Skin problems and food allergies

Dog skin problems

Itching, scaling, various skin and ear infections, hair loss, and a dull coat are common problems for dogs. The condition of the skin and fur is affected by a variety of factors. Skin disorders can be hereditary, for example atopy and allergies, or hypersensitivity reactions caused by nutrition. Other factors such as wounds, stress, and internal or external parasites can also cause skin problems. More than 30% of all veterinary visits are due to skin or ear problems. Itching is the primary symptom in 40% of skin patients. In skin diseases, it is essential to identify problems and their causes: eliminate possible adverse food reactions, strengthen and support the immune system, and curb inflammatory reactions of the skin as well as strengthen the protective skin barrier.

AFR, Adverse Food Reactions (AFR)

Adverse Food Reaction refers to an abnormal response to exposure to a food or food additive. The intolerance may occur from the first exposure or develop slowly in stages. Adverse food reactions can appear, for example, as non-seasonal pruritus, in which case the itching cannot be associated with season-induced variation like pollen, room dust, or mites. Other symptoms may include stomach symptoms such as diarrhoea or vomiting, scratching, skin licking, and ear or skin infections. About 10% to 15% of dogs have both skin and stomach symptoms. In adverse food reactions, glucocorticoid therapy is usually not effective. Adverse reactions may be caused by:

• Toxins in food, such as E. coli
• Metabolic causes such as lactose intolerance
• Food idiosyncrasies such as onions or grapes
• Pharmacologic causes such as histamine intolerance
• A non-specific food sensitization

Atopy

AFR differs from atopy in a few ways. Atopy refers to a genetic predisposition to allergies, in which the body produces immunoglobulin-E (IgE) antibodies from proteins obtained from the environment. Atopic dermatitis in dogs is an inherited inflammatory skin disease. The main symptom of an atopy patient is often seasonal itching, i.e. pruritus, during the pollen season for example. An atopic dog sensitized to environmental allergens can also react continuously, for example to room dust, moulds, or animal dandruff.

Symptoms of atopy often begin in a dog before the age of three. In elderly dogs, atopy rarely develops. The skin barrier of an atopic dog has been found to be weaker than that of a non-atopic dog (source: Evidensia). When the protective layer of the skin is weakened and the dog is exposed to various allergens through the skin, the risk of dermatitis increases. If the dog scratches or licks the skin, the symptoms often worsen. Natural bacteria and yeasts on the skin can start to overgrow and aggravate inflammation. Humid weather or other seasonal variations such as pollen can make symptoms worse. Immunotherapy is sometimes used with the objective of strengthening the immune system by administering the allergen either orally or by injection. The goal is to tolerize the immune system with the allergen that previously caused the reaction.

Food allergies and atopy are sometimes difficult to distinguish. The estimated prevalence of AD in dogs is approximately 10–15%. Before atopy treatment, it is important to eliminate ectoparasites (fleas, mange, mites), other primary skin disorders (pyoderma), and adverse food reactions by changing the diet or performing an elimination diet test. In this case, foods suspected of causing allergies are excluded from the diet. The so-called elimination diet often lasts for at least eight weeks. During the elimination diet, the dog should not be given any food other than the agreed diet. The best elimination diet comprises a separately prepared portion of home-cooked food, including added proteins, minerals, and carbohydrates, or a complete hypoallergenic veterinary diet. Most common cutaneous adverse food reactions in dogs are caused by beef, dairy products, chicken, and gluten (1).

Common skin problems in dogs:

Otitis externa

Ear infections are a fairly common problem for dogs. There are several causes of otitis either related to diseases or due to external factors. In ear infections, normal yeast and bacteria in the ear canal can start to multiply, but overgrowth might not be the real cause of the inflammation. The ear structure can predispose it to otitis externa. Reasons include, for example:

• parasites
• skin barrier weakened by atopy or food allergy
• tumours in the ear canal
• continuous wetting of the ears
• floppy ears that are not ventilated
• hairy ear canals or structural stenosis
• hypothyroidism or diseases affecting the cornea of ​​the skin

When a dog has otitis, he might scratch his ears, may keep his head tilted, the ears might have a bad odour, and there is often redness or a secretion from the earlobe or ear canal. An inflamed ear can be very sore and sensitive to the touch. Your veterinarian will be able to determine the best treatment for ear infections. Usually, the ears have to be cleaned regularly and sometimes the ears have to be medicated. The cause of ear infections needs to be identified, since ear infections caused by food allergies might not be cured unless changes are made to the diet.

