Effects of Jumping Phase, Leading Limb, and Arena Surface Type on Forelimb Hoof Movement.

During the stance phase of equine locomotion, ground reaction forces are exerted on the hoof, leading first to rapid deceleration ("braking") and later to acceleration ("propulsion") as the hoof leaves the ground. Excessive hoof deceleration has been identified as a risk factor for musculoskeletal injury and may be influenced by arena surface properties. Therefore, our objective was to evaluate the effect of arena surface type (dirt, synthetic) on hoof translation of the leading and trailing forelimbs during jump takeoff and landing. Solar hoof angle, displacement, velocity, and deceleration were captured using kinematic markers and high-speed video for four horses jumping over a 1.1 m oxer at 12 different arenas (5 dirt, 7 synthetic). Surface vertical impact and horizontal shear properties were measured simultaneously. The effects of surface type (dirt, synthetic), jump phase (takeoff, landing), and limb (leading, trailing) on hoof movement were assessed using ANOVA (p < 0.05), while the relationships of hoof movement with surface mechanical properties were examined with correlation. Slide time (p = 0.032), horizontal velocity of the hoof (p < 0.001), and deceleration (p < 0.001) were greater in the leading limb, suggesting a higher risk of injury to the leading limb when braking. However, surface type and jump phase did not significantly affect deceleration during braking.

Pilot Study: Correlation of the Surface Skin Temperature Between the Leg and Foot Using Thermographic Imaging in Captive Hawks.

The purpose of this study was to determine whether the thermal image temperatures of the tibiotarsal scaled region of the raptor leg and the plantar surface of ipsilateral foot while perching were correlated. The correlation between leg and foot temperature was sought to determine whether remote imaging of the legs can be used as a reliable predictor of foot temperature. The right and left tarsometatarsal region (Leg) and metatarsal pad (Foot) of 10 captive hawks, including 8 red-tailed hawks (Buteo jamaicensis), 1 Harris's hawk (Parabuteo unicinctus), and 1 Swainson's hawk (Buteo swainsoni) were imaged once daily over 3 consecutive days. To account for conditions of the metatarsal pad that might affect the thermal image, 3 groups were identified: Normal, Active when mild hyperemia was present, and Suspect when abrasions were noted. A significant correlation was evident when thermography readings of the tarsometatarsal region (R.Leg and L.Leg) of the unrestrained bird were compared with readings from the plantar surface of the ipsilateral metatarsal pad when restrained (R.Foot and L.Foot). The correlations for R.Leg versus R.Foot (r = 0.81) and L.Leg versus L.Foot (r = 0.74) suggest that temperatures of the tarsometatarsal region of perching hawks measured by infrared thermography may be useful to screen and monitor for the presence of thermal changes associated with inflammation of the metatarsal pad in captive hawk species.

Randomized Comparative Trial of Acupuncture and Exercise Versus Uterine Ecbolics in the Treatment of Persistent Postbreeding Endometritis in Mares.

Although exercise and acupuncture are frequently used therapies to treat persistent postbreeding endometritis, their efficacy to date is unproven. The objective of this study was to determine if exercise and acupuncture are effective methods to reduce intrauterine fluid and compare the effectiveness of these treatments to the use of uterine ecbolics. Twelve mares susceptible to postbreeding endometritis were enrolled in the study with a randomized cross-over design using both positive and negative controls. During each estrous cycle, mares were randomized into one of six treatment groups, including stall rest (SR), oxytocin, cloprostenol, exercise, electroacupuncture, and oxytocin and exercise. Each mare was challenged with an insemination dose of 500 × 106 dead sperm at time 0 hours. Intrauterine fluid measurements were taken at 0, 4, 24, 48, 72, and 96 hours postbreeding. Associations between treatment efficacy and fluid clearance were investigated using a random-effects logistic regression model that controlled for positive uterine culture. Compared with the SR negative control, exercise was the most effective treatment and had 29.7 times increased odds of fluid clearance. The second most effective treatment was oxytocin alone, with 16.9 times increased odds of fluid clearance. This was followed by cloprostenol that had 10.6 greater odds of fluid clearance, and finally, the treatment that combined exercise with oxytocin had 8.4 times greater odds of fluid clearance. Results from this study confirm that exercise and exercise combined with oxytocin are effective methods to clear intrauterine fluid.

