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- Author or Editor: Nathaniel A. White x
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Abstract
Objective—To determine outcome of percutaneous ultrasound-guided desmoplasty with simultaneous fasciotomy for proximal suspensory desmitis (ie, desmitis of the origin of the suspensory ligament) in horses that have not responded to stall rest.
Design—Retrospective case series.
Animals—27 horses.
Procedures—Medical records of horses with proximal suspensory desmitis treated by means of desmoplasty with fasciotomy were reviewed. Follow-up information was obtained through telephone conversations with owners and trainers of the horses or by examination of horses at the hospital.
Results—23 of the 27 (85%) horses, including 3 of 4 horses with forelimb lesions and 20 of 23 horses with hind limb lesions, were able to return to full work after surgery and rehabilitation. All horses had ultrasonographic evidence of healing of suspensory ligament lesions.
Conclusions and Clinical Relevance—Results suggest that desmoplasty with fasciotomy is a viable treatment option in horses with proximal suspensory desmitis that have not responded to stall rest.
Abstract
Objective—To determine clinical, scintigraphic, radiographic, and arthroscopic findings and results of treatment in horses with lameness attributable to subtle osteochondral lesions of the shoulder joint.
Design—Retrospective study.
Animals—15 horses.
Procedure—Medical records were reviewed, and results of physical examination, scintigraphy, radiography, arthroscopy, and treatment were recorded.
Results—Severity of lameness ranged from grade 1 to 4. Response to shoulder flexion or extension was variable. Twelve horses had a narrow upright foot. Intra-articular anesthesia of the shoulder joint localized the cause of the lameness to the shoulder joint in 9 of 10 horses. Scintigraphic abnormalities were detected in 4 of 6 horses. Radiographic lesions were subtle and included glenoid sclerosis, focal glenoid lysis, small glenoid cysts, and alterations in the humeral head contour. Arthroscopic evaluation confirmed clefts in the glenoid cartilage, glenoid cysts, a humeral head cyst, fibrillation of the humeral head cartilage, cartilage fragmentation, or a nondisplaced fracture of the humeral head. After treatment, 12 horses returned to their previous level of performance, 1 was sound for light riding, 1 remained lame, and 1 was euthanatized because of chronic lameness.
Conclusion and Clinical Relevance—Results suggest that a combination of physical examination, scintigraphy, and radiography is necessary to diagnose subtle osteochondral lesions of the shoulder joint in horses. Arthroscopy can be used to confirm the diagnosis and treat cartilage and subchondral bone lesions. Young and middle-aged horses with subtle osteochondral lesions of the shoulder joints have a good prognosis for return to performance following arthroscopic treatment. (J Am Vet Med Assoc 2000;217:1878–1882)
Abstract
Objective—To determine whether intraluminal distention and subsequent decompression of the equine jejunum affects intestinal blood flow, hemodynamics, and microvascular permeability.
Animals—5 healthy adult horses.
Procedure—Horses were anesthestized and underwent exploratory laparotomy. Two jejunal segments were identified as sham-operated or instrumented segments. After baseline values were obtained, intraluminal distention was created in the experimental segment to induce an intraluminal pressure of 18 cm H2O. After 120 minutes of distention, the intestine was decompressed for 120 minutes. Mesenteric blood flow, oxygen delivery, oxygen consumption, microvascular permeability, wet weight-to-dry weight ratio, neutrophil infiltration, and vascular resistance were determined and comparisons made among control, sham-operated, and experimental segments.
Results—Mean jejunal blood flow was 21.4 ml/min per kg. There was a significant decrease in mesenteric blood flow to the distended intestine (13.4 ml/min per kg). Blood flow increased significantly during the decompression period (340% of baseline blood flow). Intraluminal distention and subsequent decompression resulted in a significant increase in microvascular permeability, as determined by the osmotic reflection coefficient. Oxygen delivery and oxygen content decreased significantly during the distention period and increased during decompression. Morphologic evaluation revealed a significant increase in edema and neutrophil infiltration after distention and decompression, compared with results for the sham-operated or control segments.
Conclusions and Clinical Relevance—Intraluminal distention and decompression of the equine jejunum results in low-flow ischemia and edema, which may contribute to adhesions and ileus in the postoperative period after surgery for obstructions of the small intestines. (Am J Vet Res 2001;62:225–236)
Abstract
Objective—To identify factors associated with outcome (ie, survival and return to function) following treatment of horses with septic tenosynovitis.
Design—Retrospective case series.
Animals—51 horses with septic tenosynovitis.
Procedures—Information was obtained from medical records and through follow-up conversations with owners. Factors analyzed for an association with outcome included affected limb, etiology, duration of clinical signs prior to examination, presence of complications, primary treatment, secondary treatments, number of surgical procedures, and hospitalization time.
