Information delivery and the veterinarian-horse owner relationship in the context of Hendra virus in Australia

Abstract

Hendra virus (HeV) is an emerging bat-borne virus endemic in Australia that can be transmitted from horses to humans and has a high fatality rate for horses and people. Controversy surrounding HeV risk mitigation measures have strained the veterinarian-horse owner relationship. This study aimed to characterise the veterinarian-horse owner relationship in general and also in the context of HeV by analysing data derived from the ‘Horse Owners and Hendra Virus: A Longitudinal Study to Evaluate Risk’ (HHALTER) study. Australian horse owners were recruited via emails, social media and word-of-mouth for a series of five surveys that were administered online at six-monthly intervals over a two-year period to capture baseline knowledge, attitudes and practices of horse owners regarding HeV and any changes over time. In the current study, descriptive analyses of information sources were performed to understand the use of veterinarians as a HeV information source (Surveys 1 and 5; n = 1195 and n = 617). Ordinal logistic regression analyses were conducted to determine factors associated with the frequency of horse owner contact with a veterinarian (Survey 3; n = 636). This study found a relative increase over the study period in the proportion of horse owners who had used veterinarians as HeV information source in the last 12 months (from 51.9% to 88.3%). Owning more horses, being older, having a ‘duty of care’ for other people working with horses and deriving the main income from horse related business were factors associated with more frequent veterinary contact. Results suggest that traditional information sources such as workshops, information packs and risk training are likely to be used by horse owners. Smart phone applications should be considered for use in the future and require further investigation for horse health communication. The findings of this study may be helpful in optimising strategies for horse health information delivery.

Introduction

The veterinarian-client relationship is the foundation for professional interactions that enable veterinarians to perform their duties (AVA, 2017a). The converse is also true; the professional interactions between veterinarians and their clients build the client-veterinarian relationship. These interactions are facilitated by communication skills which are central to veterinary practice, affecting the bond between clients and their pets and directly impacting the care of the animal (Lue et al., 2008; Shaw et al., 2016). However, the importance of the veterinarian-client relationship extends beyond healthcare and welfare. The relationship fostered in these interactions is also important in biosecurity engagement programs. Being professionals who serve at the interface of the human-animal bond, veterinarians play an important role as educators in their communities (Kruger et al., 2010). Furthermore, veterinarian-client interactions are important for passive surveillance and for early detection and reporting of diseases (Evers, 2009; AVA, 2017a), enabling more efficient management of disease and timely outbreak control and veterinary public health responses (Stärk et al., 2006), and thereby minimising the impact on animals and humans.

In Australia, the relationship between veterinarians and horse owners and managers has undergone changes in recent times due to the emergence of Hendra virus (HeV) in 1994. HeV is a zoonotic disease that spills over from bats to horses and subsequently from horses to humans, but it is not highly contagious (Middleton, 2014). HeV has caused the death of over 100 confirmed and suspected equine cases in two Australian east coast states, Queensland and New South Wales (Queensland Government, 2018). Seven people have also contracted HeV and four of those people have died giving a human case fatality rate of 57 % (Middleton, 2014). The most recent human death occurred in 2009 followed by an unprecedented high number of equine outbreaks in 2011 (Queensland Government, 2018). The virus is carried by bats, specifically flying foxes (genus Pteropus) (Halpin et al., 2011). P. alecto and P. conspicillatus are regarded as the primary reservoir hosts (Smith et al., 2014; Edson et al., 2015), with transmission to horses facilitated by direct or, less likely, indirect contact with infectious body fluids, notably urine (Edson et al., 2015; Field et al., 2016; Martin et al., 2015). Infected horses shed the virus in nasal secretions, oral secretions, blood, urine, and faeces. Clinical signs in horses are highly variable and non-specific and horses may shed the virus prior to developing clinical signs (Marsh et al., 2011; Playford et al., 2010), therefore diagnosis is difficult and veterinarians, other horse professionals and owners in close contact with unvaccinated horses in HeV hotspots are at high risk.

