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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

Objective

To determine the prevalence of Mycoplasma spp in herds that were members of a milk cooperative.

Design

Epidemiologic study.

Sample Population

267 dairy herds that were members of a milk cooperative.

Procedure

Bulk-tank milk samples were collected monthly during a 6-year period from all dairies in the cooperative. Samples were submitted to the cooperative's laboratory for bacterial culture for Mycoplasma spp, using direct plating. Milk samples positive for Mycoplasma organisms were speciated.

Results

Prevalence of positive samples varied from 1.8 to 5.8% for all species of Mycoplasma and from 1.2 to 3.1% for Mycoplasma spp known to be mastitis pathogens. One mycoplasmal species was isolated initially on 99 of 198 (50.0%) dairies, but 68 of 198 (34.3%) dairies had 2 species isolated. Mycoplasma bovis, M californicum, and M bovigenitalium were consistently isolated, but M bovis (243/499; 48.6%) was the most commonly isolated species. Acholeplasma laidlawii was more prevalent in 1989 and 1995 than other years. Mycoplasma bovigenitalium and M californicum had a seasonal distribution. Less than 50 colonies per plate were isolated for most (317/500; 63.4%) bulk-tank samples. Of the milk samples with > 100 colonies/plate, Mycoplasma bovis was isolated most frequently (73/243; 30.0%).

Clinical Implications

Distribution of Mycoplasma spp varied by year, number of colonies isolated per sample, season, and herd. Therefore, it may be necessary to routinely sample bulk-tank milk, and all isolates should be speciated. Culture results from milk cooperatives should be used with other monitoring information to determine the Mycoplasma status of herds. (J Am Vet Med Assoc 1997;211:1036–1038)

Free access
in Journal of the American Veterinary Medical Association

Summary

Cardiorespiratory effects of an iv administered bolus of ketamine (7.5 mg/kg of body weight) and midazolam (0.375 mg/kg) followed by iv infusion of ketamine (200 μg/kg/min) and midazolam (10 μg/kg/min) for 60 minutes was determined in 6 dogs. Ketamine-midazolam combination was administered to dogs on 3 occasions to determine effects of prior administration of iv administered saline solution (1 ml), butorphanol (0.2 mg/kg), or oxymorphone (0.1 mg/kg). The infusion rate of ketamine and midazolam was decreased by 25% for anesthetic maintenance after opioid administration.

There were no significant differences in cardiorespiratory variables after saline solution or butorphanol administration; however, oxymorphone caused significant (P < 0.05) increases in mean arterial blood pressure, systemic vascular resistance, and breathing rate. Bolus administration of ketamine-midazolam combination after saline solution caused significant (P < 0.05) increases in heart rate, mean arterial blood pressure, cardiac index, mean pulmonary blood pressure, venous admixture, and significant decreases in stroke index, pulmonary capillary wedge pressure, arterial and mixed venous oxygen tension, arterial oxygen content, and alveolar-arterial oxygen gradient. Opioid administration was associated with significantly (P < 0.05) lower values than was saline administration for heart rate, mean arterial blood pressure, and arterial and mixed venous pH and with higher values for stroke index, pulmonary capillary wedge pressure, and arterial and mixed venous carbon dioxide tension. Prior oxymorphone administration resulted in the highest (P < 0.05) values for mean pulmonary blood pressure, venous admixture, and arterial and mixed venous carbon dioxide tension, and the lowest values for arterial oxygen tension, and arterial and mixed venous pH. Each treatment provided otherwise uncomplicated anesthetic induction, maintenance, and recovery. Time to extubation, sternal recumbency, and walking with minimal ataxia was similar for each treatment.

Free access
in American Journal of Veterinary Research

Abstract

OBJECTIVE To evaluate use of an ultrasonographically and radiographically determined value, the vertebral epaxial muscle score (VEMS), for assessing muscle mass in cats.

ANIMALS 30 healthy neutered cats of various body weights and between 1 and 6 years of age.

PROCEDURES Mean epaxial muscle height was calculated from 3 transverse ultrasonographic images obtained at the level of T13. Length of T4 was measured on thoracic radiographs, and the VEMS (ratio of epaxial muscle height to T4 length) was calculated and compared with body weight. Ratios of epaxial muscle height to various anatomic measurements also were compared with body weight as potential alternatives to use of T4 length.

RESULTS 1 cat was excluded because of a heart murmur. For the remaining 29 cats, mean ± SD body weight was 5.05 ± 1.40 kg. Mean epaxial muscle height was 1.27 ± 0.13 cm, which was significantly correlated (r = 0.65) with body weight. The VEMS and value for epaxial muscle height/(0.1 × forelimb circumference) were not significantly correlated (r = −0.18 and −0.06, respectively) with body weight, which is important for measures used for animals of various sizes.

CONCLUSIONS AND CLINICAL RELEVANCE The VEMS and value for epaxial muscle height/(0.1 × forelimb circumference) can both be used to normalize muscle size among cats of various body weights. Studies are warranted to determine whether these values can be used to accurately assess muscle mass in cats with various adiposity and in those with muscle loss.

Full access
in American Journal of Veterinary Research

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 compare myocardial concentrations of fatty acids in dogs with dilated cardiomyopathy (DCM) with concentrations in control dogs.

Sample Population—Myocardial tissues from 7 dogs with DCM and 16 control dogs.

Procedure—Myocardial tissues were homogenized, and total fatty acids were extracted and converted to methyl esters. Myocardial concentrations of fatty acids were analyzed by use of gas chromatography and reported as corrected percentages.

