Generalizability and comparability of prevalence estimates in the wild bird literature: methodological and epidemiological considerations.

Wild birds have been the focus of a great deal of research investigating the epidemiology of zoonotic bacteria and antimicrobial resistance in the environment. While enteric pathogens (e.g. Campylobacter, Salmonella, and E. coli O157:H7) and antimicrobial resistant bacteria of public health importance have been isolated from a wide variety of wild bird species, there is a considerable variation in the measured prevalence of a given microorganism from different studies. This variation may often reflect differences in certain ecological and biological factors such as feeding habits and immune status. Variation in prevalence estimates may also reflect differences in sample collection and processing methods, along with a host of epidemiological inputs related to overall study design. Because the generalizability and comparability of prevalence estimates in the wild bird literature are constrained by their methodological and epidemiological underpinnings, understanding them is crucial to the accurate interpretation of prevalence estimates. The main purpose of this review is to examine methodological and epidemiological inputs to prevalence estimates in the wild bird literature that have a major bearing on their generalizability and comparability. The inputs examined here include sample type, microbiological methods, study design, bias, sample size, definitions of prevalence outcomes and parameters, and control of clustering. The issues raised in this review suggest, among other things, that future prevalence studies of wild birds should avoid opportunistic sampling when possible, as this places significant limitations on the generalizability of prevalence data.

A survey of veterinary student attitudes concerning whether marijuana could have therapeutic value for animals.

Marijuana is increasingly recognized for its therapeutic value in human medicine. Although most veterinary research to date has been concerned with marijuana toxicity, there is some interest in the potential therapeutic value of marijuana in veterinary medicine. With the recent legalization of marijuana for recreational use in Canada in October 2018, there is a need for veterinarians and veterinary students to be in a position to address client questions and concerns on this topic. We distributed a questionnaire to current veterinary students at the Ontario Veterinary College in Guelph, Ontario, to determine their attitude(s) towards marijuana as a potential therapeutic agent in animals. The overall response rate for the questionnaire was 43.5% (207/476). Most students felt that marijuana has potential therapeutic value in animals (53.6%; 111/207), fewer were unsure (38.6%; 80/207), and a small number of students felt that marijuana does not have potential therapeutic value in animals (7.7%; 16/207). Data generated by this questionnaire identified an important distinction between two major active compounds found in marijuana: cannabidiol (CBD) and tetrahydrocannabinol (THC). Potential barriers to use in veterinary practice were also identified, including stigma and toxicity. Finally, many respondents showed an awareness of the limited scientific research regarding the safety and efficacy of marijuana in animals. Until a body of scientific literature on marijuana in animals becomes available, veterinarians may benefit from having an awareness of the different physiological and pharmacokinetic effects produced by different strains (including any adverse effects, and half-life), and a general understanding of current therapeutic applications of marijuana in humans.