Like many other species, humans and dogs live inside an incredibly hard-working organ called skin (from the Greek ‘derm’). The skin is the largest organ of the body and is capable of many complex tasks.
The skin is contiguous with the gut: imagine following an imaginary line from the surface of the skin on the outside of the body into the mucous membrane-lined mouth, through the oesophagus, stomach and small intestine, the colon or bowel and eventually the anus where it comes into contact with the outside world again. This illustrates firstly that the gastro-intestinal tract or gut is open to the outside world—and thus infection—at both ends i.e. the mouth or oral cavity and the anus and is indeed part of the entire organ we call our skin.
I am certain that several of my readers have doggos with never-ending skin issues. You may have embarked upon this reading journey in the hopes of learning more about pesky skin problems that just can’t be fixed by medicine. But first having a good understanding of the complex nature of the skin goes a long way to understand the issues it encounters.
Functions of the skin
Protection: The primary and most obvious function of the skin is protection: a living gift wrap if you will. Keeping all our bits safely inside—as important as that appears —is only one of the brilliant skills of the skin.
Temperature control: Especially important for our pets, the skin plays host to billions of strategically placed and regionally adapted hair follicles. Interestingly, there is a primary hair follicle surrounded by 3 to 15 secondary hairs. These are connected to an arrector pili muscle that, when contracted, causes the hairs to stand up straight and trap warm air (in humans we see this as goosebumps). In addition, sebaceous glands (present in larger numbers near the paws, back of the neck, rump, chin and tail root) assist in keeping the hair oiled and water-resistant, the skin soft and pliable.
Senses: Because the skin contains millions of nerve endings, it can sense temperature and texture.
If this is not enough to impress, the inner and outer layers of the body have evolved to perform very specific tasks in specialised zones. For example, the skin cells in your pup’s feet have evolved to provide a thick and undulating layer that protects against heat and puncture wounds whereas the cells lining the gut have evolved to discriminate between good and bad bacteria (immune function), maintain water and electrolyte balance and absorb nutrients.
Now just to make things more impressive, the outer layer of your dog’s body (outer skin and inner mucous membranes) has developed a symbiotic relationship with bacteria that assist them to function optimally.
Lumpy bumps arise
For ease of understanding let’s divide those nagging skin issues broadly into two categories
The first is systemic; this includes problems arising from internal imbalances like allergies, hormonal disruption, stress responses, genetic predisposition, poisoning and systemic failure.
The second category explores the possibility that the problem is due to external aggravations including chemicals and allergens making direct contact with the skin.
Despite the division, these two categories act synergistically – in other words they have separate mechanisms of action but the action of each one invariably affects the other.
Systemic causes:
For the purposes of this article, the first category will not be explored in depth as there is an extensive amount of information to be discussed for each of these issues.
Systemic disease must be tested for and diagnosed by a vet with access to laboratory facilities. A few simple tests can rule out Diabetes, Cushing’s Syndrome, Hypothyroidism, Addison’s Disease etc. These are conditions driven by hormonal fluctuations and several treatments can control the resulting problems. Allergen tests search for certain antibodies in the blood as well as skin reactions to intradermal allergen injections.
Apart from systemic disease, diet is possibly one of the biggest culprits that cause skin problems in your pets. We are living through a time when the use of toxins in food production seems not only commonplace but acceptable. Genetic modification, pesticides, herbicides, heavy metals, hormones and man-made carcinogens all find their way into the food chain. It is interesting to note that more than one-third of all agricultural crops are grown to feed farmed animals. Those crops are also intensely treated with huge amounts of pesticides. Just look up Glyphosate, Atrazine and Dicamba to name a few and consider how these chemicals make their way up through the food chain from crop to farm animal to the proteins we are feeding our pets (and ourselves).
It may be impossible to know exactly what your pet’s food contains but it stands to reason that these toxins eventually reach our plates and cause untold amounts of trouble in our systems.
The best way to find out which foods your pet is allergic to is by excluding certain regular dietary staples for a few months to see if changes occur. When it comes to allergic skin responses, some of the usual suspects are dairy, corn, rice, lamb, pork, soy, chicken, beef, eggs and wheat gluten (all of these are intensely farmed throughout the world). Add to these a whole range of chemical additives like preservatives, stabilizers, artificial colourings, fragrances and dyes. Pet food is a contentious subject and many people have strong opinions about their personal choices. Speak to nutrition specialists and holistic vets who can offer some great advice about commercial foods that are free from the allergens that may be causing problems.
Stress and the release of stress hormones into the body is also an entire subject on its own. Like humans, pets can experience stress in different ways. And as sociable animals, pets often feel our stresses just as negatively as we feel them ourselves. Long-term exposure to stress not only affects behaviour but also leads to systemic disease.
Systemic issues often occur bilaterally i.e. both ears or left and right flank etc. Some external skin issues that involve an overgrowth of bacteria or yeast where the body’s immune system is failing can be successfully treated with systemic antibiotics and medicated shampoos.
But, as this is a vet nurse article, let’s explore the external aggravators in a little more depth.