Girthiness: Retrospective Study of 37 Horses (2004-2016).

Girth aversion or girthiness is a nonspecific clinical sign anecdotally associated with multiple conditions in the horse (behavioral problems, gastric ulcers, back pain); however, studies have not been conducted to definitively correlate this clinical sign to specific pathologies. This retrospective study aims to describe the clinical signs and final diagnoses of 37 horses evaluated at the University of California, Davis with a presenting complaint of girthiness. Medical records of all horses presented to the veterinary hospital between 2004 and 2016 for girthiness were reviewed. Twelve horses were diagnosed with gastric ulceration, 10 with various orthopedic problems, 3 with ill-fitting saddles, 1 with reproductive tract neoplasia, and 10 with various diseases including liver abscessation, vena cava aneurism, sternum pain, and urinary tract infection. Identifying the exact cause of girthiness remains a challenge; however, gastric ulcers was a common finding; therefore, a clinical examination should be oriented to further investigate this condition because 92% of gastroscoped horses in this study were diagnosed with gastric ulcers.

Thermographic evaluation of primary closure and second intention healing in dairy calves.

OBJECTIVE: To evaluate the suitability of infrared thermography in assessing healing of surgically created wounds that are managed by primary closure or second intention in neonatal dairy calves during a 3-week period. STUDY DESIGN: Randomized clinical trial. ANIMALS: Six Jersey bull calves. METHODS: Two skin patches approximately 10 cm2 were shaved on each hind limb of all calves. The dorsal patch was designated the wound creation site, and the ventral patch was the control. The wound creation sites were randomly assigned for either primary closure or healing by second intention. Wounds were created by using an 8-mm biopsy punch. Thermographic imaging was performed prior to wound creation and at 0 minutes; 15 minutes; 2, 4, 8, 12, and 24 hours; and 2, 3, 4, 7, 10, 14, and 21 days postwounding. RESULTS: There were no differences in skin temperature changes observed between wounds that were managed by primary closure or second intention (P = .9934) at any time. Time after wound creation had an effect on the skin temperature (P < .0001), with skin temperature consistently warmer (P < .05) 2, 4, and 8 hours after creation of wounds compared with subsequent times. CONCLUSION: Infrared thermography was unable to detect differences in wound healing by primary closure or second intention in this model. CLINICAL SIGNIFICANCE: Thermographic monitoring to detect differences in wound healing was not evident in this model. This model might be useful in monitoring temporal changes during early wound repair.

Investigation of perioperative and anesthetic variables affecting short-term survival of horses with small intestinal strangulating lesions.

OBJECTIVE: To determine if preoperative and intraoperative physiologic variables, and surgical factors correlate with survival to anesthetic recovery or hospital discharge, repeat celiotomy, and postoperative nasogastric intubation (NGT) in horses undergoing exploratory celiotomy for small intestinal (SI) strangulating lesions. STUDY DESIGN: Retrospective case series. ANIMALS: Horses that had surgical correction of SI strangulating lesions (n = 258). METHODS: Medical records (January 2000-December 2014) of horses that had surgical correction of SI strangulating lesions were reviewed. Data collection included signalment, preoperative physical examination variables, hematologic values, presence of gastric reflux, peritoneal fluid analysis, intraoperative physiologic variables, intraoperative findings/treatments, and arterial blood gas values. Risk factors for survival to anesthetic recovery and hospital discharge were determined using exact logistic regression. RESULTS: Survival to anesthetic recovery was 76% and survival to discharge after anesthetic recovery was 79%. The difference between abdominal and peripheral lactate concentrations and intraoperative tachycardia were associated with not surviving to anesthetic recovery or hospital discharge. Intraoperative hypotension, hypocapnia, and low intraoperative packed cell volume (PCV) were negative predictors of survival to anesthetic recovery. Low intraoperative PCV was also associated with NGT postoperatively. Performing resection-anastomosis and jejunocecostomy were associated with repeat celiotomy and with not surviving to hospital discharge. CONCLUSION: Several hematological and cardiorespiratory variables show good correlation with short-term survival in horses undergoing surgery for SI strangulating lesions. These variables are easily measured and could be useful for prognosticating survival in horses presenting with SI strangulating lesions.

