Objective—To characterize medial femoral condyle (MFC) morphometrics and subchondral bone density patterns in Thoroughbred racehorses and to determine whether these variables differ between left and right limbs.
Sample—Stifle joints harvested from 6 Thoroughbred racehorses euthanized for reasons other than hind limb lameness.
Procedures—The distal portion of the left and right femurs of each cadaver was scanned via CT. Hounsfield units were converted to dipotassium phosphate equivalent densities through use of a phantom on each specimen. Medial femoral condyle width, length, height, and curvature; subchondral bone plate densities; and subchondral trabecular bone densities were analyzed in multiple sections in 5 frontal planes and 3 sagittal planes and were compared between left and right MFCs.
Results—MFC width, length, and height did not differ between left and right limbs. Regions of interest in the right caudoaxial subchondral bone plate and subchondral trabecular bone were significantly denser than their corresponding left regions of interest in the frontal and sagittal planes. A concavity in the otherwise convex articular surface of the cranial aspect of the MFC was identified in 11 of 12 specimens.
Conclusions and Clinical Relevance—A disparity was identified between left and right subchondral bone density patterns at the caudoaxial aspect of the MFC, which could be attributable to the repetitive asymmetric cyclic loading that North American Thoroughbred racehorses undergo as they race in a counterclockwise direction. The uneven region at the cranial aspect of the MFC could be associated with the development of subchondral bone cysts in horses.
To report history, physical examination findings, clinicopathologic abnormalities, treatments, and outcomes of dogs with confirmed α-amanitin toxicosis resulting from ingestion of α-amanitin–containing mushrooms, and to report whether any differences were significant between survivors and nonsurvivors.
Medical records of all dogs with confirmed α-amanitin toxicosis presented to a northern California emergency and specialty veterinary hospital between January 2006 and July 2019 were reviewed for signalment; body weight; history; physical examination findings including rectal temperature at presentation; results of serum biochemical analyses, coagulation tests, and a test for the detection of α-amanitin in urine; treatments; and outcomes. Differences for each were compared between survivors and nonsurvivors.
Among the 59 dogs, 36 were < 1 year of age; 56 had variable clinical signs that included vomiting, diarrhea, anorexia, and weakness or lethargy; and 22 had rectal temperatures > 39.2°C (102.5°F) at presentation. Cases were seen throughout the calendar year. At presentation, alanine aminotransferase activity was mildly to markedly increased in 97% of dogs, hypoglycemia was noted in 78%, and coagulation times were prolonged in 91%. Most dogs that rapidly decompensated died; however, 13 dogs survived to hospital discharge and completely recovered.
CONCLUSIONS AND CLINICAL RELEVANCE
Ability to recognize dogs with α-amanitin toxicosis on the basis of clinical signs, physical examination findings, and clinicopathologic test results is essential because mushroom ingestion is rarely observed and immediate treatment is necessary. Dogs that have marked hypoglycemia or coagulopathy may have a poor prognosis.
Objective—To evaluate a Markov-chain model for the
development of forelimb injuries in Thoroughbreds
and to use the model to determine effects of reducing
sprint distance on incidence of metacarpal condylar
fracture (CDY) and severe suspensory apparatus
Sample Population—Weekly exercise and injury
data for 122 Thoroughbreds during racing or training.
Procedure—Weekly data were used to construct a
Markov-chain model with 5 states (uninjured [UNINJ],
palpable suspensory apparatus injury [PSAI], SSAI,
CDY, and lost to follow-up [LOST]). Transition probabilities
between UNINJ and PSAI were estimated as a
function of weekly sprint distance by use of linear
regression analysis. The model was used to predict
distributions of annual CDY and SSAI incidences in
southern California racehorses and was validated by
using CDY incidence reported by racetrack practitioners.
The model was modified by reducing the number
of sprint distances that were > 6 furlongs (> 1.20 km)
by 20%, and CDY and SSAI incidences were compared
with those generated by the baseline model.
Results—The model accurately fit development of
injuries in the sample population but overestimated
development of injuries in the southern California
racehorse population. Development of and recovery
from PSAI were correlated with distance run at high
speeds. Reducing by 20% the number of sprints run
at distances > 6 furlongs significantly reduced modeled
annual CDY and SSAI incidence by 9%.
Conclusions and Clinical Relevance—Reducing the
number of sprints at distances > 6 furlongs, particularly
among horses with PSAI, reduces risk of CDY
and SSAI. (Am J Vet Res 2003;64:328–337)
To determine incidences and underlying causes of fatal intestinal inflammatory lesions (FIILs) and demographic characteristics of affected equids necropsied at any of the California Animal Health and Food Safety Laboratory facilities between January 1, 1990, and April 16, 2013.
710 equids with FIILs, including colitis, duodenitis, enteritis, enterocolitis, enteropathy, enterotyphlitis, gastritis, gastroenteritis, ileitis, jejunitis, typhlitis, or typhlocolitis, alone or in combination.
