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The effect of a single ligature on back pressure in the internal carotid artery was studied in nine horses. In six anesthetized horses, one internal carotid artery was catheterized 2 cm from its origin and blood pressure was recorded continuously. Then the artery was ligated, pressure was recorded again, and the horses were euthanatized. In another three anesthetized horses, indwelling catheters were placed in both internal carotid arteries and a loose ligature was placed proximal to one catheter. After horses recovered from anesthesia, the ligature was tied and blood pressure was recorded in both arteries on that day and 3 days later, then these horses were euthanatized. The anatomy of the cerebral arteries was examined in all nine horses. Blood pressure in the internal carotid arteries did not change after ligation. Subjectively, collateral channels considered most likely to maintain blood pressure in the ligated internal carotid artery were the caudal intercarotid artery and the cerebral arterial circle. We concluded that ligation of the internal carotid artery would not prevent severe hemorrhage from the internal carotid artery in horses with guttural pouch mycosis until the ligated artery thrombosed to the level of the lesion.

Anemia that was secondary to ovarian hemorrhage in a 4-year-old miniature horse mare was treated prior to laparotomy with polymerized ultrapurified bovine hemoglobin (PUBH). Two previous whole-blood transfusions had resulted in acute transfusion reaction, and a suitable blood donor could not be found among 9 horses, necessitating use of the blood substitute. Subsequent blood typing revealed the mare to be Aa-negative, with allo-antibodies against Aa in serum. Serious adverse reactions were not observed after infusion of PUBH, and the mare recovered. Although the safety and efficacy of using PUBH in horses has not been established, PUBH may prove to be an excellent alternative to whole-blood transfusions, when indicated.

Over a period of 5 years on a central Kentucky Thoroughbred stud farm 132 foals were evaluated for the presence of cervical vertebral malformation (CVM). Lateral cervical vertebral radiographs were obtained on 70 standing foals. These radiographs were evaluated semi-quantitatively and scored numerically for the presence of stenosis of the vertebral canal, enlarged physeal growth plates, caudal extension of the dorsal border of the orifice of the vertebral canal, angular fixation, delayed ossification of bone and degenerative joint disease. From these scores a total CVM score was given for each set of radiographs. All foals were repeatedly examined for clinical signs of neurological disease. Foals with no clinical signs of CVM had maximal total CVM scores (mean +/- sd) of 5.7 +/- 2.8 and foals affected with CVM had maximal total CVM scores of 17.0 +/- 2.8. Determination of the total CVM score was non-invasive, inexpensive and a very accurate procedure for predicting and diagnosing the presence of CVM in Thoroughbred foals up to 1 year of age.

Loop colostomy was performed in 10 horses as treatment for grade-III rectal tears (n = 6 horses), small-colon infarction (n = 2 horses), perirectal abscess and stenosis (n = 1 horse), and small-colon stricture (n = 1 horse). In 7 horses, the colostomy was constructed through a single incision low in the left flank, with closure of the incision around the stoma (single-incision technique). In 3 horses, 2 of which had colostomy performed as a standing procedure, the selected segment of small colon was placed from a flank incision into a separate, small incision low in the left flank (double-incision technique). Five horses underwent colostomy reversal (at 18 to 63 days) and 2 of these horses, both with grade-III rectal tears, recovered completely. Of 8 horses that did not survive, 6 died from the primary disease or associated complications. Technical problems associated with colostomy accounted for death of 2 horses. One horse had gastric rupture attributable to suture occlusion of the small intestine after colostomy reversal, and another horse had complications of incisional infection after repair of a peristomal hernia. Small-colon prolapse through the stoma necessitated premature reversal of the colostomy in a horse that was euthanatized because of worsening laminitis. Minor complications of the colostomy procedure were partial stomal dehiscence (n = 4 horses), partial dehiscence of the flank wound after colostomy reversal (n = 2 horses), and small ventral midline hernia after colostomy reversal (n = 1 horse). Loop colostomy may be of benefit to horses with rectal tears, provided it is done soon after the tear occurs.(ABSTRACT TRUNCATED AT 250 WORDS)

