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Abstract

OBJECTIVE To describe disorders of performance-age bucking bulls.

DESIGN Retrospective case-control study.

ANIMALS 78 bucking (cases) and 236 nonbucking (controls) beef bulls.

PROCEDURES The medical record database of a referral hospital was reviewed to identify beef bulls > 1 year old that were examined for a medical or musculoskeletal disorder between January 1, 2000, and April 1, 2014. Bucking bulls were designated as cases, and nonbucking bulls were designated as controls. For each bull, the signalment, history, physical examination and diagnostic test results, and clinical diagnosis were recorded. The frequency of each disorder was compared between cases and controls.

RESULTS Fifteen of 78 (19%) cases and 132 of 236 (56%) controls had medical disorders; however, the frequency did not differ between the 2 groups for any medical disorder. Musculoskeletal disorders were identified in 55 (70.5%) cases and 109 (46%) controls. Cases were 10.55 times as likely as controls to have horn and sinus disorders. Of the 43 (55%) cases examined because of lameness, the thoracic limb was affected in 19 (44%). Compared with controls, cases were 13.37 and 3.31 times as likely to have a musculoskeletal disorder of the vertebral region and pelvic limb, respectively.

CONCLUSIONS AND CLINICAL RELEVANCE Results indicated bucking bulls were more likely than nonbucking bulls to develop horn and sinus disorders and musculoskeletal disorders of the vertebral region and pelvic limbs. The limb distribution of lameness for bucking bulls may differ from that for nonbucking bulls.

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine effects of sedation achieved by xylazine (XYL) or acepromazine (ACE) on cardiopulmonary function and uterine blood flow in cows in late gestation.

Animals—8 cows between 219 and 241 days of gestation.

Procedure—Doses of ACE (0.02 mg/kg) or XYL (0.04 mg/kg) were administered IV. Measurements were obtained to determine cardiopulmonary effects and oxygen delivery to the uterus.

Results—Heart rate was not significantly affected by administration of ACE, but it decreased markedly after administration of XYL. Uterine artery flow was decreased at all times by XYL and was always less than for ACE. Xylazine increased uterine vascular resistance through 30 minutes and caused reduced PaO2 and increased PaCO2 at all time periods. Acepromazine caused a 5% decrease in PaO2 only at 5 minutes. Xylazine reduced oxygen delivery by 59% at 5 minutes and 32% at 45 minutes. In contrast, ACE caused a nonsignificant reduction of oxygen delivery by 16% at 15 minutes and a return to baseline values by 45 minutes

Conclusions and Clinical Relevance—Xylazine markedly reduces flow and availability of oxygenated blood to the uterus, which may critically impair delivery of oxygen to the fetus at a stressful and important time of development or delivery. Acepromazine was associated with slight reductions of much shorter duration. When XYL is used to sedate pregnant cows, it could impose physiologic distress on the fetus and potentially increase fetal morbidity and mortality. When sedation of the dam is desirable, ACE could be an alternative to XYL. (Am J Vet Res 2002;63:1695–1699)

Full access
in American Journal of Veterinary Research

Abstract

Objective

To investigate the effects of poor water quality on hematologic and biochemical analytes in hybrid striped bass.

Animals

Hybrid striped bass (reciprocal cross: female Morone chrysops × male M saxatilis) maintained in 2,000-L tanks with undergravel filters.

Procedure

Fish were acclimated to high ammonia (0.15 mg/L) and nitrate (200 mg/L) concentrations for 6 weeks prior to sample collection. Hematologic and biochemical profiles were determined for these fish and for fish kept under normal conditions (control). Comparisons were made among the 3 water qualities and with reference intervals determined previously.

Results

Significant differences in hematologic and biochemical analytes were observed between fish in the various groups; however, most of the values were within established reference intervals. All values from fish in the high ammonia concentration tank were either within the reference interval or not significantly different from control values. Fish from the high nitrate concentration tank had higher serum creatinine values and lower chloride values than did control fish, and both analytes were substantially outside the reference intervals.

Conclusion

High ammonia concentration of 0.15 mg/L did not affect any of the blood analytes measured. The hypercreatininemia and hypochloremia observed in fish from the 200 mg of nitrate/ml tank were considered to be pathologic changes associated with the high nitrate concentration.

Clinical Relevance

Determining the effects of water quality on hematologic and biochemical values helps to develop clinical pathology as a diagnostic tool in fish. (Am J Vet Res 1997;58:131–135)

Free access
in American Journal of Veterinary Research

Abstract

Objective

To investigate the effect of water temperature on hematologic and biochemical analytes in hybrid striped bass.

Animals

Hybrid striped bass (reciprocal cross; female Morone chrysops × male M saxatilis) maintained in 2,000-L tanks with undergravel filters.

Procedure

Fish were acclimated to 10. 18, 24, and 29 C water for 6 weeks prior to sample collection. Hematologic and serum biochemical profiles were then determined. Values were compared among the various temperatures, and with reference intervals previously determined.

Results

Most values were within or slightly outside the established reference intervals. The following analytes deviated notably from the reference interval: leukocyte, lymphocyte, and monocyte counts were lower than the reference intervals at 10 C; glucose values were lower at 10 and 18 C; calcium values were higher at 10 and 18 C; and total protein, albumin, globulin, and chloride values were higher at 29 C.

Conclusion

Separate reference intervals should be developed for analytes which, because of temperature, deviate notably from the reference interval. Modifications of the established reference intervals, by including fish from varied temperatures, should allow use of one reference interval for analytes, with only slight variation attributable to temperature.

