New Zealand’s ability to effectively combat a major disease outbreak in horses would be seriously hampered by the limited information on the country’s non-racing horses, researchers suggest.
A study conducted at Massey University into the demographics of the country’s non-commercial horse population noted that New Zealand is in a similar position to Australia before an outbreak of equine influence in August 2007 that required a national disease-response that cost millions.
“The lack of knowledge regarding the susceptible population impeded control, particularly the effective implementation of vaccination,” the researchers, led by Dr Sarah Rosanowski, noted.
“Currently, New Zealand is in a similar situation to Australia prior to the equine influenza outbreak, concerning the lack of availability of accurate demographic data regarding the equine population.
“Whilst the racing industry is important to New Zealand’s economy and all horses involved in the industry must be registered, there is limited information about non-racing horses.
“Therefore, designing and then implementing effective treatment and control strategies for infectious disease outbreaks would be seriously inhibited by a lack of knowledge of the characteristics of the susceptible population, particularly horses not involved in the racing industry.”
The researchers said a major difficulty in obtaining data on the equine population, particularly the non-racing or non-commercial sectors, has often been how to identify the properties or individuals of interest.
The study, published online in the Preventive Veterinary Medicine journal, is the first in a series regarding the collection of data for, and the development of, a model to evaluate the effectiveness of control strategies for equine flu in New Zealand.
The researchers set out to identify the characteristics of the non-commercial equine population at the property level, and to outline the importance of these characteristics in the context of the prevention and control of infectious disease.
They surveyed property owners on the number and type of horses kept, the purposes for which they were kept, other animals on the property, and the proximity of neighbours with horses.
The cross-sectional postal survey, in 2009, targeted non-commercial horse properties obtained from the official AgriBase agricultural property and livestock database, which has rural land-use information on 105,000 rural properties.
Properties identified in the database as breeding or training for racing were deemed ineligible. Eligible properties were those classified as non-commercial – with horses used for work, sports, leisure, agistment, and other non-commercial purposes.
In total, 899 properties were identified as being racing or breeding properties and were excluded from selection, resulting in a potential sample of 17,430 properties.
Questionnaires were mailed to 2912 properties identified in the database as having horses, selected in such a way as to be able to extend the data into a national picture.
A total of 168, or 5.8 per cent, were returned due to unknown or unregistered addresses. The remaining 2744 questionnaires were assumed to have been received by the registered decision-maker of the property.
Overall, 1044 questionnaires were returned completed.
Of the returned questionnaires, 791 respondents kept horses on the property, resulting in a response rate of sent questionnaires of 27.2 per cent.
A total of 52.7 per cent of respondents – 417 of the 791 survey responders – with horses on their properties came from either Auckland, Waikato, Manawatu or Canterbury regions.
The researchers found that, on any one property, horses could be kept for multiple purposes. Property size was not associated with whether a property had multiple reasons for keeping horses.
In total, 57.1 per cent of properties kept horses for just one reason, of which 36.5 per cent were for recreation, 18.9 per cent as pets, 16.4 per cent for competition, 14 per cent for work and 11.7 per cent for racing.
Horses were kept for two purposes on 27.9 per cent of surveyed properties, of which the most common combination was competition and recreation, at 46.1 per cent.
Horses were kept for multiple purposes on 15 per cent of responding properties.
Competition, recreation, breeding and any other activity encompassed 32.5 per cent of the multi-use group.
On 75.5 per cent of responding properties, all horses were owned by the registered decision-maker of the property.
In all, half the properties kept horses for recreation, whilst 39.8 per cent kept horses for competition.
Of the properties that kept horses for competition, 32.9 per cent kept horses that were competing in the Equestion Sports New Zealand disciplines of dressage, show jumping, eventing, endurance and para-equestrian, although these horses may not have been registered.
“Even though commercial racing properties were excluded from the sampling frame, 120 properties (15.4 per cent) still kept horses for either Standardbred or Thoroughbred racing or breeding activities,” the researchers noted.
“Thirteen per cent of the properties surveyed kept horses for work, mainly stock work.”
Reasons for keeping horses differed significantly by property size, the researchers noted, with more horses kept for work on large properties, compared with lifestyle properties.
Fewer large properties kept horses as either pets or for the racing industry than the other property sizes, while lifestyle properties kept more horses for recreation (56.8 per cent) and medium-sized properties kept more horses for breeding (17.2 per cent) than the other property sizes.
The reasons for keeping horses differed significantly by region.
On the North Island’s East Coast 52 per cent of properties kept horses for work, whilst 26.6 of properties in Northland and 23.7 per cent of properties in the Manawatu kept horses for work.
Of respondents that reported knowing whether their neighbours had horses, 58.6 of properties had at least one boundary neighbour that kept horses.
In total, 5322 horses were identified on the surveyed properties. Medium-sized properties had the greatest number of horses, with 2216 (41.6 per cent).
Medium and large-sized properties had the highest median number of horses, with four, while properties classified as lifestyle and small had three.
Livestock were kept on 90.9 per cent of horse properties. Of the properties that kept livestock, cattle were kept on 80.2 per cent, sheep on 63 per cent, and 42.3 per cent kept poultry. Cats and dogs were the most common types of companion animals, found on 79.8 per cent of properties.
The study found that 24 per cent of surveyed properties identified in the AgriBase data as having horses did not actually have a horse at the time of the survey.
The median number of horses on properties with horses was three to four, consistent with studies conducted in other countries.
“The lack of reliable data about the location of horses would be problematic in a response to an exotic disease such as equine influenza,” the authors said, noting also that the problem was not unique to New Zealand
“The effective control of infectious diseases like equine influenza cannot be expected if the commercial sector is targeted exclusively for control in the event of an outbreak.”
They continued: “In agricultural industries, disease control measures focus almost exclusively on the commercial producers within the sector, rather than on hobby farmers, even though both groups keep animals that are equally susceptible to infection.
“The same approach is likely to be taken by the New Zealand racing industry, in the event of an equine influenza outbreak.
“Most of the properties in the survey kept horses for recreation and competition and as such were unlikely to have horses that were registered with ESNZ or either of the racing codes.
“Although non-commercial horse properties were targeted for survey, properties where horses were kept for the racing industry were also identified.
“Furthermore, this study highlighted the closeness of horse properties to each other. These findings have important implications for the control of infectious diseases, both in the non-commercial sector, and the racing industry.”
The research was funded by the Ministry of Agriculture and Forestry, with AssureQuality providing the AgriBase* datasbase information.
The authors wish to extend their thanks to the property owners who participated in the survey. Their help was much appreciated and without their support this research would not have been possible.
*AgriBase was replaced by Farms Online in 2012. Farms Online is a rural properties database that is maintained by the Department for Primary Industries and Innovation (formerly the Ministry of Agriculture and Forestry). Farms Online has been designed to enable a rapid biosecurity response during an exotic disease outbreak. For more information about Farms Online, and how to register your farm go to .
Rosanowski, S.M., et al., A description of the demographic characteristics of the New Zealand non-commercial horse population with data collected using a generalised random-tessellation stratified sampling design. PREVET (2012), http://dx.doi.org/10.1016/j.prevetmed.2012.05.016