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1.
OBJECTIVE: To determine whether intravenous infusion of nitroglycerin would modify pulmonary arterial, capillary, or venous hypertension in strenuously exercising Thoroughbreds. ANIMALS: 5 healthy Thoroughbred horses. PROCEDURE: Right atrial, right ventricular, and pulmonary vascular pressures were measured. Each horse was used in a control treatment (not medicated) and a nitroglycerin infusion (20 microg/kg of body weight/min) at rest and during exercise on a treadmill. Sequence of treatments was randomized for each horse, and treatments were separated by a 7-day interval. Galloping at 14.2 m/s on a 5% uphill grade elicited maximal heart rate (mean +/- SEM, 212 +/- 2 beats/min) and could not be sustained for > 90 seconds. Nitroglycerin dosage was selected, because maximal pulmonary and systemic hemodynamic effects of i.v. nitroglycerin were elicited at 5 microg/kg/min and increasing the dosage to 20 microg/kg/min did not cause adverse effects. RESULTS: In the control treatment, exercise performed at maximal heart rate resulted in a significant increase in right atrial as well as pulmonary arterial, capillary, and wedge pressures. Nitroglycerin infusion in standing horses significantly decreased right atrial and pulmonary vascular pressures, whereas heart rate increased. Exercise in nitroglycerin-infused horses also resulted in a significant increase in right atrial as well as pulmonary arterial, capillary, and wedge pressures, and these values were not significantly different from data for the control treatment. All horses experienced exercise-induced pulmonary hemorrhage for both treatments. CONCLUSIONS AND CLINICAL RELEVANCE: I.v. administration of nitroglycerin does not modify exercise-induced pulmonary hypertension and is unlikely to affect the incidence or severity of exercise-induced pulmonary hemorrhage in Thoroughbreds.  相似文献   

2.
Six normal, healthy horses age 3-10 years underwent left and right thoracoscopic examination using a rigid telescope. A minimum of 30 days was allowed between procedures. Horses were restrained in stocks and sedated with a continuous detomidine infusion. After surgical preparation of the hemithorax elected for surgery, and administration of local or regional anaesthesia of the surgery sites, thoracoscopy was completed during two 15 min pneumothorax periods. During the procedures, the thoracic structures were viewed using a 57 cm, 10 mm diameter, 30 degrees rigid telescope connected to a digital camcorder to allow computer capture of digital images. The telescope was inserted into the thoracic cavity via 3 different intercostal spaces. The 8th, 10th and 12th intercostal spaces were randomly selected and used among horses. The exploration of each hemithorax started from the dorsal-caudal quadrant continued toward the cranial thorax and was completed by observing the diaphragmatic and caudal pulmonary region. Collapsed lung, aorta, oesophagus and diaphragm were viewed readily in either hemithorax. On exploration of the right hemithorax, the azygos vein, thoracic duct and pulmonary veins were also identified. Horses tolerated thoracoscopy well. Signs of discomfort, such as increased respiratory rate, coughing and decreased level of sedation, were associated with lung collapse in one horse, with pneumothorax on 2 occasions, and when the thorax was approached through the 8th intercostal space. Surgery performed via the 8th intercostal space was hindered by the rigidity of the 8th and 9th ribs, and by the presence of a greater musculature, which did not allow easy cranial and caudal movements of the telescope.  相似文献   

