During this investigation, the use of iohexol was compared with iotrolan for canine cisternal myelography. Iohexol and iotrolan myelography was done in 6 dogs by cisternal puncture with a 6-week interval between both procedures; each dog served as its own control. Cerebrospinal fluid (CSF) was collected for baseline analysis from each dog immediately before the contrast agent was injected. Cerebrospinal fluid samples were obtained at 1, 3, 7, and 14 days after injection of each contrast medium for cytologic and chemical analysis. Total CSF leucocyte count and glucose concentration did not change significantly in comparison with baseline data in any of the samples. After the injection of iohexol, protein concentration increased significantly in the 24-hour sample, and lactate dehydrogenase activity increased significantly in the 3-day sample. Significant difference was not found between the different samples collected at 1, 3, 7, and 14 days, compared with both contrast media. None of the dogs had seizure activity during a 5-hour postmyelographic observation period. Pathologic changes were not found by gross or microscopic examination of the spinal cord. Although a degradation in time of radiographic quality of all myelograms took place, the average radiographic score decreased more rapidly with iohexol. The average score at 90 minutes with iotrolan was comparable with the score at 45 minutes with iohexol, and the average score at 150 minutes with iotrolan was better than the score at 90 minutes with iohexol. At 5 and 10 minutes after cisternal injection, no significant difference wasobservable between the myelograms, but from 45 minutes onward, myelograms with iotrolan were superior.

Evaluation of urethral pressure profilometry (UPP) with simultaneous fine-wire electromyography of the external urethral sphincter (EUS) was conducted in 11 healthy adult male cats sedated with xylazine and ketamine. A 3.5-F urethral catheter with a closed end and two 1-mm sideports was infused with sterile 0.9% NaCl solution at a rate of 2 to 3 ml/min. A fine-wire electromyographic (EMG) electrode was placed percutaneously into or near the external urethral sphincter prior to the onset of the UPP. The maximal urethral pressure achieved and functional profile length were recorded from UPP. Setting both catheter withdrawal rate and paper speed at 5 mm/s enabled the measurement of actual urethral length directly from UPP. Sphincter EMG activity was rated as slight (+), moderate (+ +), or intense (+ + +). All recordings were replicated once during each trial for 8 cats and trials were replicated 5 to 7 days later in 4 cats. Before catheterization, EMG activity of the external urethral sphincter was rated slight (+), whereas intense (+ + +) activity accompanied insertion. The activity evoked by movement of the catheter subsided, but intense EMG activity of the external urethral sphincter was recorded from onset to completion of catheter withdrawal in all cats in both trials. The mean maximal urethral pressure was 93.1 +/- 13.29 cm H2O. The mean function urethral length was 8.1 +/- 0.93 cm. Maximal urethral pressure or function profile length did not differ significantly between recordings within trials or between trials. Simultaneous recording of EMG activity and UPP of the external urethral sphincter was shown to be a simple, noninvasive technique for assessing neuromuscular and anatomic urethral function.

Protein C content and plasminogen activity were measured in plasma from 100 horses with signs of colic. Data were analyzed by grouping horses 4 ways. Each horse was allotted to 1 of 2 outcome groups (survivors and nonsurvivors), 1 of 3 broad-category diagnosis groups (inflammatory disorders, strangulating obstructions, and all other gastrointestinal disorders), and 1 of 2 clinical management groups (medical and surgical). In a fourth grouping, all horses (although numbers of horses included in each subgroup were small) were assigned either to specific diagnostic groups that had high expectation for activated hemostasis (intestinal ischemia, endotoxemia, jugular thrombosis, peritoneal adhesions, and laminitis) or to a control group, in which active hemostasis was unlikely. Within 2 to 24 hours after admission, nonsurvivors developed lower protein C content than did survivors. Protein C content and plasminogen activity became low during hospitalization in horses with strangulating obstructions and in horses having surgery. The results from the grouping by specific diagnosis must be considered pilot data because the numbers of horses in each subgroup were small. Although not statistically significant, trends were noticed in protein C and plasminogen: (1) horses with intestinal ischemia and endotoxemia developed low protein C content and plasminogen activity, (2) protein C content became low in horses that developed peritoneal adhesions or laminitis, and (3) plasminogen activity became low in horses that developed jugular thrombosis. Low protein C content or low plasminogen activity, or both, may be useful as predictors for outcome and for these specific complications of equine colic. Protein C content and plasminogen activity were often normal at admission, but decreased by 2 to 24 hours; therefore, the hemostatic alterations appear to be an effect, rather than a cause of the gastrointestinal disorders. A return to normal values over several days may signify clinical improvement.

