Paw hygiene of assistance dogs and pet dogs compared to their users’ and owners’ shoe soles: equally clean or extra attention required?

Abstract

Background and aim. In the Netherlands, many disabled people benefit from the daily use of an assistance dog (AD). Despite the European and Dutch laws that prohibit the denial of ADs to public places, this still occurs on a regular basis. The main argument is that dogs compromise the hygiene with their presence, which could be a health hazard. Meanwhile, people are allowed to walk into and out of public places freely wearing the same shoes they wear outside. The goal of this study is to quantify Enterobacteriaceae family colonies and to investigate the presence of C. difficile on the paws of ADs and pet dogs (PDs) and the shoe soles of their users and owners, respectively. These numbers may tell that additional measures are needed to protect the hygiene in important environments, like hospitals. Materials and methods. 25 ADs and their 25 users, and 25 PDs and their 25 owners were acquired as participants for this study, that took place in February and March of 2020. Each participant was asked to walk their dogs for 15-30 minutes prior to sampling. The front paws and shoe soles were sampled using premoistened sponges and further processed for the demonstration and quantification of bacteria of the Enterobacteriaceae family as a measure of general hygiene, and the demonstration of C. difficile. Each PD owner or AD user filled out a general questionnaire about the care for their dogs, and AD users were asked to fill out an additional questionnaire on the experience of using an AD. Results. Dog paws came back negative for bacteria of the Enterobacteriaceae family more often than shoe soles, and also had lower numbers of those bacteria. This was most distinct in the comparison of PDs and their owners; the numbers were similar between ADs and their users. C. difficile was only found on one AD user’s shoe soles. Conclusions. The general hygiene of dog paws is better than that of shoe soles, mostly caused by the better general hygiene of PD paws in comparison to their owners’ shoe soles; ADs and their users had comparable levels of general hygiene. C. difficile is not a bacteria that is regularly found on dog paws or shoe soles. Possible hygiene measures for hospitals could be (wet) wipes, (sticky) mats, or overshoes for dog paws, and overshoes, brushes, (sticky) mats, and UV lights for shoe soles.