Mel Pence

Endometritis in Postparturient Cattle Associated with Bovine Herpesvirus-4 Infection: 15 Cases

Suppurative, ulcerative endometritis associated with bovine herpesvirus-4 (BHV-4) infection was identified in 15 postparturient dairy cows from 5 separate dairies. Characteristic eosinophilic to amphophilic intranuclear viral inclusion bodies were identified within degenerate endometrial lining epithelium and endothelial cells. Bovine herpesvirus-4 was confirmed as the etiology by a combination of fluorescent antibody assays, viral isolation, heminested PCR, ultrastructural examination of the uterus and inoculated tissue culture cells, and negative-stain electron microscopy of tissue culture supernatant. Viral particles measuring 70–95 nm were demonstrated in uterine epithelial and endothelial cells by electron microscopy. Bacteria including Arcanobacterium pyogenes, Escherichia coli, and an α-Streptococcus isolate were isolated from all uteri. Bovine herpesvirus-4-associated endometritis has been previously reported in sporadic cases in Europe but has not been previously reported in the United States. Endometritis associated with BHV-4 appears to be an emerging syndrome in Georgia dairy herds.

Seroprevalence and Comparison of Isolates of Endometriotropic Bovine Herpesvirus-4

Sixty-eight cases of suppurative, ulcerative endometritis associated with Bovine Herpesvirus-4 (BHV-4) in postparturient dairy cows (62 Holsteins and 6 Jerseys, mean age 4.2 years) were confirmed by a combination of histopathology, fluorescent antibody assays, electron microscopic evaluation of uterus, and polymerase chain reaction (PCR). All cases occurred in the 3- to 28-day postpartum period, and histologic lesions among various cows were consistent when compared with postpartum interval. The endometrial lining epithelium was necrotic and ulcerated from 3 to 7 days postpartum, with only mild inflammation in the lamina propria and submucosa. From 1 to 4 weeks postpartum, the ulcers were confluent to diffuse. Epithelium was replaced by fibrinonecrotic, suppurative mats, resulting in severe bacterial pyometra by day 24. Seroprevalence to BHV-4 in one dairy with a history of 18 mortality cases was 36% (107 of 296). In a random sample of 8 cows from this herd, none had serologic titers in blood sampled 2 weeks prepartum, but 3 of 8 seroconverted with significant titers of 1:8 to 1:16 at 2 weeks postpartum. By 10 weeks postpartum, all 8 cows returned to negative serologic status. Two of 6 cats from the premises also had positive titers. Random serum samples taken from 480 dairy cattle at sale barns indicated 76 (16%) were positive by serum neutralization. Clinical signs, postparturient timing, and histologic lesions were very similar to those previously reported in Belgium with BHV-4. But sequence analysis of PCR products of the glycoprotein B region of 4 separate field isolates of endometriotropic BHV-4 suggests these field isolates were more closely related to the North American nonvirulent strain DN-599 than to the endometriotropic European strain V.

The Seroprevalence of Johne's Disease in Georgia Beef and Dairy Cull Cattle

Beef and dairy cattle serum samples, collected during 2000 at sale barns throughout Georgia, were obtained from the Georgia State Brucellosis Laboratory and were used to conduct a retrospective epidemiological study. Statistical samplings of 5,307 sera, from over 200,000 sera, were tested for antibodies to Mycobacterium avium ssp. paratuberculosis, (Johnes disease) using a commercial enzyme-linked immunosorbent assay test kit. An overall period seroprevalence in all classes of cattle tested was 4.73%. The period seroprevalence in dairy cattle was 9.58%, in beef cattle it was 3.95%, and in cattle of unknown breed it was 4.72%. It was concluded that the seroprevalence of Johnes disease in cull beef and dairy cattle in Georgia is economically significant.

Effect of calf age and administration route of initial multivalent modified-live virus vaccine on humoral and cell-mediated immune responses following subsequent administration of a booster vaccination at weaning in beef calves

OBJECTIVE To compare immune responses following modified-live virus (MLV) vaccination at weaning after intranasal or SC administration of an MLV vaccine to beef calves at 2 or 70 days of age. ANIMALS 184 calves. PROCEDURES Calves were allocated to 1 of 5 groups. The IN2 (n = 37) and IN70 (37) groups received an MLV vaccine containing bovine herpesvirus 1 (BHV1), bovine viral diarrhea virus (BVDV) types 1 and 2, bovine respiratory syncytial virus (BRSV), and parainfluenza 3 virus intranasally and a Mannheimia haemolytica and Pasteurella multocida bacterin SC at median ages of 2 and 70 days, respectively. The SC2 (n = 36) and SC70 (37) groups received a 7-way MLV vaccine containing BHV1, BVDV1, BVDV2, BRSV, parainfluenza 3 virus, M haemolytica, and P multocida SC at median ages of 2 and 70 days, respectively; the control group (37) remained unvaccinated until weaning. All calves received the 7-way MLV vaccine SC at median ages of 217 (weaning) and 231 days. Serum neutralizing antibody (SNA) titers against BHV1, BVDV1, and BRSV and intranasal IgA concentrations were determined at median ages of 2, 70, 140, 217, and 262 days. Cell-mediated immunity (CMI) against BHV1, BRSV, BVDV1, and P multocida was determined for 16 calves/group. RESULTS At median ages of 140 and 217 days, BVDV1 SNA titers were significantly higher for the SC70 group than those for the other groups. Intranasal IgA concentrations and CMI increased over time for all groups. Vaccination at weaning increased SNA titers and CMI in all groups. CONCLUSIONS AND CLINICAL RELEVANCE SC administration of an MLV vaccine to 70-day-old calves significantly increased BVDV1 antibody titers before weaning.

Humoral immunity and injection-site reactions in cattle vaccinated with a multivalent clostridial vaccine administered via subcutaneous injection or via transdermal needle-free injection.

OBJECTIVE To evaluate injection-site reactions and serum antibody titers in cattle vaccinated with a clostridial vaccine administered SC or via needle-free transdermal injection. ANIMALS Sixteen 11-to 12-month-old Herefords. PROCEDURES Cattle in 2 groups were vaccinated on days 0 and 28 with a commercially available multivalent clostridial vaccine administered SC or transdermally Injection sites and serum antibody titers were evaluated at several time points after vaccination. Serum antibody titers against Clostridium perfringens beta toxin, Clostridium novyi alpha toxin, and Clostridium septicum alpha toxin were determined with an ELISA; Clostridium sordellii lethal toxin titers were determined with a toxin neutralization assay. RESULTS Firm injection site swellings developed in cattle vaccinated via either route; however, at several observation times, swellings were significantly smaller in cattle vaccinated transdermally. Serum titers against C perfringens beta toxin and C septicum alpha toxin did not differ significantly between groups after vaccination; serum titers against C novyi alpha toxin were not significantly different between groups, except on days 10 and 56, when they were significantly higher in cattle vaccinated SC. Titers against C sordellii lethal toxin were significantly higher in cattle vaccinated SC on several days after vaccination, but titers were not significantly different after day 49. CONCLUSIONS AND CLINICAL RELEVANCE Transdermal vaccination of cattle resulted in serum antibody titers that were similar to those induced via SC vaccination and caused injection-site reactions that were significantly smaller. Transdermal vaccination may be an effective technique for vaccinating cattle against clostridial diseases while minimizing local reactions that often develop after clostridial vaccination.