Recommended risk mitigation measures are based on reducing contact between horses and flying foxes and include removing feed and water containers from under trees and if possible place them under cover, restricting horses’ access to flowering/fruiting trees and shrubs that attract flying foxes and temporarily stabling horses during times of peak flying fox activity at dusk and during the night. Additionally HeV vaccination for horses has been available since late 2012 and is considered to be ‘the single most effective measure’. These recommendations are communicated to equine veterinarians and horse owners via the Queensland Department of Agriculture and Fisheries, the New South Wales Department of Primary Industries and the Australian Veterinarian Association websites and fact sheets (AVA, 2017b; NSW DPI, 2017; Queensland DAF, 2017). Although highly recommended, HeV vaccination of horses in general is currently not mandatory in Australia. In the years since the vaccine’s release in November 2012, national uptake of the vaccination has been slow and hindered by the need for repeated booster doses – initially 6-monthly, and currently annually. Uptake of the vaccine has been moderate, with over 740,000 doses having been administered to approximately 175,000 horses Australia-wide and of those 67,000 were in New South Wales and 97,000 were in Queensland (up to February 2020; R. L’Estrange, pers. comm.).

The total number of horses in Australia is unknown; however, domestic horse numbers were estimated at just under 1 million with most located in New South Wales, Queensland and Victoria (Centre for International Economics, 2007). This data suggests a vaccination uptake of approximately 17.5 % Australia-wide with somewhat higher rates in the higher HeV risk states of Queensland and New South Wales. Recent studies have shown that the attitude of horse owners towards the HeV vaccine is polarised and that perceived barriers like cost and fear of adverse reactions limit its use (Taylor et al., 2016; Wiethoelter et al., 2017). Furthermore, some horse owners are not supportive of a mandatory approach to vaccination against HeV as it would impact on their freedom of choice.

Low vaccination rates have been of concern to veterinarians, especially since they are responsible for the safety of their clients and their staff and are, themselves, at high risk of being infected by HeV. Further compounding these concerns are the recent prosecutions of three Queensland veterinarians by Workplace Health and Safety for their handling of HeV cases, however, no convictions were recorded (AVA, 2017b). Veterinarians have responded in a number of ways to the HeV threat. These include: choosing to decline to treat unvaccinated horses, mandating or promoting vaccination of horses, leaving equine practice, moving interstate, and changing clinic policies to manage risk (Mendez et al., 2012, 2013; Richmond, 2016). Veterinarians are also concerned about how to communicate the risk involved in managing HeV cases or potential exposure to HeV to horse owners, as it is their workplace health and safety responsibility (Mendez et al., 2014, 2017). Horse owners have raised questions regarding the motivation behind veterinarian’s attitudes and policies and their impact on animal welfare. These concerns resulted in the launch of an inquiry regarding the HeV vaccine and its use by veterinarians in the state of Queensland (Richmond, 2016) which supported the use of the vaccine, but concluded that the vaccine should not be made mandatory (Byrne, 2017). Protecting the veterinarian-client relationship in the midst of difficult discussions surrounding vaccine uptake and changes in veterinary policy is important (Taylor et al., 2016).

It would be difficult for clients, horse owners in this context, to build trusting relationships with their veterinarians if they are in contact infrequently. The frequency of contact with their veterinarians could provide a proxy for the quality of the horse owner-veterinarian relationship.

Considering the importance of veterinarian-client interactions and anecdotal evidence of the deteriorating relationship between equine veterinarians and their clients, this study was conducted to investigate the horse owner and veterinarian relationship in general and in regard to HeV in Australia. Specifically, the objectives of this study were to utilise quantitative approaches to: (a) assess horse owners’ use and preference for HeV information sources; and (b) identify factors associated with the frequency of horse owner contact with veterinarians.