Heat stress develops with increased total-tract gut permeability, and dietary organic acid and pure botanical supplementation partly restores lactation performance in Holstein dairy cows.

To evaluate the effects of heat stress (HS) conditions and dietary organic acid and pure botanical (OA/PB) supplementation on gut permeability and milk production, we enrolled 46 multiparous Holstein cows [208 ± 4.65 dry matter intake (DMI; mean ± SD), 3.0 ± 0.42 lactation, 122 ± 4.92 d pregnant, and 39.2 ± 0.26 kg of milk yield] in a study with a completely randomized design. Cows were assigned to 1 of 4 groups: thermoneutral conditions (TN-Con, n = 12), HS conditions (HS-Con, n = 12), thermoneutral conditions pair-fed to HS-Con (TN-PF, n = 12), or HS supplemented with OA/PB [75 mg/kg of body weight (BW); 25% citric acid, 16.7% sorbic acid, 1.7% thymol, 1.0% vanillin, and 55.6% triglyceride; HS-OAPB, n = 10]. Supplements were delivered twice daily by top-dress; all cows not supplemented with OA/PB received an equivalent amount of the triglyceride used for microencapsulation of the OA/PB supplement as a top-dress. Cows were maintained in thermoneutrality [temperature-humidity index (THI) = 68] during a 7-d acclimation and covariate period. Thereafter, cows remained in thermoneutral conditions or were moved to HS conditions (THI: diurnal change 74 to 82) for 14 d. Cows were milked twice daily. Clinical assessments and BW were recorded, blood was sampled, and gastrointestinal permeability measurements were repeatedly evaluated. The mixed model included fixed effects of treatment, time, and their interaction. Rectal and skin temperatures and respiration rates were greater in HS-Con and HS-OAPB relative to TN-Con. Dry matter intake, water intake, and yields of energy-corrected milk (ECM), protein, and lactose were lower in HS-Con relative to HS-OAPB. Nitrogen efficiency was improved in HS-OAPB relative to HS-Con. Compared with TN-Con and TN-PF, milk yield and ECM were lower in HS-Con cows. Total-tract gastrointestinal permeability measured at d 3 of treatment was greater in HS-Con relative to TN-Con or TN-PF. Plasma total fatty acid concentrations were reduced, whereas insulin concentrations were increased in HS-Con relative to TN-PF. We conclude that exposure to a heat-stress environment increases total-tract gastrointestinal permeability. This study highlights important mechanisms that might account for milk production losses caused by heat stress, independent of changes in DMI. Our observations also suggest that dietary supplementation of OA/PB is a means to partly restore ECM production and improve nitrogen efficiency in dairy cattle experiencing heat stress.

Bilateral sertoli and interstitial cell tumours in abdominal testes of a goat with polled intersex syndrome (PIS).

An 8-year-old, mixed breed, polled goat was presented for evaluation of male-like behaviour. Clinical findings included clitoromegaly, a heavily muscled neck, pronounced beard, and erect dorsal guard hairs, which are phenotypic characteristics commonly observed in intersex animals. Transrectal ultrasonography revealed the presence of two abdominal masses caudolateral to the uterine horns. Serum concentration of estradiol was elevated. Genetic evaluation was compatible with polled intersex syndrome defined by an XX karyotype without a Y chromosome or SRY gene. Based on gross and histologic evaluation, the abdominal masses were determined to be intra-abdominal testes, each of which was effaced by Sertoli cell and interstitial (Leydig) cell tumours. The Sertoli cell tumours (SCTs) represented two unique histologic patterns. Regardless of pattern, neoplastic Sertoli cells were consistently lipid laden and positive for vimentin. Interstitial cell tumours (ICTs) were negative for vimentin. Clinical and histopathologic findings suggest that prolonged exposure to steroids secreted by neoplastic Sertoli cells contributed to virilization. In addition, results from immunohistochemistry indicated that vimentin may be a valuable immunodiagnostic tool for differentiation between interstitial and Sertoli cell tumours in goats.

Modified parainguinal approach for cystic calculus removal in five equids.

This report describes a modification of the parainguinal approach for removal of cystic calculi: a ventral midline laparotomy-guided parainguinal laparocystotomy. The ventral midline approach to the abdomen is rapid and routinely used by equine surgeons. With an arm introduced to the abdomen via the ventral midline, the surgeon is able to select the ideal parainguinal laparotomy incision location that allows bladder exteriorisation with the minimum amount of tension. Because the surgeon's hand is introduced via the ventral midline incision, the parainguinal incision can be sized to just allow exteriorisation of the urinary bladder and urolith, increasing extra-abdominal bladder security during cystotomy while reducing incision size in the parainguinal region. Finally, an assistant's hand via the ventral midline incision can maintain bladder stability within the parainguinal incision during cystotomy closure.

Corticosteroids alter the differentiated phenotype of articular chondrocytes.

Experimental evidence suggests that recommended dosages of some corticosteroids used clinically as antiinflammatory agents for treating arthropathies damage articular cartilage, but low dosages may be chondroprotective. The purpose of this study was to evaluate how different concentrations of methylprednisolone affect chondrocyte function and viability. Articular cartilage and chondrocytes were obtained from young adult horses, 1.5-3.5 years of age. Corticosteroid-induced changes in collagen expression were studied at the transcriptional level by Northern blot analyses and at the translational level by measuring [3H]-proline incorporation into [3H]-hydroxyproline. Fibronectin mRNA splicing patterns were evaluated with ribonuclease protection assays. Cytotoxicity was studied using erythrosin B dye exclusion. Steady-state levels of type II procollagen mRNA decreased without concurrent changes in type I procollagen expression as the medium methylprednisolone concentrations were increased from 1 x 10(1) to 1 x 10(8) pg/ml, dropping below 10% of control values by 1 x 10(5) pg/ml. Cytotoxicity occurred as methylprednisolone levels were increased further from 1 x 10(8) to 1 x 10(9) pg/ml. Changes in total collagen (protein) synthesis were less pronounced, but also demonstrated significant suppression between 1 x 10(4) and 1 x 10(8) pg/ml. Corticosteroid-induced changes in fibronectin isoform levels were evaluated in articular cartilage samples without in vitro culture. The cartilage-specific (V + C)(-) isoform was suppressed in both normal and inflamed joints by a single intraarticular injection (0.1 mg/kg) of methylprednisolone. Combined, these data indicate that methylprednisolone suppresses matrix protein markers of chondrocytic differentiation. Decreased and altered chondrocyte expression of matrix proteins likely contributes to the pathogenesis of corticosteroid-induced cartilage degeneration.

The effects of methylprednisolone on normal and monocyte-conditioned medium-treated articular cartilage from dogs and horses.

OBJECTIVE: To study in vitro (1) the dose-response relationships between proteoglycan metabolism in normal and corticosteroid-treated articular cartilage; (2) long-term proteoglycan metabolism after treatment of articular cartilage with corticosteroids; and (3) the effect of corticosteroids on proteoglycan metabolism in articular cartilage treated with monocyte-conditioned medium (MCM). STUDY DESIGN: Equine and canine articular cartilage explants were treated with corticosteroids and MCM. Proteoglycan synthesis and degradation were measured by radioactive labeling in short-term culture, and the long-term effect of corticosteroid treatment on proteoglycan metabolism was studied in normal explants. ANIMALS: Two young cross-breed horses and 3 young Labrador retrievers. METHODS: Equine articular cartilage explants were incubated in medium containing methylprednisolone sodium succinate (MPS) at 0, .001, .01, .1, 1, and 10 mg/mL (final concentration) for 1 day and then in fresh medium without MPS. Proteoglycan synthesis was measured by incorporation of sodium [35S]sulfate at 1, 3, 7, 10, and 13 days after initial treatment with MPS. Proteoglycan release was measured from separate explants prelabeled with sodium [35S]sulfate and treated similarly. Equine articular cartilage explants were treated with equine MCM simultaneously with, and 24 hours before MPS, at 0, 0.01, 0.1, 1, or 5 mg/mL for 72 hours. Proteoglycan synthesis and degradation in these explants was compared. Proteoglycan synthesis and degradation were measured similarly in canine articular cartilage explants treated simultaneously with canine MCM and MPS at 0, 0.001, 0.01, 0.1, 1 and 10 mg/mL for 72 hours. Equine articular cartilage explants treated with 0, 0.01, 0.1, 1, and 5 mg/mL of MPS for 72 hours were evaluated histologically. RESULTS: Proteoglycan synthesis in normal equine articular cartilage was severely depressed by 10 mg/mL MPS for 24 hours, and proteoglycan synthesis failed to recover after 13 days of culture in medium without MPS. Cartilage treated with 5 mg/mL MPS had pyknotic chondrocyte nuclei and empty lacunae. Concentrations of 1 and 0.1 mg/mL MPS depressed proteoglycan synthesis in normal equine cartilage explants. For these 2 concentrations, proteoglycan synthesis recovered 2 days after MPS removal and increased significantly (P < .05) 7 days after treatment with MPS compared with controls without MPS. Concentrations of 0.001 and 0.01 mg/mL MPS did not significantly affect proteoglycan synthesis in normal equine cartilage explants. Cumulative proteoglycan loss over 13 days in culture from normal equine explants treated for 24 hours with different concentrations of MPS was not significantly different between treatment groups at any time point. MCM significantly depressed proteoglycan synthesis in both canine and equine articular cartilage explants and significantly increased proteoglycan release. These effects were prevented in the canine explants by simultaneous treatment with MPS at 1 and 0.1 mg/mL, and proteoglycan release induced by MCM in equine articular cartilage was inhibited by 1 mg/mL MPS. CONCLUSIONS: Concentrations of 1.0 and 0.1 mg/mL MPS alleviated articular cartilage degradation in MCM-treated articular cartilage in vitro. These concentrations of MPS in contact with normal cartilage explants for 24 hours are unlikely to be detrimental in the long term to proteoglycan synthesis. The response of articular cartilage to MPS was affected by treatment with MCM so that results of experiments with normal articular cartilage explants may not reflect results obtained with abnormal cartilage. CLINICAL RELEVANCE: It may be possible to find an intraarticular concentration of corticosteroid that protects articular cartilage against cytokine-induced matrix degradation yet not have prolonged or permanent detrimental effects on chondrocyte matrix synthesis.

Prognostic factors affecting survival of 507 horses with joint disease: (1983 to 1990).

Between July 1, 1983 and December 31, 1990, risk factors were determined for all horses with joint disease presented to a referral center, of being discharged, of ever becoming sound, or of being alive at 3 mo follow-up. Logistic multiple-regression models were done separately for foals (< or = 4 mo), yearlings (> 4-24 mo) and racing or nonracing adult horses (> 24 mo). The breakdown in this study was 53 foals, 87 yearlings, 141 nonracing adults, and 226 racing adults. Thirty-one foals (58%), 68 yearlings (78%), 119 non-racing adults (84%), and 213 racing adults (94%) were discharged. Foals with a less severe lameness, duration of illness of > 1 d, and infectious arthritis had increased odds of discharge. At follow-up, 12 of 18 (67%) were alive, 10 (56%) of which were sound. Yearlings with osteochondrosis had higher odds of discharge; at follow-up, 38 of 49 (78%) were alive, 32 (65%) of which were sound. For non-racing adults, horses with less severe lameness, without a miscellaneous diagnosis, or intended for pleasure use had increased odds of discharge. At follow-up, 55 of 78 (70%) were alive and 33 of 58 (57%) with soundness data became sound. Risk factors for higher odds of being alive at follow-up were carpal lameness, arthroscopic surgery, a prognosis other than poor, became sound, above-median hospitalization costs, and duration of follow-up. The 161 racing adults (76% of discharges), with follow-up, were more likely to have had osteoarthritis, higher hospital costs, hospitalization > 1 d, and arthroscopy. Sixty-four (60%) of these became sound; the odds increased if the horse was not severely lame at admission or was hospitalized for > 1 d. Risk factors and prognosis differed by age-use group among horses seen at our hospital.

Effect of synovitis and corticosteroids on transcription of cartilage matrix proteins.

OBJECTIVE: To determine whether steady-state levels of type-II procollagen, aggrecan core protein, or fibronectin mRNA in articular chondrocytes are altered by synovitis or administration of methylprednisolone acetate (MPA). SAMPLE POPULATION: Articular cartilage specimens collected from 10 ponies, 2.5 to 3.5 years old and 200 to 300 kg. PROCEDURE: 4 experimental groups were compared, using the cartilage specimens: control, MPA-treated, lipopolysaccharide-induced synovitis, and lipopolysaccharide-induced synovitis with MPA treatment. RNA was isolated from articular cartilage and compared by northern blot analysis, using equine-specific cDNA probes. RESULTS: Synovitis increased steady-state levels of type-II procollagen mRNA fivefold and of aggrecan mRNA twofold. Administration of a single intra-articular injection of MPA (0.1 mg/kg of body weight) decreased type-II procollagen transcripts in normal cartilage sixfold, without significant effect on aggrecan or total fibronectin mRNA values. MPA treatment of inflamed joints decreased type-II procollagen and aggrecan mRNA to levels that were not significantly different from those in untreated control specimens. CONCLUSIONS: Articular chondrocytes increase type-II procollagen and aggrecan synthesis in response to synovitis. MPA alters chondrocyte function in normal and inflamed cartilage, suggesting that potential changes in cartilage matrix protein synthesis should be considered when evaluating the therapeutic value of intra-articular administration of corticosteroids. CLINICAL RELEVANCE: Knowledge of how synovitis and corticosteroids (independently and in combination) affect synthesis of cartilage matrix proteins is relevant to understanding pathogenesis of traumatic osteoarthritis and improving therapeutic strategies.

Acute synovitis and intra-articular methylprednisolone acetate in ponies.

OBJECTIVE: To determine how acute synovitis, with and without intra-articular methylprednisolone acetate (MPA), affect synthesis of proteoglycan, total protein, and collagen in articular cartilage and total protein synthesis in synovial membrane. DESIGN: Synovitis was induced in 10 ponies by the injection of 0.5 ng lipopolysaccharide (LPS) into the left radiocarpal and midcarpal joints every 2 days for a total of four treatments. Synovitis was documented by clinical examination and synovial fluid analyses. Two days before euthanasia, MPA (0.1 mg/kg) was injected with the last dose of LPS into both the left and right radiocarpal and midcarpal joints of five of these ponies. Proteoglycan synthesis in articular cartilage explants from these joints was measured by incorporation of sodium [35S]sulfate. The size of the proteoglycan monomers and their aggregation with hyaluronan was assessed by size-exclusion chromatography. Protein synthesis in articular cartilage was measured by incorporation of [3H]proline and collagen synthesis by conversion of [3H]proline into [3H]hydroxyproline. Protein synthesis was measured in synovial membrane explants by incorporation of [35S]methionine. RESULTS: Ponies developed carpal effusion and mild lameness accompanied by increased total nucleated cell count and total solids in synovial fluid in response to the LPS injections. Moderate to severe synovial membrane proliferation and inflammation were observed histopathologically in joints injected with LPS but no consistent light-microscopical changes were observed in the articular cartilage from these joints. Intra-articular MPA alone was associated with decreased proteoglycan synthesis and increased protein and collagen synthesis in the cartilage explants. Total protein synthesis by synovial membrane was also increased by MPA alone. In contrast, no differences in protein or proteoglycan synthesis were observed in explants from the joints with synovitis, with or without intra-articular MPA. Treatment with MPA, LPS, and LPS/MPA did not alter proteoglycan aggregate size, but LPS-induced synovitis resulted in an increase in the second largest population of monomers. MPA increased the synthesis of small proteoglycan monomers. CONCLUSION: Based on the methods used, acute synovitis prevented changes induced by intra-articular MPA alone. Results suggested that the effect of intra-articular MPA on joint metabolism was different between inflamed and normal joints. Experimental studies must consider the effect of inflammation, as well as the potential to introduce in vitro culture artifacts when investigating the effect of intra-articular corticosteroids on chondrocyte function.

Contrast radiography of the lower urinary tract in the management of obstructive urolithiasis in small ruminants and swine.

Contrast radiographic visualization of the small ruminant and porcine lower urinary tract is an infrequently used modality for the evaluation and management of obstructive urolithiasis. The administration of contrast medium through a tube cystostomy catheter used to divert urine flow until the resolution of the obstruction may provide an easy method to evaluate the status of the urethral obstruction. Contrast fluoroscopy is utilized to monitor and visualize therapeutic flushing of the urethra. A review of 26 patients seen at the Veterinary Medical Teaching Hospital suggested that among the radiographic techniques used, positive contrast normograde cystourethrography through the tube cystostomy catheter allowed the best visualization of the lower urinary tract structures and enabled assessment of the resolution of the obstructive lesion.

Concurrent abomasal displacement and perforating ulceration in cattle: 21 cases (1985-1996).

OBJECTIVE: To evaluate the association of physical examination and clinicopathologic findings with surgical findings in cattle with concurrent abomasal displacement and perforating ulceration, to determine short- and long-term survival rates in these cattle, and to determine whether degree of peritonitis (focal vs diffuse) influences survival rates. DESIGN: Retrospective study. ANIMALS: 21 cattle with concurrent abomasal displacement and perforating ulceration and 42 cattle with uncomplicated abomasal displacement. PROCEDURE: Information on signalment, stage of lactation, physical examination findings, clinicopathologic data, surgical diagnosis, procedure(s) performed, and necropsy findings were retrieved from medical records of all cattle included in this study. Differences between physical examination findings of cattle with concurrent disease and those of cattle with uncomplicated displacements were evaluated, as were differences between survival rates in cattle with focal versus diffuse peritonitis. RESULTS: Cattle with concurrent disease had a greater probability of having pneumoperitoneum and signs of abdominal pain identified on physical examination than did cattle with uncomplicated diseases. There was no relationship between clinicopathologic data and survival time. Short-term survival rate was 38%, and degree of peritonitis significantly influenced survival time in cattle with concurrent abomasal displacement and perforating ulceration. Long-term survival rate in these cattle was 14%. CLINICAL IMPLICATIONS: Cattle with concurrent displaced abomasum and perforating ulceration have a poor chance for survival. In addition to detection of displaced abomasum, physical examination findings that can help lead to a presurgical diagnosis of this syndrome are pneumoperitoneum and signs of abdominal pain.

Abdominal surgery in foals: a review of 119 cases (1977-1994).

The case records of 119 young horses (all less than age one year) that underwent an exploratory celiotomy during a 17 year period were examined to determine the surgical findings, short- and long-term outcome, and prevalence of small intestinal disease compared to previous reports in the mature horse. Physical and laboratory values were compared for long-term survivors vs. nonsurvivors and the frequency of post operative intra-abdominal adhesions was determined. The most common cause for exploratory celiotomy was small intestinal strangulation, followed by enteritis and uroperitoneum. Six horses died during surgery, 23 were subjected to euthanasia at the time of surgery due to a grave prognosis, and 17 horses died or were destroyed after surgery, prior to discharge from the hospital; the short-term survival was 61%. Nine horses were lost to follow-up. Forty-one horses survived long-term (at least 6 months after surgery), 15 died or were subjected to euthanasia after discharge for reasons related to the prior abdominal surgery, and 8 died or were destroyed after discharge due to unrelated reasons, making the long-term survival 45%. Fifty-three (45%) of the horses presented as neonates, and 66 (55%) presented age 3-12 months. Uroperitoneum and meconium impaction were the most common disease in the neonate. Intussusception and enteritis were the most common diseases in older foals. The overall prevalence of small intestinal disease was 44%. Significant elevations in packed cell volume, heart rate, nucleated cell counts and total protein in abdominal fluid and rectal temperature were observed in nonsurvivors compared to survivors. Nonsurvivors had significantly decreased serum bicarbonate, chloride, sodium, and venous pH values. There was no evidence that location of the lesion affected long-term survival. Horses with a simple obstruction had a higher survival percentage than those with a strangulating obstruction, and horses that underwent an intestinal resection had a lower long-term survival than those horses undergoing only intestinal manipulation. Nineteen (33%) of the foals examined after the original surgery had evidence of intra-abdominal adhesions. Nine of these (16%) had adhesions that caused a clinical problem.

Concentrations of keratan sulfate in plasma and synovial fluid from clinically normal horses and horses with joint disease.

OBJECTIVE: To determine whether keratan sulfate concentrations in plasma or synovial fluid from clinically normal horses were different from concentrations in horses with joint disease and whether concentrations varied with type of joint disease. DESIGN: Case-control study. ANIMALS: 67 clinically normal horses, 10 clinically normal foals, and 160 horses with joint disease. PROCEDURE: ELISA was used to measure keratan sulfate concentrations. RESULTS: Mean plasma keratan sulfate concentration (mean +/- SEM, 580 +/- 124 ng/ml) in foals peaked at 10 weeks of age. Mean plasma keratan sulfate concentration in clinically normal horses was 200 ng/ml (95% confidence interval, 157 to 251 ng/ml). Horses with osteochondral (chip) fractures, other closed intraarticular fractures, inflammatory arthritis (synovitis), infectious arthritis, or osteochondrosis had significantly higher plasma keratan sulfate concentrations than did clinically normal horses, but horses with osteoarthritis did not. Breed, gender, and type of joint disease affected keratan sulfate concentration in synovial fluid. Standard-breds with chip fractures of the metacarpophalangeal/ metatarsophalangeal joints had significantly higher keratan sulfate concentrations in synovial fluid than did Thoroughbreds. Keratan sulfate concentrations in synovial fluid from osteoarthritic carpal joints were lower than concentrations in normal carpal joints and tarsocrural joints with inflammatory joint disease. CLINICAL IMPLICATIONS: Keratan sulfate concentration alone was not a specific marker of joint disease but was affected by various joint diseases.

Effect of methylprednisolone acetate on proteoglycan and collagen metabolism of articular cartilage explants.

OBJECTIVE: The effect of different doses of methylprednisolone acetate (MPA) on proteoglycan and collagen metabolism of articular cartilage from normal equine joints was tested in vitro. METHODS: Cultured explants were treated with 0, 0.0004, 0.004, 0.04, 0.4 and 4.0 mg/ml (approximately 10(-6)-10(-2) M) MPA for 72 h. Proteoglycan synthesis was measured by incorporation of sodium [35S]sulfate into proteoglycans and proteoglycan degradation was measured by release of total and radiolabeled proteoglycan into the culture media. The size of the proteoglycans was assessed with size exclusion chromatography under both associative and dissociative conditions. Total protein synthesis was measured by incorporation of [3H]proline and collagen synthesis by formation of [3H]hydroxyproline. RESULTS: Treatments of 0.0004, 0.004, and 0.04 mg/ml MPA caused a significant (p < 0.05) increase in total protein synthesis compared to the control, and doses of 0.0004 and 0.004 mg/ml MPA tended to increase (p < 0.1) collagen synthesis. In contrast, MPA doses of 0.04 mg/ml or less had no effect on proteoglycan synthesis compared to control. Proteoglycan, total protein, and collagen synthesis were severely depressed with the 0.4 and 4.0 mg/ml MPA treatments. The lowest doses of MPA had minimal effect on proteoglycan degradation, while 0.4 and 4.0 mg/ml MPA decreased degradation of total proteoglycan in a dose dependent fashion. Degradation of newly synthesized proteoglycan in the explants was significantly decreased (p < 0.05) by 4.0 mg/ml MPA. There was positive correlation (r = 0.83, p < 0.05) between the effect of MPA on proteoglycan synthesis and the release of total proteoglycan into the culture media. Chromatography under associative conditions showed that treatment with MPA (0.4 and 0.004 mg/ml) decreased the size and increased the polydispersity of aggrecan and induced synthesis of the small nonaggregating proteoglycans. Aggrecan monomers from cartilage treated with MPA included a population of smaller monomers, which resulted in greater polydispersity than those from control cartilage. CONCLUSION: As well as decreasing synthesis, loss of proteoglycan from MPA treated cartilage in vivo may be partly due to the synthesis of a population of smaller proteoglycans than those extracted from untreated cartilage, and these may not interact with hyaluronan and may not be retained permanently in the matrix. Methylprednisolone acetate may affect posttranslational modification of the core protein with the addition of smaller and possibly fewer glycosaminoglycan chains.

The diagnosis and surgical correction of congenital portosystemic vascular anomalies in two calves and two foals.

Two calves and two foals presented with episodic clinical signs of diffuse central nervous system disease. Portosystemic anomalies were tentatively diagnosed based on the history, clinical signs and increased serum concentrations of blood ammonia and total serum bile acids with normal concentrations of liver derived enzymes. one calf died before intraoperative contrast portography, whereas the other calf and both foals had marked clinical improvement after intensive medical therapy. Surgical correction was attempted in these three animals and was successful in one foal. A right paracostal celiotomy was superior to a ventral median approach for exposure to the portal vascular system and shunt access.

Effect of methylprednisolone and mechanical loading on canine articular cartilage in explant culture.

The objective of this study was to assess the effect of mechanical load on articular cartilage after in vitro corticosteroid exposure. Canine humeral cartilage was equilibrated for 4 days in defined medium with a serum substitute, then exposed to methylprednisolone sodium succinate for 20 h at 0, 0.01 or 1.0 mg/ml. After a drug-free recovery period, the explants were subjected to 0, 1 or 10 mega pascals (MPa) for 1 out every 5 s for 20 min, then incubated with [35S]-sulfate and [3H]-leucine for 4 h to measure proteoglycan and protein synthesis, respectively. When the loading occurred 22 h after drug exposure, proteoglycan synthesis was inhibited and protein synthesis, was unaffected by the drug. Both were stimulated by load, relative to controls. When the loading was delayed until 142 h after drug exposure, there was no biosynthetic response to load whether or not the explant had been exposed to the drug. Proteoglycan and protein synthesis 142 h after 0 or 0.01 mg/ml were unchanged or slightly higher than at 22 h, in explants which did not receive load. In contrast, biosynthesis were strongly inhibited 142 h after 1.0 mg/ml, and there was a 40% loss of proteoglycan content, relative to 22 h controls. If explants receiving 1.0 mg/ml also received heavy (10 MPa) loads 142 h later, there was a 17% reduction in total dry content suggesting severe matrix damage. These in vitro results suggest that articular load can help maintain normal cartilage metabolism after corticosteroid exposure, but also suggest that heavy loading after a sub-clinical dose can cause a marked loss of matrix solids.

A comparison of N-butylscopolammonium bromide and butorphanol tartrate for analgesia using a balloon model of abdominal pain in ponies.

The analgesic effect of N-butylscopolammonium bromide (0.3 mg/kg) using a balloon-induced model of colic in ponies was evaluated and compared with butorphanol tartrate (0.1 mg/kg). Eight adult ponies were used and each received both treatments during the two different trials. The order in which the treatment was received was randomly assigned. At the start of each trial, moderate abdominal pain was induced by inflation of a balloon placed in the lumen of the caecum. The ponies were evaluated every 5 minutes, and a cumulative pain score (CPS) was assigned. Two baseline measurements were recorded, followed by the administration of one of the two treatments. Assessments were continued for 60 minutes, or until moderate abdominal pain returned. Three ponies out of 8 responded to treatment with butorphanol tartrate, while 6 out of 8 ponies responded to N-butylscopolammonium bromide. There were no statistical differences in the CPS or duration of drug action between treatments.

Tube cystostomy for treatment of obstructive urolithiasis in small ruminants.

Tube cystostomy was used to treat 13 goats and two sheep with obstructive urolithiasis. The cystostomy tube was intermittently occluded 3 to 4 days after placement to determine if urine could be voided through the urethra. If the animal showed no discomfort during urination after the cystostomy tube had been occluded for several days, the tube was removed. This procedure was successful in relieving urethral obstruction in 12 animals. The mean time until the animal could urinate freely and until the cystostomy tube was removed was 11.5 and 14.4 days respectively. Follow-up was available for 10 animals; seven were alive with no recurrence of urinary obstruction. One goat died from unrelated to urinary obstruction 1 year postoperatively. One goat died from unknown causes, and one goat died after urinary obstruction recurred.

Repeat laparotomy for gastrointestinal disorders in cattle: 57 cases (1968-1992).

A study was conducted to investigate indications for, typical findings during, and outcome of repeat laparotomies in 57 cattle with gastrointestinal disorders. Cattle were grouped according to the reason the initial laparotomy had been performed. Group-1 cattle (n = 46) had had left or right displacement of the abomasum (LDA or RDA) or right volvulus of the abomasum. Group-2 cattle (n = 10) had had ruminal, reticular, or abomasal obstruction or perforation. Group-3 cattle (n = 7) had had obstruction, volvulus, distention, or perforation of the small or large intestine. Median interval between laparotomies was 1 month (range, 1 day to 38 months). Intraoperative findings during repeat laparotomy in group-1 cattle included LDA (n = 18), RDA (9), right volvulus of the abdomen (5), pneumoperitoneum (1), diffuse abdominal adhesions (1), cecal adhesions (1), adhesions of the rumen to the body wall (1), abscess in the cranial portion of the abdomen (1), reticular adhesions (1), localized necrosis (1), and idiopathic rumen distention (1). Intraoperative findings during repeat laparotomy in group-2 cattle included abscess in the cranial portion of the abdomen (4), no abnormalities (1), distended rumen (1), ruptured abomasum (1), recurrent abomasal impaction (1), diffuse abdominal adhesions (1), and pyloric fat necrosis (1). Intraoperative findings during repeat laparotomy in group-3 cattle included LDA (3), RDA (1), cecal volvulus (1), anastomotic rupture (1), and impacted colocolostomy (1). Seven cows and 1 calf underwent additional repeat laparotomies. Forty-four (77%) of the 57 cattle were discharged following final laparotomy. Fourteen of the 20 group-1 cattle, 1 of the 6 group-2 cattle, and 2 of the 3 group-3 cattle for which follow-up information was available were productive after repeat laparotomy.

Scintigraphy for diagnosis of avulsions of the origin of the suspensory ligament in horses: 51 cases (1980-1993).

The medical records of 34 horses with a diagnosis of avulsion of the origin of the suspensory ligament that had been admitted to the veterinary medical teaching hospital between 1980 and 1993 were identified. In addition to clinical examination, 21 of 34 horses had scintigraphy and radiography performed during their examination. The usefulness of scintigraphy and radiography were assessed by comparing the initial findings reported in the medical record to those obtained in a retrospective review of the images. Thirty other horses with scintigraphic lesions of the proximal aspect of the third metacarpal/metatarsal bone but with a confirmed diagnosis other than avulsion of the suspensory ligament served as controls for lesion specificity. Scintigraphy (bone phase, n = 21) revealed increased uptake in all horses in both reviews. Only 14 of 21 (67%) horses radiographed, however, had at least 1 lesion during the initial radiographic evaluation that was reported to be suggestive of avulsion. When the radiographs were reviewed retrospectively, the radiologist identified 18 of 21 (86%) horses with lesions consistent with avulsion. The interpretation of scintigraphy appeared to be a more repeatable and sensitive diagnostic method than radiography. However, though scintigraphy was sensitive in identifying inflammation of the proximal aspect of the metacarpal/metatarsal region, no specific diagnosis of avulsion could be made without coincident radiography; the specificity of scintigraphy in diagnosing avulsion of the suspensory ligament was only 41% (21/51).(ABSTRACT TRUNCATED AT 250 WORDS)

A one-stage marsupialization procedure for management of infected umbilical vein remnants in calves and foals.

Five Holstein calves and two foals with omphalophlebitis were treated by surgical marsupialization of the umbilical vein remnant because complete resection of the infected tract was not possible. The infected umbilical stalk was resected, and the umbilical vein remnant was marsupialized in a one-stage procedure by suturing it into the abdominal wall lateral to the abdominal incision. Antimicrobial drugs were administered, and the marsupialized tract was irrigated until closure by second intention healing. Cellulitis associated with the marsupialization site occurred in two calves but resolved with antimicrobial therapy. Owners reported that, 9 to 60 months after surgery, there were no complications associated with the procedure.