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SUMMARY

A total of 5,142 kidney tissue samples and 5,111 serum samples from mature cattle in 49 states and Puerto Rico were collected at slaughter. Age of cattle ranged from 1 to 16 years (mean, 6.6 years). Leptospires were isolated from 88 (1.7%) kidney tissues, and 2,493 (49%) sera contained antibodies against 1 or more of 12 Leptospira interrogans serovars. Leptospires were observed by immunofluorescence in 41 (0.8%) kidney tissues. Using agglutinin-absorption tests, 73 (83%) isolates were identified as serovar hardjo, 11 (12.5%) as serovar pomona, and 4 (4.5%) as serovar grippotyphosa. By use of restriction endonuclease analysis studies of chromosomal dna, all isolates differed from reference serovars but were identical to strains previously isolated from cattle or swine in the United States. Of the serovar hardjo isolates, 85% were identical to restriction endonuclease analysis type (genotype) hardjo-bovis A and 11 (15%) were identical to genotype hardjo-bovis B. Serovar pomona isolates were identical to genotypes kennewicki A (64%) or kennewicki B (36%), and serovar grippotyphosa isolates were identical to the RM 52 strain. Isolation rates were significantly (P < 0.001) higher for beef cattle than for dairy cattle and were higher (P < 0.001) for bulls than for cows. Combined culture and immunofluorescence results indicated that 2% of mature cattle were renal carriers of leptospires.

Free access
in American Journal of Veterinary Research

SUMMARY

On the basis of serologic test results and isolation of leptospires from mature cattle, distribution and prevalence of Leptospira interrogans serovars and genotypes were compared by state and region of the United States. Relationships between isolation rate and month of sample collection, mean regional temperature, and mean regional precipitation were examined. Isolation rate and seroprevalence were significantly (P < 0.001) higher for southeastern, south central, and Pacific coastal regions than for other regions of the United States. Isolates of genotypes hardjo-bovis A and kennewicki A and B, and of serovar grippotyphosa appeared to be randomly distributed. Genotype hardjo-bovis B isolates came from a southern area of the country that extends from Georgia to New Mexico. To the authors’ knowledge, this is the first recorded isolation of serovar hardjo from Hawaii. Although significant relationship was not documented between isolation rate and month or season of the year, seroprevalence for summer, fall, and winter was significantly (P < 0.001) higher than that for spring. Regional isolation rate was related more to mean temperature (r = 0.83; P < 0.05) than to mean precipitation amount (r = 0.34; P > 0.50).

Free access
in American Journal of Veterinary Research

Abstract

Objective—To determine indications for cesarean section in alpacas and llamas, and clinical management and outcome of alpacas and llamas undergoing cesarean section.

Design—Retrospective case series.

Animals—27 alpacas and 7 llamas.

Procedures—Medical records were reviewed and information gathered on signalment, anamnesis including reproductive history, physical examination findings, indication for cesarean section, anesthetic protocol, surgical technique, number of crias delivered (alive or dead), additional treatment, duration of hospitalization, and postoperative complications. Follow-up information was gathered via email or telephone interview with owners.

Results—Uterine torsion (13/34 [38%]) was the most common reason for cesarean section. The most common surgical approach was the left proximal lateral abdominal approach (21/34 [62%]). Thirty-four crias were delivered via cesarean section. Twenty (59%) were born alive and discharged from the hospital. Retained placenta was the most common complication observed after surgery. A significant association was found between prolonged dystocia and fetal death. Of the 34 dams that underwent cesarean section, 21 were rebred, and 19 of the 21 (90.5%) dams that were rebred became pregnant. Fifteen of 19 dams were confirmed to have ≥ 1 normal vaginal delivery with a live cria following cesarean section.

Conclusions and Clinical Relevance—The results of the present study indicated that cesarean section was an effective method of resolving dystocia in camelids without negatively affecting future fertility or parturition by the dam. Prompt referral of patients with dystocia is advised to improve fetal viability. Retained fetal membranes seemed to be a common complication of cesarean section in camelids but was not associated with negative outcomes.

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To describe cardiac lesions and identify risk factors associated with myocarditis and dilated cardiomyopathy (DCM) in beach-cast southern sea otters.

Animals—Free-ranging southern sea otters.

Procedure—Sea otters were necropsied at the Marine Wildlife Veterinary Care and Research Center from 1998 through 2001. Microscopic and gross necropsy findings were used to classify sea otters as myocarditis or DCM case otters or control otters. Univariate, multivariate, and spatial analytical techniques were used to evaluate associations among myocarditis; DCM; common sea otter pathogens; and potential infectious, toxic, and nutritional causes.

Results—Clusters of sea otters with myocarditis and DCM were identified in the southern aspect of the sea otter range from May to November 2000. Risk factors for myocarditis included age, good body condition, and exposure to domoic acid and Sarcocystis neurona. Myocarditis associated with domoic acid occurred predominantly in the southern part of the range, whereas myocarditis associated with S neurona occurred in the northern part of the range. Age and suspected previous exposure to domoic acid were identified as major risk factors for DCM. A sample of otters with DCM had significantly lower concentrations of myocardial L-carnitine than control and myocarditis case otters.