Results—The amount of docosatetraenoic acid (C22:4 n-6) was significantly higher in myocardial samples from dogs with DCM (range, 0.223% to 0.774%; median, 0.451%), compared with the amount in samples obtained from control dogs (range, 0.166% to 0.621%; median, 0.280%). There were no significant differences between DCM and control dogs for concentrations of any other myocardial fatty acids.

Conclusions and Clinical Relevance—Although concentrations of most myocardial fatty acids did not differ significantly between dogs with DCM and control dogs, the concentration of docosatetraenoic acid was significantly higher in dogs with DCM. Additional investigation in a larger population is warranted to determine whether this is a primary or secondary effect of the underlying disease and whether alterations in fatty acids may be a target for intervention in dogs with DCM. (Am J Vet Res 2005;66:1483–1486)

Full access
in American Journal of Veterinary Research

During 1998, 49 states, the District of Columbia, and Puerto Rico reported 7,961 cases of rabies in nonhuman animals and 1 case in a human being to the Centers for Disease Control and Prevention, a decrease of 6.5% from 8,509 cases in nonhuman animals and 4 cases in human beings reported in 1997. More than 92% (7,358 cases) were in wild animals, whereas > 7.5% (603 cases) were in domestic species (compared with 93% in wild animals and 7% in domestic species in 1997). Decreases were evident in all of the major contributing species groups, with the exception of skunks and bats. The relative contributions of the major groups to the total reported for 1998 were raccoons (44.0%; 3,502 cases), skunks (28.5%; 2,272), bats (12.5%; 992), foxes (5.5%; 435), cats (3.5%; 282), cattle (1.5%; 116), and dogs (11.5%; 113). No further discernable westward extension of the epizootic of rabies in raccoons in Ohio was reported. Twelve of the 19 states enzootic for the raccoon variant of the rabies virus and the District of Columbia reported decreased numbers of cases of rabies during 1998, compared with 13 states and the District of Columbia that reported increases during 1997. Three states, Rhode Island (143.2%), Massachusetts (77.2%), and New Hampshire (69.4%), reported increases of > 50% during 1998, compared with totals reported for 1997. In Texas, the number of cases of rabies associated with enzootic canine variants of the rabies virus remained greatly diminished; however, overall totals of reported cases of rabies increased in Texas and 12 other states where skunks are the major terrestrial reservoir of rabies. At the national level, the total of 82 reported cases of rabies among horses and mules was greater than that reported for any year since 1981 (88 cases) and represented a 74.5% increase, compared with the total for 1997. The 992 cases of rabies reported in bats during 1998 were the greatest proportionate contribution by bats since 1990. Reported cases of rabies in cats (282), dogs (113), and cattle (116) decreased 6.0%, 10.3%, and 4.9%, respectively. One indigenously acquired case of rabies reported in a human being during 1998 was the result of infection with a rabies virus variant associated with silver-haired and eastern pipistrelle bats.

Free access
in Journal of the American Veterinary Medical Association

Summary

In 1997, 49 states, the District of Columbia, and Puerto Rico reported 8,509 cases of rabies in nonhuman animals and 4 cases in human beings to the Centers for Disease Control and Prevention. Nearly 93% (7,899) were wild animals, whereas 7% (610) were domestic species. The total number of reported cases increased 19.4% from that of 1996 (7,128 cases). Increases were apparent in each of the major species groups, with the exception of cattle. The relative contributions of these groups to the total reported for 1997 were as follows: raccoons (50.5%; 4,300 cases), skunks (24.0%; 2,040), bats (11.3%; 958), foxes (5.3%; 448), cats (3.5%; 300), dogs (1.5%; 126), and cattle (1.4%; 122). The 958 cases of rabies reported in bats represented a 29.3% increase over the total reported for 1996 and the greatest number reported since 1984, with cases reported by 46 of the 48 contiguous states. The epizootic of rabies in raccoons expanded into Ohio in 1997 and now includes 19 states and the District of Columbia. Thirteen states, where rabies in raccoons is enzootic, reported increases over 1996 in total numbers of reported cases. Among these, New York (1,264 cases), North Carolina (879), Virginia (690), and Maryland (619) reported the greatest numbers of cases. Five states reported increases that exceeded 50%, compared with cases reported in 1996: Ohio (673.3%; 15 cases in 1996 to 116 in 1997), Massachusetts (144.3%; 115 to 281), South Carolina (97.9%; 96 to 190), Connecticut (97.4%; 274 to 541), and Maine (86.3%; 131 to 244). Cases of rabies associated with foci of rabies in foxes in west central Texas and in dogs and coyotes in southern Texas continued to decline, with this state reporting 78.3% fewer rabid foxes (13 cases), 26.7% fewer rabid dogs (11), and 63.2% fewer rabid coyotes (7) during 1997, compared with 1996. Reported cases of rabies in cats (300) and dogs (126) increased 12.8% and 13.5%, respectively, whereas cases in cattle (122) decreased by 6.9%. Thirty states, the District of Columbia, and Puerto Rico reported increases in rabies in animals during 1997, compared with decreases reported by 31 states and the District of Columbia in 1996. One state (Mississippi; 5 cases) remained unchanged. Hawaii was the only state that did not report a case of rabies in 1997. Four indigenously acquired cases of rabies reported in human beings were the result of infection with rabies virus variants associated with bats.

Free access
in Journal of the American Veterinary Medical Association