Results—Concurrent complications were identified in 41 (80%) horses. The primary treatment consisted of through-and-through lavage in 26 (51%) horses, tenoscopy in 20 (39%), and tenosynoviotomy combined with lavage in 5 (10%). Forty (78%) horses were discharged, and 37 (73%) survived at least 1 year after surgery; 21 of the 37 (57%) returned to their previous or a higher level of performance. Percentages of horses that survived 1 year after discharge and percentages that returned to their intended use did not vary significantly among treatments. Horses with tendon rupture or sepsis of an adjacent joint were significantly less likely to survive. Horses with tendon injury or pannus were significantly less likely to return to their intended use.
Conclusions and Clinical Relevance—Results suggested that various factors were associated with outcome in horses with septic tenosynovitis. However, surgical technique was not found to be associated with survival rate or rate of return to intended use.
Abstract
Objective—To determine clinical and ultrasonographic abnormalities in horses with primary desmitis of the palmar or plantar annular ligament (PAL) and the response to treatment.
Design—Retrospective study.
Animals—25 horses.
Procedure—Data collected from medical records included signalment, horse use, affected limb, severity and duration of lameness, results of diagnostic tests performed, ultrasonographic findings, treatment, and outcome.
Results—All horses had a prominent swelling in the region of the affected PAL, and signs of pain were evident during palpation of the swelling. In all horses, the affected PAL was thicker than normal as determined ultrasonographically. Twenty horses had hypoechoic regions in the PAL. Four horses, including 1 horse with 3 affected limbs, were treated by means of PAL desmoplasty, 9 were treated by means of PAL desmotomy, and 12 were treated with rest. Follow-up information was available for 21 horses. All 4 horses that underwent PAL desmoplasty, 4 of 7 horses that underwent PAL desmotomy, and 7 of 10 horses treated with rest alone became sound.
Conclusions and Clinical Relevance—Results suggest that primary desmitis of the PAL may be a cause of lameness in horses. Although significant differences in outcome between horses treated with rest alone versus PAL desmoplasty versus PAL desmotomy were not identified, because it is less invasive, PAL desmoplasty should be considered for treatment of horses with PAL desmitis that do not respond to conservative treatment and do not have any evidence of constriction of the digital flexor tendons. (J Am Vet Med Assoc 2005;226:83–86)
Abstract
Objective—To assess changes in systemic hydration, concentrations of plasma electrolytes, hydration and physical properties of colonic contents and feces, and gastrointestinal transit in horses with access to large amounts of grain.
Animals—6 horses with right dorsal colon (RDC) fistulas.
Procedure—In a crossover design, horses were alternately fed 1 of 3 diets: orchard grass hay ad libitum after being adapted to this diet for at least 5 days, orchard grass hay ad libitum and 4.55 kg of grain offered every 12 hours after being adapted to orchard grass hay ad libitum for at least 5 days, or orchard grass hay ad libitum and 4.55 kg of grain offered every 12 hours after being adapted to this diet for at least 5 days. Physical examinations were performed and samples of blood, colonic contents, and feces were collected every 6 hours during a 48-hour observation period.
Results—Grain ingestion had several effects, including changes in the concentrations of electrolytes in plasma; RDC contents became more homogenous, dehydrated, foamy, and less dense; RDC contents flowed spontaneously when the cannula was opened; RDC contents expanded when heated in an oven; and feces became fetid and less formed. Horses did not have any clinical signs of colic, endotoxemia, or laminitis.
Conclusions and Clinical Relevance—Changes observed in the colonic contents and feces may be explained by the large amounts of hydrolyzable carbohydrates provided by grain. Access to large amounts of grain may increase the risk of tympany and displacement of the large intestine. ( Am J Vet Res 2004;65:687–694)
Abstract
Objective—To assess changes in systemic hydration, concentrations of electrolytes in plasma, hydration of colonic contents and feces, and gastrointestinal transit in horses treated with IV fluid therapy or enteral administration of magnesium sulfate (MgSO4), sodium sulfate (NaSO4), water, or a balanced electrolyte solution.
Animals—7 horses with fistulas in the right dorsal colon (RDC).
Procedure—In a crossover design, horses alternately received 1 of 6 treatments: no treatment (control); IV fluid therapy with lactated Ringer's solution; or enteral administration of MgSO4, Na2SO4, water, or a balanced electrolyte solution via nasogastric intubation. Physical examinations were performed and samples of blood, RDC contents, and feces were collected every 6 hours during the 48 hour-observation period. Horses were muzzled for the initial 24 hours but had access to water ad libitum. Horses had access to hay, salt, and water ad libitum for the last 24 hours.