The medical records of 66 calves with atresia coli were reviewed; 64 calves were examined at the New York State College of Veterinary Medicine, and 2 calves were examined at the New Bolton Center. In each case, the site of the atresia was within the spiral loop of the ascending colon. In 1 of these calves, a segment of jejunum was also atretic. Absence of feces, progressive weakness, and abdominal distension were the most common clinical signs observed. Other congenital abnormalities were detected in 12 (18%) of 66 calves. Of the 66 calves examined, 5 were euthanatized or died on admission, and 61 had an exploratory celiotomy performed. Eight calves were euthanatized or died during the surgery. In the remaining 53 calves, surgical treatment consisted of enterotomy followed by meconium evacuation, resection of the proximal blind end (in 30 calves), and restoration of intestinal continuity. Restoration of intestinal continuity was done either by side-to-side anastomosis of the proximal to distal blind ends (5 calves), or by side-to-side or end-to-side anastomosis of the proximal blind end to the descending colon (48 calves). Of the 66 calves seen, 27 (41%) were discharged from the hospital, and 11 of these reached reproductive age (11 calves were lost to follow-up before they were 2 years old). From the 11 calves reaching reproductive age, 33 calves were born, one of which may have had atresia coli. The owners should anticipate that long-term survivors likely will have loose feces and normal offspring, but may not grow as well as otherwise expected.

Mucosa obtained from the cecum of healthy horses and incubated in vitro with 0.1 mM cycloleucine could accumulate this amino acid against an apparent concentration gradient after 60 and 120 minutes. Accumulation by the serosal (antiluminal) surface of the tissue was 3 times greater than accumulation by the mucosal (luminal) surface after 120 minutes (P less than 0.001). Cycloleucine accumulation was significantly reduced by Na deprivation after 60 minutes (P less than 0.05) and 120 minutes (P less than 0.01) and by anoxic conditions after 120 minutes (P less than 0.05). Transmucosal flux from mucosal to serosal surface of the tissue was significantly (P less than 0.05) greater than the opposing flux, but both unidirectional fluxes were small and were largely attributed to passive processes. It was concluded that the most avid transport system for cycloleucine was on the serosal surface of the horse's cecal mucosa, and an active transport system was not evident on the mucosal surface. An active transport system for amino acids on the serosal surface could be explained by the need for crypt cells, the predominant epithelial cell type in the cecum, to obtain nutrients from blood, rather than from the intestinal lumen.

The case records of 20 cows with either a third-degree perineal laceration or rectovestibular fistula were reviewed to ascertain the signalment, history, treatment, and long-term result of treatment. Fifteen cows, including 10 first-calf cows, had third-degree perineal lacerations that occurred at calving. Surgery was done in 14 of 15 cows; 10 of the 14 (71%) remained fertile. The cow that was not treated surgically was culled after 24 months because of infertility. Five cows had a rectovestibular fistula; 4 of these were treated surgically. The cow that did not have surgery healed by second intention and remained fertile, and 3 of the 4 cows in which surgery was performed were fertile. None of the cows that produced calves after the initial injury suffered a perineal laceration at subsequent calvings. Single-stage surgical repair of third-degree perineal laceration or rectovestibular fistula appeared to have a good prognosis for subsequent fertility in cows.

A repeatable procedure for fertilization of bovine ova in vitro is described. Oocytes were recovered from ovarian follicles or from oviducts near the time of ovulation following treatment of donors with pregnant mare's serum gonadotropin (PMSG) and prostaglandin F2 alpha (PGF2 alpha). For in vitro capacitation semen was incubated, then high ionic strength treated and subsequently incubated in defined medium prior to insemination of oocytes. In one experiment frozen bull semen was successfully used. In experiments with 4 bulls (B, C, D, F), 34 (43.6%) of 78 ova and 13 (19.7%) of 66 follicular oocytes were fertilized in vitro. In the last series (spermatozoa from Bull F) the fertilization of 22 (62.9%) of 35 tubal ova was achieved. In vitro development proceeded to the 8-cell stage. No fertilization in vitro followed use of one male (Bull E), even though his spermatozoa could penetrate zona-free hamster ova in vitro, and higher than usual bacterial contamination of his semen was implicated as the probable cause. Findings suggested vigorous progressive sperm motility and acrosome integrity to be important features of good sperm samples. In one experiment a 4-cell stage embryo was transferred with the result that the recipient gave birth to a normal bull calf on June 9, 1981. The first calf resulting from in vitro fertilization has been found to be completely normal.