3.
The present study was carried out to ascertain whether beta2-adrenergic receptor stimulation with clenbuterol would attenuate the pulmonary arterial, capillary and venous hypertension in horses performing high-intensity exercise and, in turn, modify the occurrence of exercise-induced pulmonary haemorrhage (EIPH). Experiments were carried out on 6 healthy, sound, exercise-trained Thoroughbred horses. All horses were studied in the control (no medications) and the clenbuterol (0.8 pg/kg bwt, i.v.) treatments. The sequence of these treatments was randomised for every horse, and 7 days were allowed between them. Using catheter-tip-transducers whose in-vivo signals were referenced at the point of the left shoulder, right heart/pulmonary vascular pressures were determined at rest, sub-maximal exercise and during galloping at 14.2 m/s on a 3.5% uphill grade--a workload that elicited maximal heart rate and induced EIPH in all horses. In the control experiments, incremental exercise resulted in progressive significant increments in right atrial as well as pulmonary arterial, capillary and venous (wedge) pressures and all horses experienced EIPH. Clenbuterol administration to standing horses caused tachycardia, but significant changes in mean right atrial or pulmonary vascular pressures were not observed. During exercise performed after clenbuterol administration, heart rate as well as right atrial and pulmonary arterial, capillary and wedge pressures also increased progressively with increasing work intensity. However, these values were not found to be statistically significantly different from corresponding data in the control study and the incidence of EIPH remained unaffected. Since clenbuterol administration also does not affect the transpulmonary pressure during exercise, it is unlikely that the transmural force exerted onto the blood-gas barrier of exercising horses is altered following i.v. clenbuterol administration at the recommended dosage.  相似文献   

4.
Objective— To evaluate use of pre‐tied ligating loop to perform thoracoscopic, large lung biopsy in normal and heaves‐affected horses. Study Design— Prospective clinical study. Animals— Normal (n=5) and heaves‐affected (n=6) horses. Methods— Lung biopsies, 1 from each hemithorax, were collected thoracoscopically using a pre‐tied ligating loop. Horses were either normal (C) or heaves‐affected with the latter being in remission (Ha) for the initial biopsy and in exacerbation (Hs) for the 2nd biopsy. Clinical variables, PaO2, and PaCO2 were used to determine the effect of surgical biopsy. Postoperative pneumothorax was monitored by serial thoracic radiographic examinations. Results— Thoracoscopic lung biopsy (n=29, 22 procedures) was well tolerated by all horses. Complication rate was 31%, including 8 ligature slippage and 1 pulmonary hemorrhage. Intranasal oxygen was administered intraoperatively to 6 horses (2 C, 1 Ha, 3 Hs) with severe hypoxemia or labored breathing. There was a significant decrease in PaO2 during surgery in horses not supplemented with oxygen. Postoperative pneumothorax (21/22 procedures) detected radiographically resolved within 3 weeks. Conclusion— Thoracoscopic lung biopsy using pre‐tied ligating loops was minimally invasive, relatively inexpensive, and fairly efficient. Heaves‐affected horses tolerated the surgery well, even when in exacerbation; however, the technique was associated with non life‐threatening complications in 31% of the biopsies, most of which required correction with additional ligating loops or more sophisticated instrumentation. Clinical Relevance— Using laparoscopic pre‐tied ligating loop for thoracoscopically‐assisted lung biopsy can be considered in horses with normal and impaired lung function but alternative instrumentation and access to intranasal oxygen must be available to the surgeon in case of complications.  相似文献   

5.
OBJECTIVE: To evaluate results of cytologic examination of specimens obtained by means of tracheal washes (TW) in 42 horses with a history of poor performance. DESIGN: Cross-sectional case series. ANIMALS: 42 horses with a history of poor performance. PROCEDURE: A TW was performed via endoscopy before and after horses exercised on a high-speed treadmill, and specimens were evaluated microscopically and graded. RESULTS: Ten (24%) horses were considered to be clinically normal before and after exercise. Pulmonary hemorrhage was diagnosed in 8 (19%) horses. One horse had evidence of exercise-induced pulmonary hemorrhage (EIPH) before exercise and pulmonary hemorrhage and allergic or inflammatory airway disease (IAD) after exercise. Five (12%) horses had IAD, and 1 had IAD and pulmonary hemorrhage after exercise. Seven (17%) horses had evidence of EIPH and IAD in both specimens. Four (10%) horses with EIPH had an increase in the proportion of hemosiderophages in the specimen obtained after exercise. Specimens obtained before exercise in 6 (14%) horses were not representative of the respiratory tract and could not be compared with specimens obtained after exercise. CLINICAL IMPLICATIONS: Interpretation of TW specimens obtained before and after exercise differed for only 5 of 36 (14%) horses. Specimens obtained after exercise were more likely to reveal airway disease. All specimens obtained after exercise adequately represented the respiratory tract, whereas 6 specimens obtained before exercise did not. Specimens obtained after exercise contained more airway secretions and had less cytologic evidence of pharyngeal contamination. Therefore, we recommend that TW samples be obtained after exercise in horses.  相似文献   