Evaluation of 3 handheld portable analyzers for measurement of L-lactate concentrations in blood and peritoneal fluid of horses with colic.

OBJECTIVE: To compare 3 portable handheld analyzers with a bench top blood gas analyzer for measurement of blood and peritoneal fluid L-lactate concentrations in horses admitted with signs of colic. STUDY DESIGN: Prospective clinical study. SAMPLE POPULATION: Blood and peritoneal fluid from horses with colic. METHODS: L-lactate concentrations in heparinized blood and peritoneal fluid were measured serially on 10 occasions to evaluate repeatability of the portable analyzers. Blood and peritoneal fluid L-lactate concentrations were simultaneously evaluated by a bench top and 3 portable analyzers and the results compared by intraclass correlation coefficients and Bland Altman plots. L-Lactate concentrations in a subgroup of peritoneal fluid samples were evaluated by a chromogenic laboratory assay and compared with the bench top and the handheld analyzers. RESULTS: Portable lactate analyzers had good intra-analyzer reliability for peritoneal fluid. Two portable analyzers had poor intra-analyzer reliability for mid concentrations of L-lactate in blood. L-lactate measurements from portable analyzers were closer to the bench top analyzer at low concentrations of L-lactate than at higher concentrations. Compared with the bench top analyzer, the Lactate Pro and Lactate Plus have the highest intraclass correlation coefficient and the smallest bias for peritoneal fluid and blood L-lactate, respectively. The bench top analyzer and the Lactate Pro had the highest level of agreement for peritoneal fluid compared with the chromogenic assay. CONCLUSIONS: Although portable analyzers are alternatives for the measurement of L-lactate concentration in field situations, clinicians need to be aware of the variable results between analyzers, especially when extrapolating means or cutoff values from studies using different lactate analyzers.

Use of digital abdominal radiography for the diagnosis of enterolithiasis in equids: 238 cases (2008-2011).

OBJECTIVE: To evaluate the sensitivity and specificity of direct digital abdominal radiography for the diagnosis of enterolithiasis in equids and to assess the effect of the number and anatomic location of enteroliths and gas distention of the gastrointestinal tract on diagnostic sensitivity of the technique. DESIGN: Retrospective case series. SAMPLE POPULATION: 238 horses and ponies ≥ 1 year old that underwent digital abdominal radiography with subsequent exploratory celiotomy or postmortem examination. PROCEDURES: For each case, 3 reviewers independently evaluated radiographic views. Radiographic images were evaluated for presence or absence and location of enteroliths and the degree of gas distention. Signalment, definitive diagnosis based on exploratory celiotomy or postmortem examination findings, and number and anatomic location of enteroliths were obtained from the medical records. RESULTS: 70 of the 238 (29.4%) equids had confirmed enterolithiasis. With regard to diagnosis of enterolithiasis via digital radiography, overall sensitivity and specificity for the 3 reviewers were 84% and 96%, respectively. Sensitivity was lower for small colon enteroliths (61.5%) than for large colon enteroliths (88.9%) and was negatively affected by gas distention of the gastrointestinal tract. Sensitivity was not affected by the number of enteroliths. CONCLUSIONS AND CLINICAL RELEVANCE: Sensitivity and specificity of digital radiography for the diagnosis of large colon enterolithiasis in equids was high. Sensitivity of digital radiography for detection of small colon enteroliths was lower than that for large colon enteroliths, but was higher than that typically associated with computed radiography. In geographic regions in which enterolithiasis in equids is endemic, digital abdominal radiography could be used as a diagnostic test for equids with colic.

Use of physiologic and arterial blood gas variables to predict short-term survival in horses with large colon volvulus.

