Diseases Of Different Organs
Allergy is a reaction to an environmental material, usually protein, which has invaded the body. The commonest allergies are seen as skin reactions or as digestive disturbances. The allergies – external sources causing allergy – can result in contact dermatitis of the type often seen in West Highland White Terriers. This breed seems to react to a large number of substances which come into contact with its skin; care is necessary in choosing bedding material.
A developing allergy is complex and more consequential than irritation, intolerance or inability to digest foods. It does not develop immediately, but begins as a period of sensitization. The identification of the substance which causes the reaction requires much detective work based on a process of elimination. Household cleaners, synthetic fibres in floor coverings and clothing, and aerosol sprays may be responsible for the occasional allergic reaction in dogs.
Food-induced allergies are relatively unusual, accounting for only one per cent of all canine allergies. The detection of the food substances which provoke an allergic reaction needs patience and relies for effectiveness on a strict regime of test feeding. The dog is put on to a basic test diet, continued over five days, of simple protein sources such as all fish or all chicken. All other foods, including vitamins, minerals and other supplements, must be excluded; drinking water is the only permitted addition. The commonest food allergens are beef, wheat, and milk. protein, and these should be introduced in turn and the effect observed. If the allergic skin reaction persists on the basic diet, it may not be necessary to look beyond that, if it is an allergy at all.
Usually only small amounts of the allergen are needed to trigger an effect, and once it has been identified the offending substance must be permanently omitted from the dog’s diet. Fortunately allergies in dogs are normally confined to one substance.
With contact or inhaled allergies it is usually necessary to remove the dog from its usual environment so that the signs can recede. If the condition remains after exhausting all likely allergens, professional help and probably hospitalization will be needed.