Mortality of Swedish horses with complete life insurance between 1997 and 2000: variations with sex, age, breed and diagnosis.

The aim of this study was to evaluate the potential usefulness of the database maintained by the Swedish insurance company Agria for providing mortality statistics on Swedish horses. Mortality statistics (incidence rates and survival) were calculated, both crudely and stratified by sex, age, breed, breed group and diagnosis, for the horses with complete life insurance, which covers most health problems. The total mortality was 415 (95 per cent confidence interval [CI] 399 to 432) deaths per 10,000 horse-years at risk, and the diagnostic mortality, including only deaths with an assigned diagnosis, was 370 (95 per cent CI 355 to 386) deaths per 10,000 horse-years at risk. The diagnostic mortality of geldings was 459 (95 per cent CI 431 to 487), of mares 345 (95 per cent CI 322 to 365) and of stallions 214 (95 per cent CI 182 to 247) deaths per 10,000 horse-years at risk. The mortality rates increased with age and differed widely between breeds. Survival analysis showed that the median age at death of the horses enrolled before they were one year of age was 18.8 years. The most common cause of death or euthanasia was joint problems, which were responsible for 140 (95 per cent CI 130 to 149) deaths per 10,000 horse-years at risk. The results of multivariable models developed by using Poisson regression generally agreed well with the crude results.

Morbidity of Swedish horses insured for veterinary care between 1997 and 2000: variations with age, sex, breed and location.

The aim of this study was to evaluate the potential usefulness of the database maintained by the Swedish insurance company Agria for providing disease statistics on Swedish horses. The demography of the horses insured for veterinary care during the period 1997 to 2000 was recorded and the incidence of morbidity, defined as horses that required veterinary care that cost more than the policy excess, was calculated. Yearly incidences were calculated for horses that required veterinary care at least once, first overall, and then for horses with complete insurance, by sex, age, breed group, breed, location and human population density. Poisson regression was applied to a multivariable model to produce estimates of relative risk adjusted for other factors in the model, such as age. The total number of horse-years at risk for those with complete insurance was over 72,000 each year. The annual incidence rate for horses that required veterinary care at least once varied from 1080 to 1190 events per 10,000 horse-years at risk; for geldings the averaged incidence rate was 1398 events, for mares it was 1042 events, and for stallions it was 780 events per 10,000 horse-years at risk. There were considerable variations in incidence rate between breeds.

Specific causes of morbidity among Swedish horses insured for veterinary care between 1997 and 2000.

The principal aim of this study was to analyse the incidence of disease due to general and more specific causes among over 100,000 horses covered by complete insurance for veterinary care by a Swedish insurance company during 1997 to 2000. The database was used to calculate the rate of cause-specific morbidity in horses of different ages, sexes and breed groups kept in different regions with different human population densities. The joints were the most commonly affected part of the body, followed by unspecified/whole body, the skin and the digestive system. The most common specific diagnosis was fetlock arthritis, followed by lameness of undefined origin, other locomotor problems, traumatic injuries to the skin, arthritis in several joints, and colic. Geldings had the highest rate of at least one disease event in the joints, unspecified/whole body, skeletal or respiratory system, whereas in the other four major systems the difference between the sexes was marginal.