A published study from Finland found identifiable dietary, genetic, and environmental factors that play a role in development of canine atopic dermatitis - a fancy name for allergies that cause skin disease, inflammation, and itching in dogs. A total of 2,236 dogs were included in the study, which began in 2009. Canine atopic dermatitis is considered an incurable inflammatory and allergic skin disease in dogs, affecting up to 10% of the dog population with usual onset of symptoms between one and three years of age.
Allergies are one of the most frustrating diseases to treat for both pet owners and veterinarians. Control, rather than cure, should be the goal.
There is definitely a genetic component to canine atopic dermatitis which can be passed down from either parent, with the most frequently affected breeds reported to be West Highland White Terriers, Boxers, English Bulldogs, Dalmations, Golden Retrievers, French Bulldogs, Bull Terriers, German Shepherds, and English Springer Spaniels. In my office I would add American Bulldogs to this list.
The Finnish study looked at factors affecting prenatal and early postnatal development of the immune system to determine potential risk factors in addition to genetic factors. Their findings support what I have found to be true in daily practice; many findings matched similar risk factors in children. Early nutritional and environmental exposures are crucial for the programming of the immune system and therefore predisposition to allergy later in life.
Factors that contributed to development of canine atopic dermatitis included:
- Maternal history of canine atopic dermatitis (one study showed up to 65% of offspring will develop allergies if one or both parents suffered with allergies, while healthy parents gave rise to only 11% of pups developing allergies)
- Dogs with greater than 50% white-colored coat were at high risk of developing allergies
- Pups delivered to mothers that were fed non-processed meat diets (raw diets or home-made meat-based diets) resulted in lower risk of developing allergies than pups whose mothers were fed ultra-processed carbohydrate-based diets (dry kibble). Heat processing of food causes denaturation of food proteins, which promotes immunogenicity and allergenicity. Dogs fed non-processed meat diets have been shown to have a greater variety of microbial populations in the gut, leading to stronger immune function.
- Maternal deworming during pregnancy resulted in less allergies in the pups. Worm infection of the mother during pregnancy has been reported to have a long-lasting impact on the fetal immune system development and disease development later in life.
- Pups started on a non-processed meat diet as their first food had a lower risk of developing canine atopic dermatitis than pups feed ultra-processed carbohydrate diets (kibble). Improved microbial populations in the gut of raw-fed puppies stimulate immune tolerance development, protecting against allergies later in life.
- Pups with sunlight exposure for one or more hours per day during the first one to two months of age showed a significantly lower risk of developing allergies.
- Pups exposed to grass and dirt in the first two months also showed lower risk of developing allergies. Pups house totally indoors in urban environments developed significantly more allergies.
This study adds good evidence to what veterinarians see in daily practice. Dogs with canine atopic dermatitis should be removed from breeding programs. Feeding meat-based non-processed diets during pregnancy and at weaning can help populate the gut with microbial diversity that will lead to a stronger immune system. Playing outside is important in the early development of the immune system as well.
For those with pets that suffer with allergies, improving the diet, regular bathing with natural products to soothe the skin, adding supplements to decrease inflammation, and adding probiotics to improve gut microbial diversity may help. I do not recommend using drugs that harm the immune system.
Allergies are frustrating to live with, frustrating to treat, and often lead to euthanasia or surrender of affected dogs. Don't give up, but be realistic in your expectations. Many dogs will improve significantly with changes in diet and supplements, but some will suffer with lifelong outbreaks.