What is An Allergy?
An allergy happens when the immune system over-reacts to normal substances in the environment (e.g. dust, pollens, foodstuffs, or clothing).
Our immune system is highly effective at protecting us against disease-causing agents such as bacteria or viruses. In an allergic reaction, the immune system reacts to harmless substances, and it’s the reaction itself that becomes the problem. The reaction involves a process known as “inflammation”, which means pain and swelling of the affected area. Whether it affects skin, airways, or the lining of the bowel, this pain and swelling causes unfortunate results for our health and that of our pets. In some people, severe allergies to allergens can result in life-threatening anaphylactic reactions, and such dramatic reactions do rarely happen in pets as well.
A variety of tests now exist to diagnose allergic conditions; these include:
- Testing the skin for responses to known allergens
- Analyzing the blood to measure immune-related substances generated by allergic reactions.
- It’s also possible to make the diagnosis by avoiding exposure to the suspected allergen and seeing if the signs of allergy go away (e.g. by removing bedding that could be causing the skin to be itchy or by putting a pet onto a special diet).
Once the diagnosis has been made, treatments for allergies include allergen avoidance (e.g.
- Giving the dog a new, non-allergic bed
- The long term use of a special diet
- Medication with anti-histamines, steroids, or other anti-inflammatory medications.
More recently, immunotherapy has become popular and successful as a way of treating skin allergies. This involves regular injections of tiny, controlled doses of the substance causing the allergy, with the aim of making the immune system familiar with the substance, so that it no longer reacts so strongly. Immunotherapy can produce excellent long term results, with over 70% of itchy allergic dogs improving following the treatment.
Perhaps a better answer would be to prevent allergies developing in the first place. But how can this be done?
There’s a genetic predisposition to allergies, and in the animal world, it’s easy to use this to our advantage. Some pedigree breeds of dogs are more prone to allergy (e.g. West Highland White Terriers and Boxers).
If you want a dog that’s less prone to developing allergies, avoid these breeds, or choose a cross-bred dog.
Allergies are a huge and increasing problem, both for pets and people. Hay fever, eczema, hives, and asthma are all increasingly prevalent in humans. Allergic skin disease is astonishingly common in dogs, and I’m seeing more asthma in cats than ever before.
The problem seems to be worse in the wealthier parts of the world. In 1980, ten percent of the human population suffered from allergies. Today, the figure is thirty percent. There’s been a similar increase in the incidence of allergic diseases in pets. Nobody knows exactly what’s caused the increase, but it’s thought to be linked to something about the Western lifestyle; there’s been no corresponding increase in allergic diseases in developing countries where people’s lifestyles have not changed over many generations.
Some believe that our modern lives are too sterile as if we’ve taken the principles of infection control and “good hygiene” too far. They believe that our immune systems are not exposed to enough viruses and bacteria; following that old saying, “the Devil finds work for idle hands”, immune reactions then happen at the wrong times, in response to normal situations. Studies in the third world have demonstrated an increase in allergic disorders as a country grows more affluent and, presumably, cleaner.