Article on tying up

["B. Miskimmin/J. Curtis" <limnos@junction.net>]

Just in case anyone is getting the impression that there is one simple
explanation for tying up (most commonly thought to be lactic acid buildup),
here is an interesting and well-written article by R.N. Oglesby DVM on the
subject:
http://www.horseadvice.com/articles/diseases/lameness/rhabdomyolysis.html

To quote from Dr. Oglesby's article on
Possible Causes:

"There have been several proposed causes for tying up. The different
histories, and varying treatments that horses respond to, strongly suggest
that we are looking at several different diseases. Some proposed causes are:

•Altered carbohydrate metabolism 
Recent work has identified abnormal carbohydrate metabolism as a cause in
many breeds of tying up. The others on the list are at this time unproven
causes of the problem. 
•Hypotension and Electrolyte imbalances
Horses which tie up during or following exercise frequently have
electrolyte imbalances. These imbalances cannot be diagnosed with simple
blood testing. •Lactate build up (unproven) 
•Too little oxygen getting to the muscles (unproven) 
•Vitamin E \ selenium deficiencies (unproven) 
•Hypothyroidism (unproven) 
•An interesting observation by the University of Calif. is that ear ticks
(Otobius megnini) have been associated with muscle spasms in more than half
a dozen cases. These muscle spasms were very much like tying up. In each
case muscle enzymes were elevated. When the ear ticks were treated the
horses got over the spasms. Other signs identified with theses horses were
colic, tremors, and seizures. (JAVMA, v207, n1)" END of quote.

I would suggest that where the proposed cause is listed as "unproven", it
likely means that the hypothesis has not been adequately tested.  It does
not necessarily mean that the proposed cause is incorrect (although it MAY
mean exactly that).  I say this because nowhere did Dr. Oglesby state that
the proposed cause was "proven to be incorrect". The article has lots of
other information on tying up and is well worth reading.  Hope this helps.

Brenda