The medical records were reviewed, and data collected included animal age, sex, geographic origin, necropsy submission date, and breed, purpose, or characteristic of use. Descriptive statistics were compiled and reported as numbers and percentages.
Colitis (323/710 [45.5%]), enteritis (146/710 [20.6%]), and typhlocolitis (138/710 [19.4%]) were the most common FIILs, and the underlying cause of most FIILs was categorized as either undetermined (465/710 [65.5%]) or bacterial (167/710 [23.5%]). The most common bacteria responsible for FIILs were Clostridium spp and Salmonella spp.
CONCLUSIONS AND CLINICAL RELEVANCE
Results indicated that the underlying cause for most FIILs could not be identified; however, when it was identified, it was most commonly bacterial and typically Clostridium spp or Salmonella spp, which could be useful information for practitioners when evaluating and managing horses and other equids with intestinal distress. In addition, results underscored the need for improved diagnostic procedures and strategies to determine underlying causes of FIILs in equids. Knowledge of the most common FIILs and their underlying causes may help in diagnosing and mitigating intestinal disease in equids.
Objective—To assess individual and combined associations of high-speed exercise and horseshoe characteristics with risk of forelimb proximal sesamoid bone fractures and proximal sesamoid bone midbody fractures in Thoroughbred racehorses.
Animals—269 deceased Thoroughbred racehorses.
Procedures—A case-control study design was used to compare 121 horses with a fracture of at least 1 of 4 forelimb proximal sesamoid bones (75 horses had a midbody fracture) and 148 horses without a forelimb proximal sesamoid bone fracture. Univariable and multivariable logistic regression analyses were used to evaluate potential risk factors for association with proximal sesamoid bone fracture.
Results—Compared with horses that died without proximal sesamoid bone fractures, horses that died with proximal sesamoid bone fractures were more likely to be sexually intact males, spend more time in active trainingand racing, complete more events, train and race longer since their last layup, have higher exercise intensities during the 12 months prior to death, and have greater cumulative distances for their career. Horses with proximal sesamoid bone midbody fractures were more likely to be sexually intact males, train and race longer since their last layup, and have higher exercise intensities during the 12 months prior to death.
Conclusions and Clinical Relevance—Limitingexercise intensity and the continuous time spent in activity duringa horse's career may decrease the frequency of forelimb proximal sesamoid bone fractures in Thoroughbred horses.
OBJECTIVE To evaluate veterinarian-client communication and veterinarian and client satisfaction with veterinary visits before and after veterinarians underwent a 6-month communication skills training program in a practice setting.
PROCEDURES The practice team (3 veterinarians, 5 veterinary technicians, 1 receptionist, and 1 office manager) participated in a 6-month educational program (intervention) that included interactive communication modules, individual coaching, and a communication laboratory. For each of the veterinarians, 6 appointments were video recorded and 30 additional clients completed a visit satisfaction survey both before and after the intervention. The Roter interaction analysis system was used to analyze the video-recorded appointments.
RESULTS After the intervention, appointments were 5.4 minutes longer and veterinarians asked 60% fewer closed-ended lifestyle-social questions, provided 1.4 times as much biomedically related client education, and used 1.5 and 1.25 times as much facilitative and emotional rapport communication, respectively, compared with before the intervention. Clients provided veterinarians with 1.3 times as much biomedically related information and engaged in twice as much social conversation. After the intervention, veterinarians perceived their clients as complaining less and being more personable and trusting, and clients felt more involved in the appointment and reported that the veterinarian expressed greater interest in their opinion.
CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that the intervention resulted in veterinarians who spent more time educating and building rapport with their clients and facilitating client input in an unhurried environment, which enhanced overall veterinarian visit satisfaction and various aspects of client visit satisfaction.
Objective—To assess concurrently the effects of
moderate ligamentous suspensory apparatus injury
(MLSAI), racing-speed exercise, and horseshoe characteristics
on risk of catastrophic suspensory apparatus
failure (SAF) or metacarpal condylar fracture (CDY)
in forelimbs of racehorses.
Sample population—Cadavers of 301 Thoroughbred
racehorses (108 with SAF, 33 with CDY, and 160 control
Procedure—A cross-sectional epidemiologic study
was used to describe distributions and relationships
between MLSAI, exercise, and horseshoe variables.
Logistic regression was used to assess potential risk
factors for developing SAF and CDY.
Results—Exercise variables were more highly associated
with age than height of a steel bar affixed to the
ground surface of the front of a horseshoe (ie, toe
grab) or sex. Marginal associations were detected
between MLSAI and age and height of toe grab.
Higher risk for developing SAF was associated with
MLSAI, use of a pad on a horseshoe, longer interval
since last period of ≥ 60 days without a race or timed
workout (ie, layup), 2 to 5 career races, and higher
intensity of recent exercise. Higher risk for developing
CDY was associated with MLSAI, male horses, age
between 2 and 5 years, higher intensity of recent
exercise, and longer interval since layup.