6.
The medical records of 10 horses with invasive neoplasms of the penis, prepuce, and/or superficial inguinal lymph nodes in which treatment involved en bloc resection and penile retroversion were reviewed. All were geldings and ranged in age from 12 to 25 years (mean, 19 years). Evaluation of biopsy specimens obtained before surgery confirmed lymphosarcoma in 1 horse and squamous cell carcinoma in 9 horses. Typical history included swelling, ulceration, and abscessation of the penis and prepuce and large superficial inguinal lymph nodes. Complications after surgery included dehiscence of the urethrostomy site (4 horses), dehiscence of the ventral skin incision (1 horse), urine scalding of 1 hind limb (1 horse), cystitis (1 horse), severe hemorrhage (1 horse), and diarrhea (1 horse). One horse was euthanatized during hospitalization, because of severe dehydration secondary to diarrhea. At necropsy, firm nodules were scattered in the pulmonary parenchyma, myocardium, thyroid gland, parathyroid glands, cranial mediastinum, kidneys, and hilar lymph nodes. Microscopic examination of the nodules revealed undifferentiated carcinoma. Nine horses were discharged from the hospital between 1 and 5 weeks after surgery. The mean follow-up interval was 27 months (range, 6 to 96 months). Eight horses had no evidence of recurrence. One horse had recurrence of neoplasm at 6 months and was euthanatized 12 months later.  相似文献   

7.
A 16-year-old Thoroughbred gelding was evaluated for respiratory disease and found to have a primary lung tumor on postmortem examination. A tentative antemortem diagnosis was made on the basis of results of radiography and cytologic examination of a needle aspirate guided by ultrasonography. A histologic diagnosis of bronchioalveolar adenocarcinoma was made. Thoracic neoplasia is rare in horses. The most frequently reported primary pulmonary tumor is the granular cell tumor.  相似文献   

8.
Strangulating volvulus of the large colon was treated by resection and anastomosis of the colon in 9 horses. Tissue specimens were obtained at the site of the resection for histologic evaluation. An attempt was made to correlate the appearance of the colon at the time of surgery to the histologic evaluation and the eventual outcome. Six of the 9 horses (66%) survived. This is in contrast to a reported survival of 34.7 to 36% after decompression and reduction of colonic volvulus. Survival after surgery could not be predicted on the basis of visual assessment or histologic examination.  相似文献   

