Skin problems and food allergies

Feline skin problems

Cats are known to be neat animals that clean their fur several times a day. In a healthy cat, the coat should be smooth and clean. Redness, excessive licking, flaking, dull hair or hair loss, and red patches on the skin can indicate skin problems. Skin disorders can be hereditary, for example atopy and allergies, or hypersensitivity reactions caused by food. Other possible causes of skin problems in cats include fungal inflammation, wounds, stress, and internal or external parasites. When it comes to skin diseases, it is essential to identify the problems and their causes: eliminate infections and parasites, remedy possible adverse food reactions, strengthen and support the immune system and skin metabolism, and curb inflammatory reactions of the skin while strengthening its protective barrier.

Adverse food reactions (AFR)

Adverse food reaction refers to an abnormal response of the body or the immune system to exposure to a food or food additive. While an intolerance may occur upon the first exposure, it can also develop slowly in stages. Adverse food reactions might appear as non-seasonal pruritus, in which case the itching cannot be associated with season-induced changes such as increased levels of pollen or dust. Other symptoms may include stomach problems like diarrhoea or vomiting, scratching, skin licking, and skin infections. In adverse food reactions, glucocorticoid therapy is usually not effective. Adverse food reactions represent a vast group of immunologic and non-immunologic disorders:

• Food allergy, food anaphylaxis
• Toxins in food (bacterial toxins, mycotoxins, pesticides, herbicides)
• Metabolic causes (lactose intolerance)
• Pharmacologic causes (histamine, chocolate, raisins, onion)
• Food idiosyncrasies and non-specific food sensitivity
• Dysbiosis (disrupted microbiota)

Atopy

Food allergies differ 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 cats is an inflammatory skin disease in which the skin’s moisture balance is upset. The main symptom of atopy is typically seasonal itching, i.e. pruritus, caused, for example, by pollen in spring or dust mites in winter. An atopic cat sensitized to environmental allergens can also react continuously to irritants such as room dust, mould, and dander. It has been determined that feline atopy is not as strongly hereditary as atopy in canines. Some cats with atopy also suffer from asthma.

When the protective layer of the skin is weakened, exposing a cat to various allergens, the risk of dermatitis increases. If the cat scratches or licks the skin, the symptoms often worsen. Natural bacteria and yeasts on the skin can start to overgrow and aggravate inflammation. Seasonal variations such as pollen can also make symptoms worse. Atopy can be managed with desensitization or hyposensitization therapy. Some atopic cats may benefit from omega-3 supplementation, topical treatment with special shampoos and cosmetics, or cortisone.

Food allergies and atopy are sometimes difficult to distinguish from one another. Before atopy treatment, it is important to eliminate ectoparasites (ear mites, demodicosis, the biting louse Felicola subrostratus, fleas) and other primary skin disorders. Adverse food reactions can be ruled out by changing the diet or by using a so-called elimination diet, which involves excluding foods suspected of causing allergies from the diet. An elimination diet typically lasts for at least eight weeks, during which the cat should not be given any food other than the agreed diet. The best elimination diet is either based on separately prepared servings of home-cooked food with proteins, minerals, and carbohydrates, or uses a specially formulated hypoallergenic veterinary cat food. Most common cutaneous adverse food reactions in cats are caused by beef, dairy, chicken products, and gluten (1).

Common skin problems in cats

Ectoparasites

The cat flea (Ctenocephalides felis) is the most common cause of itching and miliary dermatitis in cats. The cat flea is common in Europe, and flea allergy dermatitis is one of the most common skin disorders. Feline scabies is a disease caused by the parasite Notoedres cati, a species of mite that lives inside the cat’s skin. It causes severe itching, inflammation, and scaling of the skin. Feline scabies is not common in pet cats.

