Risks and variations
Though these miniatures are largely Shetland derived, the constant breeding decisions designed to produce small size, have
lead to significant differences between minis and other pony breeds. Veterinarians treating miniatures should be aware that
biochemical values for some blood parameters are significantly different between miniatures (AMH) and full-size horses (FSH).
Minis tend to have fewer red blood cells, lower hemoglobin and reduced overall PVC (See Table 1). They have lower T3 and T4
levels naturally and also seem to have a higher incidence of hypothyroidism than seen in FSH. Serum potassium is normally
elevated in minis.
Table 1. Clinical biochemical values for american miniature horses(Amh) and full-size horses (fsh)
Miniature horses grow a proportionately thicker and longer coat in the winter compared to most other horse breeds. Therefore,
they need substantial protein content in their diets during these months. Nutrition in the miniature is challenging because
these special horses have certain unique dietary needs, but they are volume limited and must not be overfed. Hepatic lipidosis
can be a significant problem in miniatures, though it is relatively rare in the general horse population, according to Dr.
Terry Gerros of Salem, Ore. Gerros says stressful conditions — such as transport, showing and recent foaling, along with improper
diet — can predispose to hyperlipemia and should be avoided by feeding miniatures a lower-calorie and higher-fiber diet.
Miniatures seem to be poor drinkers in general, and many breeders comment that adequate water intake, though one of the most
basic concepts in equine nutrition, is very important in these horses. Remind your clients to be sure that all of their minis,
even the smallest, have easy access to fresh water sources. Because of this tendency to reduce fluid intake, miniatures are
more prone to fecoliths or enteroliths compared to full-size horses. This problem and potential diagnosis always should be
on the mind of a clinician presented with a miniature exhibiting signs of colic.
Also, potentially contributing to feco-liths and colic are problems with dentition that results in poor chewing. Miniatures
have large teeth for their proportionately small jaws, and many miniatures often exhibit various degrees of dwarfism, which
can affect the orientation of the teeth and the bones of the jaw. Routine dental examinations and correct management can improve
the health and longevity of miniatures significantly. Healthy and well-cared-for miniatures are among the longest lived of
all equine breeds; a mini named Angel, which lived at the Horse Protection Society of North Carolina, survived for 50 years
with good veterinary care. Miniature hand floats are available from many companies, as well as attachments for power equipment,
that work in the small mouths of miniatures.
Deworming programs are very important in miniatures because intestinal parasites grow to the same size even though they are
living in a much smaller host. Proportionally then, miniatures are at greatest risk from intestinal parasites, and solid deworming
programs should be strictly adhered to. Clients should try to use good weight estimations, with assistance from a veterinarian
if needed, when deworming to avoid under dosing, with resultant poor worm control, and overdosing, with potentially dangerous
medical consequences. Daily dewormers work well in miniatures and because of their small size, such a daily program along
with periodic rotational paste can be efficient, effective and economical.
These miniatures show the typical domed head and shortened face that characterize dwarfism in the breed.