Retinol esterification was demonstrated in vivo and in vitro in lamb kidney. Retinol labeled with hydrogen-3 injected into the renal artery of lambs appeared in the labeled retinyl ester fraction in the renal vein. Degree of tracer incorporation into retinyl esters increased with vitamin A intake. In homogenates, activity was concentrated in microsomes and enhanced fourfold by addition of adenosine 5'-triphosphate and coenzyme A to the incubation mixture. These findings suggest that the esterification is a function of fatty acyl coenzyme A:retinol acyl transferase. Renal esterification may play a role in retinol homeostasis.

A technique of nasoduodenal (N-D) intubation and intestinal decompression was developed and used in the horse to explore the prevention of gastric and intestinal distention after abdominal surgical operation. Three styles of tubes (2 single-lumen tubes and 1 double-lumen tube) were positioned in the duodenum of 12 mature horses (10 experimental and 2 clinical) during laparotomy (without enterotomy), and an iatrogenic occlusion at the small intestine was created and later released in the 10 experimental horses. The 2 clinical horses had an exploratory laparotomy to correct a natural obstruction of the small intestine. After each horse recovered from surgical manipulation, suction was used to keep fluids from accumulating in the cranial part of the gastrointestinal tract. In 5 of the 12 horses, the most simple N-D tube was positioned successfully and functioned properly. Three of the 5 horses which were fasted before surgical manipulation (to obtain an empty stomach) survived without postsurgical complications. Volume of reflux material was measured. Clinical data, such as periods of comfort during decompression without giving analgesics, were recorded. Necropsies were done on 10 of the 12 horses (9 experimental and 1 clinical). Although already tested in 2 clinical horses, use of the N-D tube remains experimental, and the N-D tube functioned only in horses which were fasted before surgical manipulation. Perfection of a safe and dependable means of emptying the equine stomach of its solid ingesta before gastrointestinal intubation is done, is the next step in affording greater clinical application of the N-D tube for gastrointestinal decompression.

Six mouse and 13 rat monoclonal antibodies (mAb) recognizing HLA-DR, DQ and DP antigens were used for the detection of cell surface class II MHC antigens of equine lymphocytes. The monoclonal antibodies were tested against peripheral blood lymphocytes (PBL) from a panel of thoroughbred horses, using two-color fluorescence flow cytometry. Seven of these mAbs reacted with both surface immunoglobulin positive (sIg+) and surface immunoglobulin negative (sIg-) lymphocytes. sIg+ cells stained consistently brighter than sIg- cells. The fluorescence pattern did not vary from donor to donor for each of the mAbs tested, except for SFR1-MI.2, which reacted with a variable intensity with cells from 47 of 53 horses tested. Immunoprecipitation with mAb SFR1-MI.2 and analysis by two-dimensional electrophoresis demonstrated the presence of light and heavy chains equivalent to HLA class II alpha and beta chains. Antibody N297 (DQ specific), previously shown to react with an epitope expressed on human B cells but not on mitogen-induced T cells, reacted only with sIg+ cells in 42 of 53 horses tested. The lack of staining of horses sIg- cells with N297 may be due to a low or lack of expression of this determinant on these cells or to a weak cross-reactivity of this antibody with equine antigens.

Frequencies of equine leukocyte antigen distribution were determined by complement-mediated cytotoxicity testing among populations of Thoroughbred and Standardbred horses, including animals affected with equine sarcoid and laminitis. A highly significant association is described between the presence or history of sarcoid lesions in Thoroughbreds and the expression of the major histocompatibility complex (MHC)-encoded antigens, W3 and B1. No association was found between antigenic expression frequencies and laminitis in either breed. These findings suggest that a strong relationship exists between the equine MHC and a predisposition to sarcoid.

A permanent, transvenous, atrioventricular, sequential pacing system was implanted successfully in a 7-year-old Quarter Horse gelding with complete heart block. The transvenous atrial and ventricular electrodes were placed in their respective positions in the heart, using real-time, 2-dimensional echocardiography. The horse was able to return successfully to competition as a show horse.

Seven foals, 2 horses, and 2 calves were presented to the George D. Widener Hospital for Large Animals at New Bolton Center and the Large Animal Clinic at Auburn University for surgical repair of cleft palate. All animals had preexisting pneumonia. Initial repair of cleft palate in 6 foals, 2 horses, and 2 calves was performed via mandibular symphysiotomy. Primary repair of cleft soft palate in a foal was attempted through a pharyngotomy incision after fracture of the basal hyoid bone; however, exposure was inadequate and mandibular symphysiotomy had to be done. Dehiscence of a portion of the cleft palate occurred in all cases (10 of 11) that survived the immediate postoperative period. A 2nd repair was attempted in 3 foals; however, dehiscence of the palate recurred. Osteomyelitis of the mandibular symphysis developed in 6 animals; dehiscence of the lower lip occurred in 3 animals. Serious complications after surgery led to euthanasia or death of 5 animals. Of the 6 surviving animals, 4 did not grow normally. All survivors experienced chronic nasal discharge often contaminated with food material. Although mandibular symphysiotomy provided adequate exposure for surgical repair of cleft palate, serious complications have not been overcome.

