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1.
Vet Med Int ; 2019: 3202184, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31341609

RESUMEN

The objective of this trial was to evaluate a test-and-cull approach to controlling bovine leukemia virus (BLV) in US dairy herds with a low BLV prevalence. Despite worldwide distribution of the virus, 21 nations have eradicated BLV from their dairy cattle and are currently considered 'BLV-free.' In contrast, the US has attempted no industry-wide BLV control programs and has experienced an increase in BLV prevalence among dairy cows to about 40%. This raises concerns about production efficiency, herd health, and sustainability. In a pilot field trial with three Midwestern-US dairy herds, a test-and-cull approach using ELISA screening of milk samples was successful in reducing BLV prevalence in two herds. In the third herd, BLV prevalence increased following the introduction of infected heifers that were raised at an out-of-state calf raising facility. This trial demonstrated that a test-and-cull approach to BLV control can be successful in US dairy herds with low BLV prevalence, but ongoing surveillance is necessary to prevent reintroduction of the virus.

2.
J Am Vet Med Assoc ; 254(11): 1335-1340, 2019 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-31067187

RESUMEN

OBJECTIVE: To determine the prevalence of bovine leukemia virus (BLV) in beef bulls; evaluate the presence of BLV provirus DNA in blood, smegma, and semen samples; and analyze whether blood BLV proviral load was associated with differential blood cell counts. DESIGN: Observational cross-sectional study. ANIMALS: 121 beef bulls ≥ 2 years old from 39 Michigan herds. PROCEDURES: Blood, smegma, and semen samples were collected from each bull during a routine breeding soundness examination. An ELISA was used to detect serum anti-BLV antibodies. A coordination of common motifs-quantitative PCR assay was used to detect BLV provirus DNA in blood, smegma, and semen samples. Bulls with positive results on both the BLV serum ELISA and coordination of common motifs-quantitative PCR assay were considered infected with BLV. RESULTS: 19 of 39 (48.7%) herds and 54 of 121 (44.6%) bulls were infected with BLV. Provirus DNA was detected in the blood of all 54 and in smegma of 4 BLV-infected bulls but was not detected in any semen sample. Lymphocyte count was significantly greater in BLV-infected bulls than in uninfected bulls. The proportion of BLV-infected bulls with lymphocytosis (16/54 [29.6%]) was greater than the proportion of uninfected bulls with lymphocytosis (6/67 [9%]). Lymphocyte count was positively associated with BLV proviral load in BLV-infected bulls. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that almost half of beef bulls and herds were infected with BLV, and BLV provirus DNA was detected in the smegma of some BLV-infected bulls. Bulls may have an important role in BLV transmission in beef herds.

3.
Theriogenology ; 126: 187-190, 2019 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-30557791

RESUMEN

Bovine leukosis is a chronic lymphoproliferative disorder that leads to significant economic losses in the beef and dairy industries. The major route of virus transmission is believed to be iatrogenic through the transfer of blood containing infected lymphocytes. In addition, BLV proviral DNA has been identified in nasal secretions, saliva, milk, colostrum, semen and smegma; however, natural transmission of BLV through these secretions has not been clearly demonstrated. The use of bulls for natural breeding has been identified as a risk factor in BLV infected dairy herds. However, the risk of BLV-infected bulls transmitting the virus is unknown. The objective of this study was to evaluate the potential for BLV transmission during natural breeding between a BLV-infected bull and uninfected heifers. Forty healthy, BLV seronegative, and proviral-negative beef heifers were randomly assigned to one of two groups: control heifers (n = 20) exposed to a BLV seronegative and proviral negative bull and challenged heifers (n = 20) exposed to a BLV seropositive and proviral-positive bull. Each group was housed with the bull for a period of 38 days in a 5-acre pasture to replicate the housing of commercial beef cattle during the breeding season. Blood samples were collected from heifers at -60, -30 and 0 days prior to breeding and day 30, 60 and 90 after the breeding period ended. Blood samples were tested for BLV antibodies by ELISA and BLV proviral DNA by CoCoMo-qPCR. New infection was not detected by ELISA or CoCoMo-qPCR in any of the challenge or control heifers at any time point during the study. Based on these results, BLV infected bulls that are healthy and aleukemic may not be a significant risk of BLV transmission during a defined breeding season.


Asunto(s)
Leucosis Bovina Enzoótica/transmisión , Virus de la Leucemia Bovina/aislamiento & purificación , Animales , Cruzamiento/métodos , Bovinos , Leucosis Bovina Enzoótica/epidemiología , Femenino , Factores de Riesgo , Esmegma/virología
4.
Vet Med Int ; 2018: 5831278, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30534354

RESUMEN

Objective: To estimate current US herd-level and animal-level prevalence of bovine leukemia virus (BLV) in dairy cows and characterize epidemiologic features. Design: Cross-sectional observational study design and survey. Animals: 4120 dairy cows from 103 commercial dairy herds in 11 states across the US. Procedures: Milk samples were collected from dairy cows through routine commercial sampling and tested for anti-BLV antibodies by antibody capture ELISA. Based on the ELISA results of a sample of an average of 40 cows per herd, within-herd apparent prevalence (AP) was estimated by a directly standardized method and by a lactation-weighted method for each herd. Within-herd AP estimates were summarized to give estimates of US herd-level and animal-level AP. Differences in AP by lactation, region, state, breed, and herd size were examined to characterize basic epidemiologic features of BLV infection. Results: 94.2% of herds had at least one BLV antibody positive cow detected. The average within-herd standardized AP was 46.5%. Lactation-specific AP increased with increasing lactation number, from 29.7% in first lactation cows to 58.9% in 4th and greater lactation cows. Significant differences were not observed based on region, state, breed, or herd size. Conclusions and Clinical Relevance: These results are consistent with a historical trend of increasing prevalence of BLV among US dairy cattle. Given the findings of other studies on the negative impacts of BLV infection on milk production and cow longevity, these findings are clinically relevant for veterinarians counseling dairy clients on the risks of BLV to their herds.