9.
In the present study we examined, if in Icelandic horses an increase in heart and/ or breathing rate is physiological and breed dependend or a sign of a pulmonary or cardiac disease. Therefore we examined 37 Icelandic horses with the prereport of being healthy. During clinical lung examination four horses showed symptoms of a pulmonary disease like increased breathing rate and enforced breathing at rest. These horses were excluded from the study. The other 33 horses were clinically normal. 17 of these horses were unridden (untrained) and 16 horses were regularly worked (trained). After clinical examination in all horses analysis of arterial blood gas, endoscopy with tracheo- bronchial secret analysis and radiographic examination of the lung were carried out. Additionally electro- and echocardiographic examinations and standardised exercise tests with determination of heart and breathing rate as well as plasma lactate values were performed in all horses. During electro- and echocardiographic examination no pathological findings were observed. In total 22 of the 33 horses showed abnormal lung findings. Seven horses had mild signs of RAO and 15 horses had mild signs of interstitial bronchitis. Three horses had additional pulmonary haemorrhage. Eleven out of the 33 horses showed no abnormal lung findings. The breathing rate at rest differed not significantly between horses with (21 +/- 1/min) or without (23 +/- 2/min) pulmonary findings. The heart rate also did not differ significantly between horses with (39 +/- 1/min) or without (42 +/- 1/min) pulmonary findings. In contrast to this the trained Icelandic horses with abnormal pulmonary findings had significantly higher heart rates (p = 0.01) and significantly lower breathing rates (p = 0.009) compared to those without abnormal pulmonary findings. During echocardiography Icelandic horses with abnormal pulmonary findings had significantly larger left atrial diameter (without abnormal pulmonary findings: 82 +/- 7 mm, with abnormal pulmonary findings: 90 +/- 8 mm, p = 0.02). Compared to the untrained Icelandic horses (5.4 +/- 2 mmol/l) the trained horses showed significantly lower plasma lactate values (3.1 +/- 2 mmol/l, p = 0.001) immediately after exercise. After exercise the icelandic horses with abnormal pulmonary findings had significantly higher breathing rates (p < 0.05) and longer recovery periods (30 minutes) than horses without abnormal respiratory findings (15 minutes). Recovery of heart rate after exercise showed no differences between groups.  相似文献   

10.
The stimulation of pulmonary beta2-adrenergic receptors causes a decrease in vascular resistance. Thus, the present study was carried out to examine whether concomitant administration of clenbuterol-a beta2-adrenergic receptor agonist, to horses premedicated with furosemide would attenuate the exercise-induced pulmonary capillary hypertension to a greater extent than furosemide alone, and in turn, affect the occurrence of exercise-induced pulmonary hemorrhage (EIPH). Experiments were carried out on six healthy, sound, exercise-trained Thoroughbred horses. All horses were studied in the control (no medications), furosemide (250 mg i.v., 4 h pre-exercise)-control, and furosemide (250 mg i.v., 4 h pre-exercise)+clenbuterol (0.8 microg/kg i.v., 11 min pre-exercise) experiments. The sequence of these treatments was randomized for every horse, and 7 days were allowed between them. Using catheter-tip-transducers whose in-vivo signals were referenced at the point of the left shoulder, pulmonary vascular pressures were determined at rest, sub-maximal exercise, and during galloping at 14.2 m/s on a 3.5% uphill grade--a workload that elicited maximal heart rate. In the control study, incremental exercise resulted in progressive significant (P<0.05) increments in heart rate, right atrial as well as pulmonary arterial, capillary and venous (wedge) pressures, and all horses experienced EIPH. Furosemide administration caused a significant (P<0.05) reduction in mean right atrial as well as pulmonary capillary and venous pressures of standing horses. Although exercise in the furosemide-control experiments also caused right atrial and pulmonary vascular pressures to increase significantly (P<0.05), the increment in mean pulmonary capillary and wedge pressures was significantly (P<0.05) attenuated in comparison with the control study, but all horses experienced EIPH. Clenbuterol administration to standing horses premedicated with furosemide caused tachycardia, but significant changes in right atrial or pulmonary vascular pressures were not discerned at rest. During exercise in the furosemide+clenbuterol experiments, heart rate, mean right atrial as well as pulmonary arterial, capillary and wedge pressures increased significantly (P<0.05), but these data were not different from the furosemide-control experiments, and all horses experienced EIPH as well. Thus, it was concluded that clenbuterol administration is ineffective in modifying the pulmonary hemodynamic effects of furosemide in standing or exercising horses. Because the intravascular force exerted onto the blood-gas barrier of horses premedicated with furosemide remained unaffected by clenbuterol administration, it is believed that concomitant clenbuterol administration is unlikely to offer additional benefit to healthy horses experiencing EIPH.  相似文献   