To study the normal motility of the cecum and right ventral colon (RVC) in 3 mature Shetland ponies, a 6-part, indwelling, intraluminal catheter system was used to measure intraluminal pressure changes. Three catheters were placed in the cecum at 10, 25, and 40 cm from the cecocolic orifice, and 3 catheters were placed in the RVC at 10, 20, and 30 cm from the cecocolic orifice. Recordings were made during the interdigestive period beginning 2 weeks after surgical operation was done. Frequent, low-amplitude peaks (0.35 +/- 0.13 coordinated peaks/min) were seen involving the cecal body and caudal cecal base, which represented a haustra-to-haustra mixing pattern. Coordinated pressure peaks originated in the cecal body and progressed to the cranial cecal base (0.07 +/- 0.01/min) or originated in the cranial cecal base and progressed to the cecal body (0.07 +/- 0.04/min). Associated with a loud rush of ingesta heard on transabdominal auscultation and progression of liquid ingesta confirmed with barium contrast radiography, there was a series of coordinated, progressive pressure peaks which originated in the cecal body, sequentially involved the cecal base, traversed the cecocolic orifice, and extended into the RVC (0.36 +/- 0.05/min). It seemed that a pacemaker region existed in the cecal body and initiated the important aborally propagated progressive pattern responsible for the transit of ingesta from the cecum to the RVC. A separate mechanism for the transit of gas was not identified. In the RVC, infrequent, nondirectional, low-amplitude segmental pressure peaks (0.12 +/- 0.06/min), and aborally progressive coordinated pressure peaks originating at the beginning of the RVC (0.09 +/- 0.02/min), occurred.(ABSTRACT TRUNCATED AT 250 WORDS)

Skin expansion was used in three horses, one heifer, and one dog to aid in the repair of cosmetic defects. Skin expansion was produced by inserting an expandable silicone device subcutaneously and gradually inflating the device with saline. Skin expansion allowed skin to be mobilized and sutured over cosmetic defects without excessive tension. A successful outcome was achieved in four of the five cases reported here. In one animal, two attempts to create a pocket for a silicone prosthesis failed because the expanders ruptured. Complications included implant failure, wound dehiscence, and exposure of an expander. Skin expansion can be used to enable closure of skin defects in areas where skin tension usually precludes repair by local transposition.

An intravascular procedure was used to occlude the internal carotid artery of two horses with epistaxis caused by guttural pouch mycosis. In each horse, the affected internal carotid artery was ligated close to its origin. A balloon-tipped catheter was introduced into the artery distal to the ligature, and its tip was advanced beyond the site of infection. The balloon was then inflated so that the infected segment of artery was isolated from the cerebral vascular system. The catheters were removed at 14 and 51 days, and both horses were returned to training and racing. Neither horse had further episodes of epistaxis.

Selected physical and laboratory findings in 29 horses with acute abdominal crisis were evaluated retrospectively with a logistic regression equation to predict survival or death. Of 17 variables examined, 2 were found to have good predictive correlation. Serum lactate and packed cell volume had a combined predictive value of 94%. Packed cell volume mean values of 43 and 50%, respectively, differentiated survival from death. Serum lactate values of 28.18 mg/dl and 51.28 mg/dl differentiated survival and death. Analysis of data from a previous study of 36 horses with the logistic regression equation predicted survival rate of 96% accuracy, further substantiating the statistical model.

