To Clip or Not to Clip

by Barbara Bird CMG

As the summer heats up, so does the conversation among groomers about the pros and cons of clipping down double-coated dogs. Summer is the season for clip downs, or is it?  There are many groomers hold the position that pet owners are asking for shave downs, and we have the tools and skills to do the job. We should do it.  If one groomer refuses, another will accept the client and take home the money. Many groomers agree with pet owners that removing a thick coat is the humane response. On the other hand, a growing number of groomers are reluctant to shave some coats and will attempt to educate the client and redirect them to a less radical solution to the heat problem.

Function of the Canine Coat

Together the skin and coat of all mammals form the largest sensory organ. Hair is an appendage of the skin; it is not a separate system. The main purpose of dog hair is to regulate body temperature; it holds in body heat in the winter and dissipates heat from the sun in the summer.1, 2  The coat also provides protection from environmental elements and the sun.3  The canine coat features a compound hair follicle where there are several or many secondary (undercoat) hairs and a single primary (topcoat) hair.

2-HairshaftThe longer the hair, the more it can dissipate the heat away from the skin.  Light colored hair reflects heat, while dark colored hair absorbs and holds heat.  Black, short-haired dogs are the most uncomfortable in the heat and long, light-haired animals will be the most comfortable.2  Profuse or thick undercoat, however, will trap heat next to the skin, regardless of color.

It is a common mistake by humans to assume that dogs experience their coats the same as we would experience their coats.   Humans have eccrine sweat glands over most of the body that serve thermoregulation.  Dogs do not. Dogs pant, humans sweat.  When dogs pant on a hot day, it does not mean that they need to have their entire hair coat removed.

Here’s how one science writer puts it: “In the case of man, the removal of clothing during hot weather increases the ability to lose heat by evaporation of moisture. The dog does not have this ability and therefore his insulation is a protection to him during hot weather. If the animal loses his insulation during very hot weather, by having his coat clipped for instance, he runs the risk of not being able to maintain his body temperature. His skin temperature loss probably is not only inefficient but, since he does not perspire, he will probably increase the temperature of his skin and his body temperature as well.” 4

Coat Growth and Growth Types

Mammalian hair grows in a three-phase process: anagen, or growth phase, catagen, a transition phase, and telogen, the resting phase.  Two distinct types of canine coat can be identified by their main growth patterns: Anagen Predominant coats have a majority of hairs in the growing stage at any time. The growth stage is prolonged.  Hair growth and shedding occurs in a mosaic pattern, sprinkled throughout the body. These are coats of indeterminate length that can be trimmed with little concern for re-growth.  Examples of this type of coat are Poodles and Shih Tzu. Most of the “low shedding” breeds have anagen predominant coats.  Telogen Predominant coats will have a majority of hairs in the resting phase at any time.  This type of coat is found on Nordic breeds (aka Spitz breeds), such as Huskies, Malamutes, Chows, and Pomeranians.

The telogen phase for these dogs may be prolonged, even for years.5  Hair growth, as well as catagen transition and telogen phase is patterned and occurs in waves, often in relation to changes of light and temperature in the environment.  Characteristic of these coats is that the secondary hairs are on a much faster cycle than the guard hairs.  When coats of this type are shaved down, they sometimes present problems re-growing a new coat.

Post Clipping Alopecia – Hair Cycle Arrest

47846Post Clipping Alopecia simply means lack of hair growth after clipping.  It is a medical category coined by veterinarians to identify cases where dogs were shaved for surgeries and had significant delay in growing hair at various sites.  Post-grooming problems with hair growth are included in this category.  Although most medical references will maintain that the hair will grow back within 12-24 months, some veteran groomers have witnessed extended or permanent failure of the coat to regrow, or situations where the coat itself is permanently altered, becomes wooly, thick, fuzzy, is lacking in guard hairs, or loses color.

