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in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine whether 4 mg of estradiol cypionate (ECP) administered prophylactically to highrisk postparturient dairy cows decreases incidence of postpartum metritis.

Design—Randomized, placebo-controlled, triplemasked clinical trial.

Animals—250 postparturient dairy cows in a herd with postparturient hypocalcemia, retained fetal membranes, dystocia, stillbirth, or twins.

Procedure—Cows were given 4 mg of ECP (treatment) or 2 mL of vegetable oil (control) by IM injection within 24 to 36 hours of calving. Monitoring rectal temperatures and evaluation for metritis was performed once daily for 10 days. Cows with fever ≥ 39.7°C (103.5°F) were treated with 1.5 g of ceftiofur hydrochloride.

Results—When assessed by ordinal logistic regression, there were no differences between groups in incidence of mild or severe metritis. Cows that calved during the second or third quarter of the year were at increased risk of metritis, compared with those that calved during the fourth quarter. Following stratification by lactation (first and ≥ 2), it was observed that multiparous cows that did not receive antimicrobials during the first 3 days of the postparturient period were 5 times as likely to have metritis, compared with cows treated with antimicrobials on the basis of fever or other concurrent disease.

Conclusions and Clinical Relevance—Prophylactic administration of ECP to dairy cows at high risk for metritis did not reduce risk for metritis. Treating multiparous cows with antimicrobials on the basis of fever during the early postpartum period was associated with decreased incidence of metritis. (J Am Vet Med Assoc 2003;223:846–851)

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in Journal of the American Veterinary Medical Association

Objective

Validate, by sensitivity and specificity analyses, use of somatic cell count (SCC) to predict bacteriologically positive subclinical mastitis in a California dairy herd with low SCC.

Design

Study of monthly dairy herd improvement SCC obtained from the immediate preceding lactation and individual cow composite milk sample microbiologic isolates collected at calving.

Animals

515 California dairy cows with SCC and culture data.

Procedure

Somatic cell count sensitivity and specificity analyses with combinations of SCC parameter and at various thresholds were done, using the bacterial isolates as the standard.

Results

Combination of SCC threshold and SCC parameters could not be developed that had sufficient sensitivity and specificity to be a useful predictor of cows that would calve with subclinical mastitis.

Clinical Implication

Under the conditions at this particular dairy, SCC could not be used as a basis of prediction of cows that would calve with bacteriologically positive subclinical mastitis or require selective nonlactating-cow antibiotic treatment. (J Am Vet Med Assoc 1996;208:1054–1057)

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To assess the use of flunixin meglumine as an adjunct treatment for diarrhea in calves.

Design—Clinical trial.

Animals—115 calves with diarrhea that were 1 to 21 days old at enrollment.

Procedure—Calves that developed diarrhea were randomly assigned to receive no flunixin meglumine (controls), a single dose of flunixin meglumine (2.2 mg/kg [1.0 mg/lb]), or 2 doses of flunixin meglumine administered 24 hours apart. Serum IgG concentration and PCV were measured prior to enrollment in the trial. Calves were evaluated daily to determine rectal temperature, fecal consistency, demeanor, and skin elasticity score . The primary analytic outcome was days of sickness (morbiddays).

Results—Calves with fecal blood and treated with a single dose of flunixin meglumine had fewer morbiddays and antimicrobial treatments, compared with controls. Although not significant, calves given 2 doses of flunixin meglumine in 24 hours had fewer morbid-days than untreated control calves. Regardless of severity of diarrhea, calves without fecal blood did not benefit from the use of flunixin. For calves with fecal blood, failure of passive transfer (low serum IgG concentration) was an independent risk factor for increased morbid-days.

Conclusions and Clinical Relevance—Treatment with a single dose of flunixin meglumine resulted in fewer antimicrobial treatments and morbid-days in calves with fecal blood. As observed in other studies, calves with failure of passive transfer were at high risk for poor outcomes. This emphasizes the importance of developing and implementing effective colostrum delivery programs on dairy farms. (J Am Vet Med Assoc 2003;223:1329–1333)

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in Journal of the American Veterinary Medical Association

Objective—

To determine whether treating cows with antimicrobials at the end of lactation would lower the incidence of clinical mastitis, improve milk production, and decrease somatic cell count (SCC) in the subsequent lactation.

Design—

Randomized blind field trial.

Animals—

233 Holstein cows from a single herd. All cows were in lactation 2 or greater.

Procedure—

Cows were randomly assigned to treatment groups. Treated cows were given procaine penicillin G and novobiocin by intramammary infusion. Control cows were not treated. Farm personnel recorded cases of clinical mastitis. Milk yield and SCC were recorded during the subsequent lactation.

Results—

Treatment did not significantly reduce the incidence of clinical mastitis when data for all cows were grouped or when data were stratified by lactation groups (lactation 2 vs lactation ≥ 3) or by last SCC (≤ 500,000 cells/ml vs > 500,000 cells/ml). Somatic cell counts (first, mean of first 5, maximum of first 5) for treated and control cows were similar, and proportions of treated and control cows with SCC > 500,000 cells/ml at least once were not significantly different. Treated cows produced 179 kg (394 lb) more milk during the first 17 weeks of lactation than did control cows.

