With the warm weather upon us, Dr Neil McIntosh reveals how to treat your dog's pollen allergies
“It’s summertime and the livin’ is easy, Fish are jumping and the cotton is high.” And that, dear itchy dog owner, is the problem. The cotton is high! And so is the pollen count! Humans who are affected by hay fever, better called pollen allergy, get runny, red eyes and they sneeze and wheeze. Dogs, on the other hand, itch. And boy can they itch.
Seasonal pollen allergy affects up to 10 percent of our dogs and, left untreated, it creates misery and often irreversible changes to their skin. It is caused by an inherited predisposition to develop hypersensitivity-mediated skin disease against environmental allergens. You don’t need to be a vet to diagnose it, but beware! It can be mistaken for many other conditions, some of which can be exacerbated by incorrect treatment.
What pollen allergy in dogs looks like
Inflammation and itching occurs in the face, ears, feet, belly and armpits. There may be brown saliva staining of the feet, caused by licking and you will see excoriation, hair loss, increased pigmentation and skin thickening. Ear and eye infections are common, hence the head shaking, ear scratching, face rubbing and hind leg “air-guitaring!”
And then what?
Scratching becomes a way of life. It spreads secondary bacteria and yeasts such as staphylococcus and malassezia, which cause further flaking and pyoderma and are often the cause of failure of treatment when only the underlying allergy is considered.
Why does it happen?
We don’t really know. There is no point in the body mounting such an extreme reaction to harmless pollens. The science part is slightly bewildering. Seasonal pollen allergy is thought to be associated with dysregulation of cytokine production and aberrant T cells. The long and the short of it is the release of inflammatory chemicals including histamine and interleukins. Additionally, it is likely that patients have a defective epidermal barrier, a bit like an unwaxed car, that allows allergens to stick. Many seasonally allergic dogs go on to develop other allergies, with 30 percent being allergic to the house dust mites, dermatophagoides farina. Common pollen allergies include wheat, couch grass, dockens and sweet vernal. Remember, some trees, such as birch and alder, produce pollen pretty early in the season.
Can we predict hayfever in dogs?
Not really. We know it is very common in Westies but Labradors and golden retrievers figure highly too. Careful dam and sire selection is important as familial history of the condition makes it far more likely in offspring. Some say there is a link between month of birth and development of allergy. The theory is that dogs born during the pollen season are sensitised in the first few months of life. It is very uncommon in dogs less than a year old, except in Shar peis, who don’t appear commonly on the shooting field. Inexplicably, it affects females more than males.
My dog is affected by pollen allergies. What can I do?
Blood testing can reveal the allergens involved, allowing an animal-specific desensitisation vaccine to be produced, but the process is expensive (circa £500). Avoid outdoor activities at times of high pollen concentration, remembering that high wind and low humidity promote dissemination. Heavy rainfall improves air quality, while light showers worsen it. Rinsing dogs after exercise to wash away pollen can help. Glucocorticoid steroids such as prednisolone can be effective at controlling the itch but they encourage weight gain, increase thirst and urination, can induce cystitis and increase the likelihood of secondary infections. Stop them if your dog appears worse but remember they should not be suddenly withdrawn if they have been used for a while! Cyclosporines given at 5mg/kg are very effective, but considerably more expensive. Within the last few months, a new tablet medication, called Apoquel, has been introduced. It is extremely good at controlling the itch without side effects and is cheaper than cyclosporines.
Proper medicated shampoos, high-dose antibiotics, specific ear treatments, anti-histamines and skin supplements can all help.
Any last advice?
Yes! You may just be scratching the surface of your dog’s problem so get to your vet to review the treatment. They might be able to make the “livin’ more easy” for your dog.