The Taboo
Topic DWAR
Emotion often rules the breeding of horses . Perhaps you ’ ve found yourself encouraged by the perceived need to produce a copy of a beloved steed whose qualities are admired or possibly show ring rewarded . History is full of “ mistake ” crosses that produced champion results . But the flip side can be the creation of an unfavorable replica of those faults seen in the parents . Experts say In the Miniature breed , the stakes for breeding arbitrarily are even higher . The genetic mutation , dwarfism is also thrown in for good measure and can produce a horse with multiple physical maladies and heartbreaking results .
Dwarfism is defined as the “ underdevelopment of the body characterized by an abnormally short stature often with underdeveloped limbs and other defects .” Dwarfism is a recessive genetic disorder where both parents must pass on an affected allele to the offspring . Equine dwarfism is most prevalent in Shetland ponies , Miniature horses , Friesians , mustangs , and miniature donkeys .
Dwarfism was very prevalent in the early days of Miniature horse breeding . When “ little horses ” were at their zenith , correct breeding practices and conformation considerations were merely an afterthought . The pursuit of a quick monetary return assured the smallest equine would bring the largest price tag . It ’ s taken 40 years , but in many breeding programs dwarfism is on the downhill slide , thanks to selective breeding , perfected by educated horsemen and women . w
The birth of a dwarf foal is often an accident and unexpected . To produce a dwarf foal , both parents must be carriers of the dwarf gene . But what makes it more confusing , is a breeding pair can have several normal foals before producing a dwarf . It can be the luck of the draw each time as to which copy of each pair of chromosomes is passed on . The same untested horses ( sire and dam ) can produce champion foals for years and then produce a dwarf . Although some breeders have seen a decline in the
30 Miniature Horse World SUMMER 2018 numbers of dwarves they themselves have produced , the bloodlines they ’ ve culled could continue to propagate the genes , unknowingly continuing the lineage that passes the mutation along .
WHY TEST ? Contrary to popular belief , there are unscrupulous people who breed to produce dwarves . To an unsuspecting novice or first time horse owner , their deformities are passed off as cuteness .
If you are actively breeding Miniatures , and you are not sure if the lines you are crossing are carriers , it would improve not only the breed for you to test , but it would likely increase the value of your herd . As stated before , you may own a horse that doesn ’ t exhibit any characteristics but may still be a carrier . If both parents carry one copy of the dwarf gene there is a 25 % chance that the foal will inherit two copies of the gene and thus , be a dwarf . If the foal just inherits the gene from one parent , it is a carrier but not a dwarf . The unknown still born , red – bag births or aborted dwarves are typically not documented by breeders and therefore remain the unknown pieces of the dwarf puzzle . As additional testing is completed on a broader base of bloodlines , it is hoped these foaling dystocias can be reduced or possibly eliminated from the breed . Recognizing a dwarf by sight can be tricky , if not impossible . Horses can appear perfect outwardly , but have deformities on the inside such as a collapsed pharynx . Some deviations or maladies don ’ t appear at birth but will materialize during the first years of life , such as seizures , breathing or choking episodes . Dwarves can vary in size , although most are between 18 and 25 inches with some slightly bigger .