One parasite that is common in pet cats, however, is the ear mite (Otodectes cynotis), which can be identified by a brown secretion in the ears resembling coffee grounds. The mite is difficult to detect with the naked eye, but a veterinarian can confirm the diagnosis by examining the ear secretion under a microscope. The biting louse (Felicola subrostratus) is a small parasite that causes severe itching and hair loss.  Demodicosis, also called demodectic mange, is caused by an over population of the Demodex cati mite and is quite common, often passing from mother to kitten. For healthy cats, demodicosis may not result in any symptoms, but if a cat’s immune system is weakened, the condition can cause inflamed, bald, and itchy patches of skin. A demodicosis infection in an adult cat warrants a closer examination to determine what underlying disease is lowering the animal’s immune resistance. Although it is fairly rare, cats are also known to have contagious demodectic mange (Demodex gatoi). Cheyletiellosis (Cheyletiella blakei) causes severe flaking dermatosis and itching in cats, but it can also be asymptomatic. Cheyletiellosis can cause pruritic dermatosis in other pets and even in humans.

Fungal infection

A common cause of fungal infection in cats is Microsporum canis. Fungal infection is especially common in young and elderly cats or in cats with an impaired immune system. Fungal infection is characterised by red, scaly, and itchy patches on the skin. The coat may break at rash sites. The cat is infected by other cats or in places with fungal spores. The infection can also be transmitted to humans. If one cat is diagnosed with a fungal infection in a household with multiple cats, all of them should be treated.

Pain and stress

Sometimes pain or illness can cause skin problems indirectly. A cat often licks a sore area, such as a limb that is sore from joint pain. Feline idiopathic cystitis (FIC), an infection of the lower urinary tract, can cause pain in the abdominal area and is sometimes detected when a cat licks its belly until it is nearly hairless. The owner may be mistaken in thinking there is some other skin problem, even though the root cause is pain in the area that the cat is licking. Stress can cause a variety of skin symptoms. A cat may lick itself constantly, and the condition of the fur may deteriorate. The cause of stress should be determined in order to alleviate symptoms. Common causes of stress in cats include encountering other cats in the territory, inadequate hygiene (e.g. cat toilets are dirty or too small for the number of cats using them), and a cat’s inability to act out species-specific behaviours such as playing and preying.

Brit Veterinary Hypoallergenic

Brit VD Hypoallergenic is a specially formulated diet for cats made with ingredients with a low risk for food allergy. It is a so-called monoprotein food, which means it does not contain animal-origin raw materials other than salmon protein. Salmon meat and salmon oil are generally well tolerated raw materials with a low risk of food allergy. Brit VD Hypoallergenic contains no chicken fat, which is commonly used in pet foods as an energy source. Cats that are very sensitive to chicken can develop symptoms from chicken fat even if all the protein residues have been removed. Brit VD Hypoallergenic is gluten free, grain free, corn free, soy free, rice free, and potato free. Gluten-free yellow pea, buckwheat, and apple, which carry a low food allergy risk, have been used as sources of carbohydrates.

The Brit VD Hypoallergenic diet is rich in the omega-3 fatty acids DHA and EPA derived from plankton, which help control inflammatory reactions. Brit VD Hypoallergenic contains prebiotics and the probiotic E. faecium to support the function of the immune system. Vitamin E acts as an antioxidant for fatty acids, vitamin C stimulates immunity and the formation of collagen, and B vitamins, especially biotin, are important for the skin and coat. Zinc is an essential trace element for skin integrity. A special complex of bioactive vitamins, minerals, and omega-3 fatty acids supports skin metabolism and strengthens the skin barrier. Brit VD Hypoallergenic can be used as part of the therapeutic treatment of feline skin problems such as atopy, adverse food reactions, itching, and skin inflammation. It is also suitable for cats in which adverse food reactions are causing gastrointestinal symptoms as well as for cats with chronic gastrointestinal problems. The efficacy of Brit VD Hypoallergenic has been clinically proven.

Regardless of the cause of a skin disorder, it is important to keep in mind that all skin disorders have a negative impact on the quality of the skin barrier and increase epidermal turnover. That is 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 amounts of omega-3 fatty acids with DHA and EPA and the 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