The case records of 23 horses with cecal perforation (CP) were reviewed. The horses averaged 4.5 years of age (6 weeks to 13 years) and included 9 intact males, 12 mares, and 2 geldings. Twelve of the horses were Standardbreds, 9 were Thoroughbreds, and 1 each, a Belgian and Morgan. The horses were allotted to 2 groups: group I-13 hospitalized horses in which CP occurred unexpectedly, and group II-10 horses with CP at the time of admission. The horses characteristically had been sick or affected with disease unrelated to the cecum. Sixteen horses had been given nonsteroidal anti-inflammatory drugs before the onset of CP. Twelve of the 13 hospitalized patients (group I) had vague, scarcely recognizable clinical signs of gastrointestinal disease before CP. The clinical signs and clinical laboratory changes that appeared in affected horses were identifiable with severe endotoxin shock, secondary to peritoneal contamination with ingesta and bacteria. All horses died. At necropsy of the horses, the cecum was large and firm and was filled with ingesta, and the colon was empty; however, in 1 postpartum mare, the cecum and colon contained the usual amount of ingesta and were normal in size. In all horses, a single perforation was present, which appeared at various sites. The most common was a transverse perforation along the ventral aspect of the cecal body. Gross and microscopic examinations uncovered no existing disease near the perforation site or in other areas of the cecal wall or cecocolic orifice.(ABSTRACT TRUNCATED AT 250 WORDS)

A 13-year-old Thoroughbred mare had a 2-week history of weight loss and intermittent fever. Examination of abdominal and pleural fluid revealed peritonitis and pleuritis. Ultrasonography of the ventral abdominal midline revealed an intra-abdominal mass. Exploratory celiotomy was performed, but the mass was not surgically excisable. The mare was euthanatized and necropsied. Histologically, the mass was determined to be a fibrosarcoma of omental origin.

Infected abdominal incisions in 7 cattle and 3 horses were resutured with monofilamentous stainless steel retention sutures. After debridement of devitalized and infected tissue, wound edges were apposed with simple interrupted vertical (5 cattle, 3 horses) or horizontal (2 cattle) mattress sutures, placed through all layers of the body wall. Sutures were placed 2 to 3 cm apart over rubber tubing, 3 to 5 cm from wound edges. In 5 of the 10 operations, skin and subcutaneous tissue were left unsutured. The repaired wounds were supported with an encircling elastic roll bandage and sterile compresses. Animals were confined to a box stall for approximately 60 days. Steel sutures and rubber tubing were removed when they no longer provided support, usually 14 to 21 days after placement. Superficial wound infection and local pressure necrosis resulted from the suturing, but resolved with additional surgical or medical treatment, debridement, or irrigation with dilute povidone-iodine solution. Cosmetic and functional healing resulted in 7 of the animals.

Patent ductus venosus was diagnosed in a 10-week-old Holstein heifer with acute onset of collapse and marked tenesmus. Additional clinical signs observed during the course of hospitalization included depression, anorexia, hind limb ataxia, bruxism, and poor growth. Clinicopathologic test results included high blood ammonia concentration, prolonged sulfobromophthalein half-life, and high serum bile acid concentration. Liver biopsy revealed mild periportal fibrosis, but no appreciable hepatocyte atrophy. Mesenteric portography and percutaneous ultrasonography confirmed the patent ductus venosus. An atrial septal defect prosthesis was placed in the ductus venosus, using a catheterization technique. After surgery, however, clinicopathologic test results were unchanged. Ultrasonography revealed that the prosthesis had pulled away from one side of the vessel. When the calf was 10.5 months old, surgical correction was achieved by a transhepatic ligation technique. Ultrasonography confirmed closure of the ductus venosus during and after surgery. Blood ammonia and serum bile acid concentrations and sulfobromophthalein half-life were normal 3 weeks after surgery. The calf had no further episodes of hepatoencephalopathy and was successfully bred at 18 months of age.

Three groups of lambs were fed a low carotene diet supplemented with vitamin A proprionate equivalent to 0, 100 or 12,000 micrograms retinol per kilogram per day via rumen cannulae. These groups were mildly deficient, normal (control) and intoxicated, respectively. After 17 weeks, abomasal cannulae were implanted, [15-3H]retinol was injected into the abomasum, and jugular blood was sampled for 48 hours. After 7 days, the tracer was injected into a jugular vein, and blood was sampled for 48 hours. Rates of retinol and retinyl ester transport and retinol clearance from plasma reflected intake (P less than 0.05); clearance of retinyl esters was unaffected. Mean efficiencies of total vitamin A (retinol and retinyl ester) transfer from digestive tract to plasma were 86, 60 and 60%, whereas those of retinol were 91, 58 and 14% (P less than 0.05) for mildly deficient, control and intoxicated lambs, respectively. Thus lower transfer efficiencies were associated with higher transport rates of plasma retinol and retinyl ester and with increased clearance of retinol but not retinyl ester from plasma. These results suggest that vitamin A transfer from intestine to plasma is sensitive to vitamin A intake, and that retinol is the primary form of vitamin A affected.

