Download Evaluating the cost effectiveness of control strategies for

Research Project 2010
Evaluating the cost effectiveness of control strategies for strangles in
the New Zealand horse population
Dr Naomi Cogger & Sarah Rosanowski
An EpiCentre and Massey Equine Research Group project
The project will be comprised of two parts:
1. A survey of breeders and trainers to investigate the occurrence and risk factors associated
with strangles outbreaks
2. A survey of non-racing or breeding horses to investigate the occurrence of health problems,
with specific interest in strangles
Outbreaks of infectious disease can have severe consequences for both animal welfare and the
economic efficiency of an industry. Maintaining the high health status of the equine population in
New Zealand is of economic importance, as the racing industries account for approximately 1 % of
the national gross domestic product. Additionally, the negative economic impact associated with
disease outbreaks can be mitigated through targeted disease surveillance, control, prevention and
treatment strategies (Sanson, 2005; León et al., 2006), as long as information about the population
at risk, as well as the disease of interest are known. Currently, in New Zealand, little is known about
the impact of strangles on the equine population.
The aim of Part 1 is to establish the current prevalence of strangles in the racing industry, identify
factors that affect whether or not a horse becomes infected with strangles and to examine how
strangles spreads through groups of horses on a stud or in a training yard.
Stud masters and trainers in the Waikato and Auckland region will be selected for survey and invited
to participate in the research through face to face interviews. These regions have been chosen for
two reasons, firstly the high numbers of training and breeding establishments in the area and
secondly, because there was a strangles outbreak in this area during the 2009/10 breeding season.
Questions in the survey will relate to the 2009/10 and the 2010/11 breeding or racing season, to
compare management practices over these two time periods. All the results given by participants
will be kept confidential and when results are published, studs and stables will be kept anonymous.
The aim of Part 2 is to identify the most common diseases affecting this population and how these
diseases are diagnosed and controlled. Previous research has shown that there are close linkages
between the racing and non-racing sectors, so any disease that is present in the non-racing
population could easily be spread into the racing population. However the impact that infectious
diseases, like strangles, have on the racing sector is far greater than that of the non-racing sector.
Questionnaires will be used to gather information on horses kept for non-racing purposes. The
questions will ask respondents about any diseases occurring in their horses in the last 12 months,
who diagnosed these diseases (a veterinarian or themselves) and how these diseases were managed
or treated. These data can then be compared to those collected from the racing sector to identify if
differences in the occurrence of strangles in the two populations exist.
These surveys will help to clarify the impact that strangles has on the racing industry and will
highlight the role that non-racing horses have in maintaining and spreading the disease. Overall, this
project aims to address the lack of information available about strangles in the New Zealand equine
industry and develop a framework by which horse owners and the industry can make an objective
decision on whether the benefits of control outweigh the costs.
What effect does strangles have on the racing industry?
An EpiCentre and Massey Equine Research Group project
In 2009, Sarah Rosanowski, a PhD student based at Massey University, started her project in
investigating how equine influenza would spread through the New Zealand horse population. Stud
masters were interviewed about the movement patterns of horses onto the stud during breeding
time. Sarah says “it quickly became apparent that strangles was a real concern for the industry at
that time”. Although most studs took action to prevent disease with vaccination and on stud disease
management strategies like cleaning crushes daily, the useful of these activities was unknown.
During the first stage of her research, properties not involved in the racing industry were also
studied. Owners of non-racing horses were asked about how often they moved their horses and
how far these horses travelled. This information was used together with data on the use of these
horses to identify types of properties that would be more likely to spread diseases, if there was an
outbreak. Links between racing and non-racing properties were highlighted. Sarah would like to
thank all those that provided information for this study, and more information about this study will
be available soon.
Sarah is now about to start the second stage of her research, investigating the impact that strangles
has on the racing industry. For this work, Sarah wants to interview stud masters and trainers, to see
what they do on their studs or in their stables to prevent or treat strangles, and which practices are
best at preventing strangles from spreading. From this, Sarah hopes to estimate how common
strangles was between 2009 and 2010.
On top of this, the horses that are not involved in the racing industry will be studied, as these horses
could act as a source of disease, increasing the chances of an outbreak in the racing or breeding
sectors. Non-racehorse owners will be asked what diseases their horses have had in the last 12
months, and how those diseases were diagnosed and treated.
This work will benefit the racing industry as it will help to identify ways to control strangles that are
based on the New Zealand equine industry and provide information on how common strangles is in
our horse population. This project will go on to evaluate the cost effectiveness of treatment and
control options, so that not only will control be more effective from a disease perspective, but it will
also save trainers and breeders money.