Identification of modifiable pre- and postnatal dietary and environmental exposures associated with owner-reported canine atopic dermatitis in Finland using a web-based questionnaire

PLoS One. 2020 May 29;15(5):e0225675. doi: 10.1371/journal.pone.0225675. eCollection 2020.

Abstract

A cross-sectional hypothesis generating study was performed to investigate modifiable exposures such as whether feeding pattern (a non-processed meat based diet, NPMD, or an ultra-processed carbohydrate based diet, UPCD), certain environmental factors and their timing of exposure might be associated with the development of canine atopic dermatitis (CAD). Also, genetic and demographic factors were tested for associations with CAD. The data was collected from the validated internet-based DogRisk food frequency questionnaire in Finland. A total of 2236 dogs were eligible for the study (the owners reported 406 cases and 1830 controls). Our main interest was to analyze modifiable early risk factors of CAD, focusing on nutritional and environmental factors. We tested four early life periods; prenatal, neonatal, early postnatal and late postnatal periods. Twenty-two variables were tested for associations with CAD using logistic regression analysis. From the final models we identified novel dietary associations with CAD: the NPMD during the prenatal and early postnatal periods had a significant negative association with the incidence of CAD in adult dogs (age above 1 year). Oppositely, UPCD was associated with a significantly higher risk for CAD incidence. Other variables that were associated with a significantly lower risk for CAD were maternal deworming during pregnancy, sunlight exposure during early postnatal period, normal body condition score during the early postnatal period, the puppy being born within the same family that it would stay in, and spending time on a dirt or grass surface from 2 to 6 months. Also, the genetic factors regarding maternal history of CAD, allergy-prone breeds and more than 50% white-colored coat all showed a significant positive association with CAD incidence in agreement with previous findings. Although no causality can be established, feeding NPMD early in life seemed to be protective against CAD, while UPCD could be considered a risk factor. Prospective intervention studies are needed to establish the causal effects of the protective role of NPMD on prevalence of CAD during the fetal and early postnatal life.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Dermatitis, Atopic / diagnosis*
  • Dermatitis, Atopic / etiology
  • Dermatitis, Atopic / pathology
  • Diet / adverse effects*
  • Dog Diseases / diagnosis*
  • Dog Diseases / etiology
  • Dog Diseases / pathology
  • Dogs
  • Environmental Exposure / adverse effects*
  • Feeding Behavior / physiology
  • Humans
  • Internet
  • Risk Factors
  • Surveys and Questionnaires

Grants and funding

Vetcare Oy Ltd (www.vetcare.fi) paid the IT company that host the internet based FFQ and lent one of their researchers to collaborate with us on the FFQ in 2009 (not an author of this paper). The Swedish Cultural Foundation (http://www.kulturfonden.fi/in-english; Grant number 13/3307- 1304), MUSH Ltd. (www.mushbarf.com) and Moomin characters Ltd. (http://www.moomin.com/en/) paid a researcher to prepare the FFQ data for analysis in 2014-16 (not an author of this paper). A second Swedish Cultural Foundation grant (http://www.kulturfonden.fi/in-english; Grant number 18/138798) paid the salary of the lead author of this study, Manal Hemida. The company Natures Variety Ltd. (www.naturesvariety.com) provided general funding that was used for the salary of Siru Salin. The specific roles of this author is articulated in the ‘author contributions’ section. All other authors are on University salary or student grants. During the last five years the authors have also conducted three crowdfundings that have given the research group funds used for research expenses such as open access publishing. One of them was handled through Dr. Mercola (www.mercola.com). There has been no additional external funding received for this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.