Electromyographic activity and emptying of the abomasum were studied in 3 sheep. Pacesetter potentials (PP), with a frequency of 6.06 +/- 0.05 (X +/- SEM) cycles/minute and propagated distally with an increased conduction velocity approaching the pylorus, were recorded from the distal 11 cm of the antrum. Spike burst and fused action potentials (AP) were superimposed on a variable percentage of PP. The aborad propagation of both types of AP was associated with abomasal emptying at the net rate of 12.61 +/- 1.38 (X +/- SEM) ml/minute. Intraabomasal infusion of 50 ml of a 300 mM solution of either acetic, propionic, or butyric acid was associated with a marked decrease in abomasal AP activity and in the emptying rate. Butyric acid was most effective, followed by propionic and acetic acids. The importance of the results in relation to the pathogenesis of left displaced abomasum (LDA) in dairy cows was noted.

Balloon-tipped catheters were used to occlude the external carotid artery and its branches in nine horses with hemorrhage caused by guttural pouch mycosis. The internal carotid artery on the affected side was occluded simultaneously in four horses and had been occluded previously in two others. In three horses, a single balloon-tipped catheter was inserted in the external carotid artery beneath the floor of the guttural pouch and its tip was advanced blindly into distal branches. In one horse, the superficial temporal artery was occluded briefly during surgery by a balloon-tipped catheter so a catheter inserted into the external carotid artery could be diverted into the maxillary artery. In the other five horses, the external carotid artery was occluded proximally and the maxillary artery was occluded immediately caudal to the alar canal by a balloon-tipped catheter inserted into the major palatine artery. Serious postoperative hemorrhage did not occur in eight horses, but one horse that had a single balloon-tipped catheter inserted into the external carotid artery had profuse hemorrhage 11 days after surgery and was euthanatized. One horse was euthanatized because of persistent dysphagia. The only complication related to use of balloon catheters was a mild incisional infection in one horse. It was concluded that the external carotid and maxillary arteries must be occluded on both sides of the eroded segment to prevent hemorrhage from normograde and retrograde flow.

A mare was examined for episodic choking and an abscess in the perilaryngeal region. One month before referral, the mass progressively enlarged, causing esophageal choking. An extraluminal compression of the esophagus 90 cm from the external nares was found on endoscopy and contrast radiography. Serosanguinous fluid aspirated from the mass contained keratinized squamous cells and neutrophils, compatible with an esophageal cyst. Surgical exploration was performed, with incomplete surgical excision. The remaining portion of the cyst was marsupialized and treated locally with a 2% inorganic iodine solution. Further episodes of esophageal choke in this horse have not been reported.

The horse with an abdominal crisis caused by acute gastro-intestinal tract obstruction develops hypovolaemia, haemoconcentration, electrolyte depletion, metabolic acidosis and shock. During preparation for operation, treatment with fluids, antibiotics and bicarbonate will impede metabolic imbalance. Stomach decompression may slow the passage of sodium, water and potassium to the gut lumen, reduce pain and minimize the risk of stomach rupture. Selected laboratory determinations and the monitoring of arterial and venous pressures will provide a measure of security, and serve as a guide to replacement therapy. In the post-surgical period, vigilance must be directed towards potassium and bicarbonate imbalance and adequate hydration.

Two female Standardbred foals 2 and 3 months of age were presented with signs of gastroduodenal obstruction that was confirmed with contrast radiography and exploratory surgery. Ventral midline celiotomy was performed, showing stenosis of the duodenum proximal and distal to the hepatopancreatic ampulla. The common hepatic duct, the pancreatic duct, and the sigmoid section of the duodenum proximal to the stenosis were greatly dilated. To bypass the intestinal obstruction, a side-to-side duodenojejunostomy was performed. Obstruction of the common hepatic duct was relieved by side-to-side hepaticojejunostomy. In addition, jejunojejunostomy was performed distal to the other anastomoses. Both foals recovered. On admission, the foals' total bilirubin, aspartate aminotransferase, and gamma glutamyl transferase levels were greatly elevated. During the subsequent 6 to 8 months, they returned to normal. Six months after the first surgery, one foal was readmitted with an acute abdominal crisis. At surgery, there was greater than 360 degrees clockwise rotation of the mesenteric root involving most of the jejunum. At necropsy, the previously created stomas were patent. The liver and bile duct were grossly and histologically normal. The second foal continues to progress normally 12 months after surgery.

