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Summary

Over a 10-year period, cecocolic intussusception was diagnosed in 11 of 842 horses undergoing surgical treatment for colic at the New York State College of Veterinary Medicine. Eight horses died or were euthanatized because of poor prognosis determined at surgery or because of postoperative complications. Three horses recovered without complication after manual reduction of the intussusception and partial typhlectomy, using an intestinal stapling device.

Free access
in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE To determine the anatomic location and clinical signs of thymoma in goats and long-term outcomes in a subset of goats treated by tumor excision.

DESIGN Retrospective case series.

ANIMALS 13 goats with a histologic diagnosis of thymoma at the Cornell University Hospital for Animals between 1990 and 2014.

PROCEDURES Medical records of goats with thymoma were reviewed and data were evaluated regarding signalment, clinical signs, diagnostic imaging results, thymoma size, treatment, and outcome. Follow-up information was obtained via contact with the owners and review of medical records.

RESULTS 8 goats had a mediastinal mass, 4 had a palpable ventral cervical mass, and 1 had both types of masses. Median age at the time of diagnosis was 9.5 years (range, 3 to 12 years). Goats with a mediastinal mass had respiratory distress or marked tachypnea. Six goats were treated surgically, including all 5 with a ventral cervical mass. All 5 goats with a ventral cervical mass survived with no tumor recurrence for ≥ 1 year after excision. Only 2 goats with a mediastinal mass survived to hospital discharge.

CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that the prognosis for goats following excision of ventral cervical thymomas was favorable, whereas goats with mediastinal thymomas appeared more likely to have severe clinical signs and a guarded prognosis.

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To compare postoperative complications, short- and long-term survival, and surgical times for hand-sewn end-to-end (EE), stapled functional end-toend (FEE), and stapled side-to-side (SS) anastomotic techniques for jejunal resection in horses.

Design—Retrospective study.

Animals—59 horses.

Procedure—Medical records were reviewed to obtain signalment, diagnosis, treatment, and outcome for horses that underwent jejunojejunostomy in our hospital. Only horses that recovered from anesthesia were included in the study.

Results—Among the 59 horses, there were 33 EE, 15 FEE, and 11 SS anastomoses. No difference was found in duration of surgery among the 3 techniques. The most common postoperative complications were colic episodes (56%), ileus (53%), diarrhea (20%), and adhesions (15%). Horses with SS anastomosis had a significantly shorter duration of postoperative ileus than the EE group did. No significant difference in duration of postoperative ileus was found among the other groups. No difference was found among the 3 anastomotic techniques in regard to survival rate at the time of discharge, 6 months after surgery, or 1 year after surgery. Overall survival rates after jejunal anastomosis were 88% at the time of discharge, 65% at 6 months after surgery, and 57% at ≥ 1 year after surgery.

Conclusions and Clinical Relevance—The handsewn EE, stapled FEE, and stapled SS anastomotic techniques should be considered equivalent methods for small intestinal anastomosis in the horse. However, the stapled SS technique may be preferred because of possible decreased duration of postoperative ileus. (J Am Vet Med Assoc 2002;220:215–218)

Full access
in Journal of the American Veterinary Medical Association

SUMMARY

To determine whether abnormal airway pressures have a role in development of dorsal displacement of the soft palate (ddsp), measurements of tracheal and pharyngeal pressures were correlated with nasopharyngeal morphology in exercising horses. Exercising videoendoscopy and measurement of tracheal and pharyngeal pressures were used in 14 clinically normal horses and 19 horses with intermittent ddsp. The pressure signals were superimposed on the videoendoscope image, and both images were saved simultaneously on a videocassette for slow motion analysis to determine the instant displacement occurred in the respiratory cycle. Horses were submitted to an escalating 8-minute high-speed test with a maximal speed of 14 m/s. Compared with clinically normal horses, horses with intermittent ddsp did not have excessively negative inspiratory pressures during exercise. Eight horses displaced the soft palate during inspiration, 4 horses displaced it during expiration, and 7 displaced it by swallowing. Some horses displaced the soft palate at the beginning of the exercise trial, before reaching maximal speed, some horses displaced it at the peak speed, and some horses displaced it when slowing down. Epiglottic size in horses with ddsp was within normal limits, ruling out epiglottic hypoplasia as a cause of ddsp during exercise. Airway pressures were significantly (P < 0.002) altered after ddsp. Pharyngeal and tracheal inspiratory pressures were less negative, whereas pharyngeal expiratory pressure became less positive and tracheal expiratory pressure became more positive after displacement, suggesting a decrease in airflow and an increase in expiratory resistance in the upper airway.