Results—Enteral administration of a balanced electrolyte solution and Na2SO4 were the best treatments for promoting hydration of RDC contents, followed by water. Sodium sulfate was the best treatment for promoting fecal hydration, followed by MgSO4 and the balanced electrolyte solution. Sodium sulfate caused hypocalcemia and hypernatremia, and water caused hyponatremia.
Conclusions and Clinical Relevance—Enteral administration of a balanced electrolyte solution promoted hydration of RDC contents and may be useful in horses with large colon impactions. Enteral administration of either Na2SO4 or water may promote hydration of RDC contents but can cause severe electrolyte imbalances. (Am J Vet Res 2004;65:695–704)
Abstract
Objective—To quantify peripheral blood neutrophil apoptosis in equine patients with acute abdominal disease (ie, colic) caused by strangulating or nonstrangulating intestinal lesions and compare these values with values for horses undergoing elective arthroscopic surgery.
Animals—20 client-owned adult horses.
Procedures—Peripheral blood was collected from horses immediately prior to and 24 hours after surgery for treatment of colic (n = 10) or elective arthroscopic surgery (10), and neutrophils were counted. Following isolation by means of a bilayer colloidal silica particle gradient and culture for 24 hours, the proportion of neutrophils in apoptosis was detected by flow cytometric evaluation of cells stained with annexin V and 7-aminoactinomycin D. Values were compared between the colic and arthroscopy groups; among horses with colic, values were further compared between horses with and without strangulating intestinal lesions.
Results—Percentage recovery of neutrophils was significantly smaller in preoperative samples (median, 32.5%) and in all samples combined (35.5%) for the colic group, compared with the arthroscopy group (median, 66.5% and 58.0%, respectively). No significant differences in the percentages of apoptotic neutrophils were detected between these groups. Among horses with colic, those with strangulating intestinal lesions had a significantly lower proportion of circulating apoptotic neutrophils in postoperative samples (median, 18.0%) than did those with nonstrangulating lesions (66.3%).
Conclusions and Clinical Relevance—The smaller proportion of apoptotic neutrophils in horses with intestinal strangulation suggested that the inflammatory response could be greater or prolonged, compared with that of horses with nonstrangulating intestinal lesions. Further investigations are needed to better understand the relationship between neutrophil apoptosis and inflammation during intestinal injury.
Abstract
Objective—To estimate the national incidence of, operation-level risk factors for, and annual economic impact of colic among horses in the United States during 1998 and 1999.
Design—Epidemiologic survey.
Animals—21,820 horses on 1,026 horse operations in 28 states.
Procedures—Horses were monitored for colic for 1 year, and results were recorded in a log that was collected quarterly. Operation-level data were collected via 4 on-site personal interviews. Associations between colic and independent variables adjusted for size of operation were determined.
Results—Annual national incidence of colic in the US horse population was estimated to be 4.2 colic events/100 horses per year. Case fatality rate was 11%, and 1.4% of colic events resulted in surgery. Annual cost of colic in the Unites States was estimated to be $115,300,000.
Conclusions and Clinical Relevance—The national impact of equine colic is substantial because of the high case fatality rate. (J Am Vet Med Assoc 2001; 219:67–71)
Abstract
Objective—To identify apoptosis in equine intestines and determine whether apoptosis is associated with gastrointestinal tract disease or a specific tissue layer of intestine.
Animals—38 horses that underwent surgery or were euthanatized for small or large intestine obstruction, strangulation, or distension and 9 control horses euthanatized for reasons other than gastrointestinal tract disease or systemic disease.
Procedure—Specimens were collected at surgery from intestine involved in the primary lesion and distant to the primary lesion site or at necropsy from several sites including the primary lesion site. Histologic tissue sections were stained with H&E, and apoptosis was detected by use of the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling technique. The number of apoptotic cells per hpf was counted in the mucosa, circular muscle, longitudinal muscle, and serosa.
Results—Apoptotic nuclei were seen in all layers of intestine. An increased number of apoptotic cells was found in the circular muscle of the intestine from horses with simple obstruction, compared with strangulating obstruction or healthy intestine. Intestine distant from a primary strangulating lesion had higher numbers of apoptotic cells than did intestine distant from a simple obstructive lesion or intestine taken at the site of a strangulating or simple obstructive lesion.
Conclusions and Clinical Relevance—Intestine from horses with obstructing or strangulating lesions in the small intestine and large colon had high numbers of apoptotic cells possibly because of ischemic cell injury and subsequent inflammation. Whether substantial apoptosis affects intestinal function is not yet known. (Am J Vet Res 2003;64:982–988)
