Objectives—To compare abomasal emptying rates in calves after suckling milk replacer or 3 common orally administered electrolyte solution components.
Animals—5 male calves < 35 days of age.
Procedures—Calves with a cannula fitted in the abomasal body were fed 2 L of milk replacer with or without parenteral administration of atropine (0.01 mg/kg, IV, then 0.02 mg/ kg, SC, q 30 min) or isotonic (150mM) solutions of sodium acetate, NaHCO3, or NaCl in a randomized crossover design. Abomasal emptying rates were determined via scintigraphy, acetaminophen absorption, ultrasonography, and change in abomasal luminal pH.
Results—Scintigraphic half-emptying time, time of maximal plasma acetaminophen concentration, ultrasonographic half-emptying time, and pH return time indicated similar abomasal emptying rates following suckling of isotonic sodium acetate, NaHCO3, and NaCl solutions, whereas the emptying rate of milk replacer was significantly slower. Mean maximal abomasal luminal pH was highest following suckling of NaHCO3 (pHmax = 7.85) and lowest following suckling of NaCl (pHmax = 4.52); sodium acetate (pHmax = 6.59) and milk replacer (pHmax = 5.84) yielded intermediate pH values.
Conclusions and Clinical Relevance—Isotonic solutions of sodium acetate, NaHCO3, and NaCl were rapidly emptied from the abomasum but varied markedly in their ability to alkalinize the abomasum. Sodium bicarbonate–containing orally administered electrolyte solution might increase the frequency of infection or severity of clinical disease in diarrheic calves treated for dehydration by causing prolonged abomasal alkalinization.
Objective—To measure the amount of heat generated
during 3 methods of equine dental reduction with
Design—In vitro study.
Sample Population—30 premolar and molar teeth
removed from mandibles of 8 equine heads collected
at an abbatoir.
Procedure—38-gauge copper-constantan thermocouples
were inserted into the lingual side of each tooth
15 mm (proximal) and 25 mm (distal) from the
occlusal surface, at a depth of 5 mm, which placed
the tip close to the pulp chamber. Group-NC1 (n = 10)
teeth were ground for 1 minute without coolant,
group-NC2 (10) teeth were ground for 2 minutes without
coolant, and group-C2 (10) teeth were ground for
2 minutes with water for coolant.
Results—Mean temperature increase was 1.2°C at
the distal thermocouple and 6.6°C at the proximal
thermocouple for group-NC1 teeth, 4.1°C at the distal
thermocouple and 24.3°C at the proximal thermocouple
for group-NC2 teeth, and 0.8°C at the distal thermocouple
and –0.1°C at the proximal thermocouple
for group-C2 teeth.
Conclusions and Clinical Relevance—In general, an
increase of 5°C in human teeth is considered the maximum
increase before there is permanent damage to
tooth pulp. In group-NC2 teeth, temperature
increased above this limit by several degrees, whereas
in group-C2 teeth, there was little or no temperature
increase. Our results suggest that major reduction
of equine teeth by use of power instruments
causes thermal changes that may cause irreversible
pulp damage unless water cooling is used. (J Am Vet
Med Assoc 2004;224:1128–1132)
Case Description—6 horses were determined to have torsion of a liver lobe at 4 referral institutions over a 21-year period.
Clinical Findings—Clinical findings were nonspecific but often included signs of marked inflammation. Two of the 6 horses were examined because of colic, and 2 were assessed because of peritonitis that failed to respond to treatment; the remaining 2 horses were examined because of nonspecific clinical signs that included inappetence, lethargy, and weight loss. The results of laboratory tests were widely variable, and values for liver enzyme activities were typically within reference limits or only mildly increased. Most affected horses had markedly increased peritoneal nucleated cell counts.
Treatment and Outcome—Exploratory laparotomy and resection of the affected liver lobe was performed in 5 horses. Three of those patients survived to discharge.
Clinical Relevance—Results suggested that diagnosis of liver lobe torsion in horses may be difficult because clinical signs and results of laboratory testing are nonspecific and variable. Most affected horses had markedly abnormal peritoneal fluid. The prognosis for hepatic lobe torsion can be good, and early surgical correction is expected to improve outcome.
Case Description—Two geldings, aged 11 and 17 years, were examined for treatment of ureteroliths located approximately 10 cm proximal to the bladder.
Clinical Findings—Ureteral obstruction was an incidental finding in 1 horse that was referred because of urinary tract obstruction and a cystic calculus. This horse did not have clinical or laboratory evidence of renal failure, although severe hydronephrosis was evident on transabdominal ultrasonography. The second patient had a serum creatinine concentration of 6.3 mg/dL (reference range, 0.8 to 2.2 mg/dL) and mild hydronephrosis of the affected left kidney.
Treatment and Outcome—In both patients, the obstructed ureter was exteriorized through a flank incision as a standing procedure, and the calculus was crushed and removed with a uterine biopsy forceps introduced through a ureterotomy approximately 25 cm proximal to the calculus. The cystic calculus was removed through a perineal urethrostomy by lithotripsy, piecemeal extraction, and lavage. The horse without azotemia developed pyelonephritis in the affected kidney and was euthanatized because of complications of a nephrectomy 13 months later. In the horse with azotemia, the serum creatinine concentration decreased after surgery, and the horse returned to its intended use. However, it was euthanatized approximately 2 years after surgery because of progressive renal failure, and a large nephrolith was found in the previously unobstructed right kidney.