Dr. Linda Frank, a leading researcher in the study of canine hair and alopecia, considers post-clipping alopecia to be a condition of hair cycle arrest.  Simply put, the hairs enter the telogen phase and eventually fall out, but new growth is not initiated.5  A similar condition exists among a group of disorders called Alopecia X, which include what Malamute breeders call Coat Funk and Pomeranian breeders call Black Skin Disease.  Alopecia X disorder(s) are spontaneous, not related to clipping.6, 7

The incidence of post-clipping alopecia from grooming is unknown. Many cases go unreported and undiagnosed. About Alopecia X, the Pomeranian Charitable Trust notes that,  “The reports of cases that recoat using a particular method (and not having responded to other methods) tend to confirm the concept that we are looking at multiple causes which can produce similar results. The number of confirmed ‘Clipper Alopecia’ cases appears with greater frequency than thought previously. Commonly these cases recoat spontaneously after two years.” 8

In some cases of poor re-growth or hair loss, the dog has an underlying health problem such as hypothyroidism that has not yet been detected.  The shave down just brings the condition to light.  It is important that dogs with post-clipping alopecia be referred to a veterinarian to be tested for endocrine disorders.  These diseases are treatable and have effects on the overall health of the animal.  Alopecia X and post clipping alopecia have no established treatments.

Does the clipping itself cause the arrest of the hair growth cycle?

Inquiring minds want to know!   The cause of poor re-growth or hair loss after clipping has not been determined.  Dr. Frank says, “The plush-coated breeds may have Alopecia X or simply have been shaved during the normal telogen phase of the hair cycle.” 5  McKeever Veterinary Dermatology Clinic says, “The exact mechanism is unknown, but one theory is that decreased perfusion of hair follicles, secondary to vasoconstriction due to cooling of the skin by removal of the hair, may lead to premature termination of the growing phase. Alternatively, it may simply reflect a very long resting period before the next hair growth cycle.6

It is not possible to determine if the dog that suffers from hair loss after a shave down has a pre-existing Alopecia X that may have manifested regardless of the grooming.  Because these poor hair growth conditions are considered cosmetic and have no far reaching health concerns, they have low priority for study.  The uncertainty about the cause of post-clipping alopecia has much to do with the fact that scientists have not yet been able to identify the precise trigger that sends a hair from telogen phase into anagen phase and the creation of a new hair shaft.

Once they identify what triggers the growth message, they will be closer to knowing what is missing in hair cycle arrest. Meanwhile, it’s important to remember that while we can’t say that clipping causes hair cycle arrest, we also can’t say that it doesn’t.

Why do some coats grow back and others don’t?

We simply don’t know.  The fact that close clipping does not always result in hair cycle arrest would suggest that there are multiple factors in play that create the alopecia. The clipping must line up with some other factors.  Unfortunately, previous clipping with successful regrowth is not a reliable predictor of what might happen the next time a dog is clipped down.  Older dogs seem at greater risk, possibly because the amount of telogen hairs increases in senior dogs. Very young dogs with coats that are not fully developed also seem at greater risk.  Overall health is certainly a factor to consider.  Outdoor dogs are more subject to sunburn, which can further complicate coat growth.  None of these factors, however, can be relied upon to predict whether a particular dog is going to re-grow a shaved coat.  It’s a roulette game.  Use your clippers and take your chances!

Many rescue organizations dealing with Nordic breeds are making strong recommendations that their breed not be clipped down except in a situation of medical necessity. 9, 10  This position against shave downs is not a fad or a trend; it is a position that has evolved through decades of experience and the realization of the possible consequences of the decision to remove a whole coat.  A dog’s coat may attract a mate in the wild, but in the City, it attracts a pet owner.  Loss of the animal’s appearance can make a rescue unadoptable.  It can be devastating to a pet owner, especially when other people make assumptions about the animal being ill or poorly cared for.  Engaging the veterinarian in the decision to clip off a Nordic coat makes the procedure and extension of veterinary care, and the vet bears the burden if the coat does not re-grow.

