EQUINE | Equine Disease Update
EQUINE | Equine Disease Update
Germany , South Africa , and South Korea re ¬ corded cases of contagious equine metritis . Eight cases involving six premises were confirmed in Germany , a single case in a stallion in South Africa , and 20 cases of2,086 horses surveyed were positive in South Korea .
A single case of equine coital exanthema ( EHV- 3 ) was confirmed in Kentucky , USA .
The USA reported eleven cases of Nocardioform placentitis and abortion in Kentucky associated with Amycolatopsis and / or Crossiella spp . infection .
Equine arteritis virus was detected in frozen semen during pre-entry quarantine by Argentina .
The USA reported a limited number of cases of salmonellosis , some due to serogroup B and others serogroup Cl Salmonellae . Clostridial enteritis in foals was recorded by the USA . Some were caused by C . difficile Type A Toxin genotype or Type B Toxin genotype , others by C . perfringens Type A Toxin genotype . Isolated cases of C . piliformis ( Tyzzer ’ s disease ) and C . novyi were also confirmed . Two cases of Coronavirus infection were recorded , neither life-threatening .
Several cases of equine proliferative enteropathy in foals were diagnosed in Kentucky and Pennsyl-vania , USA .
South Africa reported a reduced incidence of equine encephalosis , mostly in Gauteng and Mpumalanga Provinces compared to previous years . Cases of West Nile ( 22 ) and Middelburg virus ( 30 ) infections were detected across South Africa , mostly in Gauteng Province .
Genetics and Genomics in Racing : Speed Isn ' t Everything
Genetics refers to the study of genes and the way traits or conditions are passed down from one generation to another . Genomics , on the other hand , describes the study of all genes ( the genome ) including interactions of genes with each other and the environment . Although much of the genetic and genomic research done in Thoroughbreds is applied to racing performance , the full breadth of application for genetic and genomic research goes beyond that of faster horses .
Genetics and genomics allow for a more com ¬ plete understanding of both simple and complex diseases . From a genetic perspective , “ simple ” is a term used to describe a disease that follows a single gene pattern of inheritance . These diseases are controlled by one gene , with other genes and outside factors having very little influence ( i . e , the presence of the gene = disease ). Diseases in ¬ herited in this way are typically qualitative , where an animal either has the disease or it doesn ’ t ( e . g . lethal white foal syndrome ). Complex diseases , on the other hand , are usually controlled by not one but many different genes and are often affected by environmental factors , such as nutrition and living conditions ( e . g . Cervical Vertebral Stenotic Myelopathy aka Wobblers ). This combination of both genetic and environmental factors results in complex or “ multifactorial ” diseases . Basically , three different scenarios determine the manifesta ¬ tion of a complex disease :
No genetic predisposition + Environmental triggers = No clinical signs of disease
Genetic predisposition + No environmental triggers = No clinical signs of disease
Genetic predisposition + Environmental triggers = Highly varied clinical signs
As a result , complex genetic diseases can be extremely difficult to diagnose early and / or prevent using traditional methods such as pedigree analyses and veterinary evaluations . In some instances , a simple disease may even be classified as complex based on the inability
18 • Equine Health Update •