Written by Alyssa Morrison
Edited by Shania Sheth and Sharon Park
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Hi everyone! This article on Pet Allergies is the next addition to our Animals in healthcare series. Read on to learn more about how allergens impact pets, as well as how being exposed to pets can help improve human health.
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70% of American households have pets, yet pet allergies affect 10-20% of the world. The allergen comes from proteins in pet dander, saliva, and urine; these allergens are shown to spread and have high concentrations in large public places but research and testing for these allergies is still lacking. Part of this is due to the differences in data available for allergies to cats versus to dogs. Majority of the data available is specialized in cat allergies for sensitized individuals (had IgE antibodies to stop reactions to allergens). Additionally, to the lack of research behind these allergens, allergy variants have increased, especially types of asthma specifically linked to pets. Pet allergens are so common that they can be detected in households with no history of pets. The increasing amount of allergens contributes to the claim that “exposure to animal allergens lead to allergic sensitization, and progression to clinically relevant allergic symptoms” (Chan and Leung).
Allergens and Research:
One of the first leading studies involving pet allergies was by NHANES (National Health and Nutrition Examination Survey) from 1976-80 and 1988-1994 where in separate studies, six common allergens were tested and results found that for the cat allergen (protein), reactivity doubled, causing worse reactions, which followed a common trend at the time (allergens’ presence increased). More tests have continued to come out testing hypotheses around the development of IgE antibodies and lowering allergic reactions in infants through exposure. Results showed that high exposure within a child’s first year led to lower risk of certain allergic diseases and allergic sensitization.
Immunotherapy:
The main effect of high exposure to any allergen is the production of IgG4, which is a specific antibody that can block IgE responses like redness and itchiness, runny nose, trouble breathing, etc. This is somewhat like immunotherapy, which is increasing the exposure to a certain allergen to change the immune system's response. In this area, advancements for dog allergens are higher than for cats and subcutaneous immunotherapy (allergen injection immunotherapy) has shown effectiveness for dog allergies. This was first seen in 1963 where 11 subjects had subcutaneous immunotherapy with a dog allergen and developed antibodies for the allergy.
Recent Studies:
With related studies in the past, the next step would be a vaccine to completely remove the allergy. Scientists from Osaka Prefecture University have identified molecules that make up dog allergens and specific parts of antibodies that control the immune system’s reaction. The goal was to create a vaccine that focused on giving small amounts of antigens (what determines the immune system’s reaction) to help change the immune system response. The current state of the vaccine is finding protein candidates to receive amounts of the antigens. This could be a leading study in hypoallergenic vaccines not only for pets but other allergens.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------Thanks for reading this article in our Animals in Healthcare series! We hoped you learned about how dogs and cats can help create antibodies in humans, that can protect individuals from diseases.
If you enjoyed this article, check out our article on Sleep and the Immune System, written by Harshita Parmar.
Thanks for reading, and until next time,
Alyssa and the Writing Committee :)
References:
James, John. “Pet Allergy: Are You Allergic to Dogs, Cats, or Other Animals?” Asthma and Allergy Foundation of America, June 2022, https://www.aafa.org/pet-dog-cat-allergies/.
Ownby, Dennis, and Christine Cole Johnson. “Recent Understandings of Pet Allergies.” F1000Research, F1000Research, 27 Jan. 2016, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4755411/#ref-34.
Chan, Sanny K, and Donald Y M Leung. “Dog and Cat Allergies: Current State of Diagnostic Approaches and Challenges.” Allergy, Asthma & Immunology Research, The Korean Academy of Asthma, Allergy and Clinical Immunology; The Korean Academy of Pediatric Allergy and Respiratory Disease, 1 Feb. 2018, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5809771/.
“Researchers Lay Groundwork for Potential Dog-Allergy Vaccine.” ScienceDaily, ScienceDaily, 22 Dec. 2021, https://www.sciencedaily.com/releases/2021/12/211222153207.htm.