Hoof wall separation disease (HWSD) is an
autosomal
An autosome is any chromosome that is not a sex chromosome. The members of an autosome pair in a diploid cell have the same morphology, unlike those in allosome, allosomal (sex chromosome) pairs, which may have different structures. The DNA in au ...
recessive
In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and t ...
genetic hoof disease in
horse
The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 million y ...
s.
[UC Davis Veterinary medicine: ''Connemara Pony Hoof Wall Separation Disease'']
accessed April 25, 2015 Research is being carried out at, among others,
UC Davis School of Veterinary Medicine The University of California, Davis, School of Veterinary Medicine is the largest veterinary school in the United States. Established in 1948, the school is the primary health resource for California's various animal populations. In 2020, the school ...
in
Davis
Davis may refer to:
Places Antarctica
* Mount Davis (Antarctica)
* Davis Island (Palmer Archipelago)
* Davis Valley, Queen Elizabeth Land
Canada
* Davis, Saskatchewan, an unincorporated community
* Davis Strait, between Nunavut and Gre ...
,
California
California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...
.
[''Hoof Wall Separation Syndrome in Connemara Ponies'']
, Accessed November 4, 2014 The disease has been found in
Connemara ponies and was earlier referred to as hoof wall separation syndrome, HWSS.
Symptoms
The disease develops among foals from the age of one to six months and typically occurs during their first year of life.
The frontal edge of the hoof cracks and splits. Pieces of hoof wall chip off in bits. This cracking, chipping and peeling may involve the whole of the dorsal hoof wall. The deficit means that when the hoof wall reaches the ground (and weightbearing load) the wall breaks away from above the level of the sole. Thus the affected pony has to walk on the sole of the hoof with no support provided by the dorsal hoof wall. All four feet are similarly affected. This can be very painful for the animal, which may lead to the necessity of having the horse put down.
[ HWSD may be confused with ]white line disease
White line disease (also known as seedy toe) is a fungal infection of the horse's hoof. As the name suggests, it attacks the white line, which connects the sole to the hoof wall. It is sometimes mistaken for hoof wall separation disease, but is n ...
(onychomycosis
Onychomycosis, also known as tinea unguium, is a fungal infection of the nail. Symptoms may include white or yellow nail discoloration, thickening of the nail, and separation of the nail from the nail bed. Toenails or fingernails may be affected ...
)
Origin and cause
The disease is an autosomal recessive condition, which means that both parents of the foal must carry the gene in order for the disease to hit their offspring.[ The disease is associated with a ]frameshift mutation
A frameshift mutation (also called a framing error or a reading frame shift) is a genetic mutation caused by indels ( insertions or deletions) of a number of nucleotides in a DNA sequence that is not divisible by three. Due to the triplet nature ...
in the gene coding for the protein serpin B11.[
]
Tests and treatment
Genetic predisposition may be confirmed through a DNA test.[ There is no treatment as such, owners can attempt to manage the condition though various types of hoof care, and/or the use of special shoes. Such treatment is expensive and labour-intensive. Environmental conditions can make the condition worse (alternating wet/dry hooves). Protecting the hooves from such variations may reduce the effect of the disease.][
]
References
{{reflist
External links
Connemara Pony Research Group
The CPRG is a group of private individuals concerned about the hoof issue appearing in the Connemara Pony breed. It was this group that was responsible for initiating the genetic research into HWSD undertaken by the Bannasch Laboratory, U C Davis, California.
*More information on the conditions can be downloaded fro
Pamphlet on HWSD
Horse diseases
Equine hoof