of the skin as well! It is best practice getting familiar with alternative tools that are kinder your dog's skin but still suitable for his specific coat-type. For more on tools, consider reading my other blog post here.

  2. Clipping the coat short - Where regular grooming sessions are simply not an option, clipping a double coat short may be the only solution for the purposes of welfare and comfort. In grooming terms, this would be referred to as a 'welfare groom' and is typically only recommended for dogs that are too elderly and/or poorly to withstand long or regular grooming sessions, neglect cases, severe behavioural cases and/or where a dog carer is too elderly/poorly to commit to regular grooming sessions. To re-emphasise, clipping a double-coated breed should not be done too hastily and effort made to salvage as much of the coat length possible - Dr Sophie Bell recommends a 5 or 7 blade clip-off at the most to help give the skin some level of protection if possible (see Further Resources).


How do I keep my clipped dog safe during Summer?


When the skin is exposed to extreme temperatures it is more susceptible to parasites, infection, trauma and/or other skin disorders. Supervision and due diligence is key.


Considering:


  • Time management - walking a dog before sunrise and after sunset is best practice in Summer for all dogs, but always for dogs with little hair since it tends to be cooler and not as sunny. Equally, in colder months trying to walk a dog at the warmest points of the day and introducing them positively to jumpers can help keep them warm. There may be natural products such as sun care balms that could be used to help protect exposed skin to UV rays as well - seek out a qualified professional for guidance prior.

  • Pre-plan walking routes - walk in areas with ample shade, fresh grass and where there's less of a chance of picking up parasites.

  • Consider installing air-conditioning - if you can afford to, consider installing air conditioning in your home if it is prone to becoming too warm. Alternatively, looking at the use of fans, cooling mats and other means to help keep your dog cool in Summer is crucial.

  • Hydration - keeping your dog hydrated is imperative to ensuring that the skin and coat remain in the best condition possible. Water is also going to help keep a dog cool and so having constant access to fresh water is a non-negotiable. If your dog is prone to gulping water in warmer weather you can also try some water/ice-based mental enrichment activities to help prevent bloat.

  • Mental enrichment - if your dog is struggling with less walks, consider introducing some more mental enrichment activities indoors or in a shaded and secure garden to help keep them occupied and engaged such as Sniffaris and Digging Pits. Look up ACE Freework for further ideas.

  • Prevention - review your dog's lifestyle and consider ways that might help improve the quality of their skin and coat for the future. Consider whether there are any medical reasons why your dog struggles and seek out Veterinary advice if you haven't already addressed them and are concerned. Good nutrition also helps to keep a dog's skin and coat healthy and again Dr Sophie Bell recommends giving your dog Omega 3 & 6 Fatty oils to help substantially reduce coat/skin related issues (topically and/or orally). Lastly, being more organised and committed to regular, positive grooming sessions (if possible) can help prevent the need to shave your dog's coat in the future - feel free to contact me for support in devising a bespoke care plan for you and your dog based on my holistic grooming protocol here.


Summary

The quality of a dog's hair relies on the skin being healthy, and so both the hair and the skin play an equally significant role in ensuring successful thermoregulation occurs.


It is easy to rely on clipping a dog's coat short but without understanding the potential contraindications it can be a real risk the overall health and well-being of your dog.


I hope that this blog post has been informative and has helped you to understand the bigger picture when it comes to clipping coats for the purposes of temperature control, and if you feel there are parts of it that are outdated and/or inaccurate I would ask that you contact me directly so that I may review and update where necessary.

 

Further Resources



Bibliography


Home: Daata-ICDG Certification (no date) DAATA. Available at: https://www.daatacertification.com/ (Accessed: 01 July 2024).


Madewell BR, Conroy JD, Hodgkins EM. Sunlight-skin cancer association in the dog: a report of three cases. J Cutan Pathol. 1981 Dec;8(6):434-43. doi: 10.1111/j.1600-0560.1981.tb01033.x. PMID: 7334163.


Sanborn, L.J. (2007) Long-Term Health Risks and Benefits Associated with Spay / Neuter in Dogs, Naia Online. Edited by L.S. Katz. Available at: https://cpt-training.com/blog/recent-research-raises-concerns-regarding-early-spayingneutering/ (Accessed: 01 July 2024).


Jenkins, J.B. (2022) Thin Skin, thick hair & the canine immune system, Groomer to Groomer. Available at: https://www.groomertogroomer.com/thin-skin-thick-hair-the-canine-immune-system/ (Accessed: 01 July 2024).


Grucsa, A. (2022) Dog whiskers: What to know, WebMD. Edited by A. Flowers. Available at: https://www.webmd.com/pets/dogs/what-to-know-dogs-whiskers (Accessed: 01 July 2024).


Deepak, D., Varun, V.K. and Within, M.V. (2022) Successful melatonin therapy in a rare case of post clipping alopecia in golden retriever dog, The Pharma Innovation Journal. Available at: https://www.thepharmajournal.com/archives/2022/vol11issue6S/PartG/S-11-5-203-566.pdf (Accessed: 01 July 2024).


Baldness and hormone-related skin disorders in dogs (2022) Symptoms, Causes, Diagnosis, Treatment, Recovery, Management, Cost. Available at: https://wagwalking.com/condition/baldness-and-hormone-related-skin-disorders (Accessed: 01 July 2024).


Mair (2022) The integumentary system, Seek a K9 Massage. Available at: https://seekak9massage.co.uk/the-integumentary-system/ (Accessed: 01 July 2024).


Protexin (2023) A guide to canine and feline skin health, Improve Veterinary Practice. Available at: https://www.veterinary-practice.com/article/protexin-guide-to-skin-health (Accessed: 01 July 2024).


Llera, R. and Buzhardt, L. (no date) Why do dogs have whiskers?: VCA Canada Animal Hospitals, VCA Animal Hospitals. Available at: https://vcahospitals.com/know-your-pet/why-do-dogs-have-whiskers (Accessed: 01 July 2024).


Ward, E. and Hunter, T. (n.d.). The Importance of Your Pet’s Skin and Coat and the Role of Diet | VCA Animal Hospitals. [online] VCA. Available at: https://vcahospitals.com/know-your-pet/the-importance-of-your-pets-skin-and-coat-and-the-role-of-diet#:~:text=Diets%20rich%20in%20omega%2D3 [Accessed 01 Jul. 2024].


RVC (2022). Heatstroke in dogs and cats - prevention, symptoms and first aid tips for pet owners. [online] Rvc.ac.uk. Available at: https://www.rvc.ac.uk/small-animal-vet/teaching-and-research/fact-files/heatstroke-in-dogs-and-cats [Accessed 1 Jul. 2024].


Moriello, K. (2018). Structure of the Skin in Dogs - Dog Owners. [online] MSD Veterinary Manual. Available at: https://www.msdvetmanual.com/dog-owners/skin-disorders-of-dogs/structure-of-the-skin-in-dogs#Epidermis_v3206804 [Accessed 1 Jul. 2024].

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