Clinical Relevance

Determining the effects of temperature on the hematologic and biochemical values helps develop clinical pathology as a diagnostic tool in fish. (Am J Vet Res 1997;58:126–130)

Free access
in American Journal of Veterinary Research

SUMMARY

Six mature Holstein bulls were each given 10 mg of phenylbutazone (pbz)/kg of body weight, po. Of the 6 bulls, 3 were given 10 mg of pbz/kg by rapid iv administration 4 weeks later. Plasma concentration-vs-time data were analyzed, using nonlinear regression modeling (sum of exponential functions). The harmonic mean of the biologic half-life of pbz was 62.6 ± 12.9 hours after oral administration and 61.6 ± 7.2 hours after iv administration. The mean residence time was 94.61 ± 8.44 hours and 90.49 ± 8.93 hours for oral and iv administration, respectively. The mean total body clearance was 0.0015 ± 0.0003 L/h/kg, with the mean apparent volume of distribution 0.134 ± 0.021 L/kg. Mean bioavailability was 73 ± 2% after oral administration. Phenylbutazone was adequately absorbed from the gastrointestinal tract in bulls. The apparent volume of distribution was small, indicating that pbz distributed mainly into plasma and extracellular fluid. The total body clearance was also small, which accounted for the long half-life of pbz in bulls.

Free access
in American Journal of Veterinary Research

SUMMARY

Six mature Holstein bulls were given an 8-day course of phenylbutazone (pbz) orally (loading dose, 12 mg of pbz/kg of body weight and 7 maintenance doses of 6 mg of pbz/kg, q 24 h). Plasma concentration-vs-time data were analyzed, using nonlinear regression modeling. The harmonic mean ± pseudo-sd of the biologic half-life of pbz was 61.8 ± 12.8 hours. The arithmetic mean ± sem of the total body clearance and apparent volume of distribution were 0.0021 ± 0.0001 L/h/kg and 0.201 ± 0.009 L/kg, respectively. The predicted mean minimal plasma concentration of pbz with this dosage regimen was 75.06 ± 4.05 μg/ml.

The predicted minimal plasma drug concentration was compared with the observed minimal plasma drug concentration in another group of bulls treated with pbz for at least 60 days. Sixteen mature Holstein bulls were given approximately 6 mg of pbz/kg, po, daily for various musculoskeletal disorders. The mean observed minimal plasma concentration of pbz in the 16 bulls was 76.10 ± 2.04 μg/ ml, whereas the mean predicted minimal plasma concentration was 74.69 ± 3.10 μg/ml.

Dosages of 4 to 6 mg of pbz/kg, q 24 h, or 10 to 14 mg of pbz/kg, q 48 h, provided therapeutic plasma concentrations of pbz with minimal steady-state concentrations between 50 and 70 μg/ml.

Free access
in American Journal of Veterinary Research

Summary

Approximately 10 of 100 young heifers that had recently delivered their first calf—members of a large Colorado dairy herd—had a syndrome of swollen teats and distal portions of the hind limbs, prefemoral lymphadenopathy, transient fever, rough coat, decreased milk production, and subsequent weight loss and reproductive inefficiency. Acute clinical signs of disease were associated with large numbers of Eperythrozoon wenyonii seen on blood smears, and resolution of signs correlated with reduction or disappearance of the parasite. Other known causes of peripheral edema could not be documented. The parasite was transmitted to 4 of 7 nonlactating dairy cows destined to be culled and a splenectomized calf via IV inoculation of blood from parasitemic heifers, but clinical signs of infection were not induced.

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine duration of administration, complications, and frequency of aortic thromboembolism associated with administration of low molecular weight heparin (dalteparin) in cats.

Design—Retrospective study.

Animals—57 cats treated with dalteparin.

Procedure—Data were recorded from the medical records of cats treated with dalteparin, and owners were contacted by telephone for information regarding ease of administration and possible adverse effects.

Results—Dalteparin was easily administered by owners. Median dose was 99 U/kg (45 U/lb) once or twice daily. Bleeding complications were infrequent. Of 43 cats with cardiomyopathy that received owner-administered dalteparin for a median follow-up time of 172 days, 8 cats developed documented or possible arterial thromboembolism.

Conclusions and Clinical Relevance—Dalteparin was easily administered by owners and was well tolerated by cats. Whether dalteparin administration can reduce the frequency or severity of arterial thromboembolism is not yet known. (J Am Vet Med Assoc 2004;225:1237–1241)

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective

To determine and compare hematologic reference intervals for hybrid striped bass from different culture systems and for 2 types of hybrid.

Design

Observational comparison study.

Animals

Clinically normal sunshine bass (reciprocal hybrid striped bass, female Morone chrysops × male M saxatilis) raised in high-density recirculating systems, sunshine bass raised in tanks with biofilters, and palmetto bass (original hybrid striped bass, female M saxatilis × male M chrysops) raised in tanks with biofilters.

Procedure

Hematologic reference intervals were determined for fish from the different production systems, following the National Committee for Clinical Laboratory Standards guidelines. Reference intervals from the 3 groups were compared.

Results

Reference intervals were significantly different between sunshine bass in the 2 culture systems and between sunshine and palmetto bass. Many of the differences were slight, but notable differences were observed. Sunshine bass in recirculating systems had higher total leukocyte, lymphocyte, neutrophil, and monocyte counts than did either hybrid in tanks. Palmetto bass had a greater number of neutrophils than monocytes, whereas sunshine bass had more monocytes than neutrophils. Additionally, palmetto bass had a lower PCV and hemoglobin value than did either group of sunshine bass.

Conclusions

Separate reference intervals should be developed for hybrid striped bass in different culture systems and for different types of hybrids.

Clinical Relevance

Determining reference intervals for hybrid striped bass provides a tool to assess the health status of these fish. (Am J Vet Res 1996; 57:618–623)

Free access
in American Journal of Veterinary Research