11.
Six healthy, awake, and pharmacologically restrained mature horses were studied in order to define the changes in cardiopulmonary function during and after exploratory thoracoscopy and to determine the presence of postoperative complications occurring 48 hours after thoracoscopy. In a randomised 3 x 3 latin square design with 2 replications, 18 procedures were performed: 6 right (RTH) and 6 left thoracoscopies (LTH) and 6 sham procedures (STH). Prior to each procedure a physical examination and a bronchoalveolar lavage fluid analysis were performed. During thoracoscopy and sham protocols, horses were sedated with a continual drip of detomidine HCl and data were collected at 6 time intervals: T1 (baseline), T2 (10 min detomidine administration), T3 (first 15 min pneumothorax), T4 (5 min recovery from pneumothorax), T5 (second 15 min pneumothorax), and T6 (10 min recovery from the second pneumothorax and detomidine). An endoscopic thoracic examination was conducted during the 2 pneumothorax periods. An identical protocol was followed for sham procedures without surgery or pneumothorax. Data were analysed by ANOVA with time and surgical procedure as main factors. Physical examinations, thoracic radiography and ultrasound, CBC and bronchoalveolar lavage fluid analysis were performed 48 h after thoracoscopy. Heart rate, respiratory rate, and cardiac output decreased following detomidine administration. There was a trend for cardiac output to be lower during thoracoscopy. Mild systemic hypertension was associated with thoracoscopy although there was no effect on pulmonary arterial pressure. Total and pulmonary vascular resistances were increased following detomidine administration. Thoracoscopy caused a further increase in systemic and pulmonary vascular resistances especially during the second pneumothorax. Arterial O2 tension decreased following detomidine administration and was further decreased during the second pneumothorax period. PaO2 values were lower when thoracoscopy was performed on the left rather than the right hemithorax. No significant complications were found during the 48 h follow-up evaluation. A subclinical postoperative pneumothorax occurred in 2 horses, one of which had sustained a lung laceration by the trocar. Thoracoscopy performed in healthy, awake, and pharmacologically restrained horses did not have detrimental cardiopulmonary effects and did not cause postoperative complications within the first 48 h period.  相似文献   

12.
OBJECTIVE: To report the clinical and surgical findings and outcome for horses with strangulating obstruction caused by herniation through the proximal aspect of the cecocolic fold. STUDY DESIGN: Retrospective study. ANIMALS: Nine horses. METHODS: Medical records were reviewed for clinical signs, surgical findings and technique, and outcome. Cadaver ponies and necropsy specimens were also used to study the regional anatomy of the cecocolic fold. RESULTS: The ileum and distal jejunum were strangulated in 8 horses, whereas in 1 horse the small intestine and the left ascending colons were incarcerated in a rent in the cecocolic fold. Two horses were euthanatized at surgery, 6 horses had a small intestinal resection (mean length, 3 m; range, 1.5-6.4 m) and an end-to-side jejunocecostomy, and the entrapment was reduced without resection in the horse that had small intestine and ascending colon incarceration; cecocolic fold defects were not closed. One horse was euthanatized 36 hours after surgery because of endotoxemia. Six horses were discharged; 4 were available for long-term follow-up, of which 2 were euthanatized, and 2 were euthanatized 12 and 18 months after surgery because of colic signs. Variations in thickness of the cecocolic fold were observed in specimens obtained from necropsy of other horses and ponies. CONCLUSIONS: Reasons for this defect are unknown, although observed anatomic differences in cecocolic fold thickness may contribute to the development of defects. CLINICAL RELEVANCE: Reduction of the entrapped bowel is easiest when traction is placed on the bowel at a 90 degrees to the base of the cecum. Intestinal incarceration through rents within the proximal part of the cecocolic fold should be considered as a differential diagnosis for strangulating obstruction in horses.  相似文献   

