Thursday, 4 June 2015

Post Clipping Alopecia

To Clip or Not to Clip: A Summertime Conversation

As the summer heats up, so does the conversation among groomers that 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 that 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.  The 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.  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. Post 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.  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. 9

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.”

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.   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. 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. Poor re-growth is not only a cosmetic matter.  Without sufficient hair coat, a dog may be more at risk of skin cancer.  An alarming statistic published by VPI Insurance is that dogs are thirty five times more likely than humans to have skin cancer.  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!

Article Credit:  

BBird's GroomBlog

 The Art and Science of Pet Grooming