Free access
in American Journal of Veterinary Research

Abstract

Objective—To investigate whether upper airway sounds of horses exercising with laryngeal hemiplegia and alar fold paralysis have distinct sound characteristics, compared with unaffected horses.

Animals—6 mature horses.

Procedure—Upper airway sounds were recorded in horses exercising on a high-speed treadmill at maximum heart rate (HRMAX) under 3 treatment conditions (ie, normal upper airway function [control condition], and after induction of left laryngeal hemiplegia or bilateral alar fold paralysis) in a randomized crossover design. Fundamental frequency, spectrograms using Gabor transform, and intensity characteristics of acquired sounds (peak sound level [soundpeak] and highest frequency of at least –25 dB sound intensity [F25max]) were evaluated.

Results—Evaluation of the fundamental frequency of the time domain signal was not useful. Sensitivity and specificity (83 and 75%, respectively) of spectrograms were greatest at maximal exercise, but the exact abnormal condition was identified in evaluation of only 12 of 18 spectrograms. Increased accuracy was obtained using soundpeak and F25max as discriminating variables. The use of soundpeak discriminated between control and laryngeal hemiplegia conditions and F25max between laryngeal hemiplegia and alar fold paralysis conditions. This increased the specificity of sound analysis to 92% (sensitivity 83%) and accurately classified the abnormal state in 92% of affected horses.

Conclusions and Clinical Relevance—Sound analysis might be a useful adjunct to the diagnosis and evaluation of treatment of horses with upper airway obstruction, but would appear to require close attention to exercise intensity. Multiple measurements of recorded sounds might be needed to obtain sufficient accuracy for clinical use. (Am J Vet Res 2002;63:1707–1713)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine the phase and quantitate the electromyographic (EMG) activity of the genioglossus, geniohyoideus, hyoepiglotticus, omohyoideus, sternohyoideus, sternothyroideus, and thyrohyoideus muscles of clinically normal horses during strenuous exercise.

Animals—7 clinically normal adult horses (2 Thoroughbreds and 5 Standardbreds).

Procedures—Bipolar electrodes were surgically implanted in the aforementioned muscles, and horses were subjected to an incremental exercise test on a high-speed treadmill. The EMG, heart rate, respiratory rate, and static pharyngeal airway pressures were measured during exercise. The EMG was measured as mean electrical activity (MEA). The MEA values for maximal exercise intensity (13 or 14 m/s) were expressed as a percentage of the MEA measured at an exercise intensity of 6 m/s.

Results—MEA was detected during expiration in the genioglossus, geniohyoideus, sternohyoideus, and thyrohyoideus muscles and during inspiration in the hyoepiglotticus and sternothyroideus muscles. Intensity of the MEA increased significantly with exercise intensity in the genioglossus, geniohyoideus, and hyoepiglotticus muscles. Intensity of the MEA increased significantly in relation to expiratory pharyngeal pressure in the geniohyoideus and hyoepiglotticus muscles.

Conclusions and Clinical Relevance—Once exercise intensity reached 6 m/s, no quantifiable additional increase in muscular activity was detected in the omohyoideus, sternohyoideus, sternothyroideus, and thyrohyoideus muscles. However, muscles that may affect the diameter of the oropharynx (genioglossus and geniohyoideus muscles) or rima glottis (hyoepiglotticus muscle) had activity correlated with the intensity of exercise or expiratory pharyngeal pressures. Activity of the muscles affecting the geometry of the oropharynx may be important in the pathophysiologic processes associated with nasopharyngeal patency.

Full access
in American Journal of Veterinary Research

SUMMARY

We examined the electromyographic activity of the costal portion of the diaphragm and the transverse abdominal and external oblique muscles in 6 chronically instrumented awake adult horses during eupneic breathing, during 2 levels of hypercapnia (fractional concentration of inspired CO2; FI CO2 = 0.4 and 0.6), and during 2 levels of hypocapnic hypoxia (FI CO2 = 0.15 and 0.12). Using the inert gas technique, we also measured the end-expiratory lung volumes of the 6 horses during eupnea, 6% CO2 challenge, and 12% O2 breathing. During eupneic breathing, phasic electrical activity of these 3 muscles was always present and was preceded by the onset of mechanical flow. At progressive levels of hypercapnia, the magnitude of inspiratory and expiratory electrical activity increased, and for the expiratory muscles, this recruitment coincided with significant (P < 0.05) increases in peak expiratory gastric pressure. However, during hypocapnic hypoxia, differential recruitment patterns of the respiratory muscles were found. The electrical activity of the diaphragm increased in magnitude and occurred sooner relative to the onset of mechanical flow. The magnitude and onset of abdominal expiratory activity failed to increase significantly during these episodes of hyperpnea and this pattern of activity coincided with decrements in peak expiratory gastric pressure. Despite alterations in muscle recruitment patterns during these hyperpneic episodes, end-expiratory lung volume remained unchanged. Thus, we conclude that adult horses respond similarly to awake dogs during peripheral and central chemoreceptor stimulation.