Clinical Implications—

Treating cows with antimicrobials at the end of lactation increased 17-week milk production during the subsequent lactation and, at current milk prices, was financially preferable to not treating them. (J Am Vet Med Assoc 1997;211:207–211)

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in Journal of the American Veterinary Medical Association

Summary

A 12-month study was undertaken in a 9-veterinarian dairy practice to determine patterns of uterine prolapse and factors associated with posttreatment survival. Of 220,000 cows in herds visited by veterinarians from the practice, 200 (0.09%) developed prolapses mostly (155/169 with data) in the first 24 hours after calving. Most cows (130/200) had prolapses during fall and winter months, and assistance was required in 47 of 200 calvings that resulted in prolapses.

Treatment of affected cows (n = 196) consisted of cleansing and replacement of the uterus, insertion of perivulvar retention sutures, local and systemic administration of antibiotics, and parenteral administration of dexamethasone and oxytocin. Calcium was administered to cows with milk fever (n = 117) and to multiparous cows without milk fever attended by veterinarian 9 (n = 8). Crude recovery rate after 2 weeks was 72.4%, but recovery was significantly better if the calf was born alive (P = 0.001), the cow was primiparous (P = 0.03), the cow did not have stage-3 milk fever (P = 0.003), or if the cow was attended by veterinarian 9 (P = 0.01). Time to treatment was not significantly associated with recovery, but affected cows were treated mostly (127/156) within 2 hours of occurrence of the prolapse. By multivariable analysis, presence of a liveborn calf, parity, and lack of stage-3 milk fever, but not attending veterinarian, were significant (P < 0.05) prognostic indicators of 2-week survival.

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in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE To validate the effectiveness of a penetrating captive bolt device with a built-in low-pressure air channel pithing mechanism (PCBD) as a 1-step method for euthanasia of cattle.

DESIGN Clinical trial.

ANIMALS 66 feedlot steers and heifers (weight, 227 to 500 kg [500 to 1,100 lb]) that were not expected to survive or finish the feeding period with their cohorts.

PROCEDURES Cattle were transported to a university facility and euthanized with the PCBD. For each calf, clinical variables were monitored and recorded immediately before and for at least 10 minutes after application of the PCBD. Following euthanasia, the head of each calf was removed and trauma to the brain and skull was assessed and scored.

RESULTS Death was successfully achieved with the PCBD without application of an ancillary technique in all 66 cattle; however, 4 (6%) cattle required a second or third shot from the PCBD because of technical errors in its placement. All shots from the PCBD that entered the cranial vault successfully rendered cattle unconscious without a return to sensibility.

CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that the PCBD was an effective 1-step method of euthanasia for use in mass depopulation of feedlot cattle.

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in Journal of the American Veterinary Medical Association

Objective—

To determine whether heifers with naturally acquired congenital exposure to Neospora sp would transmit the infection to their offspring during gestation.

Design—

Prospective cohort study.

Animals—

Neonatal heifers on a dairy with a history of Neospora sp infections were selected for the study on the basis of their serum titers to Neospora sp, as determined by the use of indirect fluorescent antibody testing. Seropositive heifers (n = 25) had titers ≥ 1:5,120 and seronegative heifers (25) had titers ≤ 1:80. All heifers were raised and bred on the dairy, and samples were obtained from heifers and their calves at the time of calving.

Procedure—

Blood samples were tested for Neospora sp antibodies. Histologic evaluations, Neospora sp immunohistochemical examinations. and protozoal culturing were performed on samples obtained from selected offspring (second-generation calves).

Results—

Seropositive heifers gave birth to calves with titers ≥ 1:1,280 to Neospora sp. All offspring from seropositive heifers that were necropsied had evidence of Neospora sp infection. All seronegative heifers and their offspring had titers < 1:80 to Neospora sp.

Clinical Implications—

Congenitally acquired Neospora sp infection can persist in clinically normal heifers and be transmitted transplacentally to their offspring. Vertical transmission can be a way by which neosporosis is maintained in herds. (J Am Vet Med Assoc 1997;210:1169–1172)

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in Journal of the American Veterinary Medical Association

Summary:

Four dairy cows that had been successfully rebred following fetal Neospora infection and abortion were identified from 2 drylot dairies. All 4 cows had uncomplicated pregnancies with the birth of 5 full-term calves. The calves all had high precolostral serum IgG antibodies. The precolostral antibodies to Neospora sp as determined by indirect fluorescent antibody test ranged from 5,120 to 20,480, compared with maternal serum and colostral antibody titers from 320 to 1,280. Two calves had mild neurologic limb deficits. Three calves had mild nonsuppurative encephalomyelitis and Neospora organisms were found in the CNS of 3 calves. Findings indicate that repeat transplacental Neospora infections occur in cows. Additionally, calves born from cows with a history of Neospora fetal infection and abortion may have congenital Neospora infections and/or neurologic dysfunctions at birth. The Neospora indirect fluorescent antibody test appears to be a useful antemortem test for detection of calves exposed in utero to Neospora organisms.

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in Journal of the American Veterinary Medical Association