Skin Allergies

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Allergic skin conditions form the largest and potentially most complex and frustrating medical conditions that our pets may suffer. They may start as early as a few months of age or start to manifest for the first time in ageing pets. There are a few major categories that cause pet skin allergies. Each of these categories, generally speaking, affects different areas of the body.


This is the most common form of allergy that our pets suffer. Atopy refers to pets that suffer allergies to “inhaled” allergens such as pollens, dust and dust mites. Dogs are particularly prone. They inhale these allergens in through the respiratory system and actually react with allergic, inflamed skin. Characteristically, the most commonly affected sites are the ears and the paws. These areas become inflamed, red and itchy. The dog starts to scratch, lick and rub. Secondary to this inflammation and self trauma, bacteria and or yeast that lives on the skin surface in all animals, then starts to replicate and cause an ongoing infection. This infection is what we call “secondary” to the inciting allergy.


Obviously a very common cause of allergies in pets. Characteristically they most commonly affect the back near the base of the tail. Some dogs and cats are not overly sensitive to fleas and will only start to scratch once a large number of fleas build up. Other individuals are highly sensitive and even one flea bite will set of an allergic reaction that lasts for days to weeks. In these individuals, you may in fact never see the flea, just the allergy. The commonest mistake people make is thinking that the allergy could not be caused by fleas, as they have never seen a flea. Scratching around the tail base in Summer means fleas 90% of the time, even if fleas are never seen. You have an allergic pet.

Contact allergy: 

Any plant can cause allergies in any particular individual, however wandering dew and grasses are the most common offenders. Commonly, contact allergy sufferers are scratching underneath on their bellies and under their armpits, where they run over and rub against the allergen, ie: they “contact” it.

Food allergies: 

Any food can potentially cause an allergy, but in fact overt food allergies are more rare than the above groups. To rule out food allergies is a difficult and involved process. There are some theories that the unnatural foods that are commercial foods may in fact not only cause food allergies in themselves, but potentially contribute to all the above groups of allergies as well. Dr Bruce Syme is a veterinarian who has produced a “raw natural “ diet based on kangaroo meat and crushed grains and vegetables. He theorizes that pets bought up on these natural diets are far less likely to develop not only food allergies, but also all other allergies.


Pet skin allergies start as a mild red colour of the skin and the patient may scratch just a little, or shake their ears, or rub their skin along the ground. If mild this is often all that occurs.

As the allergy worsens, the skin becomes far more obviously inflamed. If the patient is allowed to keep scratching this inflamed skin, bacteria and yeast that live on the skin now reproduce and cause an ongoing infection. At this stage we need to treat both the allergy, and now the infection. These are the “secondary” pet skin allergies as described above.



This is the mainstay of what we call “symptomatic” treatment of patients with skin allergies. The advantage of cortisone is that it is very cheap, and very effective. Also, used in small doses, side effects in cats and dogs are very minor and rare. Humans are far more sensitive to the side effects of cortisone, and often clients are reluctant to use cortisone, likening their pets experience to their own. Fortunately, the same is not true with our pets. If larger doses of cortisone are needed long term to control the itch, then side effects become more of a potential problem.


These don’t have the potential side effects of cortisone. They are extremely effective in humans, but unfortunately our pets are far less sensitive, and anti-histamines may only reduce the itch a little, or not at all. We often try various anti-histamines to see if we can reduce the dose of cortisone needed to control symptoms in severely affected patients.

Anti-biotics and anti-fungals: 

These are used in either topical or tablet form to control the “secondary” infections discussed above. For true, deep seeded infections, often 4 to potentially 8 week treatment courses are needed. This is why it is very important for pet owners to get treatment early in the course of allergic dermatitis, and not wait until secondary infections have taken hold.


This is a non-cortisone treatment that is often effective in getting dogs that suffer severe allergies off cortisone. It is a lot more expensive and unfortunately a percentage of patients don’t tolerate the drug, resulting in vomiting and diarrhea. But for pateints tolerating the drug well, it is a viable alternative to long term cortisone use.


Done at the skin and allergy specialist centre this is a fantastic option for long term severe allergy sufferers. It is expensive, and there is about a 25% failure rate, but for those majority of dogs that respond well, it is a great option. Initially the skin specialist will do skin testing to actually identify what the allergens are. Then they make up a serum which is given to the patient as a course of injections which “de-sensitises” the patient to the allergies. The allergens stop causing a problem, the pet stops scratching, and life is good again, without the need for cortisone.

Getting Back to Nature: 

refer to Vets All Natural diet by Bruce Symes, and to his website As discussed briefly above, Bruce has had good success using natural diets, along with a course of probiotics, antioxidants, and omega 3 fatty acids in order to get off the unnatural processed foods that commercial foods are, and improve the pets overall health. This seems to have a good chance of getting many pets allergies under control and off cortisone. I would recommend all sufferers of chronic allergies to try this regime first, for if it works, we have a much healthier patient long term, and no need for ongoing drugs. If it doesn’t work, which it may not, we still have all the other treatment options above.