13.
Four horses (aged 1 to 18 years) with no apparent respiratory or cardiovascular abnormalities underwent thoracotomy and partial resection of a cranial lung lobe. A stapling instrument was used. Pulmonary function testing prior to and 30 days following surgery showed no significant change in inspiratory or expiratory resistance, compliance, or work of breathing. Postoperative complications consisted of a mild pneumothorax in all horses and localized incisional infection in two horses. All horses displayed a temporary decrease in forward motion of the forelimb on the operated side. Postmortem examination was performed 30 days after surgery; pleural thickening and adhesions between the lung and thoracotomy site were found. The excisionai margin of each cranial lobe was straight with slight puckering due to multiple surgical wire staples. Adjacent tissue collapse and compression were confined to an area no greater than 1 cm from the staples. Beyond this compression, the remaining lung at the surgical site was histologically normal. Subsequently, one horse suffering from recurrent episodes of clinical signs attributed to pleuropneumonia underwent left thoracotomy and partial lung resection followed by a right thoracotomy 48 days later. The horse's condition improved postoperatively, and he was able to undergo normal conditioning and racing.  相似文献   

14.
OBJECTIVE: To correlate clinical score, intrapleural pressure, cytologic findings of bronchoalveolar lavage fluid (BALF), and histologic lesions of pulmonary tissue in horses affected with summer pasture-associated obstructive pulmonary disease (SPAOPD). ANIMALS: 8 adult horses affected with SPAOPD and 6 adult horses without evidence of respiratory tract disease. PROCEDURE: Clinical score, change in intrapleural pressure (deltaPpl) during tidal breathing, results of cytologic examination and bacteriologic culture of BALF, and results of histologic examination of pulmonary parenchyma were evaluated. RESULTS: Clinical scores for SPAOPD-affected horses (median, 5.75; range, 4.0 to 7.5) were significantly greater, compared with clinically normal horses (median, 2.0; range, 2.0 to 3.0). Cytologic examination of BALF from SPAOPD-affected horses revealed predominantly nondegenerate neutrophils. Histologic lesions were identified throughout pulmonary tissue and included severe accumulation of mucus and neutrophils within the small airways, metaplasia of bronchiolar goblet cells, and mild peribronchial infiltrate. Histologic examination of specimens collected via percutaneous biopsy was predictive of disease and corresponded to findings at postmortem examination. Clinical score and deltaPpl were highly correlated with mucus accumulation in the airways of affected horses. Peribronchial inflammatory infiltrate correlated with percentage of neutrophils in BALF of affected horses. CONCLUSIONS AND CLINICAL RELEVANCE: Clinical scoring and deltaPpl provided valid estimates of disease severity. Findings from cytologic examination of BALF of SPAOPD-affected horses varied, although, in most instances, it was diagnostically useful. Severe mucus accumulation in the airways was the most remarkable histopathologic finding in SPAOPD-affected horses. Examination of biopsy specimens collected from pulmonary parenchyma was consistently useful in diagnosing SPAOPD.  相似文献   

15.
The sudden death of two horses was attributed to the rapid and acute development of pulmonary aspergillosis. One horse was making excellent postoperative progress after a jejunal resection and anastomosis for intestinal adhesions. The other horse was being treated routinely for equine protozoal myeloencephalitis (EPM). Signs of fever and an increased respiratory rate were detected shortly before death in the first horse, but no premonitory clinical signs characteristic of pulmonary infection were detected in the horse being treated for EPM. Both horses developed rapidly debilitating, acute pulmonary mycosis and died unexpectedly.  相似文献   

