Isolation and differentiation of bovine mammary gland progenitor cell populations

OBJECTIVE: To isolate bovine mammary gland cells with stem cell characteristics. SAMPLE POPULATION: Monolayers of bovine mammary gland cells. PROCEDURE: Mammary gland cell populations were separated by use of selected media supplements. Phenotypic characteristics were examined via light and transmission electron microscopy. Cellular expression of casein and connexin 43 was identified immunohistochemically. A scrape-loading and dye transfer assay was used to examine the mammary gland cell populations for homogenous gap junctional intercellular communication (GJIC). RESULTS: Subpopulations of mammary gland cells grown in vitro are classified on the basis of their distinct morphologic features and ability to communicate via gap junctions. Ultrastructurally, 2 morphologically distinct cell types were classified as type I and II cells. Type I cells were small light undiffertiated cells and large light undifferentiated cells that were deficient in functional gap junctions (as is characteristic of stem cells). Type II cells included large light differentiated cells and terminally differentiated cells; GJIC was functional in type II cells. Type II cells had cytoplasmic expression of connexin 43, whereas, type I cells did not. All cells expressed casein. CONCLUSIONS AND CLINICAL RELEVANCE: Subpopulations of bovine mammary gland cells with stem cell characteristics were identified. Phenotypic differences are observed among type I bovine mammary gland cells with stem cell characteristics. Gap junctional intercellular communication may be necessary for the differentiation of stem cells. Characterization of bovine mammary gland stem cells and their progeny may provide a new tool with which to study mammary gland health.     

Use of a polymerase chain reaction assay to detect bovine herpesvirus type 2 DNA in skin lesions from cattle suspected to have pseudo-lumpy skin disease

Beef cattle from a herd in north Alabama were examined because of an outbreak of nonfatal skin disease characterized by discrete circumscribed areas of inflammation that developed on the skin from the neck to the hips. Areas of inflammation, which tended to be superficial, underwent necrosis and scabbed over. The scabs eventually dropped off leaving discrete, round, whitish, hairless lesions that were 1.2 to 2.5 cm diameter. Because clinical signs were consistent with those expected with pseudo-lumpy skin disease (PLSD) caused by bovine herpesvirus type 2 (BHV-2), samples from 16 representative animals were submitted for BHV-2 testing. All 16 animals were seropositive for BHV-2, but the virus could not be isolated from skin biopsy specimens or buffy coat samples. Results of a polymerase chain reaction assay incorporating primers designed to amplify 2 DNA sequences from BHV-2 were positive for 3 of the 10 cattle, suggesting that skin lesions in these cattle were a result of PLSD. Our findings suggest that PLSD may be more common and widespread in the United States than suggested by the frequency with which BHV-2 has been isolated from cattle with PLSD-like skin lesions.     

Usefulness, completeness, and accuracy of Web sites providing information on osteoarthritis in dogs

OBJECTIVE: To evaluate the quality of information regarding osteoarthritis (OA) in dogs currently available on the World Wide Web. DESIGN: Survey study. PROCEDURE: 5 search engines were searched with the keywords "dog," "degenerative joint disease," "canine," and "osteoarthritis," and the first 50 sites listed by each search engine were analyzed. Unique Web site addresses were distributed to 3 diplomates of the American College of Veterinary Surgeons, who provided a standardized evaluation of each site. RESULTS: 30 unique Web sites were evaluated. Twenty (66%) provided information consistent with conventional knowledge as outlined in textbooks and peer-reviewed literature, 8 (27%) provided experimental or anecdotal information in addition to conventional knowledge, and 2 (7%) provided misleading information. Mean scores for overall usefulness of the information provided in regard to clinical features of and treatment for OA were 1.3 and 1.5, respectively (1 = information of minimal use; 5 = very useful information). Twenty-three (77%) sites encouraged pet owners to seek the advice of a veterinarian. Twenty-three (77%) sites were given overall quality scores < 2, and 7 (23%) were given scores between 2 and 3 (1 = site was counterproductive; 5 = site was very valuable). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that the quality of information currently available on the Web that addresses OA in dogs is questionable. Although most of the sites conveyed some conventional information with reasonable accuracy, the information was incomplete, of minimal use, and often considered counterproductive.     