The effects of method of seminal collection and a diuretic on retrograde flow of spermatozoa into the urinary bladder of rams were examined. In experiment 1, semen and urine were collected from 8 rams during the nonbreeding season. Prior to seminal collection, all rams were given furosemide and a sample of urine was obtained during micturition. Semen was then collected from each ram with an artificial vagina or by electroejaculation in alternate weeks for 4 weeks, and the urine released during the first postseminal collection micturition was collected in 4 consecutive samples. The volume of electroejaculates was larger (P < 0.0001) than the volume of ejaculates, but the total number of spermatozoa in the electroejaculate or in the ejaculate were not different (P > 0.1). Urine obtained before seminal collection was azoospermic or contained few, nonmotile spermatozoa (mean +/- SD = 0.053 +/- 0.114 x 10(6)/ml). The adjusted spermatozoal concentration (mean +/- SD = 1.630 +/- 2.258 X 10(6)/ml) in the urine collected after seminal collection was 31 times higher (P < 0.0001) and there were motile spermatozoa in most (97%) of the samples. The spermatozoal concentration in sequential samples of urine was not different (P > 0.1) between samples and was not affected (P > 0.1) by the method of seminal collection. There was a trend, approaching significance (P = 0.052), for an effect of method of seminal collection on the percentage of retrograde flow. Retrograde flow ranged from 0.21 to 19.38% when semen was collected with an artificial vagina and from 0.03 to 94.60% when semen was collected by electroejaculation and varied (P = 0.02) among rams within the 2 methods of seminal collection. In experiment 2, the 8 rams used in experiment 1 were given injections of 0.9% physiologic saline solution or furosemide in alternate weeks prior to seminal collection with an artificial vagina. Furosemide increased (P = 0.009) the volume of urine voided during the first postejaculation micturition, but did not influence (P > 0.1) the time from exposure of rams to the teaser to ejaculation, seminal characteristics, number of spermatozoa in the urine, or the percentage of retrograde flow. There was a trend (P < 0.1) for more rams to have motile spermatozoa in the postejaculation urine after treatment with furosemide. Administration of furosemide prior to seminal collection facilitates the noninvasive collection of pre- and postejaculation samples of urine for the determination of retrograde flow.

Twelve ponies were used to evaluate the reliability of an abdominal adhesion model and the efficacy of intraperitoneal infusion of sodium carboxymethylcellulose in preventing abdominal adhesions. A celiotomy was performed on each of the 12 ponies and the serosa of the distal portion of the jejunum was abraded with a dry gauze sponge at 5 locations. In addition to the serosal damage, a single 2-0 chromic gut suture was placed through the seromuscular layer of the jejunum in the center of the abraded area. After closure of the celiotomy, a 1% solution of sodium carboxymethylcellulose (7 ml/kg of body weight) was infused into the peritoneal cavity of 6 ponies. The other ponies served as untreated controls. All ponies were euthanatized 14 days after surgery. All ponies in the control group had abdominal adhesions at the time of necropsy. Four of the 6 ponies in the treatment group were free of adhesions. There was a significant (P < 0.0001) difference in the total number of adhesions between the 2 groups.

