Can dogs suffer from environmental allergies? Yes, they can. However, environmental allergies in dogs do not present the same as humans with “hay fever.” Canine Atopic Dermatitis (AD) is defined as a genetically predisposed inflammatory and itchy allergic skin disease with characteristic clinical features. However, diagnosing canine AD can be difficult as the disease has no definitive clinical signs.
Veterinarians have to rule out other skin conditions that can resemble, or overlap, with canine AD. This can be a frustrating and time-consuming process. Typically, dogs with AD exhibit five or more of the following signs:
- Age of onset less than three years of age
- Live mostly indoor
- Corticosteroid-responsive pruritus (itch)
- Chronic or recurrent yeast infections
- Affected front feet
- Affected ear pinnae
- Non-affected ear margins
- Non-affected dorsolumbar area
The initial clinical sign of canine AD is pruritus (itchiness), which may include scratching, licking, rubbing, chewing, scooting and head shaking. Depending on the offending allergens, the itch may be seasonal (pollens) or non-seasonal (house dust, dust mites, moulds). Eighty per cent of patients with initially seasonal disease will progress to year-round disease over a one to four year period.
In Canada, there is seasonal variation in allergens. In most Canadian climates tree pollens reach their peak in April-May, grass pollens in June-July and ragweed in August-October. As indoor humidity increases, moulds and house dust mites (HDM) also increase; for example, moulds are found in carpets and window frames and on moist surfaces such as in kitchens and bathrooms. Moulds can also be found outdoors on lawns, vegetation and compost. House dust mites often reach their highest concentration in bedrooms and basements.
Breeds Affected by Canine AD
A wide variety of breeds are known to be predisposed to canine AD including Shar Peis, Cairn, Scottish and West Highland White T erriers, Lhasa Apso, Shi-Tzu, Dalmatians, Irish and English setters, Golden and Labrador Retrievers, French Bulldogs, Boxers, Miniature Schnauzers, Cocker Spaniels and English Bulldogs as well as associated cross breeds.
Patience is required while your Veterinary health care team works through the process of disease elimination.
From the Canadian Animal Health Institute (www.cahi-icsa.ca)