Clinical Relevance—The technique used for ureterolith removal was successful in both horses in this report, did not require sophisticated equipment, and could be effective in the early stages of ureteral obstruction as a means of restoring urine flow and renal function. The outcome in the horse with advanced unilateral renal disease without azotemia would suggest that nephrectomy should be considered as a treatment in such patients.
OBJECTIVE To purify and characterize equine vitamin D-binding protein (VDBP) from equine serum and to evaluate plasma concentrations of VDBP in healthy horses and horses with gastrointestinal injury or disease.
ANIMALS 13 healthy laboratory animals (8 mice and 5 rabbits), 61 healthy horses, 12 horses with experimentally induced intestinal ischemia and reperfusion (IR), and 59 horses with acute gastrointestinal diseases.
PROCEDURES VDBP was purified from serum of 2 healthy horses, and recombinant equine VDBP was obtained through a commercial service. Equine VDBP was characterized by mass spectrometry. Monoclonal and polyclonal antibodies were raised against equine VDBP, and a rocket immunoelectrophoresis assay for equine VDBP was established. Plasma samples from 61 healthy horses were used to establish working VDBP reference values for study purposes. Plasma VDBP concentrations were assessed at predetermined time points in horses with IR and in horses with naturally occurring gastrointestinal diseases.
RESULTS The working reference range for plasma VDBP concentration in healthy horses was 531 to 1,382 mg/L. Plasma VDBP concentrations were significantly decreased after 1 hour of ischemia in horses with IR, compared with values prior to induction of ischemia, and were significantly lower in horses with naturally occurring gastrointestinal diseases with a colic duration of < 12 hours than in healthy horses.
CONCLUSIONS AND CLINICAL RELEVANCE Plasma VDBP concentrations were significantly decreased in horses with acute gastrointestinal injury or disease. Further studies and the development of a clinically relevant assay are needed to establish the reliability of VDBP as a diagnostic and prognostic marker in horses.
Objective—To determine effects of sodium
hyaluronate (HA) on corticosteroid-induced cartilage
matrix catabolism in equine articular cartilage
Sample Population—30 articular cartilage explants
from fetlock joints of 5 adult horses without joint disease.
Procedure—Articular cartilage explants were treated
with control medium or medium containing methylprednisolone
acetate (MPA; 0.05, 0.5, or 5.0 mg/mL),
HA (0.1, 1.0, or 1.5 mg/mL), or both. Proteoglycan (PG)
synthesis was measured by incorporation of sulfur
35-labeled sodium sulphate into PGs, and PG degradation
was measured by release of radiolabeled PGs
into the medium. Total glycosaminoglycan (GAG) content
in media and explants and total explant DNA
Results—Methylprednisolone acetate caused a
decrease in PG synthesis, whereas HA had no effect.
Only the combination of MPA at a concentration of
0.05 mg/mL and HA at a concentration of 1.0 mg/mL
increased PG synthesis, compared with control
explants. Methylprednisolone acetate increased
degradation of newly synthesized PGs into the medium,
compared with control explants, and HA alone
had no effect. Hyaluronate had no effect on MPAinduced
PG degradation and release into media.
Neither MPA alone nor HA alone had an effect on total
cartilage GAG content. Methylprednisolone acetate
caused an increase in release of GAG into the medium
at 48 and 72 hours after treatment. In combination,
HA had no protective effect on MPA-induced
GAG release into the medium. Total cartilage DNA
content was not affected by treatments.
Conclusions and Clinical Relevance—Our results
indicate that HA addition has little effect on corticosteroid-
induced cartilage matrix PG catabolism in articular
cartilage explants. (Am J Vet Res 2005;66:48–53)
Objective—To examine the relationship between abdominal surgery and nosocomial Salmonella infections and the relationship between high caseload in combination with abdominal surgery and nosocomial Salmonella infections in hospitalized horses with signs of gastrointestinal tract disease.
Procedures—To accomplish the first objective, 1 to 4 control horses were matched with each nosocomial case horse on the basis of admission date of a primary case horse. The frequency of abdominal surgery and other investigated exposure factors were compared between nosocomial case horses and control horses. For the second objective, 4 control horses were matched with each nosocomial case horse on the basis of year of admission. The frequency of high caseload (≥ 26 inpatients), abdominal surgery, and other factors was compared between nosocomial case horses and control horses.
Results—The odds of nosocomial Salmonella infection were 8 times as high (odds ratio = 8.2; 95% confidence interval = 1.11, 60.24) in horses that underwent abdominal surgery, compared with the odds for horses that did not undergo surgery. High caseload alone or in combination with abdominal surgery was not associated with increased risk of nosocomial Salmonella infection.
Conclusions and Clinical Relevance—Abdominal surgery was identified as a risk factor for nosocomial Salmonella infections in horses. Horses that undergo abdominal surgery require enhanced infection control and preventative care. Risk of nosocomial Salmonella infections may be reduced by implementation of biosecurity measures (such as the use of plastic boots, gloves, and footbaths) immediately after surgery.