Even though the genetic defect known as Warmblood Fragile Foal Syndrome (WFFS) has been taking the warmblood breeding world by storm for the past two months, it has taken until 6 June 2018 for the World Breeding Federation for Sport Horses (WBFSH) to issue a statement.
WBFSH will wait until their General Assembly in December (!) to discuss the defect with the various studbooks and decide on measures. It remarkably praises the action of the studbooks to ordered their breeders test their horses (only NRPS, KWPN and Swedish warmblood have made stallion testing mandatory!).
However the WBFSH does not even touch upon the lackadaisical attitude of the German studbooks, who refuse to oblige their stallion keepers to test their breeding stallions, but once again put the financial burden and responsibility on the shoulders of the mare owners!
Statement WBFSH on WFFS
To date the rare genetic mutation that results in Warmblood Fragile Foal Syndrome (WFFS) has been fairly unknown. It recently started gaining massive media attention.
The syndrome is characterised by soft tissue abnormalities that display in the form of extremely fragile and friable skin, lax and hyper-extensible limb joints, as well as lesions on mucosal surfaces. Skin may tear and ulcerate easily as a result of contact with normal surroundings. The condition is fatal, due to the high rate of infections of lesions and skin tears. Foals are usually euthanised within a few days of birth.
The recessive mutation will only result in an affected foal if the genotype of the foal is homozygous for the recessive gene. When breeding to two carriers (N/WFFS) to each other, there is a 50% chance that offspring born are also carriers. The chance of an affected foal (WFFS/WFFS) when breeding two carriers to each other is 25%, as is the chance of breeding a non-carrier (N/N).
Since an affected foal inherits the disease by receiving one defective gene from each parent, the birth of affected foals can be prevented by breeding a carrier to a non-carrier. In this case there is an equal chance of producing a non-carrier or a carrier foal.
At present there are various reported statistics on the prevalence of carriers in the warmblood population. Some references cite around 6%, whereas some even cite around 10% or 11%. This is an indication that we do not know enough about the disease, as a much bigger population of horses needs to be tested for carrier status to obtain statistically significant numbers.
The WBFSH believes that there is no need for immediate panic. However, every foal lost has a significant impact, either emotional, financial or both, on the breeder and the mare. Therefore, the President of the WBFSH considers it a priority that more information becomes available through research and collection of accurate statistics, in order to obtain a clear picture of the impact or potential impact this disease may have on the warmblood breeding industry. Current statistics may not be accurate to due unknowingly undiagnosed cases of affected foals born or pregnancies aborted.
During the next WBFSH General Assembly, taking place in Hungary in December 2018, horse welfare will be a central theme, and genetic diseases including WFFS will be discussed as a relevant topic with respect to this.
The WBFSH feels that its studbook members have dealt pro-actively and responsibly, giving their breeders sound advice about how to best handle the present situation. Many have quickly started recommending the testing of breeding stock, such that breeders can make informed choices when selecting stallions for their mares. This is an important part of responsible breeding and horse welfare and should always be at the forefront of every breeder’s mind in breeding matters in general.
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