Alternative Approaches

A thorough carding of the coat or deshedding will usually render a Nordic coat “breathable” and comfortable for the dog.  Deshedding is best done on clean, conditioned, coat.  To attempt to brush out a matted Malamute before the bath is groomer torture.  A bathing system is a must-have for working products through thick double coats. SaveUrFur has designed a system to power shed in the tub with their special products. Likewise, a recirculating bathing system will power shampoo through the double coat and use the conditioner to slide hair off the dog. By using water pressure to break through the packed coat and slide undercoat into the tub, you can save up to half your time of blow drying with hair flying.

Using silicone-based products can help remove vast amounts of packed undercoat.  Silicone ingredients dry to a glass-like surface on the hair shaft and help the loose hair slide out.  You can spray a silicone detangler on a damp coat and dry it in.  If you have a recirculating bathing system, you can add one or two ounces of silicone detangler to your conditioning phase and rinse it through.  There also deshedding products available from several manufacturers.  Good products, good water pressure and a powerful dryer will enable the groomer to work out nearly any double coat. Clipping the underbelly and underchest can help a thick-coated dog cool off without damaging the coat.  The rear end and forechest can be trimmed with a snap-on comb to further lighten the look and feel of the coat without risking coat damage, coat alteration or poor re-growth. Air can move through the coat, the dog can cool off by laying on a cool surface, and you have achieved a trimmed up “summarized” appearance. Win-Win!