16.
A 4-year-old Paint mare was examined because of respiratory tract infection, dermatitis, and weight loss of 2 months' duration. Initial examination revealed generalized pruritic dermatitis, ocular and nasal discharges, and stranguria. Laboratory abnormalities included leukopenia and hypoalbuminemia. Further examination of the respiratory tract revealed grade III of IV pharyngitis and pyogranulomatous pneumonia. Endoscopic examination of the bladder revealed a prolific mass at the junction of the bladder and urethra. Hypoproteinemia was suspected to be caused by protein-losing enteropathy. On histologic examination, skin, rectal, pharyngeal, and urethral biopsy specimens were characterized by infiltration of eosinophils and lymphocytes, and a diagnosis of multisystemic eosinophilic epitheliotropic disease was made. The horse improved following treatment with dexamethasone, trimethoprim-sulfamethoxazole, and an antihistamine and was discharged after 19 days of hospitalization. Treatment with dexamethasone was continued for 4 weeks after hospitalization but was then discontinued. Eight months after discharge, the horse was performing as a pleasure horse and did not require any medical treatment. Multisystemic eosinophilic epitheliotropic disease is typically associated with a poor prognosis in horses. The dermatitis, protein-losing enteropathy, and lower respiratory tract disease in this horse were consistent with previous reports; however, pharyngitis and urethritis have not, to our knowledge, been previously reported in horses with this disease.  相似文献   

17.
Furosemide premedication of horses 4 h prior to exercise significantly attenuates exercise-induced pulmonary capillary hypertension which may help diminish the severity of exercise-induced pulmonary haemorrhage. As pulmonary hemodynamic effects of furosemide may be mediated via a reduction in plasma volume (which is most pronounced 15-30 min postfurosemide administration, with plasma volume recovering thereafter), we hypothesized that administration of furosemide at intervals shorter than 4 h before exertion may be more effective in attenuating the exercise-induced rise in pulmonary capillary blood pressure. Thus, our objective was to determine whether furosemide-induced attenuation of exercise-induced pulmonary arterial, capillary and venous hypertension would be enhanced when the drug is administered at intervals shorter than 4 h before exercise. Using established techniques, right atrial, and pulmonary arterial, capillary and wedge (venous) pressures were ascertained in seven healthy, sound, exercise-trained Thoroughbred horses in a randomized split-plot experimental design. Measurements were made at rest and during exercise performed at maximal heart rate (217 +/- 3 beats/min) in the control (no medications) experiments and following furosemide administration (250 mg intravenously (i.v.)) at 1, 2, 3 and 4 h before exercise. Sequence of treatments was randomized and 7 days were allowed between experiments on each horse. Although furosemide administration in the four treatment groups caused only insignificant changes in the pulmonary arterial, capillary and wedge pressures of standing horses, furosemide-induced reduction in mean right atrial pressure achieved statistical significance in the 2 h postfurosemide experiments. In the control studies, exercise was attended by statistically significant increments in mean right atrial, as well as pulmonary arterial, capillary and wedge pressures. Although exercise in each of the four furosemide experiments was also attended by significant increments in right atrial as well as pulmonary vascular pressures, in the 1, 2 and 3 h postfurosemide experiments, mean right atrial pressure increased to a significantly lower value than in the control study. Exercise-induced changes in pulmonary vascular pressures in the 1 h postfurosemide experiments were not different from the pressures in the control study. There was a significant attenuation of exercise-induced pulmonary capillary and venous hypertension in the 2, 3 and 4 h postfurosemide experiments, but significant differences among these treatments were not found. Thus, these data did not support the contention that administration of furosemide at intervals shorter than 4 h before exercise is more effective in attenuating exercise-induced pulmonary capillary or venous hypertension in Thoroughbred horses.  相似文献   

18.
A six-year-old arabian stallion was admitted to The Ohio State University Veterinary Hospital for evaluation and repair of a comminuted fracture of the second phalanx. The horse developed impaired arterial oxygenation during surgey and pulmonary edema post-operatively. We postulate that impaired arterial oxygenation resulted from atelectasis of the dependent lung during annesthesia, and the pulmonary edema occurred following re-expansion of the atelectatic of the initiating cause of the edema, removal of excess lung water from the alveoli, and restoration of normal arterial oxygenation. The horse was fully recovered within 12 hours of initiation of clinical signs of respiratory compromise. The horse was fully recovered within 12 hours of initiation of clinical signs of respiratory compromise. This report describes re-expansion pulmonary edema due to reperfusion injury in a horse, treatment of the condition, and a possible explanation of the pathogenesis of this pulmonary pathology.  相似文献   