OBJECTIVE: To determine if preoperative physical examination and blood work values, intraoperative physiologic variables, and intraoperative treatments can be correlated with survival to anesthetic recovery and short-term survival to hospital discharge in horses that undergo exploratory celiotomy for large colon volvulus (LCV) with and without colon resection. STUDY DESIGN: Retrospective case series. ANIMALS: Horses (n = 156) undergoing exploratory celiotomy for correction of LCV ≥ 360(ο) . METHODS: Medical records (January 2000-December 2009) of horses that had surgical correction of LCV ≥ 360(ο) were reviewed. Data collection included signalment, preoperative physical examination variables and hematologic values as well as intraoperative physiologic variables, intraoperative treatments, and arterial blood gas values. Risk factors for survival to anesthetic recovery and hospital discharge were determined using exact logistic regression. RESULTS: High preoperative heart rate and packed cell volume were associated with not surviving to anesthetic recovery or hospital discharge. A low intraoperative total serum protein concentration was associated with not surviving to anesthetic recovery or to hospital discharge. Intraoperative tachycardia and hypercapnia were associated with not surviving to hospital discharge. Intraoperative hypotension was a negative predictor of survival to anesthetic recovery. There was no increase in death for horses in which a resection and anastomosis was performed compared with those having manual correction. CONCLUSIONS: Several hematologic and cardiorespiratory variables that are easily measured preoperatively and intraoperatively show good correlation with postanesthetic survival in horses undergoing surgical correction of LCV. These measurements might be useful for prognosticating survival in horses admitted for correction of LCV ≥ 360(ο) .

Intrathoracic pulsion diverticulum in a horse.

This is a report of a 12-year-old Swedish Warmblood gelding with a ruptured esophageal pulsion diverticulum associated with atypical clinical signs of colic and septic peritonitis on presentation. The location of this diverticulum at the hiatus was unique and was most likely responsible for the unusual presentation of this horse.

Myenteric ganglionitis as a cause of recurrent colic in an adult horse.

CASE DESCRIPTION: A 10-year-old Lipizzaner stallion was evaluated over the course of 1.5 years because of intermittent, recurrent colic. CLINICAL FINDINGS: The horse was initially treated medically for gastric ulcers; dietary changes were made, and a deworming protocol was instituted, without resolution of colic episodes. Subsequently, the horse underwent exploratory celiotomy and a large colon volvulus was identified with diffuse colonic wall thickening. A pelvic flexure biopsy sample was submitted for histologic examination, which revealed lymphocytic (CD3-positive T cells) myenteric ganglionitis (MG). The horse developed a cecal impaction after surgery, which did not resolve, despite aggressive medical management; subsequently a complete cecal bypass was performed. Cecal and colonic wall biopsy samples were evaluated histologically and confirmed the diagnosis of MG. After surgery, the horse developed a large colon impaction, which initially responded to aggressive medical treatment, and the horse was discharged. TREATMENT AND OUTCOME: Despite rigorous feed restrictions and prokinetic and corticosteroid treatment, the horse continued to have signs of colic and was euthanized 3 weeks after discharge from the hospital because of a recurrent large colon impaction. Intestinal biopsy samples obtained at the time of death revealed chronic changes in intramural ganglia consistent with generalized MG. CLINICAL RELEVANCE: MG is a rare disease in horses, causing gastrointestinal motility dysfunction and signs of colic, which is challenging to diagnose and treat successfully. Further studies are needed to identify the etiology of this disease and to explore treatment options.

Use of pelvic flexure biopsy scores to predict short-term survival after large colon volvulus.

OBJECTIVE: To (1) determine if histologic scores of pelvic flexure biopsies can predict short-term survival in horses with large colon volvulus (LCV) and (2) identify clinical variables predictive of short-term survival. STUDY DESIGN: Case series. ANIMALS: Horses (n = 28) with LCV (≥ 360°). METHODS: Medical records (January 2000-February 2008) of 28 horses were reviewed and clinical data recorded. Pelvic flexure biopsies were reviewed by 2 board-certified veterinary pathologists, unaware of clinical history and outcome, using 2 scoring systems. Exact logistic regression analysis was used to determine the relationship between histopathology scores (tissue viability), clinical data, and short-term survival (hospital discharge). RESULTS: Twenty-four horses (86%) survived to hospital discharge. Using a similar cutoff, neither scoring system was capable of predicting short-term survival. One scoring system failed to correctly predict clinical outcome in 5/25 horses (20%) and the other failed in 6/28 horses (22.4%). Heart rate (at admission and 24 hours after surgery) and packed cell volume 24 hours after surgery were significantly associated with short-term survival. CONCLUSION: Histopathologic evaluation of pelvic flexure biopsies did not accurately predict short-term survival in a significant proportion of horses with LCV in this study.

