Allergies in Pets - Atopy
A seasonal curse
Hay Fever and other common allergens can affect our pet’s health too
What is Atopy?
Atopy, or Atopic dermatitis, is an allergic skin disease that causes itching. It is one of the two most common skin allergies in dogs and cats, along with flea allergy dermatitis.
Causes of allergies in Pets
Sometimes, our pet’s immune system can "overreact" to foreign substances (allergens or antigens) in the environment.
Typical Atopy-causing allergens include:
Pollens (from grasses, trees and weeds)
Dust mites
Moulds
How do pets get Hay Fever?
It was previously thought these allergens were inhaled (similar to asthma in people).
Nowadays absorption of allergens in pets can occur through the skin, especially skin in closest contact with the ground.
Parts of your pets’ body that absorb the allergen are:
In between the toes (causing feet licking)
Under the armpits and groin (causing licking or biting)
Even the skin around the bottom where they sit on the ground (causing "scooting" - dragging the bottom along the ground)
Hay Fever vs food allergies in Pets
Atopy can be inherited or may be seasonal. Food allergies are more likely to be year-round, like Atopy Dermatitis, but that is far less common.
In puppies or young dogs with severe skin itch, particularly targeting the front of the thighs and stifles, food allergy should be considered.
Other diseases that could cause pruritus include fleas, mites, bacterial and fungal infections, and food allergies. A mild infection, stress or boredom may also be enough to initiate itching and other clinical signs.
Atopy will usually get worse every year, and a seasonal allergy can develop into a year-round problem. Older dogs can develop Atopy, particularly if they have been introduced to a new environment.
Environmental factors that cause Hay Fever in Pets:
A change in environment may kick start Atopy
A change in address (moving to a new yard)
Weather events – floods can cause a change in the microbial environment that causes or worsens Atopy
Large releases of pollen – pollens are air-borne, so a dog may react to pollen from a plant that isn't even found in your yard
It is important to know that it is common for animals to be allergic to more than one thing, which can make diagnosis an ongoing process.
Symptoms of Hay Fever in Pets
The first signs of Atopy are usually seen between 1 and 3 years of age, though this is variable.
Dogs and Cats:
Fur on top of the feet is stained brownish with saliva – caused by excessive licking
Licking and chewing Skin around the bottom, armpits and tummy (where little hair grows)
Initially this is a low grade itch, and pets will only lick in the evening when they begin to settle for the day.
When the rash and dermatitis progresses, they can stop what they are doing and lick and scratch anytime.
Scratching, chewing and licking will cause redness, hair loss, dry flaky skin and a variety of other signs.
Symptoms of Atopy in dogs:
Dogs can rub their face on the ground, and shake their heads with red, irritated ears.
Inflamed infected ears (if left untreated)
Frustratingly, examination of these ears often reveals no infection, just mild redness, yet the pet's are often really irritated. Within 1 - 3 weeks however, these ears - if no treatment is offered - become inflamed, infected and irritated. So we normally start treatment before the ears become infected.
Symptoms of Atopy in cats:
Over grooming – excess fur in the vomit or faeces
Hair loss and/or raw, inflamed skin
Lesions appear
Multiple small scabs over the body
Rubbing of the face, neck and ears may also be seen
How to diagnose Atopy in Pets
Diagnosis depends on careful consideration of all the presenting signs and ruling out all other diseases that could be causing symptoms. It is important to understand the idea of “the itching threshold".
A certain number of allergens may be well tolerated by your pet, and cause no signs of disease. But a small increase in the allergen load, may be enough to take your pet 'over the edge'. The more information you can give us, the better we will be able to correctly diagnose the problem.
Keeping a detailed history is very important. We need to know when the problem started, when it is at its worst, what treatments have been used before, etc.
Diagnosis may involve some or all of the following:
Examination
A very close-up look at the skin - looking under the microscope for signs of bacterial or fungal infection
Skin Scrapings to look for mange mites
Plucking hairs - for mites or fungi
Trial therapy for Flea Allergy or Sarcoptic Mange
Trial therapy with antibiotics or antifungal drugs
Elimination Diet Trials to test for food allergy
Intradermal Skin Test - to find out what allergens your pet reacts to. Small extracts of various allergens are injected into the skin, and reactions are observed
Blood Allergy Testing may be an alternative if intradermal testing is not possible. Referrals to specialist dermatologists are available
Some of these tests may need to be done more than once before a final diagnosis is made, or repeated later during the course of the disease.
Treatment
There is usually no complete cure, but most cases can be successfully controlled. There are numerous options available, and possibly the best result will be achieved with a combination of treatments. Given the various known causes for Atopy, we work with your pet’s particular case in coming up with the most practical treatment plan.
Please give the clinic a call if you find yourself concerned about your pet and we can decide on the best plan of action with you. Ph: 6884 9900 or after hours 0418 638 380.