Topic:Epidemiology
Epidemiology in horses involves the study of the distribution and determinants of health-related states and events in equine populations. It encompasses the investigation of patterns, causes, and effects of diseases and health conditions within horse populations. This field of study aims to identify risk factors for disease and targets for preventive healthcare. Key components of equine epidemiology include disease surveillance, outbreak investigation, and the study of disease dynamics within herds or regions. Research in this area often focuses on infectious diseases, zoonotic diseases, and the impact of environmental factors on equine health. This page compiles peer-reviewed research studies and scholarly articles that explore various aspects of epidemiology in horses, including disease prevalence, transmission pathways, and strategies for disease prevention and control.
Immunization of man and animals against influenza by oral and intranasal routes. Live human and equine influenza virus strains modified by serial passage on allantois-on-shell system (AOS) in the presence of normal horse serum were administered orally or intranasally to volunteers or horses. Mostly mild clinical short-lasting reactions, replication in nasal mucosae, transmission to placebo recipients and significant local or circulating antibody rises were observed following administration to volunteers of strains modified by five or less serial passages on AOS in the presence of normal horse serum (NHS). Milder clinical reactions, no replication, no viral transmission and...
Incidence and nature of horse-riding injuries. A one-year prospective study. A prospective one-year study of horse-riding accidents was performed in an area with a very high frequency of amateur riding. Totally 174 patients with riding injuries were registered--66% children--making an incidence of only 0.7 per thousand riding occasions. However, many of these injuries were of a severe nature, one leading to death and 27 of the patients reporting persisting symptoms at follow-up one year after the accident. Eleven per cent of the accidents lead to cerebral injuries and 44% to fractures, mainly of the upper extremities. Eleven per cent required hospitalization and 17% op...
Suppression of synthesis of an IgG subclass in a persistent viral infection. Comparison of immunoglobulin levels of nine horses before and after infection with equine infectious anaemia (EIA) virus demonstrated a significant depression of serum IgG(T) at 2 months (P less than 0-001) and at 1 year (P less than 0-01) after infection. In contrast, the levels of IgGa were significantly increased at both times after infection. Another sixteen horses with EIA for 1-4 months were examined and there was also significant depression (P less than 0-001) of IgG(T) when compared to pre-infection levels. No significant changes in IgG(T), IgGa and IgM were noted in fourteen normal ho...
Tumours of the prostate and penis. Tumours of the male genital tract, excluding the testes, are relatively rare in the six major domestic animals. The most important tumours are prostate carcinoma and transmissible venereal tumour of the penis in dogs, fibropapilloma of the penis in bulls, squamous papilloma and squamous cell carcinoma in horses, and squamous papilloma in pigs. Four histological types of canine prostate carcinoma exist: alveolar papillary, acinar, organoid, and poorly differentiated. The biological behaviour of prostate carcinomas is similar to that in man, with frequent metastasis to the regional pelvic nodes,...
Equine toxoplasmosis: a survey for antibodies to Toxoplasma gondii in horses. A nationwide sample of horses was tested to determine the prevalence of toxoplasma antibodies in equine animals. Of 1,294 serum samples from horses tested by the microtitration indirect hemagglutin test, 20% were positive. Among the popular breeds of horses, the following antibody prevalences were found: Arabian, 19%; Paint, 22%; Quarter Horses, 13%; Thoroughbred, 24%; and Standardbred, 17%. The antibody prevalence increased from 2% in horses 1 year of age to 18% in 2-year-olds, and rose to 38% in horses 12 years of age. Significant differences were not evident by broad geographic locations ac...
A field study of persistence of antibodies in California horses vaccinated against western, eastern, and Venezuelan equine encephalomyelitis. As a result of the continuing threat of Venezuelan equine encephalomyelitis (VEE), a study was made to determine if revaccination against VEE (TC-83 vaccine) was feasible and if revaccination could be incorporated into other routine vaccination practices. Of the horses given annual vaccination with bivalent western equine encephalomyelitis (WEE) and eastern equine encephalomyelitis (EEE) vaccine, 57% retained detectable serum-neutralizing (SN) antiboyd titers for VEE 18 months after the initial VEE vaccination was given. Of horses with no record of WEE-EEE vacinnation, 100% retained detectable...
