Hyperlipemia is a somewhat rare occurrence in the general horse population but seems to be slightly more prevalent in the miniature breed. This condition comes on suddenly and can have deadly consequences if not diagnosed rapidly and treated in an aggressive manner.
 
Hyperlipemia is self explanatory if a person examines the word carefully. “Hyper” means overactive, over-abundant, excessive, etc. “Lipemia” is derived from the word lipid which means fat. For some reason fat reserves in the horse rapidly start entering the bloodstream. As we understand it, this overloads the horse’s liver and if the situation is not corrected very quickly, liver failure occurs and the horse dies.
 
From the resources we have consulted, there does not seem to be a clear picture as to why horses suddenly contract this condition. It can effect them in a matter of a few days with fatal consequences if it goes undiagnosed and untreated. There seems to be a connection to stress situations such as foaling, transportation, high internal parasite load, excessive weight; although under-weight horses can also be effected. Mares who have recently foaled or who are lactating (producing milk for the foal) appear to be the highest risk group.
 
From what we have been told, the most notable symptom is that the horses become quite depressed and refuse to eat almost everything. They are not interested in grain, hay or pasture. We have not personally experienced this critical problem with any of our horses but have been in contact with a number of folks who have.  All of those who we have talked with have said that the situation was very touch and go with their horse.  The key appears to have been when the problem was diagnosed.  Those who went to the veterinarian early had greater success than those who took the “hide and watch” attitude at home for a few days.  Apparently the liver becomes so overwhelmed with the metabolized fat that it cannot function properly.  Early diagnosis is the key with aggressive treatment to follow.  Some have told us that their veterinarians were not well versed on Hyperlipemia which caused some delay in the diagnosis and treatment.  Some of the cases were treated successfully.  Unfortunately others were not and wonderful horses have been lost in a matter of a few days due to this fast progressing situation.
 
Diagnosis of this problem is through a variety of blood tests. Treatment is to stem the release of fat from the body tissues, break down the over abundant fat in the bloodstream, provide nutrition to the horse. Apparently the treatment can get exotic depending on how advanced the condition has become. Insulin and glucose are used to keep the body from releasing more fat into the blood stream. Heparin (an anti-coagulant) is used to break down the fat that is already in the bloodstream. The horse’s pH balance needs to be regulated. In short, Hyperlipemia is scary and definitely a life threatening condition that comes on quickly and requires immediate attention.
 
This would be a good topic for miniature horse owners to discuss with their veterinarians for precautionary reasons if for none other.