Objective—To determine the value of serial measurements of peritoneal fluid lactate concentration (PFL) for detecting strangulating intestinal lesions (SLs) in referred horses with signs of colic.
Design—Retrospective cohort study.
Animals—94 horses with signs of colic.
Procedures—Medical records of horses evaluated between September 2006 and February 2010 because of signs of colic were reviewed. All included horses had ≥ 2 peritoneal fluid samples collected, including one at admission and another within 1 to 6 hours after admission. Of the 94 horses, 26 were assigned to the SL group on the basis of findings at surgery or necropsy and 68 were assigned to the nonstrangulating intestinal lesion group because their signs of colic resolved with medical management. Peritoneal fluid lactate concentration was measured by use of a handheld lactate monitor. Data were analyzed by use of univariable and multivariable logistic regression analysis.
Results—PFL at admission > 4 mmol/L, an increase in PFL over time, and especially an increase in PFL over time in horses with a PFL < 4 mmol/L at admission (OR, 62; sensitivity, 95%; specificity, 77%) were significant predictors of horses with an SL.
Conclusions and Clinical Relevance—Serially determined PFL was a strong predictor for differentiating horses with SLs from horses with nonstrangulating intestinal lesions. Given the high OR, sensitivity, and specificity of these tests, serially determined PFL may have potential as a screening test for identifying horses with SLs. Further evaluation of the clinical value of PFL for predicting SLs in a prospective, multicenter study is warranted.
Objective—To compare the outcome of horses with nephrosplenic entrapment of the large colon (NSELC) that were treated nonsurgically by IV administration of phenylephrine and exercise with that of horses treated by IV administration of phenylephrine and a rolling procedure under general anesthesia.
Design—Retrospective case series.
Animals—88 horses with NSELC.
Procedures—Horses examined between 2004 and 2010 because of acute abdominal pain that had NSELC on the basis of findings on abdominal palpation per rectum, abdominal ultrasonography, or both were included. Medical records were reviewed to obtain information on treatment (IV administration of phenylephrine and exercise vs IV administration of phenylephrine and a rolling procedure) and outcome.
Results—Overall, 85% (75/88) of horses with NSELC responded to exercise or rolling under general anesthesia. The success rate of rolling under general anesthesia (42/50 [84%]) was significantly higher than the success rate of exercise after IV administration of phenylephrine (24/38 [63.2%]). Resolution of NSELC was achieved by rolling under general anesthesia in 8 of 14 horses that initially failed to resolve with exercise.
Conclusions and Clinical Relevance—A rolling procedure performed under general anesthesia had a higher success rate than exercise after IV phenylephrine administration for resolution of NSELC in horses, suggesting that rolling could be considered as the initial medical treatment. The rolling procedure may be labor intensive and should only be attempted in a surgical facility in the event that exploratory laparotomy is required
OBJECTIVE To evaluate 2- and 3-year-old and career race performance of Thoroughbred racehorse prospects with and without osteochondral fragmentation of the accessory carpal bone (ACB) identified on yearling presale radiographs.
DESIGN Retrospective, matched cohort study.
ANIMALS 47 nonlame Thoroughbreds with (exposed cohort) and 94 nonlame Thoroughbreds without (unexposed cohort) osteochondral fragmentation of ACB facture identified on yearling sales repository radiographs.
PROCEDURES Repository radiographic interpretation reports for September yearling sales of a large Kentucky auction house from 2005 through 2012 were reviewed, and race records were collected and analyzed. Race performance was compared between horses with and without ACB fracture chosen from the same sale to identify associations between racing performance and ACB fracture.
RESULTS No significant differences were identified between horses with or without ACB fracture in their incidence of starting a race as a 2- or 3-year-old and the number of races started, earnings, or earnings per start for 2- or 3-year-old or career race performance. There was no significant difference in performance between horses with or without concurrent carpal osteoarthritis, nor did performance differ between horses with ACB fracture alone and those with ACB fracture and other radiographic abnormalities found to be associated with poorer performance in previous studies.
CONCLUSIONS AND CLINICAL RELEVANCE ACB fracture with or without carpal osteoarthritic changes identified on repository radiographs of Thoroughbred yearlings was not associated with poorer racing performance or lower likelihood of starting a race as a 2- or 3-year-old, compared with outcomes for unaffected horses.
Objective—To compare bony changes in the metacarpophalangeal joint (MCPJ) of racehorses with (cases) and without (controls) biaxial proximal sesamoid bone (PSB) fracture as determined by 2 grading scales applied to images of cadaveric forelimbs obtained by means of standing MRI (sMRI).
Sample—Forelimbs from 74 Thoroughbred racehorses (21 cases and 53 controls) that were euthanized at a Florida racetrack.
Procedures—Both forelimbs were harvested from cases and controls. Each forelimb underwent sMRI to obtain images of the MCPJ. Two grading scales were described and used for image evaluation; one assessed the density of the PSBs, and the other assessed the integrity of the subchondral bone (SCB) plate at the distopalmar aspect of the third metacarpal bone (MC3). Logistic regression was used to compare the grades between case and control limbs.