Evaluation of bacteriologic culture of individual and pooled fecal samples for detection of Mycobacterium paratuberculosis in dairy cattle herds

OBJECTIVES: To determine the sensitivity of bacteriologic culture of pooled fecal samples in detecting Mycobacterium paratuberculosis, compared with bacteriologic culture of individual fecal samples in dairy cattle herds. STUDY DESIGN: Cross-sectional study. ANIMALS: 24 dairy cattle herds. PROCEDURE: Individual and pooled fecal samples were submitted for bacteriologic culture, and results were compared between these groups. RESULTS: Ninety-four and 88% of pooled fecal samples that contained feces from at least 1 animal with high (mean, > or = 50 colonies/tube) and moderate (mean, 10 to 49 colonies/tube) concentrations of M paratuberculosis, respectively, were identified by use of bacteriologic culture of pooled fecal samples. Prevalences of paratuberculosis determined by bacteriologic culture of pooled and individual fecal samples were highly correlated. CONCLUSIONS AND CLINICAL RELEVANCE: Bacteriologic culture of pooled fecal samples provided a valid and cost-effective method for the detection of M paratuberculosis infection in dairy cattle herds and can be used to estimate prevalence of infection within a herd.     

Surgical removal of a mammary adenocarcinoma and a granulosa cell tumor in an African pygmy hedgehog

A 3-year-old, female African pygmy hedgehog (Atelerix albiventris) was referred with a history of hematuria. Hyperglycemia and glucosuria were found at presentation. Mammary adenocarcinoma and a granulosa cell tumor were found and removed surgically. Glucosuria and hematuria resolved, and the hedgehog has done well for 10 mo postoperatively.     

Replication of bluetongue virus and epizootic hemorrhagic disease virus in pulmonary artery endothelial cells obtained from cattle,sheep, and deer

OBJECTIVE: To compare replication of bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV) in pulmonary artery endothelial cells (ECs) obtained from juvenile cattle, sheep, white-tailed deer (WTD; Odocoileus virginianus), and black-tailed deer (BTD; O hemionus columbianus). SAMPLE POPULATION: Cultures of pulmonary artery ECs obtained from 3 cattle, 3 sheep, 3 WTD, and 1 BTD. PROCEDURE: Purified cultures of pulmonary artery ECs were established. Replication, incidence of infection, and cytopathic effects of prototype strains of BTV serotype 17 (BTV-17) and 2 serotypes of EHDV (EHDV-1), and (EHDV-2) were compared in replicate cultures of ECs from each of the 4 ruminant species by use of virus titration and flow cytometric analysis. RESULTS: All 3 viruses replicated in ECs from the 4 ruminant species; however, BTV-17 replicated more rapidly than did either serotype of EHDV. Each virus replicated to a high titer in all ECs, although titers of EHDV-1 were significantly lower in sheep ECs than in ECs of other species. Furthermore, all viruses caused extensive cytopathic effects and a high incidence of cellular infection; however, incidence of cellular infection and cytopathic effects were significantly lower in EHDV-1-infected sheep ECs and EHDV-2-infected BTD ECs. CONCLUSIONS AND CLINICAL RELEVANCE: There were only minor differences in replication, incidence of infection, and cytopathic effects for BTV-17, EHDV-1, or EHDV-2 in ECs of cattle, sheep, BTD, and WTD. It is not likely that differences in expression of disease in BTV- and EHDV-infected ruminants are attributable only to species-specific differences in the susceptibility of ECs to infection with the 2 orbiviruses.     

Evaluation of flunixin meglumine as an adjunct treatment for diarrhea in dairy calves

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 (morbid-days). RESULTS: Calves with fecal blood and treated with a single dose of flunixin meglumine had fewer morbid-days 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.