In a message dated 3/16/2005 6:28:15 A.M. Central Standard Time,
[log in to unmask] writes:

The  problem of the fusion together of lumbar vertebrae is one I am dealing
with  in my current research project, comparing riding, traction and
free-living  horses. Such phenomena are described in the veterinary
literature. For  example:

Townsend, H. G. G. and D. H. Leach (1984). "Relationship  between
intervertebral joint morphology and mobility in the equine  thoracolumbar
spine." Equine Veterinary Journal 16(5):  461-65.

Stecher, R. M. (1961). "Ankylosing lesions of the spine of the  horse."
J.A.V.M.A. 138(5): 248-55.

There doesn't seem to be any  concensus about why the vertebrae fuse. And
there probably is no simple  answer. Such fusions are not uncommon, as you
can see from the above  articles. I have seen fusion between the 5th and 6th
lumbar vertebrae in a  4 year old Chinese chariot horse. I think that the
horse was too young for  the fusion to be either age related or probably
even life-style related,  since at 4 years it couldn't have been used long
for  traction.

Interesting. I don't have enough of a sample of Romano-Dutch horses  to make
any firm statements about the vertebral fusion as a breed or population  trait
(as Melanie Wilson suggests), but the frequency of the phenomenon in  general
certainly raises that possibility. I also have an email out to a  colleague
who is a lifelong rider and has worked as a veterinarian's assistant.  If she
offers any additional insight, especially from the medical end, I'll be  sure
to post it here.

Erik  Filean, M.A.
Department of Anthropology
114 Macbride Hall
The  University of Iowa
Iowa City, Iowa, USA 52242