Abdominal computed radiography for the diagnosis of enterolithiasis in horses: 142 cases (2003?2007).

OBJECTIVE: To evaluate the sensitivity and specificity of abdominal computed radiography (CR) for the diagnosis of enterolithiasis in horses and to examine how these parameters are affected by the number and anatomic location of enteroliths and by gas distension of the gastrointestinal tract. DESIGN: Retrospective case series. ANIMALS: Horses ? 1 year old that underwent abdominal CR and subsequent exploratory laparotomy or postmortem examination. PROCEDURES: 3 reviewers blinded to signalment, history, clinical signs, and diagnoses separately evaluated abdominal computed radiographs of horses included in the study. Each set of radiographs was evaluated for the presence or absence of enteroliths, the amount of gas distention, and the image quality. Signalment, definitive diagnosis on the basis of findings on exploratory laparotomy or postmortem examination, and the number and location of enteroliths were obtained from medical records. RESULTS: Of the 142 cases reviewed, 58.4% (83/142) had confirmed enterolithiasis. For the 3 reviewers, overall sensitivity was 85% and specificity was 93%. Sensitivity was lower for small colon enteroliths than for large colon enteroliths (50% and 94.5%, respectively) and was significantly affected by gas distention. Sensitivity was not significantly affected by the number of enteroliths. CONCLUSIONS AND CLINICAL RELEVANCE: Computed radiography provided high sensitivity and high specificity for the diagnosis of enterolithiasis in horses. Caution should be exercised when the radiographic results are negative, as the sensitivity for small colon enterolithiasis was relatively low and gas distension negatively affected detection of enteroliths. Abdominal CR is indicated as a diagnostic test in horses examined for colic in geographic regions in which enterolithiasis is endemic.

Prevalence of gastric ulcers in Thoroughbred broodmares in pasture: a preliminary report.

Gastroscopic examinations were performed in 62 Thoroughbred broodmares (33 pregnant, 29 non-pregnant) at one breeding farm to investigate the prevalence of gastric ulceration. Age, pregnancy status, race earnings, last race start, herd size, medical history, number of live foals, breeding years, feed type and number of feedings were recorded, plus coat condition and body condition score were determined. Twenty-one mares were re-evaluated after foaling, and the foaling date, foal weight at birth and placenta weight were recorded. The overall prevalence of gastric ulcers was 70.9%, with a median ulcer score of 3.0 (range: 2-5). Most ulcers were present on the squamous portion of the stomach, while two mares had glandular ulcers. There were no differences in the presence, location and severity of gastric ulcers between pregnant and non-pregnant mares. Furthermore, there were no significant associations between the variables measured and the presence of gastric ulceration. The prevalence of gastric ulceration in this specific population of horses was higher than expected and further investigation is warranted to determine the factors that contributed to this finding.

Disorders of the infraspinatus tendon and bursa in three horses.

