Nerve Damage & Sweating... article for Carla

Robin <Eclectk1@...>

Hi Carla,
Found this over on "The Horse" ( again, I can't
state enough that I think this has got to be one of if not the
greatest source of current medical information out there for horse
owners right now. The magazine is well worth its subscription rate
in my mind... This article is from their website... I would think
that you can do a symmetry comparison with tail pulling, shoving hind
quarters etc. pretty darn well yourself, using some common sense and
looking for any and all difference between one side and the other...
just more food for your veterinarian, or for, even better, a major
vet hospital -- as to the choice between the two you have relatively
close to you, give each a call and ask to speak to their best equine
neurologist or neurological specialist -- and tell them up front
where you are, what the symptoms are & that they're slight, and that
you have both schools as an option and is there someone at one that
they would think would be particularly the better bet for your
situation... these guys at vet schools are generally GREAT at
fielding this sort of conversation... Looking forward to hearing how
this is progressing for you & your baby....

Desert Springs Sport Horses
(best viewed in explorer 4.x or newer)

Frank Milne Lecture: The Equine Spine


For the third year in a row, the AAEP offered a Frank Milne State of
the Art Lecture, sponsored by Pfizer Animal Health. The subject of
the in-depth talk this year was the spinal cord. The lecturer was
I.G. Joe Mayhew, BVSc, PhD, Dipl. ACVIM, FRCVS, Dipl. ECVN, of the
University of Edinburgh in Scotland.

Mayhew divided the lecture into two parts--"The Healthy Spinal Cord"
and "The Diseased Spinal Cord."

The spinal cord of a 500 kilogram (approximately 1,100-pound) horse,
he said, is two meters (about 6 1/2 feet) long.

"The lengths of these spinal (and corresponding vertebral) sections,"
he said, "are important in explaining why focal compressive spinal
cord lesions in horses less often result in evidence of gray matter
damage such as profound weakness, reflex loss, and muscle atrophy and
sensory loss compared with evidence in small animals."

Basic tests that should be included in a physical examination to
assist in detection of a spinal cord disorder, he said, include
symmetry of neck, trunk, and limbs; external thoracolaryngeal (slap)
reflex; tail and anal tone; anal reflex; examination of rectum and
bladder; postures adopted at rest; gait at walk and trot; gait while
turning; and faster gaits.

There also are certain syndromes wherein an organic spinal cord or
vertebral column lesion might be suspected, but usually not proved,
Mayhew said. They include prominent toe dragging; intermittent,
unusual lameness; prominent sinking with dorsal lumbar pressure;
throwing to the ground when a saddle is applied; rearing violently
when first ridden; shivering; string-halt-like movements; other
spastic movements; extreme difficulty getting up; and lying down a

In an effort to locate possible lesions, Mayhew said, the
practitioner should conduct a neurological examination.

"After evaluation of the head for evidence of brain and cranial nerve
disorders," he said, "an evaluation of the neck, forelimbs, trunk,
hindlimbs, tail, and anus is then undertaken. Evidence of bony and
muscular asymmetry, localized sweating, focal muscle atrophy,
decreased pain perception, and localized painful response should be
searched for and documented.

"Areas of sweating and decreased sensation, and depths and diameters
of muscle masses suspected as being atrophied, should be measured
accurately. The degree of limb involvement and the characteristic of
any abnormality are recorded in order to determine the site and
extent of any neurological lesion.

"Extensor weakness in a limb is best evaluated by observing for
muscle trembling, buckling on a limb when turning, and the ease in
which the patient can be pulled to the side by the tail, both while
standing still and while moving.

"Flexor weakness may be more evident as dragging of a toe and a low
foot flight, particularly while turning.

"Subtle weakness in the thoracic (front) limbs may be accentuated by
performing a hopping test wherein one forelimb is held up and the
horse made to hop laterally away from the examiner on the other

"Pelvic limb and/or thoracic limb weakness can be detected by
attempting to pull on the halter and tail at the same time. Normal,
alert horses resist such pulling whereas a weak animal is easy to
pull to the side.

"Mild degrees of ataxia (lack of muscle coordination) can be detected
by performing additional postural maneuvers. Considerable time
usually is spent in performing serpentine maneuvers, circling wide
and tight, elevating the head while walking the patient on a flat and
a sloped surface, turning tightly upon stopping abruptly from a trot,
and backing.

"The overall severity of any gait abnormality in each of the four
limbs can be graded 1 through 4, as subtle, mild, moderate, or

When the neurological examination is completed, Mayhew said, the
examiner might be able to decide if and where any possible spinal
lesion exists. If it still isn't clear, he said, the examiner should
return to the patient for an even more critical evaluation.

Mayhew described a number of spinal cord disorders, their causes, and
treatment protocols.

He concluded his presentation with these words: "If this paper sparks
an interest in diseases of the spinal cord of horses in just one
practitioner, it will have been worthwhile. I am sure that Dr. Frank
Milne would agree with that."

--Les Sellnow


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