Skin problems are among the most common reasons cat and dog owners seek veterinary advice.
Being itchy due to skin problems can cause a lot of discomfort for dogs, and
sometimes skin problems may also be a sign of other underlying health issues.
The most common causes of skin problems in cats and dogs are allergies from parasites
like fleas, environmental allergies, and adverse food reactions.
Fleas: Dogs are sensitive to fleas and can develop allergies causing serious skin disease. Flea allergies can be quite severe, even if fleas are not seen on your dog. Pets with flea allergies are allergic to the flea saliva and become very itchy after being bitten. Use of flea prevention products under the direction of a veterinarian can help prevent itchiness associated with flea allergy dermatitis. As well as treating your dog, it is important to also treat the surrounding environment. As 90% of the flea population live off your dog, treating areas where your dog spends most of its time is important e.g. pet bedding, vacuuming the house if your pet is welcome indoors.
Mange: Mange is a skin disease caused by several different species of mites. Mite infections tend to be non-seasonal – they can occur all year round. Some species of mites are found in the skin and hair follicles. The signs of a mite infection depend on which mite is present and skin lesions can occur anywhere on the body. Demodectic mange tends to cause hair loss, bald spots and sores. Sarcoptic mange causes intense itch with hair loss, reddened skins and sores.
Ringworm: Despite the name, ringworm is not caused by a worm but is a fungal infection. It’s also highly contagious and can spread to other animals and humans, so it’s important to seek advice from your vet if you suspect your dog is infected. Ringworm lesions in dogs typically appear as circular, crusty bald patches. Treatment can involve medicated shampoo or oral medications depending on the severity of infection.
Food Allergies: Dogs can become allergic to the food they eat. Food allergies in dogs are typically to protein, with the most common offenders being beef, dairy, chicken and egg. Dogs with food allergies usually have very itchy skin on the face, feet, ears and around the anus. Some dogs may also have gastrointestinal signs of food allergy including increased bowel movements and vomiting. In order to diagnose a food allergy, your dog will need to be exclusively fed a diet that it is not allergic to for a period of 8-12 weeks; this is called a food elimination trial. The diet chosen by your veterinarian may contain proteins that your dog is not allergic to or a commercial hydrolysed diet, where the proteins are so small the body does not mount an allergic react to them. When your dog is taking part in a food elimination trial, it is important not to feed it any treats or human food as this can interfere with the results.
Environmental Allergies: Environmental allergies are typically seasonal and occur in young dogs less than three years of age. Environmental allergies are usually genetic and are more common in certain breeds. Contact with environmental allergens such as pollens, grass or dust mites cause intense itch of the face, feet, ears, chest and tummy. Environmental allergies are often diagnosed as a matter of exclusion. This means that adverse food reactions, flea allergy dermatitis, infection, and other causes of skin problems may have to be ruled out before the problem is attributed to environmental allergens. Dogs can also be tested for environmental allergies with either an intradermal skin test or a blood test. Limiting your dog’s exposure to an environmental allergen is ideal but not always practical! Environmental allergies are managed with a combination of medications, medicates washes, environmental changes, and diets that support the skin.
Bacterial Skin Infections: Bacterial skin infections are often a complication when dogs are suffering from another allergy caused by fleas, their environment or food. They can occur when your dog scratches and breaks the skin allowing bacteria to infect the wound. Your vet will be able to determine the type of infection and treat it accordingly.
Yeast Infections: Yeast is commonly found on the skin of dogs, particularly in the ear canal, between the toes and around the anus. Dogs with floppy ears are most at risk, but all dogs can be affected. The yeast organisms are opportunistic; this means they take advantage to grow and infect the skin when the conditions are right. Infections can occur in high humidity (e.g. Summer), after swimming or as a secondary infection to allergic skin disease. Yeast infections cause itchy skin with hair loss, reddened areas and thickening of the skin. Skin lesions are usually accompanied by an offensive smell. Yeast is a fungus and infections are usually treated using ear ointments and medicated shampoos.
Dandruff: Dogs like people can get dandruff. Dandruff in dogs is usually caused by dry skin or skin irritation. The quality of food that we feed our dogs can reflect in their skin and coat. As the coat and skin are constantly being shed and replaced, the skin has a high need for protein. Feeding your dog a diet that contains high quality sources of protein is essential for healthy skin and coat. Diets that are high in omega 3 and 6 fatty acids, contain certain vitamins (e.g. B group vitamins) and minerals (e.g. zinc) have been proven to support healthy skin and coat in dogs.
Autoimmune Disorders: Sometimes skin conditions that won’t heal are caused by underlying immune disorders where your dog’s immune system attacks cells in its own body. Canine Lupus and Pemphigus are examples of autoimmune diseases in dogs. Skin lesions are usually severe with ulcerations and crusting, and your dog may be overall unwell. Your vet will be able to diagnose and advise treatment.