Objective—To examine total protein concentration
and cell counts of sequentially collected samples of
CSF to determine whether blood contamination
decreases in subsequent samples and whether formulas
used to correct nucleated cell count and total
protein concentration are accurate.
Procedure—For each horse, 3 or 4 sequential 2-ml
samples of CSF were collected from the subarachnoid
space in the lumbosacral region into separate
syringes, and blood was obtained from the jugular
vein. Total protein concentration, nucleated cell
count, and RBC counts were determined in all samples.
Results—Among 3 sequential samples, total protein
concentration and RBC count were significantly lower
in samples 2 and 3, compared with sample 1.
Nucleated cell count was significantly lower in sample
3, compared with sample 1. Among 4 sequential samples,
total protein concentration and RBC count were
significantly lower in samples 2, 3, and 4, compared
with sample 1. Nucleated cell count was significantly
lower in samples 3 and 4, compared with sample 1.
For 3 correction formulas, significant differences in
corrected values for nucleated cell count and total
protein concentration were detected between sample
1 and sample 3 or 4.
Conclusion and Clinical Relevance—Because
iatrogenic blood contamination decreases in sequential
CSF samples, a minimum of 3 samples should be
collected before submitting the final sample for analysis.
Formulas to correct nucleated cell count and total
protein concentration are inaccurate and should not
be used to correct for blood contamination in CSF
samples. (J Am Vet Med Assoc 2000;217:54–57)
Objective—To evaluate the safety of sodium bisulfate
for use in horse barn environments by determining its
irritant effect on skin and hooves.
Animals—6 female mixed-breed ponies.
Procedure—Sodium bisulfate was applied to clipped
intact skin of 6 ponies to evaluate its irritant effect
after single (48 hours) and repetitive (6 h/d for 10 days)
applications; similar areas of skin were used as
untreated control sites. In addition, sodium bisulfate
was applied to the sole of both front hooves of each
pony and covered with wet gauze, and the entire hoof
was covered with adhesive tape for 48 hours.
Results—Contact with moistened sodium bisulfate
for 48 hours had no effect on pony skin. Contact with
sodium bisulfate for 6 hours on 10 consecutive days
did not cause gross changes but did cause mild to
moderate microscopic changes including epidermal
necrosis, hyperkeratosis, capillary congestion,
edema, and diffuse mixed inflammatory cell infiltrate.
All changes were limited to the epidermis and superficial
dermis. Gross changes in hoof sole, signs of
lameness, and increase in digital pulse pressure or
pulse intensity were not detected.
Conclusions and Clinical Relevance—Duration of
contact with sodium bisulfate in this study was in
excess of that expected under typical husbandry conditions.
Despite this fact, gross changes in skin and
hooves were not detected. Microscopic lesions were
confined to the epidermis and superficial dermis.
Results suggest that contact with sodium bisulfate
under these conditions is safe. (Am J Vet Res
Objective—To compare the effect of thyrotropin-releasing hormone (TRH) administration on endogenous ACTH concentrations in healthy horses and those with pituitary pars inter-media hyperplasia and compare the test with the dexamethasone suppression test (DST).
Design—Prospective case series.
Animals—15 horses with clinical signs of pituitary pars intermedia dysfunction (PPID), 4 horses with equivocal signs of PPID, and 29 horses without signs of PPID.
Procedures—ACTH concentrations prior to and after administration of TRH were measured 61 times in 48 horses. Results of the DST (cortisol response) were compared with those of the TRH test in 29 horses. Thirty-three horses (24 with no clinical signs of PPID, 5 with clinical signs of PPID, and 4 with equivocal clinical signs of PPID) were euthanized and necropsied and their pituitary glands evaluated.
Results—ACTH concentrations increased in all horses, but magnitude and duration of increase were significantly higher in horses with PPID. Endogenous ACTH concentrations were influenced by season. The ACTH baseline concentrations and response to TRH were not correlated with results of the DST. Results of DST were abnormal only in clinically abnormal horses or those with pars intermedia hyperplasia, but were within reference range in 17 of 26 tests in these horses.
Conclusions and Clinical Relevance—The ACTH response to TRH is a useful test for diagnosis of pituitary gland hyperplasia, particularly in horses in which baseline ACTH concentrations are within reference range. The DST was specific but not sensitive and was inconsistent for individuals, and results often did not agree with the TRH test response.
Objective—To determine application rate and effectiveness
of sodium bisulfate to decrease the fly population
in a horse barn environment.
Sample Population—12 privately owned farms in
Procedure—Application rates of sodium bisulfate
were approximately 2.3 kg/stall, 1.1 kg/stall, and 0.5
kg/stall. Two or 3 stalls were treated, and 1 or 2 stalls
were not treated (control stalls) at each farm. Farm
personnel applied sodium bisulfate in treated stalls
daily for 7 days. Fly tapes were hung from the same
site in treated and control stalls. After 24 hours, the
fly tape was removed, flies adhering to the sticky surface
were counted and recorded, and a new fly tape
was hung. This procedure was repeated daily during
each of the testing periods.
Results—Following the application of 2.3 kg of sodium
bisulfate/stall, the numbers of flies collected on
the fly tape were significantly decreased in treated
stalls, compared with control stalls during the same
time periods on 9 of the 12 farms evaluated.
Following the application of 1.1 kg of sodium bisulfate/
stall, fly numbers were significantly decreased in
treated stalls on 6 of the 9 farms evaluated. Following
the application of 0.5 kg of sodium bisulfate/stall, fly
numbers were significantly decreased in the treated
stalls on 3 of the 4 farms evaluated.
Conclusions and Clinical Relevance—Our findings
suggest that sodium bisulfate would be effective for
fly control in horse barns. (Am J Vet Res 2000;