Occurrence of second and third instars of Gasterophilus intestinalis and Gasterophilus nasalis in stomachs of horses in Kentucky. The occurrence of 2nd and 3rd instars of Gasterophilus intestinalis and Gasterophilus nasalis was determined in 476 horses during the 22-year period from 1951 to 1973. Overall, G intestinalis infected 98.7% of the horses and averaged 168/horse; whereas G nasalis infected 80.7% of the horses and averaged 52/horse. Aggregate average total numbers for G intestinalis ranged from a low of 50 in September to a high of 229 in March, and for G nasalis, from a low of 14 in September to a high of 82 in February. Horses were infected by 2nd or 3rd instars of both species on a year-round basis. Differenti...
Recent observations concerning Klebsiella infections in stallions. A high incidence of Klebsiella contamination in German 'Warmblut' and Thoroughbred stallions is reported. The organism was recovered from the nostrils, prepuce, pre-ejacultory secretion and, in some cases, on the body surface, in the faeces and on the ground of the covering (mating) yard. Fertility was not affected. However, differences of virulence were observed and Type 5 proved to be the most pathogenic.
Carbonic anhydrase isozymes in American ponies and riding horses: a new polymorphic high-activity type isozyme. A study of the erythrocyte carbonic anhydrases of 219 American ponies and 76 riding horses has revealed the presence of five variants of the low-activity CA B isozyme and two variants of the high-activity CA C isozyme. The previously undetected variant of CA C was found only in the pony population and had an allele frequency of 8.9%. A family study of animals possessing the CA B variant A2 showed an unexpected high frequency of inheritance.
The frequency of infertility in thoroughbred mares. In a group of 852 Thoroughbred mares, 69-7% had foals which survived beyond 6 weeks, 7-1% had dead, premature or full-term foals and 1-1% had foals which died within 6 weeks after birth. Possible factors which may have influenced these data are mentioned.
The gnotobiotic foal in the study of infectious diseases. A method of rearing germ-free gnotobiotic foals is described. To date, four foals have been infected with rhinopneumonitis and the only clinical signs of infection have been a transient fever and leukopaenia; no detailed results are, as yet, available.
A review of the influence of nutrition upon the oestrous cycle and early pregnancy in the mare. Attention is drawn to the beneficial effect of improved nutrition during winter and early spring on the ovarian activity of mares. Furthermore, the necessity of an adequate plane of nutrition during early pregnancy to prevent embryonic resorption is stressed.
A survey of eggs in the oviducts of mares. A total of 424 eggs was recovered from flushings of 176 pairs of oviducts. Of these eggs, 324 were in a state of advanced degeneration (Type 4) and ten appeared to have been recently ovulated (Type 1). The number of eggs/oviduct varied from 0 to 13, most being up to 3 eggs, but fifty oviducts contained no eggs. It is widely believed that unfertilized ova are selectively retained in the oviducts but an alternative explanation for their presence is put forward.
Control of fertility in Thoroughbred horses in West Germany. A central control system for German Thoroughbred horses is described. Autumn examination of mares and stallions enables them to be classified according to breeding potential. The results of 25 years of study are reported.
Retention of tubal eggs in mares. Genital tracts from 227 mares slaughtered in various reproductive states were investigated to study egg retention in the oviducts. Eggs were found in 88-2% of 212 non-pregnant mares; the number/mare ranged from 0 to 21, and averaged 4-34. Retained eggs were twice as common in heavy as in light breeds and were found more frequently in early than in late pregnancy. Eggs were not found in the oviducts of two anovulatory post-partum mares. A few globular masses, probably consisting of desquamated tubal mucosa, were frequently lodged in the distal region of the ampulla and appeared, to some extent ...
Experimental studies on equine herpesvirus type 1 infections. The EHV-1 viruses of fetal origin grew better and had a wider tissue culture host range than those isolated from horses with respiratory diseases. Comparisons of a fetal isolate (F/304) and a respiratory disease isolate (R/NM-3) in partly immune horses showed that the F/304 virus infected horses more readily, grew better in the nasopharynx, was more likely to cause abortion, and was excreted to a greater extent into the environment.