Results—Biaxial PSB fracture was associated with a total PSB grade (sum of lateral and medial PSB grades) ≥ 5 for the fractured limb, total MC3 SCB grade (sum of lateral and medial MC3 SCB grades) ≥ 5 for the contralateral limb, and the presence of orthopedic disease in the contralateral MC3.
Conclusions and Clinical Relevance—For cases with biaxial PSB fracture, the density of the PSBs in the affected limb was greater and the MC3 of the contralateral limb was more likely to have orthopedic disease, compared with those for controls. Further evaluation of sMRI as a screening tool for identification of racehorses at risk of biaxial PSB fracture is warranted. (J Am Vet Med Assoc 2015;246:661–673)
OBJECTIVE To compare bony changes of the third metacarpal bone (MC3) of Thoroughbred racehorse cadavers with (cases) or without (controls) catastrophic condylar fracture by use of standing MRI.
SAMPLE 140 forelimbs from 26 case horses (both forelimbs) and 88 control horses (single forelimb).
PROCEDURES Bone marrow lesions (BMLs), identified as a decrease in T1-weighted (T1W) signal and increases in T2*-weighted (T2*W) and short tau inversion recovery (STIR) signals, and dense bone volume percentage (DBVP), identified as decreases in T1W, T2*W, and STIR signals, in the distopalmar aspect of MC3 were recorded. Logistic regression was used to compare fractured and nonfractured limbs of cases and fractured limbs of cases with randomly selected limbs of controls.
RESULTS Among cases, fractured limbs were significantly more likely to have BMLs (26/26 [100%]) than were nonfractured limbs (7/26 [27%]). Fractured limbs of cases were significantly more likely to have BMLs (26/26 [100%]) than were limbs of controls (6/88 [7%]). Among cases, there was no significant difference in DBVP between fractured and nonfractured limbs in lateral (26% vs 21%, respectively) or medial (25% vs 20%, respectively) condyles. However, DBVP was significantly greater in fractured limbs of cases than in limbs of controls for lateral (26% vs 16%, respectively) and medial (25% vs 18%, respectively) condyles.
CONCLUSIONS AND CLINICAL RELEVANCE Standing MRI revealed a significantly greater degree of bone change in racehorses with condylar fracture when comparing fractured and nonfractured limbs of case horses and fractured limbs of case horses with randomly selected limbs of control horses.
Objective—To determine the association between
high-speed exercise and risk of injury while racing
among Thoroughbreds in Kentucky.
Design—Matched case-control study.
Animals—206 Thoroughbreds that sustained a musculoskeletal
injury while racing and 412
Thoroughbreds that were not injured during the same
Procedure—Data regarding official timed workouts
and races and the Beyer's numbers for the 3 races
before the race during which injury occurred were
extracted from past performance charts and compared
between injured horses and control horses.
Results—For injured horses, cumulative distance of
high-speed exercise during the 1- and 2-month periods
prior to the race in which injury occurred was significantly
less than that of control horses; for either
period, a difference of 10 furlongs was associated
with approximately 2-fold greater risk of injury.
Beyer's numbers were significantly higher for injured
horses than for control horses. These effects
remained significant after adjusting for age and
results of prerace physical inspection.
Conclusions and Clinical Relevance—In Kentucky,
injured horses had significantly less cumulative highspeed
exercise than did control horses during the 1-
and 2-month periods prior to the race in which injury
occurred. These results differ from those observed in
California. The association of injury with cumulative
high-speed exercise appears to vary among regions in
the United States. (J Am Vet Med Assoc 2000;
Objective—To compare endoscopic findings of the
upper portion of the respiratory tract in Thoroughbred
yearlings with their subsequent race records to determine
whether subjective assessment of airway function
may be used as a predictor of future racing performance.
Animals—427 Thoroughbred yearlings.
Procedures—Endoscopic examination findings were
obtained from the medical records and the videoendoscopic
repository of the Keeneland 1996
September yearling sales. Racing records were
requested for the yearlings through the end of their 4-year-old racing season (1997–2000). Twenty-nine measures
of racing performance were correlated with
endoscopic findings. Subjective arytenoid cartilage
movement grades were determined, using a 4-point
grading scale (grade 1 = symmetrical synchronous
abduction of the arytenoid cartilages; grade 4 = no
substantial movement of the left arytenoid cartilage).
Results—Of the 427 Thoroughbred yearlings included
in this study, 364 established race records, and 63 did
not. Opinions regarding suitability for purchase, meeting
conditions of the sale, and the presence of
epiglottic abnormalities had no significant association
with racing performance. Arytenoid cartilage movement
grades were significantly associated with many
of the dependent variables. However, palatine abnormalities
were not predictive of inferior racing performance.
Conclusions and Clinical Relevance—Thoroughbred
yearlings with grade-1 and -2 arytenoid cartilage
movements had significantly better racing performance
as adults, compared with yearlings with grade-
3 arytenoid cartilage movements. In contrast, epiglottic
and palatine abnormalities were not predictive of
inferior racing performance. Therefore, evaluation of
laryngeal function, but not epiglottic or palatine abnormalities,
using the 4-point grading system, should be
the major factor in developing recommendations for
prospective buyers. (J Am Vet Med Assoc 2001;219: