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Summary

Medical records of 35 cattle with small-intestinal volvulus were reviewed. Surgical correction was performed on 32 cattle, and 17 of these cattle were discharged from the hospital. Mean duration of clinical signs for survivors was not significantly different from that for nonsurvivors, and the most commonly recorded clinical signs were abdominal pain, anorexia, lethargy, abdominal distention, and dehydration. Physical examination of cattle with intestinal volvulus revealed tachycardia, tachypnea, and nor-mothermia. Rectal examination findings included distended small intestine, scant feces or mucus, and tight bands coursing dorsoventrally in the middle portion of the abdomen. Clinicopathologjc testingre-vealed azotemia, hypocalcemia, hyperglycemia, and leukocytosis with a left shift. Nonsurvivors had significantly lower mean preoperative venous blood phi and mean base excess and higher mean serum potassium concentration than did survivors.

A diagnosis of volvulus of the entire small intestine was made during surgery in 25 cattle, whereas volvulus of the distal jejunum and ileum was diagnosed during surgery in 7 cattle. Survival rate following surgical correction of volvulus of the entire small intestine (44%) was not significantly different from survival rate following surgical correction of volvulus of the distal jejunum and ileum (86%). However, survival rate for dairy cattle (63%) was significantly higher than survival rate for beef cattle (22%).

To determine potential risk factors for the development of small-intestinal volvulus, epidemiologic data from cattle admitted to veterinary teaching hospitals throughout North America were collected by searching records entered into the Veterinary Medical Data Base. Between 1967 and 1991, 190 of 242,745 cattle had small-intestinal volvulus. Surgical correction was performed in 130 cattle, and 75 cattle were discharged from the hospital Among cattle seen at veterinary teaching hospitals, dairy cattle had an increased risk of developing small-intestinal volvulus, compared with beef cattle, and cattle > 7 years old had a decreased risk, compared with cattle < 2 months old. Female cattle were more likely to suffer from intestinal volvulus than were male cattle.

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in Journal of the American Veterinary Medical Association

Summary

Medical records of 12 calves ≤1 month old, with fracture of the femoral diaphysis, were reviewed. Ten calves were within 1 week of birth at the time of diagnosis. Open reduction was accomplished by use of a lateral approach. Retrograde intramedullary pinning was accomplished in all calves, using 2 (n = 4 calves) or 3 (n = 8 calves) pins. Cerclage wire was used to supplement fixation in 7 calves. A closed continuous suction drain was placed along the lateral aspect of the femur in every calf.

Postsurgical complications included seroma formation over the middle gluteal musculature (n = 5 calves), pin migration (n = 6 calves), and osteomyelitis (n = 1 calf). Pin migration was observed in 4 calves that had been treated with nonthreaded trochar point pins.

Fractures in 10 of 12 calves (83%) were considered to have healed satisfactorily. One calf was euthanatized because of septic osteomyelitis of the femur. One calf was euthanatized because of persistent lameness and pin migration. Pins were removed in 8 of 12 calves (67%) between the 13th and 90th postoperative days. Results of this study indicate that application of intramedullary pins may be a useful solution for management of femoral diaphyseal fracture in young calves.

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in Journal of the American Veterinary Medical Association

Summary

A prospective study evaluating preoperative prognostic indicators in 80 cattle with abomasal volvulus was done. Surgical correction of the abomasal volvulus was performed in all animals. After surgery, cattle were categorized into 3 groups: productive (acceptable milk production or appetite, n = 59), salvaged (poor milk production or appetite, n = 10), and nonsurvivors (n = 11). Mean values for study variables did not differ significantly between salvaged and nonsurvivor groups. Cattle in these 2 groups were combined to form a nonproductive group, which was compared with the productive group. Productive cattle had a significantly lower preoperative heart rate than nonproductive cattle, were less dehydrated, had lower serum alkaline phosphatase (alp) activity and serum creatinine concentration, more frequent rumen contractions, higher serum Na+ and Cl concentrations, and had been inappetent for a shorter period. Significant differences were not detected in blood pH, base excess, anion gap, pcv, and serum K+ concentrations between the 2 groups. Feces from nonproductive cattle tended to be reduced in volume and were significantly darker.

A number of preoperative prognostic indices were evaluated by calculating the sensitivity, specificity, and positive predictive value (+pv) of each variable and by using logistic regression. Positive predictive values were generally higher in identifying productive cattle than nonproductive cattle. High +pv for productive animals were observed for cattle with normal hydration status (+pv, 0.96), serum creatinine concentration ≤ 1.5 mg/dl (+pv, 0.91), serum alp activity ≤ 100 IU/L (+pv, 0.90), serum Cl concentration ≥ 95 mEq/L (+pv, 0.90), and heart rate ≤ 80 beats/min (+pv, 0.88). Positive predictive values for nonproductive animals exceeded 0.50 only in cattle with heart rates ≥ 120 (+pv, 0.67) or ≥ 100 beats/min (+pv, 0.56), serum alp activity > 100 IU/L (+pv, 0.55), or ≥ 6% dehydration (+pv, 0.52). Anion gap ≥ 30 mEq/L was a poor prognostic indicator (+pv, 0.33). Logistic regression was used to identify 4 variables (hydration status, heart rate, period of inappetence, and serum alp activity) that had good predictive value. Preoperative determination of heart rate, hydration status, and period of inappetence appears superior to routinely used laboratory tests in determining the prognosis of cattle with abomasal volvulus. The cause of the high serum alp activity in nonproductive cattle needs to be determined.

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in Journal of the American Veterinary Medical Association

Summary

Atrial premature complexes (apc) were identified in 16 cows over a 2-year period. Fourteen cows had concurrent gastrointestinal disease. Variation in the intensity of the first heart sound and an occasionally irregular heart rhythm were evident during thoracic auscultation. Neither cardiac murmurs nor pulse deficits were detected in any cows, and clinical signs of heart failure were lacking. Three cows had apc immediately prior to or after development of atrial fibrillation.

The heart rate when apc were diagnosed ranged from 48 to 124 beats/min (mean, 77 ± 20 beats/min), and the apc frequency ranged from < 1 to 23/min (mean 9.4 ± 8.0). The P-wave morphologic characteristics in 4 cows with apc was abnormal. The coupling index of the apc varied between 0.44 and 0.95, with a mean of 0.73. Aberrant ventricular activation was usually associated with a short coupling interval (coupling index < 0.60) and was observed in 3 cows.

Ten cows were determined to be hypocalcemic and 4 cows hypokalemic when apc were identified. Atrial ectopic activity could not be detected in 12 cows after resolution of the concurrent gastrointestinal disorder or electrolyte abnormality. Atrial premature complexes may be a functional cardiac disorder in cattle, unrelated to structural heart disease. The potential for apc to progress to sustained atrial arrhythmias such as atrial fibrillation should be considered.

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in Journal of the American Veterinary Medical Association

SUMMARY

Pharmacokinetics and bioavailability of rifampin in adult sheep were investigated by use of high-performance liquid chromatography for determination of serum concentrations. Eight adult ewes were given rifampin po at the rate of 50 mg of rifampin/kg of body weight. Three weeks after the first experiment, the sheep were given rifampin po and iv at the rate of 20 mg/kg in a cross-over design, with 1 week between treatments. Serum obtained over a 36-hour period was analyzed for rifampin and a potential metabolite, 25-desacetyl-rifampin, using reverse-phase chromatography with uv detection at 254 nm. Data were analyzed by compartmental and noncompartmental models. Analysis by the noncompartmental model of rifampin serum concentrations after iv administration yielded a mean ± sd total body clearance of 1.16 ± 0.21 ml/min/kg, apparent volume of distribution at steady state of 0.45 ± 0.06 L/kg, and terminal elimination rate constant of 0.15 ± 0.04 hour−1. The harmonic mean of the elimination half-life was 4.56 hours. Because of incomplete and continuing absorption, bioavailability was extremely variable after oral administration. Desacetylrifampin was not detected. On the basis of pharmacokinetic values, serum concentrations measured in this study, and published minimal inhibitory concentrations, the dosage of 20 mg of rifampin/kg, po, every 24 hours should provide adequate serum concentrations for treatment of rifampin-susceptible bacterial infections in sheep.

Free access
in American Journal of Veterinary Research

Summary

The abomasal luminal pressure was determined during surgery in 54 dairy cows with abomasal volvulus (av) and another 50 dairy cows with left displaced abomasum. The luminal pressure was high in all cattle with av and 49 (98%) cattle with left displaced abomasum. Luminal pressure was significantly higher in cattle with av (median, 11.7 mm of Hg; range, 4.1 to 32.4 mm of Hg) than cattle with left displaced abomasum (median, 8.7 mm of Hg; range, 3.5 to 20.7 mm of Hg). Among cattle with av, abomasal luminal pressure was significantly higher in cattle that died or were sold for slaughter following surgery (median, 20.6 mm of Hg; n = 8) than in cattle that were retained in the herd (median, 11.0 mm of Hg; n = 46). The luminal pressure was weakly correlated with the preoperative serum alkaline phosphatase activity but not correlated with duration of inappetence before surgery. Calculation of likelihood ratios and construction of a response operating characteristic curve for cattle with av indicated that a cutoff value of 16 mm of Hg for luminal pressure optimized the distribution of cattle into productive and nonproductive groups. The sensitivity, specificity, positive predictive value, and negative predictive value of a luminal pressure < 16 mm of Hg in predicting a productive outcome were 0.83, 0.75, 0.95, and 0.43, respectively.

Free access
in Journal of the American Veterinary Medical Association

Summary

A prospective study evaluating the prognostic value of surgical and postoperative findings in 80 cattle with abomasal volvulus was performed. Surgical correction of abomasal volvulus was performed in all animals. After surgery, cattle were categorized into 3 groups: productive (acceptable milk production or appetite, n = 59), salvaged (poor milk production or appetite, n = 10), and nonsurvivors (n = 11). Cattle with omasal-abomasal volvulus had a significantly (P < 0.005) worse prognosis than cattle without omasal involvement. Large abomasal fluid volume, venous thrombosis, and blue or black abomasal color before decompression were all indicative of a poor prognosis. Most cattle had poor or fair appetites the first day after surgery; productive animals had marked improvement in appetite over the next 3 days. All cattle observed to have a good appetite within 3 days after surgery were later determined to be productive animals. The heart rate decreased in all groups after surgery; however, tachycardia (heart rate > 80 beats/ min) was sustained in cattle that were later salvaged for slaughter. Diarrhea was observed after surgery in 54% of cattle. The duration of diarrhea was significantly shorter (P = 0.009) in productive cattle than in salvaged and nonsurviving cattle. The presence or absence of diarrhea was only of predictive value when considered in conjunction with the estimated abomasal fluid volume.

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in Journal of the American Veterinary Medical Association

Summary

Seven mature dairy cows from 6 herds were obtained with history, clinical signs of disease, and laboratory findings suggestive of advanced paratuberculosis. A surgically implanted collection chamber was used to obtain peripheral tissue fluid. Blood, mammary gland flush fluid, and collection chamber flush fluid (ccff) samples were obtained 6 times over a 2-week period from each cow. Mononuclear cell-rich portions of these fluids obtained by gradient centrifugation were submitted for bacteriologic culture of Mycobacterium paratuberculosis and for total and differential cell counts.

Bacteriologic culture of feces for M paratuberculosis and complete necropsy performed on each cow at the conclusion of the study confirmed the diagnosis of paratuberculosis. Numbers of tissue macrophages obtained from ccff samples were lower than expected. Mean (± SD) differential count of tissue macrophages collected from ccff was 65.57 (± 23.39). Mean calculated tissue macrophages (total cell count × differential count) collected from ccff samples was 623.1 (±784.55) cells/μl. Mycobacterium paratuberculosis was isolated from 1 of 42 (2.4%) collections of mononuclear cell-rich portions of plasma and from 2 of 42 (4.8%) ccff samples. Mycobacterium paratuberculosis was not isolated from any collections of mammary gland flush fluid. The collection and processing techniques used in this study did not enhance detection of M paratuberculosis infection in cows with advanced paratuberculosis, beyond that of ileocecal lymph node biopsy or fecal culture.

Free access
in American Journal of Veterinary Research

Abstract

Objective—To determine risk factors for development of sequestra in cattle and identify factors associated with a successful outcome.

Design—Retrospective study.

Animals—110 cattle.

Procedure—Medical records of cattle treated at veterinary teaching hospitals in North America were reviewed. To determine risk factors for osseous sequestration, breed, age, and sex of cattle with osseous sequestration were compared with breed, age, and sex of all other cattle admitted during the study period.

Results—110 cattle were included in the study. Three had 2 sequestra; thus, 113 lesions were identified. Most sequestra were associated with the bones of the extremities, most commonly the third metacarpal or third metatarsal bone. Ninety-two animals were treated surgically (ie, sequestrectomy), 7 were treated medically, 3 were initially treated medically and were then treated surgically, and 8 were not treated. Follow-up information was available for 65 animals treated surgically and 6 animals treated medically. Fifty-one (78%) animals treated surgically and 5 animals treated medically had a successful outcome. Cattle that were 6 months to 2 years old had a significantly increased risk of developing a sequestrum, compared with cattle < 6 months old. Cattle in which sequestrectomy was performed with the aid of local anesthesia were significantly more likely to undergo 2 or more surgical procedures than were cattle in which sequestrectomy was performed with the aid of general anesthesia.

Conclusions and Clinical Relevance—Results suggest that sequestrectomy will result in a successful outcome for most cattle with osseous sequestration. (J Am Vet Med Assoc 2000;217:376–383)

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in Journal of the American Veterinary Medical Association