From 1977 to 1986, guttural pouch tympany was diagnosed in 15 horses--11 fillies and 4 colts. Review of the medical records provided results of physical, microbiologic, radiographic, and endoscopic examinations, treatment protocols, complications, and recovery rate. All affected horses had visible swelling in the parotid gland region, 9 had abnormal respiratory noise, 5 had pneumonia, and 1 had dysphagia. Six horses were treated by median septum fenestration alone, and in 8 horses, this procedure was combined with resection of the mucosal flap at the pharyngeal orifice of the eustachian tube. One horse was not treated. Follow-up information was obtained for 13 horses. Rate of recurrence was 33% (2/6) after fenestration alone and was 29% (2/7) when both procedures were combined. One horse that had been treated using combined procedures died of pneumonia, and a horse treated unsuccessfully by septum fenestration was euthanatized because of persistent dysphagia. Eight horses greater than 2 years old when follow-up information was obtained were reported to be healthy, and 4 of these had raced successfully.

A procedure developed to occlude the internal carotid artery of horses with guttural pouch mycosis was modified was modified and evaluated in nine clinically normal horses. The left internal carotid artery was ligated at its origin and occluded distally with an intraluminal balloon catheter. In four horses, the balloon-tipped catheters were left in place until these horses were euthanatized at 4 to 244 days after surgery. In the remaining horses, the catheters were removed after 10 to 14 days by a cutdown procedure, and these horses were euthanatized 1 to 60 days after catheter removal. In both groups, gross and histologic examinations revealed that occlusive thrombosis had developed in sections of artery distal to the balloon. Postoperative complications were not encountered.

Unilateral nephrectomy was done on 4 cows with renal disease. The history and clinical signs varied and were not pathognomonic for disease of the urinary system. Serum creatinine and BUN concentrations were normal in each cow prior to nephrectomy, in spite of advanced renal disease. Results of urinalysis were abnormal in 3 cows. Cystoscopic examination aided in the diagnosis, by revealing unilateral hematuria in 1 cow. Palpation per rectum revealed a large abdominal mass adjacent to the kidney in 2 cows. Exploratory celiotomy was necessary in 3 cows to determine the exact nature of their disease. Nephrectomy was easily performed; however, ligature security was critical. A biopsy of the remaining kidney at the time of nephrectomy aided in determining medical therapy and prognosis. Three cows recovered from the effects of the disease and became productive members of the herd. One cow was euthanatized because of end-stage renal disease in the remaining kidney.

Three adult sheep were prepared with a denervated pouch of fundus of the abomasum and a reentrant fistula system that connected the remaining proximal and distal portions of the abomasum. The proximal cannula of the reentrant system was close to the omasoabomasal orifice, allowing for easy collection of fluid leaving the omasum. Intravenous injection of 0.5, 1.0, or 2.0 microgram/kg/hr of synthetic human gastrin I caused a marked decrease in flow rate of fluid from the omasum. The concentration of particulate matter in the digesta was inversely related to rate of omasal outflow. An increase in acid output from the denervated abomasal pouch during gastrin injection indicated that the hormone was given at pharmacologically effective doses. Results indicate that gastrin has a modulating effect on the flow of ingesta through the ruminant forestomachs. Actual sites of action were not identified.

When sheets of mucosa from the cecum of clinically normal horses were incubated in vitro with radiolabeled L-alanine, they could accumulate this amino acid against an apparent concentration gradient after 60 to 150 minutes of incubation. The active transport system for L-alanine was on the serosal surface of the mucosal sheet only. L-Alanine accumulation at 60 minutes was partly inhibited by 20 mM glycine (P less than 0.01), 0.5 mM ouabain (P less than 0.05), and Na deprivation (P less than 0.02). Anoxia for 60 minutes increased L-alanine accumulation, but had adverse effects on cell structure and intracellular cation distributions. Transmucosal fluxes induced a small, but significant (P less than 0.05), net secretion of L-alanine, and the mean (+/- SEM) transmucosal potential difference was 7.3 +/- 0.7 mV over the period of flux measurement. It was concluded that L-alanine was accumulated by the serosal surface of the cecal mucosa, possibly to provide substrate for tissue metabolism. There was no evidence that the cecal mucosa could actively transport this amino acid from the luminal bathing medium.