Furunculosis

Furunculosis is an inflammation of the paws between the dog’s toes. The dog tends to lick the inflamed toes and may limp. Furunculosis can be caused by external and internal factors. Internal factors include food-induced reaction or stress reflected in the constant licking of the paws. External causes can be fungal or bacterial inflammation of the skin. The paws should be kept clean and dry and the hair between the footpads kept as short as possible. Licking should also be prevented. If furunculosis is suspected to be related to food allergies, the cause should be identified.

Hair loss

 Seasonal hair loss is normal for a dog, but sometimes hair loss is excessive and the coat may be brittle and dull. Hair loss can be related to diet and health. Hair loss can be caused by, for example:

• allergies that cause the skin to flake and the dog to scratch
• external or internal parasites
• dietary insufficiencies (e.g. B vitamins, zinc, biotin, fatty acids)
• changes in hormonal function
• diseases such as Cushing's disease or hypothyroidism

Hot Spot

Hot spot dermatitis is associated with moisture, often swimming, and is common especially in dogs with dense fur and a thick undercoat. Hot spot dermatitis is caused by streptococcal bacteria that are naturally present in the dog’s skin. Moist, thick, and dirty fur as well as scratches on the dog’s skin promote the growth of bacteria and the development of inflammation in areas where the skin is damaged. Hot spot dermatitis is a red, swollen, and purulent area on the dog’s skin and might not always be immediately noticeable under a thick coat. The dog may scratch or lick itself, and the skin is itchy and sore. The hot spot area can quickly expand into even palm-sized patches on the dog’s skin.

As first aid, shave the hair off around the hot spot to allow the skin to breathe. The skin can be very sore, and sometimes the dog must be taken to the veterinarian for sedation to get the hair shaved. Inflamed skin should be cleaned with a disinfectant suitable for dogs. The area can also be washed with a disinfectant shampoo. The dog must not be allowed to lick or scratch the area, so you may need to use a collar until the skin has healed. Prolonged inflammation is often treated with antibiotics or cortisone. If the hot spot is recurring, the root cause must be determined.

Brit Veterinary Diet Hypoallergenic

Brit VD Hypoallergenic food for dogs contains none of the most common allergens. It is a so-called monoprotein food, i.e. it does not contain animal-origin raw materials other than dried salmon meat and hydrolysed salmon protein. Salmon meat and salmon oil are generally well tolerated raw materials. Brit VD Hypoallergenic also contains no chicken fat, which is often used in pet foods. Dogs that are very sensitive to chicken can also develop symptoms from chicken fat even if all protein residues have been removed. Brit VD Hypoallergenic food is gluten free, grain free, corn free, soy free, and rice free and contains no potatoes. Yellow pea, buckwheat, and apple have been used as sources of carbohydrates without gluten, the most common allergen.

Brit VD Hypoallergenic food contains prebiotics and probiotic E. faecium to support the immune system. It is also rich in omega-3 fatty acids DHA and EPA, which help control inflammatory reactions. Vitamin E acts as an antioxidant for fatty acids, vitamin C stimulates the functioning of the immune system and the formation of collagen, and B vitamins, including biotin, are important for the skin and especially the coat. Zinc is a particularly essential trace element for skin integrity. Brit VD Hypoallergenic can be used as part of the therapeutic treatment of canine skin problems (e.g. atopy, adverse food reactions, otitis externa). It is also suitable for dogs with adverse food reactions causing gastrointestinal symptoms as well as in chronic gastrointestinal symptoms (e.g. diarrhoea, IBD). Brit VD Hypoallergenic has clinically proven efficacy.

Regardless of the cause of a skin disorder, it is important to keep in mind that all skin disorders have a negative impact on skin barrier quality and increase epidermal turnover. That’ why an inseparable part of the treatment of any skin disorder is nutritional support of skin metabolism, which is best provided with a special diet containing sufficient amount of omega-3 fatty acids with the DHA and EPA, vitamins, minerals, and amino acids that are important for skin metabolism. Brit VD Hypoallergenic is an ideal choice.

1) Ralf S. Mueller, Thierry Olivry, and Pascal Prélaud. Critically appraised topic on adverse food reactions of companion animals (2): common food allergen sources in dogs and cats. BMC Vet Res. 2016; 12: 9. Published online 2016 Jan 12. doi:  10.1186/s12917-016-0633-8