Research published by the Wayne County Health, Environment, Allergy and Asthma Longitudinal Study (WHEALS) in 2011 suggests that there is no advantage to selecting a non-allergenic dog breed. In comparing homes with so-called hypoallergenic dogs against those with other breeds of dogs, no difference in allergen (Canis familiaris 1 or Can f 1) levels was found.
The Theory Behind the Hypoallergenic Dog Breed Concept
Allergies to dogs are generally triggered by the presence of Can f 1,which is found in saliva, dander and urine. The dog breeds suggested by the American Kennel Club as potentially less likely to cause allergic reactions include the Bedlington Terrier, Bichon Frise, Irish Water Spaniel Kerry Blue Terrier, Maltese, Poodle, Portuguese Water Dog, Schnauzer, Chinese Crested and Xoloitzcuintli.
These breeds generally shed less and, therefore, theoretically produce less dander. The AKC wisely does not promote the dog breeds as 100% hypoallergenic and reminds people that management of the home environment is also necessary to reduce exposure to allergens.
The ‘hypoallergenic-dog’ theory does not take into account the fact that allergen Can f 1 is also found in saliva and urine. In addition, prior to the WHEALS study, little research had been done on actual levels of dander produced by different breeds of dog, so it was simply an interesting theory.
WHEALS Study Refutes Less-Dander-Exposure Theory
The study looked at the amount of dander produced by various breeds of dog using four different criteria:
- Purebred dogs only – hypoallergenic vs non-hypoallergenic breeds
- Purebred and mixed breed with at least one hypoallergenic parent vs purebred non-hypoallergenic comparison
- Hypoallergenic purebred and mixed breeds with at least one hypoallergenic parent vs non-hypoallergenic purebred and mixed breeds with no hypoallergenic parent.
- AKC recognized hypoallergenic dog breeds only.
The results showed that 163 of 173 homes (94.2%) had detectable levels of Can f 1 using any of the classification criteria. When adjusted for the weight of the dog, length of ownership, amount of time the dog was indoors, type of floor surface and location of residence, there was no statistically significant difference in the amount of Can f 1 produced by dog breeds considered hypoallergenic and those deemed non-hypoallergenic.
The study collected floor samples to test for levels of Can f 1 rather than collecting samples from the dogs. This suggests that lower dander levels on the dog do not directly translate into lower allergen levels in the home, which is consistent with the information provided by the American College of Allergy, Asthma and Immunology (ACAAI) which states that it may take weeks of meticulous cleaning to remove all animal hair and dander.
Reducing Dog Allergen Levels in the Home
While the study is disappointing for those who had pinned their hopes on being able to select a dog breed that was less likely to induce allergic reactions, there are things that can be done to reduce the presence of dog allergens in the home.
- Choosing a shorter-haired breed. Even though long–haired dog breeds do not produce more Can f 1, they can pick up more of other types allergens, including pollen and mold spores, on that long coat.
- Clipping the coat short, frequent bathing (talk to your vet about how often and what to use to reduce your dog’s risk of skin problems) or even wiping the dog down regularly with a damp cloth may help reduce both Can f 1 and other allergen accumulation.
- If you develop serious allergic reactions, avoid kissing or hugging the dog, to reduce exposure to Can f 1.
- The ACAAI recommends the use of a central air cleaner for at least 4 hours a day. Heating and air–conditioning filters, particularly HEPA (High Efficiency Particulate Arresting) filters, as well as regular vacuuming and other regular house cleaning help physically remove Can f 1 from the environment.
- In some cases an allergist may recommend immunotherapy (allergy shots) if a dog owner is unwilling to give up his or her pet.
The WHEALS study is the first of its kind to be published. The self-critique suggests that further work needs to be done, such as:
- Evaluate a larger sample size
- Verify the amount of time the dog spends in the room which is sampled
- Include further assessment of individual dog breed production of Can f 1.
Until such research is done, the case for purchasing a hypoallergenic breed remains in serious question.
Nicholas, CE et al. 2011. Dog allergen levels in homes with hypoallergenic compared with nonhypoallergenic dogs. Am J Rhinol Allergy.25(4):252-256.