19.
The present study was carried out to examine whether intravenously administered pentoxifylline-a phosphodiesterase inhibitor which increases red blood cell deformability and decreases blood viscosity-would attenuate the magnitude of exercise-induced pulmonary capillary hypertension in healthy, fit Thoroughbred horses and in turn, diminish the occurrence of exercise-induced pulmonary hemorrhage (EIPH). Experiments were carried out on six healthy, sound, exercise-trained Thoroughbred horses. Hemodynamic data were collected at rest, and during exercise performed at 8 and 14 m/sec on 3.5% uphill grade in the control (no medications) and the pentoxifylline (8.5 mg/kg, i.v.) experiments. The sequence of treatments was randomized for every horse and 7 days were allowed between treatments. Galloping at 14 m/sec on 3.5% uphill grade elicited maximal heart rate. In both treatments, simultaneous measurements of phasic and mean right atrial and pulmonary arterial, capillary and wedge pressures were made using catheter-tip-manometers whose signals were carefully referenced at the point of the left shoulder. In the control study, exercise resulted in progressive significant increments in heart rate, right atrial and pulmonary arterial, capillary and venous pressures; thereby, confirming that exercising Thoroughbreds develop significant pulmonary hypertension. All horses experienced exercise-induced pulmonary hemorrhage (EIPH) in the control experiments. Pentoxifylline administration to standing horses caused anxiety, tachycardia, muscular fasciculations/tremors and mild sweating, but statistically significant changes in right atrial and pulmonary arterial, capillary and venous pressures were not detected. Exercise in the pentoxifylline treatment also resulted in progressive significant increments in heart rate and right atrial as well as pulmonary vascular pressures, but these data were not statistically significantly different from those in the control study and the incidence of EIPH remained unchanged. Thus, it was concluded that i.v. pentoxifylline is ineffective in attenuating the exercise-induced pulmonary arterial, capillary and venous hypertension in healthy, fit Thoroughbred horses.  相似文献   

20.
Clinical records and thoracic radiographs of 19 horses with a confirmed pathologic diagnosis of silicosis were reviewed. These horses had histories of varying degrees of chronic weight loss, exercise intolerance, and respiratory distress. At the time of presentation, two horses were asymptomatic. Ten horses were geldings and nine were female. The mean age of the 19 horses was 10.7 +/- 5.5 years. Fourteen horses were identified as being from the Monterey-Carmel Peninsula of midcoastal California. An abnormal, structured interstitial pulmonary pattern was identified on thoracic radiographs in each horse. The interstitial pulmonary changes were classified as miliary (13 horses), reticulonodular (4), or linear interstitial (2), and were best visualized dorsally and caudodorsally. In addition to the abnormal interstitial pulmonary pattern, areas of pulmonary consolidation were evident caudodorsally in seven horses. Other thoracic radiographic features included: hilar lymphadenopathy (4 horses), pleural effusion/thickening (4), cranial mediastinal lymphadenopathy (2), hyperinflation (1), and a discrete pulmonary mass (1). Necropsy findings in eight horses and results of lung biopsies in an additional five horses showed a diffuse, multifocal, granulomatous pneumonia with areas of pulmonary fibrosis. Cellular infiltrates included predominantly macrophages with intracellular and/or extracellular crystalline material, occasional lymphocytes, and giant cells. Similar cellular changes were also identified, during necropsy, in the hilar and tracheobronchial lymph nodes in each of the eight horses, although gross enlargement of the lymph nodes was present in only six horses. The radiographic and pathologic findings of these 19 horses are consistent with chronic or the accelerated forms of silicosis that are recognized in humans.  相似文献   

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