Conclusions and Clinical Relevance—Recognition
of MLSAI and rehabilitation of affected horses should
reduce incidence of SAF and CDY. Horses in long-term
continuous training with recent high-intensity
exercise are at greater risk for injury. Use of pads in
horseshoes was associated with SAF, although the
relationship may not be causal. (Am J Vet Res 2004;65:1508–1517).
Objective—To measure passive spinal movements induced during dorsoventral mobilization and evaluate effects of induced pain and spinal manipulative therapy (SMT) on passive vertebral mobility in standing horses.
Animals—10 healthy adult horses.
Procedures—Baseline vertical displacements, applied force, stiffness, and frequency of the oscillations were measured during dorsoventral spinal mobilization at 5 thoracolumbar intervertebral sites. As a model for back pain, fixation pins were temporarily implanted into the dorsal spinous processes of adjacent vertebrae at 2 of the intervertebral sites. Vertebral variables were recorded again after pin placement and treadmill locomotion. In a random-ized crossover study, horses were allocated to control and treatment interventions, separated by a 7-day washout period.The SMT consisted of high-velocity, low-amplitude thrusts applied to the 3 non–pin-placement sites. Control horses received no treatment.
Results—The amplitudes of vertical displacement increased from cranial to caudal in the thoracolumbar portion of the vertebral column. Pin implantation caused no immediate changes at adjacent intervertebral sites, but treadmill exercise caused reductions in most variables. The SMT induced a 15% increase in displacement and a 20% increase in applied force, compared with control measurements.
Conclusions and Clinical Relevance—The passive vertical mobility of the trunk varied from cranial to caudal. At most sites, SMT increased the amplitudes of dorsoventral displacement and applied force, indicative of increased vertebral flexibility and increased tolerance to pressure in the thoracolumbar portion of the vertebral column.
Objectives—To establish reference mechanical nociceptive threshold (MNT) values of the equine thoracic limb and to assess the use of MNT values to detect pain associated with induced osteoarthritis in the middle carpal joint.
Animals—24 adult horses.
Procedures—MNT values were evoked by a pressure algometer at 17 sites within each thoracic limb during 2 baseline sessions conducted an average of 5 days apart. Effects of age, sex, weight, and wither height on MNT values were assessed separately for each site. Tolerance of horses to the procedure was graded subjectively and correlated with MNT values. Synovitis and osteoarthritis were induced arthroscopically in the middle carpal joint of 1 randomly selected thoracic limb. The opposite limb served as a sham-operated control limb. Mechanical nociceptive threshold values were recorded weekly and correlated with clinical, radiographic, and necropsy scores measured over 10 weeks. Lower MNT values corresponded with increased pain, whereas higher MNT values indicated reduced pain.
Results—A gradual increase in MNT values was detected from proximal-to-distal sites of the thoracic limbs. High MNT values were recorded for geldings and tall horses. In general, tolerance to procedure scores was positively correlated with overall pooled MNT values within each thoracic limb. From 2 to 6 weeks after surgery, the osteoarthritic limb had significantly reduced MNT values within the carpal region. The osteoarthritic limb also had significant changes in clinical examination, radiographic, and necropsy scores, which were poorly correlated with MNT values.
Conclusions and Clinical Relevance—Pressure algometry provided objective assessment of nociception of the thoracic limb; however, MNT values were poorly correlated with clinical variables used to assess osteoarthritis.
Objective—To assess the accuracy and reliability of a
visual method of evaluating horseshoe characteristics.
Animals—1,199 Thoroughbred racehorses.
Procedure—Characteristics of 1 forelimb horseshoe
were visually assessed on horses immediately
prior to racing by 5 field observers at 5 major
racetracks in California. Characteristics evaluated
included horseshoe type; toe grab height; and the
presence of a rim, pad, and heel traction devices.
Sensitivity and specificity for observer assessment
of horseshoe characteristics were calculated by
comparing observer assessments to a postmortem
laboratory standard for horses that died within 48
hours of a race. Intraobserver agreement was
assessed in a subset of horses by comparing horseshoe
observations made before and after the
horse's race. Interobserver agreement was evaluated
by comparing horseshoe assessment among
observers who examined the same subset of horses
prior to racing on select days.
Results—The sensitivity and specificity of this visual
method of evaluating horseshoe characteristics were
good and ranged from 0.75 to 1 and 0.67 to 1, respectively.
Agreement beyond chance (weighted kappa
values) between observers and the laboratory standard
for toe grab height was fair (0.60 to 0.62).
Intraobserver and interobserver agreements (kappa
values) were high (0.86 to 0.99 and 0.71 to 1, respectively).
Conclusions and Clinical Relevance—Visual observation
of horseshoes can be a feasible and reproducible
method for assessing horseshoe characteristics
prospectively in a large cohort of horses under
racing conditions. (Am J Vet Res 2004;65:1674–1679)