Use of microangiography is now essential for the study of microcirculation in various organs. Renal microangiographic studies have been reported in rats, rabbits, dogs, human beings, and mice. However, we could not find any report on use of the technique in cattle, despite high incidence of renal disease in that species. The perfusion technique used in mice was improved over that of our previous report, and was applied to normal and diseased bovine kidneys. For the microangiographic technique, composition of the contrast medium, pressure of the injection, duration of perfusion, and washing of kidneys with heparinized saline solution before perfusion are important. In cattle, 1- to 2-mm-thick sections of the kidneys were generally necessary to observe renal vasculature: arcuate and interlobular arteries, afferent arterioles, and glomerular capillaries. In normal bovine kidneys, the angiographic and microangiographic findings were easily recognized as normal, compared with those of normal mice. In affected bovine kidneys, which histologically represented glomerulonephritis and pyelonephritis, angiography and microangiography revealed corresponding findings.

We developed a single-pedicle, axial pattern tubed skin flap that could be transferred to an in vitro perfusion apparatus. On the basis of results of prosections, angiography, contact radiography, and surviving-length studies, it was concluded that a single-pedicle, axial pattern skin flap measuring 4 cm X 12 cm incorporating the caudal superficial epigastric artery would survive to its entire length. Subsequently, a surgical (stage 1) procedure was developed for the routine preparation of single-pedicle, axial pattern tubed skin flaps. Healing after the stage-1 procedure was evaluated by visual inspection and fluorescein angiography. Stage-1 procedures were performed successfully 149 of 160 (93%) times. A second surgical (stage 2) procedure was developed for routine cannulation of the caudal superficial epigastric artery and harvest of the tubed skin flap. Stage-2 procedures were performed successfully 136 of 144 (94%) times.

A dot ELISA was developed for detection of antibodies to Mycobacterium paratuberculosis. The assay was evaluated by testing sera from cattle that were determined, by bacteriologic culturing of feces, to be infected with M paratuberculosis and were suspected of having clinical disease. Further evaluation involved testing sera from cattle in which M paratuberculosis had not been isolated from feces on several attempts. Results of the dot ELISA were positive for sera from 86 of 101 infected cattle, and results were negative for sera from 64 of 64 noninfected cattle. Results of conventional ELISA and agar gel immunodiffusion (AGID) tests were positive for 79 of 99 and for 51 of 101 infected cattle, respectively. The dot ELISA also was evaluated by comparing results of testing 708 sera with results of bacteriologic culturing of matched fecal samples from 262 cattle in 3 central Ohio dairy herds known to include cattle infected with M paratuberculosis. Results of the dot ELISA were positive for 25 of 39 sera from cattle with positive results on culturing of concurrently obtained fecal specimens. The dot ELISA results were negative for 661 of 669 sera from cattle with negative results to culturing of concurrently obtained fecal specimens. The 39 sera from cattle with positive results on bacteriologic culturing of matched fecal specimens had positive results for ELISA and the AGID test 25 and 14 times, respectively. The 669 sera from cattle with concurrently negative results on bacteriologic culturing of feces had negative results to ELISA and the AGID test 559 and 668 times, respectively.

Bovine immunoglobulin isotype-specific murine monoclonal antibodies were used in sandwich radioimmunoassays to detect and quantitate bovine IgG1, IgG2, IgM, and IgA in culture fluids. The concentrations of bovine immunoglobulins in unknown samples were extrapolated from standard curves generated with bovine monoclonal immunoglobulins. The lowest detection limits for the bovine immunoglobulin isotypes ranged from 65 to 270 ng/ml.

Enzyme-linked immunosorbent assay screening of antibody produced against aflatoxin was accomplished by a new and simple procedure. To demonstrate the new indirect ELISA technique used, antibody against aflatoxin M1 was produced in female BALB/CJ mice by immunization with an aflatoxin M1-bovine serum albumin conjugate. Instead of coating test-plate wells with purified antibody (direct ELISA) or synthesizing a second protein-aflatoxin conjugate (aflatoxin M1-poly-L-lysine) to coat test-plate wells, wells were coated with the readily available aflatoxin M1-bovine serum albumin and aflatoxin B1-bovine vine serum albumin. This method, applicable for any aflatoxin conjugated by the common cyclopentano-carboxymethoxyl-oxime technique, eliminates the more time-consuming and technically difficult portions of earlier direct and indirect ELISA. The new technique can be valuable in continued efforts toward development of new and improved immunoassays against aflatoxin metabolites.