Skin is the body’s largest organ, representing 12%–24% of body weight. It has multiple functions: providing a barrier and environmental protection, regulating temperature, producing pigment and vitamin D, and sensation. Anatomically, skin consists of many layers, the most important being the epidermis. In the base (basal layer) of the epidermis, cells grow and multiply, then transition from living to dead cells at the surface (stratum corneum or SC) and are eventually shed. Anything disturbing this process can lead to dry skin, known as “scale”.
Mild and uncomplicated flaky skin may be caused by:
- A poor diet.Essential nutrients, contained in high quality foods, are needed for a healthy skin and coat. Poor nutrition can be a risk in many situations, but especially during lactation, when feeding hungry pups leads to reduced nutrient and calorie intake. Changing feeding during lactation to account for this is essential. If there’s a chance that diet might be an issue, speak to your vet practice about the best diet for your pet. They may suggest supplements containing essential fatty acids to help improve skin and coat health. A large parasite burden can also reduce nutritional intake so keeping up to date with anti-parasite prevention is important.
- Irritating shampoos or topical products.Human shampoo is formulated for more acidic human skin so can dry out and irritate canine skin. Switch to a doggy shampoo, preferably recommended by your vet or a trusted groomer. Excessive bathing can also dry out your dog’s skin. Some dogs only require bathing when dirty, and certainly no more than monthly unless your vet has recommended a bathing regime for skin disease.
- Cold weather. Cold, windy weather, combined with indoor heating, dries our pet’s skin as it does our own. Your vet may recommend a moisturising shampoo and perhaps essential fatty acid supplements. Regular brushing helps stimulate natural oils.
The appearance of scale can vary a lot. A patient usually needs a hands-on examination by your vet to help differentiate between a mild, harmless dry skin and scale caused by conditions that may require medical intervention:
Mange mites can cause increased scale alongside other signs. Treatment depends on the mite involved and may include spot-on, tablet or topical formulations.
- Sarcoptes mites cause thick scale or scabbing, hair loss, and intense itching, known as Fox Mange. It can be hard to diagnose as mites may not easily be found on skin scrapes. Blood tests may help but often diagnosis is confirmed by observing improvement with treatment. Be careful if you suspect Fox Mange, as humans can be affected.
- Demodex mitescause finer scale, hair loss, but rarely itching unless they have a secondary bacterial infection. These mites can be seen on microscopic examination of skin scrapings. Your vet can recommend the best treatment option for your dog.
- Cheyletiella mitesare rarely seen in dogs. They cause thick flakes of ‘walking dandruff’ in the coat and can affect humans.
- Fleas can irritate your dog’s skin and some can have an allergy to their saliva, causing a more extreme reaction. Scaling, intense itching and hair loss may occur. You may be able to spot the fleas or the flea dirt hiding in your dog’s coat. Purchase a flea treatment recommended by your vet and don’t forget to treat other pets and the environment too or the problem will never go away.
- Skin allergiesare common, causing itchy, red, inflamed skin as well as some scaling. Occasionally, some dogs may have gastrointestinal signs as well, and ear problems are quite common. Dogs can be allergic to many things including fleas, dust, pollens, shampoos or food. Allergies are diagnosed primarily by elimination of other possible causes. Your vet can advise on regular flea prevention, food trials, and talk you through medications, shampoos and supplements that may help. Sadly, skin allergies are usually incurable, and they can be frustrating for owners and cause long-term distress to pets. We aim for the best management possible, often using many approaches simultaneously to keep the itching under control.
- Bacterial and fungal infectionsmay cause dry skin. Bacterial skin infection (pyoderma) can vary in appearance but classically appears as rings of scale around a central area of hair loss. It’s itchy and when deep can ooze and form thick scabs. Fungal infections can also appear like rings of scale (ringworm) and can be infectious to people. Antibiotic and antifungal treatments can be prescribed by your vet if diagnosed or suspected. Dogs with underlying skin allergies are more susceptible to infections so diagnosing and managing any underlying disease is crucial.
- Hormonal diseases can cause changes to skin and hair growth. Hypothyroidism(low levels of the hormone thyroxine) and Cushing’s disease(an excess of a natural steroid) can result in a dull and brittle coat, dry skin, hair loss, pigmentation and secondary infection. Both conditions can be diagnosed with blood tests but it can sometimes be challenging to interpret the results. Hypothyroid dogs may have low energy and weight gain and can be treated with lifelong medication. Dogs with Cushing’s disease will normally drink and urinate excessively, have thin skin that bruises easily, a pot bellied appearance and a higher chance of urinary tract infections. Once diagnosed, medical treatment is usually effective but again needs to be lifelong.
- Ichthyosis is an uncommon birth skin defect causing skin cells to grow abnormally. The condition is reported in a range of breeds, including the Jack Russell Terrier, Cairn Terrier, West Highland White Terrier and Golden Retriever. Fine ‘peeling’ as a pup is often unnoticed but as the patient ages, large flakes of skin come away, sometimes with underlying darkening of the skin. Diagnosis is via skin biopsy and treatment is difficult, involving special shampoos, supplements and treating secondary infections.
- Epitheliotropic lymphomais a rare skin cancer most common in boxers and golden retrievers, that in the generalised form can initially appear as dry skin. Sometimes the skin has a generalised raspberry colour and the dog may have enlarged lymph glands. The disease has other presentations including plaques and solid masses. Diagnosis is via skin biopsies, and in generalised form carries a grave prognosis even with chemotherapy.
Although dry skin can sound simple, and may be so, it is always worth getting your pet checked by a vet in case there is more to it than meets the eye.