REFERENCES  AND FURTHER READINGS
  1. Structure and Function of the Skin and Hair Coat in Dogs, Virginia Wells, www.petplace.com.
  2. Hair Length and Temperature Tolerance, Robert Jay Russell, Ph.D, Web Article, May 1997. http://www.lgd.org/library/hairlength.htm.
  3. Sunburn in Dogs: An Overview, author unknown, http://www.petwave.com/Dogs/Dog-Health-Center/Skin-Disorders/Sunburn/Overview.aspx
  4. Temperature Adaptation in Northern Dogs, Ted Greenlee, Northern Dog News, March 1971.
  5. Hair Today Gone Tomorrow, Dr. Linda Frank, Seminar Notes March, 2007, http://www.pomeraniancharitabletrust.org/5022/5064.html Note: An overview of canine alopecia by a key scientist in the field, written in a less technical style than her scholarly works.
  6. Post Clipping Alopecia, McKeever Veterinary Dermatology Clinic,  Eden Prairie, MN, online library, www.mckeevervetderm.com/8701.html.
  7. Alopecia X, Linda A. Frank, MS, DVM, Diplomate ACVD, Presentation to the Australian College of Veterinary Dermatology, July 2011, ANZCVS Dermatology Chapter Proceedings 2011.
  8. Recoated Pomeranian. A pictorial review of an alopecic Pomeranian restored to good coat by a groomer. Method including daily scrubbing of the skin. http://www.pomeraniancharitabletrust.org/5022/18991.html.
  9. Bay Area Rescue Keeshonden www.keeshonrescue.org. “They need their thick coats to protect their skin. A clipped coat mats more quickly and is more easily damaged. Keeshonden are also prone to a condition called “post-clipping alopecia,” which can happen any time a Keeshond is clipped. Veterinary dermatologists advise that this breed should be clipped only for medical reasons.”
  10. South Florida Siberian Husky Rescue, http://www.sibrescue.com/tip-shave.html “Shaving the dog does nothing to keep the dog cool. It just makes the human feel better when looking at the coated dog. The Siberian Husky has little to no pigmentation in its skin. If you shave the Husky, you expose it to the sun without protection. Now you have a dog that can come up with a variety of skin problems including skin cancer.”
 ADDITIONAL REFERENCES AND READING ABOUT HAIR LOSS
Alopecia X, http://www.marvistavet.com/html/body_alopecia_x.html. Categorizes Post Clipping Alopecia under Alopecia X.
Understanding Coat Funk, Daitsch, Vicki, PhD, www.malamutehealth.org, 2004. http://www.malamutehealth.org/articles/cf_understanding.htm
Lack of Hair Growth in Dogs, Dr. Rosanna Marsalla, PetPlace.com. http://www.petplace.com/dogs/lack-of-hair-growth-in-dogs/page1.aspx.
Note: A good explanation of factors which affect hair growth.
Black Skin Disease, Pomeranian Club of Canada, www.pcoc.net/black-skin-disease.htm.
Note: An overview of the disorder and reporting of several protocols that have successfully recoated affected Poms.
ABOUT HAIR
Hair-science.com. Note: Outstanding graphics and clear explanations of the structure and growth cycle of human hair.
Exogen, Shedding Phase of the Hair Growth Cycle: Characterization of a Mouse Model, Milner, Yoram, et al, Journal of Investigative Dermatology (2002) 119, 639–644; doi:10.1046/j.1523-1747.2002.01842.x
Note: First report describing a distinct shedding phase of the hair cycle, named exogen.“
Teloptosis and Kenogen: Two new concepts in human trichology. Arch Dermatol. 2004 May; 140(5):619-20
http://www.hairsite.com/hair-loss/board_entry-id-32593-page-1-order-qty-category-1.html
Note: Far from being pushed off by the underlying new anagen hair, as quite simplistically thought before, the teloptotic hair is the result of the loss of adhesion between cells of the club hair and those of its epithelial envelope.
The canine hair cycle – a guide for the assessment of morphological and immunohistochemical criteria
Tabitha Müntener, Marcus G. Doherr, Franco Guscetti, Maja M. Suter, Monika M. Welle, Veterinary Dermatology, Volume 22, Issue 5, pages 383–395, October 2011
Stenn, K. S., and R. Paus. Controls of Hair Follicle Cycling. Physiol Rev 81: 449–494, 2001.
Note: A seminal work on the description of the hair growth cycle and its study.
From Telogen to Exogen: Mechanisms Underlying Formation and Subsequent Loss of the Hair Club Fiber, Claire A Higgins, Gillian E Westgate and Colin A B Jahoda Journal of Investigative Dermatology (2009) 129, 2100–2108; doi:10.1038/jid.2009.66;
http://www.nature.com/jid/journal/v129/n9/full/jid200966a.html
Note: This very technical article gives credence to the notion that both telogen and exogen phases have distinct early and late stages, and gives an intricate insight into the shedding process.
Epithelial stem cells in the hair follicle bulge contribute skin epidermal cells during wound healing (Ito et al., Nature Medicine 2005). Ito M, Liu Y, Yang Z, Nguyen J, Liang F, Morris R, Cotsarelis G . Nature Medicine 2005; 11:1351-1354.  PMID: 16288281
Note: This study demonstrated that epithelial bulge cells, which are responsible for hair follicle renewal during the hair cycle, significantly contribute to skin wound healing. This study also demonstrated that epithelial bulge cells are required for hair follicle renewal but not for skin epidermis under normal homeostatic conditions.
Factors that control hair follicle cycling, Desmond J. Tobin BSc., PhD., FRCPath., FSB. Centre for Skin Sciences, School of Life Sciences, University of Bradford, Bradford, West Yorkshire, BD7 1DP, Great Britain.
Note: We know that hair becomes increasingly telogenic with age.
Mechanism That Controls Activation Of Stem Cells During Hair Regeneration Identified. University of Southern California. “ScienceDaily, 16 Jan. 2008. Web. 13 May 2012. http://www.sciencedaily.com/releases/2008/01/080116135214.htm.
Note: The findings suggest that hair stem cells are regulated not only by the micro-environment within one hair follicle — as has previously been thought — but also by adjacent hair follicles, other skin compartments and systemic hormones, in a hierarchical order.
New Treatments for Baldness? Scientists Find Stem Cells That Tell Hair It’s Time to Grow, ScienceDaily (Sep. 1, 2011),
http://www.sciencedaily.com/releases/2011/09/110901134641.htm.
Note: The researchers identified stem cells within the skin’s fatty layer and showed that molecular signals from these cells were necessary to spur hair growth in mice, according to research published in the Sept. 2 issue of the journal Cell.

Add Comment