Conclusions and Clinical Relevance—Cardiac disease is an important cause of death in southern sea otters. Domoic acid toxicosis and infection with S neurona are likely to be 2 important causes of myocarditis in sea otters. Domoic acid–induced myocarditis appears to progress to DCM, and depletion of myocardial L-carnitine may play a key role in this pathogenesis. (Am J Vet Res 2005;66:289–299)

Full access
in American Journal of Veterinary Research
in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE To determine the effects of grape seed extract (GSE), lutein, and fish oil containing omega-3 fatty acids on oxidative stress, migration, proliferation, and viability of lens epithelial cells (LECs).

SAMPLE Lens capsules or cultured LECs obtained from canine cadavers.

PROCEDURES An antioxidant reductive capacity assay was used to determine reducing capability of each substance. The LECs were cultured and incubated with various substances, including N-acetyl cysteine (NAC), when appropriate, and dimethyl sulfoxide (DMSO) as positive and vehicle control substances, respectively. A dichlorofluorescein assay was used to evaluate reactive oxygen species (ROS) production, and a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to determine cell viability. Ex vivo posterior capsule opacification (PCO) was used to evaluate LEC migration and proliferation.

RESULTS Antioxidant reductive effects of GSE surpassed those of NAC, lutein, and fish oil containing omega-3 fatty acids. The GSE reduced ROS production in LECs, compared with the DMSO vehicle control, whereas lutein was pro-oxidative. All test substances reduced cell viability. Ex vivo PCO was not altered by GSE, was decreased by lutein, and was increased by fish oil containing omega-3 fatty acids, compared with results for the DMSO vehicle control.

CONCLUSIONS AND CLINICAL RELEVANCE Only GSE had significant antioxidant capabilities and reduced ROS production; however, no effect on ex vivo PCO was detected. Fish oil containing omega-3 fatty acids increased ex vivo PCO. No conclusions could be made regarding antioxidant effects of these substances on LECs. These findings suggested that the substances will not decrease PCO.

Full access
in American Journal of Veterinary Research

Abstract

OBJECTIVE

To evaluate outcomes of tibial tuberosity avulsion fractures (TTAF) in dogs with implants left in situ past skeletal maturity and to compare clinical outcomes with published outcomes in dogs whose implants were removed 4 to 6 weeks postoperatively.

ANIMALS

47 client-owned dogs.

PROCEDURES

In this retrospective study, 47 dogs had surgery to correct a TTAF before 10 months of age and had the implants left in situ past skeletal maturity. Of these, 42 were followed for a median of 36 months postoperatively. Short- and long-term complications were recorded and compared with historically published data in which the implants were removed within 6 weeks of surgery.

RESULTS

14% (6/42) of our population experienced minor long-term complications (stiffness and lameness), 6% (3/47) experienced major short-term complications (repair failure), and 14% (6/24) experienced major long-term complications (implant removal). There was no difference in long-term outcomes when compared with results of historical reports in which implants were removed 4 to 6 weeks postoperatively. Client satisfaction was high, with 93% (38/41) grading outcomes as excellent and 95% (39/41) stating they would have surgery performed again in retrospect.

CLINICAL RELEVANCE

Immature dogs with surgically repaired TTAFs have favorable long-term outcomes when the implants were left in situ past skeletal maturity. Dogs with TTAF repairs may not need implant removal unless it becomes clinically necessary. Avoiding a second procedure will decrease patient morbidity, recovery time, and cost.

Full access
in Journal of the American Veterinary Medical Association

Abstract

Case Description—A 12-year-old Miniature Dachshund with a history of permanent endocardial pacemaker implantation performed 7 weeks previously was admitted for routine dental prophylaxis.

Clinical Findings—Preanesthetic ECG revealed normal ventricular capture. Thoracic radiographic findings included caudomedial displacement of the endocardial pacemaker lead. Echocardiography revealed moderate chronic degenerative valve disease with moderate left atrial and ventricular dilation. After induction of anesthesia, loss of ventricular capture was detected. The dog recovered from anesthesia and had improved ventricular capture. The following day, surgical exposure of the cardiac apex revealed perforation of the right ventricular apex by the passive-fixation pacemaker lead.

Treatment and Outcome—A permanent epicardial pacemaker was implanted through a transxiphoid approach. Appropriate ventricular capture and sensing were achieved. The dog recovered without complications. Approximately 2 months later, the dog developed sudden respiratory distress at home and was euthanized.

Clinical Relevance—In dogs with permanent pacemakers and loss of ventricular capture, differential diagnoses should include cardiac perforation. If evidence of perforation of the pacemaker lead is found, replacement of the endocardial pacemaker lead with an epicardial pacemaker lead is warranted.

Full access
in Journal of the American Veterinary Medical Association