CASE DESCRIPTION: 3 horses with penetrating wounds to the shoulder area were examined because of forelimb lameness. CLINICAL FINDINGS: All horses had physical examination findings (decreased cranial phase of the stride, swelling in the shoulder region, and signs of pain on manipulation of the shoulder) that were suggestive of problems in the upper portion of the forelimb. Injury to the biceps tendon or bursa was the primary differential diagnosis in each instance, but no abnormalities involving those structures were found. Radiographic and ultrasonographic imaging revealed injuries to the caudal eminence of the greater tubercle of the humerus, the infraspinatus tendon, and the infraspinatus bursa. Examination with ultrasound was more sensitive than radiography at detecting both osseous and soft tissue changes. TREATMENT AND OUTCOME: All 3 horses responded favorably to treatment with antimicrobials and non-steroidal anti-inflammatory drugs. Although initial response to standing lavage was favorable in 1 horse, endoscopic lavage was later required. Standing removal of fracture fragments was performed in 2 horses. Ultrasonographic imaging was helpful in monitoring the response to treatment and changes in the affected structures. All 3 horses eventually became sound after treatment. CLINICAL RELEVANCE: Infraspinatus bursitis and tendonitis should be included in the differential diagnoses of horses with shoulder lameness. Diagnosis and monitoring should include ultrasonographic monitoring. The prognosis for return to soundness after appropriate treatment appears to be good.

Hemoperitoneum in horses: 67 cases (1989-2004).

OBJECTIVE: To evaluate clinical findings, underlying causes, and short-term outcome associated with hemoperitoneum in horses. DESIGN: Retrospective case series. ANIMALS: 67 horses with hemoperitoneum. PROCEDURES: Medical records of horses with hemo-peritoneum (excluding postoperative abdominal hemorrhage) from 1989 through 2004 were analyzed. Information obtained included history, signalment, physical examination findings, diagnostic test results, and short-term outcome. RESULTS: Breed distribution was 28 Thoroughbreds, 13 Arabians, 10 Quarter Horses, 5 Warmbloods, 3 Appaloosas, and 1 each of 8 other breeds. There were 40 mares, 23 geldings, and 4 stallions. Median age was 12 years (range, 1 month to 40 years). Signs of abdominal discomfort were the primary complaint in 79% of horses. Clinical findings included shock (60%) and pale mucous membranes (60%). Median heart rate was 76 beats/min (range, 30 to 216 beats/min), median respiratory rate was 30 breaths/min (range, 8 to 92 breaths/min), median Hct was 31% (range, 10.5% to 73.0%), and total protein concentration was 5.8 g/dL (range, 3.3 to 8.7 g/dL). Cause of hemoperitoneum was attributed to trauma (25.4%), neoplasia (17.9%), uterine artery rupture (13.4%), mesenteric injury (11.9%), disseminated intravascular coagulopathy (6.0%), other causes (3.0%), and idiopathic causes (22.4%). Fifty-one percent of horses survived to hospital discharge, 37% were euthanized, and 12% died. Poor short-term outcome was significantly associated with high respiratory rate and certain underlying causes. CONCLUSIONS AND CLINICAL RELEVANCE: Hemoperitoneum is an infrequent but important cause of abdominal discomfort in horses. Predominant underlying causes were trauma, neoplasia, and idiopathic causes. Identification of underlying cause is important because of its association with outcome.

Biomechanical investigation of the association between suspensory ligament injury and lateral condylar fracture in thoroughbred racehorses.

Objective-To determine whether partial transection of the medial branch of the suspensory ligament (MBSL) alters equine third metacarpal bone (MC3) condylar surface strains and forelimb, distal joint angles in a manner consistent with promotion of lateral condylar fracture. Study Design-In vitro biomechanical experiment. Sample Population-Right forelimbs from 7 Thoroughbred horse cadavers. Methods-Lateral and medial MC3 condylar, dorsal and abaxial, bone surface strains and distal joint angles were measured both before and after partial transection of the MBSL during in vitro axial limb compression. Dorsal, principal bone strains and abaxial, uniaxial, and proximodistal strains were compared before and after MBSL partial transection at 1,400-, 3,000-, and 5,600-N loads. Results-Bone strains increased in all locations with increasing axial load. All lateral condylar bone strains were significantly higher, and abaxial surface medial condylar bone strain was significantly lower, after partial transection of the MBSL. Respective distal joints became more flexed or extended as axial load increased but were not significantly different after partial transection of the MBSL. Conclusions-Partial transection of the MBSL increases in vitro MC3 lateral condylar bone surface strains. Clinical Relevance-Loss of integrity of the medial branch of the suspensory ligament could increase the risk for lateral condylar fracture in Thoroughbred horses by amplifying bone strain in the lateral condyle.