Free access
in American Journal of Veterinary Research

Summary

Repeatability of measurements of peak and mean tracheal and pharyngeal pressures in exercising horses was determined. Five athletically fit horses were subjected to repeated (n = 5) standardized exercise trials. Static pressures in the trachea, nasopharynx, and mask were determined. At least 96% of all mean pressure measurements were within 5 cm of H2O of the mean value for any horse. Peak pressure measurements were less repeatable, but at least 96% of all measurements were within 10 cm of H2O of the mean peak measurements for any horse. In 10 horses galloping at 14 m/s, the 95% confidence interval for peak treacheal and pharyngeal inspiratory pressures ranged from —40 to —50 cm of H2O and —20 to — 26 cm of H2O, respectively. During expiration, the 95% confidence interval for peak tracheal and pharyngeal pressure at the same speed ranged from 15 to 28 cm of H2O and 10 to 24 cm of H2O respectively. During inspiration, horses with induced laryngeal hemiplegia had static pressure measurements generally outside that range. We conclude that determination of tracheal and pharyngeal pressures is a potentially useful adjunct for assessment of the proximal portion of the respiratory tract.

Free access
in American Journal of Veterinary Research

Abstract

Objective—To evaluate whether administering a tart cherry juice blend (TCJB) prior to exercise would reduce skeletal and cardiac muscle damage by decreasing the inflammatory and oxidative stress response to exercise in horses.

Animals—6 horses.

Procedures—Horses were randomly allocated into 2 groups in a crossover study with a 2-week washout period and orally administered either TCJB or a placebo solution (1.42 L, twice daily) in a double-masked protocol for 2 weeks prior to a stepwise incremental exercise protocol. Horses were tested for serum activities of creatine kinase and aspartate aminotransferase (AST) and concentrations of cardiac troponin I (cTnI), thiobarbituric acid reactive substances (TBARS; an indicator of oxidative stress), and serum amyloid A (SAA; an indicator of inflammation). To ensure that treatment would not result in positive results of an equine drug-screening protocol, serum samples obtained from each horse prior to and after 2 weeks of administration of TCJB or the placebo solution were tested.

Results—All horses had negative results of drug screening at both sample times. The exercise protocol resulted in a significant increase in TBARS concentration, SAA concentration, and serum AST activity in all horses. Administration of TCJB or placebo solution was not associated with an effect on malondialdehyde or SAA concentrations. However, administration of TCJB was associated with less serum activity of AST, compared with administration of placebo solution.

Conclusions and Clinical Relevance—Administration of TCJB may diminish muscle damage induced by exercise.

Full access
in American Journal of Veterinary Research

Abstract

Objective

To determine whether dorsal displacesment of the soft palate (DDSP) results in pulmonary artery hypertension and leads to increases in transmural pulmonary artery pressure (TPAP); to determine whether pulmonary hypertension can be prevented by prior administration of furosemide; and to determine whether tracheostomy reduces pulmonary hypertension.

Animals

7 healthy horses.

Procedure

Horses were subjected to 3 conditions (control conditions, conditions after induction of DDSP, and conditions after tracheostomy). Horses were evaluated during exercise after being given saline (0.9% NaCI) solution or furosemide.

Results

Controlling for drug, horse, and speed of treadmill, DDSP-induced increase in intrathoracic pressure was associated with a significant increase in minimum (36 mm Hg), mean (82 mm Hg), and maximum (141 mm Hg) pulmonary artery pressure, compared with values for control horses (30, 75, and 132 mm Hg, respectively). Increases in pulmonary artery pressure did not induce concomitant increases in TPAP. Tracheostomy led to a significant reduction of minimum (53 mm Hg), and mean (79 mm Hg) TPAP pressure, compared with values for control horses (56 and 83 mm Hg, respectively). When adjusted for horse, speed of treadmill, and type of obstruction, all aspects of the pulmonary artery and TPAP curves were significantly decreased after administration of furosemide, compared with those for horses given saline (0.9% NaCI) solution.

Conclusions

DDSP was associated with increases in pulmonary artery pressure but not with increases in TPAP.

Clinical Relevance

Expiratory obstructions such as DDSP are likely to result in pulmonary hypertension during strenuous exercise, but may not have a role in the pathogenesis of exercise-induced pulmonary hemorrhage. (Am J Vet Res 1999;60:485-494).

Free access
in American Journal of Veterinary Research