External causes:
As a vet nurse, I spend a lot of time in discussions with my clients when medicine has failed to correct skin problems. External challenges to the skin can often be seen unilaterally i.e. on one side of the body only. Becoming more aware of your pet’s daily habits goes a long way to understanding what they are exposed to.
Household chemicals
To clean, sanitise or disinfect? Cleaning removes physical dirt and dust from surfaces whereas sanitising temporarily removes bacteria. Disinfection kills bacteria.
It is a sad reality that consumers have been brainwashed into buying and using an array of toxic chemicals (primarily used in hospitals to kill harmful pathogens) to ‘clean’ their homes when the ingredients in many household cleaners are disinfectants rather than just cleaners. We have been indoctrinated by marketing tactics employed by companies to believe that powerful and toxic chemicals are the accepted way of cleaning. We believe that cleaning equals sterilising and although it is very important to remove harmful bacteria in our homes, it is unreasonable to believe the home can be sterile.
Considering the unsettling rise in the number of microbes that are becoming resistant to cleaning compounds and anti-biotics, it seems logical that flushing tonnes of these products into our waterways through daily household use should be avoided. Many environmentally-friendly cleaning options exist on the market but simple and effective sanitising (not sterilising) options are right there in your cupboard. Things like vinegar and bicarb, salt and even hot water can be used to sanitise most surfaces. Check out my article on anti-microbial resistance here for more on this subject.
Most commercial cleaning products contain harsh and harmful ingredients that can negatively affect your own and your pet’s skin. Bleach (sodium hypochlorite), hydrogen peroxide, ammonia, formaldehyde, phenols, isopropyl alcohol, Phthalates, QACs (quaternary ammonium compounds) and non-ionic and anionic detergents are all toxic to animals and we don’t often consider how much exposure our pets have every day to these chemicals. Many products rely on strongly acidic or alkaline ingredients as a method of cleaning. Your dog’s outer skin pH should be maintained at 6.5 to 7.5 to ensure the presence of ‘friendly’ bacteria that assist in protecting against more harmful types of microbes.
The products listed above are volatile which means accidental inhalation can cause severe irritation to the throat and lungs. Ingestion is toxic but your pet’s skin is coming into contact with them daily just by walking around the house or lying on fabrics impregnated with these compounds.
Cleaning products used on floors in the home can affect the skin on your dog’s paws or, if they have a habit of lying on cleaned surfaces, one may see skin issues on the belly and chest.
Washing powder and laundry detergent
Now let’s get a little technical. Detergent (otherwise known as a surfactant) breaks the surface tension of water and attracts grease and oils to make cleaning easier (consider how dry your hands feel after washing the dishes). Remembering the vital oils in your dog’s coat which protect the skin, detergents cannot discern the difference between good oils and fatty stains. Detergents strip natural oils from your pet’s skin, leaving it dry and irritated.
Enzymes are another ingredient in washing powders and liquids. A detergent enzyme is a protein that reacts with water and stains (protease breaks down proteins, amylase breaks down starch, and lipase breaks down fats/oils). Another commonly used enzyme is meat tenderiser and has the same catalytic effect. The reason why it is so difficult to find washing powder without enzymes is they tend to work well to remove stains in cold water, thus reducing the need to use extra energy by heating water for laundry. But, in the same way that detergents can’t tell the difference between good and bad oils, neither can enzymes. So apart from breaking down stains, they also break down oils and proteins in your dog’s skin. Without getting more technical, certain enzymes in washing powder inhibit bacteria as well. This may sound like a good thing but remembering the trillions of friendly bacteria situated in the layers of the skin that compete with pathogens, killing them is counter intuitive.
Continual exposure of the skin to enzymes can often lead to dry, itchy patches all over your dog’s body.
So what is the solution?
Some of my readers have no doubt exhausted the veterinary laboratories with all the tests done on their poor, itchy pups. You may have ruled out systemic disease and tried various diets but your dog’s skin is still causing discomfort and pain. It may be time to create an inventory of all the chemicals your dog’s skin is exposed to daily. Ask yourself, does my pet swim in a chlorinated pool or rub up against something regularly in the house? Do they lie in the hot sun for extended periods? Do they lick or ingest eat strange things?
Also, look up the ingredients of all the sprays and liquids you use in the house—you may be surprised at their negative effects. Change your washing powder to non-biological and/or rinse everything at least twice after washing (clothing and surfaces). Stay away from cleaning products that promise the destruction of 99.9% of germs or products containing chlorhexidine, QACs and formaldehyde (those are the last bastions used by hospitals to kill harmful microbes and we are unwittingly creating superbugs at home by negligent use).
Your pet’s immune system—aided by a diet that includes an array of vitamins and minerals from sources other than meat—has the power to protect against a myriad of problems. Employing harsh chemicals on your pet’s skin, be it in the form of detergents or anti-microbials should only be considered when skin issues are overpowering the body’s innate power to heal itself. The trick is to keep your pet holistically healthy from what they eat, and how they exercise to what they come into contact with daily in their environment.
Your pet’s body, just like your own, is an entire universe of complex interactions. Each system works symbiotically with the next and disease can throw the entire unit and its parts off balance.
Remember to think holistically when it comes to your beloved friend and here’s hoping they remain healthy and happy and itch-free for years to come.
©Liz Roodt 2024