5.
Front Vet Sci ; 4: 112, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28770217

RESUMEN

Bovine leukemia virus (BLV) is a retrovirus that is highly prevalent in US dairy herds: over 83% are BLV infected and the within-herd infection rate can be almost 50% on average. While BLV is known to cause lymphosarcomas, only 5% or fewer infected cattle will develop lymphoma; this low prevalence of cancer has historically not been a concern to dairy producers. However, more recent research has found that BLV+ cows without lymphoma produce less milk and have shorter lifespans than uninfected herdmates. It has been hypothesized that BLV infection interferes with normal immune function in infected cattle, and this could lead to reduced dairy production. To assess how naturally infected BLV+ cows responded to a primary and secondary immune challenge, 10 BLV+ and 10 BLV- cows were injected subcutaneously with keyhole limpet hemocyanin (KLH) and dimethyldioctadecylammonium bromide. B- and T-cell responses were characterized over the following 28 days. A total of 56 days after primary KLH exposure, cows were re-injected with KLH and B- and T-cell responses were characterized again over the following 28 days. BLV+ cows produced less KLH-specific IgM after primary immune stimulation; demonstrated fewer CD45R0+ B cells, altered proportions of CD5+ B cells, altered expression of CD5 on CD5+ B cells, and reduced MHCII surface expression on B cells ex vivo; exhibited reduced B-cell activation in vitro; and displayed an increase in BLV proviral load after KLH exposure. In addition, BLV+ cows had a reduced CD45R0+γδ+ T-cell population in the periphery and demonstrated a greater prevalence of IL4-producing T cells in vitro. All together, our results demonstrate that both B- and T-cell immunities are disrupted in BLV+ cows and that antigen-specific deficiencies can be detected in BLV+ cows even after a primary immune exposure.

6.
Front Microbiol ; 8: 818, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28536568

RESUMEN

Campylobacter jejuni, a leading cause of gastroenteritis in humans, is a foodborne pathogen that can reside in chickens, pigs, and cattle. Because resistance to fluoroquinolones and macrolides, which are commonly used to treat human infections, has emerged in C. jejuni, it is imperative to continously monitor resistance patterns and examine the genetic variation in strains from human infections and animal reservoirs. Our previous study of C. jejuni from human campylobacteriosis cases showed a significantly higher rate of tetracycline resistance compared to national trends, and identified multilocus sequence type (ST)-982 and a history of cattle contact to be associated with tetracycline resistance. To further investigate these associations, we conducted a cross-sectional study to determine the frequency of antimicrobial resistance and examine the genetic diversity of C. jejuni recovered from 214 cattle at three Michigan herds. Overall, the prevalence of C. jejuni was 69.2% (range: 58.6-83.8%) for the three farms, and 83.7% (n = 113) of isolates were resistant to one or more antimicrobials. Resistance to only tetracycline predominated among the cattle isolates (n = 89; 65.9%) with most resistant strains belonging to ST-459 (96.5%) or ST-982 (86.4%). Among the 22 STs identified, STs 459 and 982 were more prevalent in one feedlot, which reported the use of chlortetracycline in feed upon arrival of a new herd. PCR-based fingerprinting demonstrated that the ST-982 isolates from cattle and humans had identical banding patterns, suggesting the possibility of interspecies transmission. Resistance to macrolides (1.5%) and ciprofloxacin (16.3%) was also observed; 14 of the 22 ciprofloxacin resistant isolates represented ST-1244. Together, these findings demonstrate a high prevalence of antimicrobial resistant C. jejuni in cattle and identify associations with specific genotypes. Continuous monitoring and identification of risk factors for resistance emergence are imperative to develop novel methods aimed at decreasing pathogen persistence in food animal reservoirs and the frequency of resistant infections in humans.

7.
Vet Immunol Immunopathol ; 182: 125-135, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27863543

RESUMEN

Bovine leukemia virus (BLV) is a retrovirus that is widely distributed across US dairy herds: over 83% of herds are BLV-infected and within-herd infection rates can approach 50%. BLV infection reduces both animal longevity and milk production and can interfere with normal immune health. With such a high prevalence of BLV infection in dairy herds, it is essential to understand the circumstances by which BLV negatively affects the immune system of infected cattle. To address this question, BLV- and BLV+ adult, lactating Holstein dairy cows were vaccinated with Bovi-Shield GOLD® FP® 5 L5 HB and their immune response to vaccination was measured over the course of 28days. On day 0 prior to vaccination and days 7, 14 and 28 post-vaccination, fresh PBMCs were characterized for T and B cell ratios in the periphery. Plasma was collected to measure titers of IgM, IgG1 and IgG2 produced against bovine herpesvirus 1 (BHV1), Leptospira hardjo and L. pomona, as well as to characterize neutralizing antibody titers produced against BHV1 and bovine viral diarrhea virus types 1 and 2. On day 18 post-vaccination, PBMCs were cultured in the presence of BHV1 and flow cytometry was used to determine IFNγ production by CD4+, CD8+ and γδ T cells and to investigate CD25 and MHCII expression on B cells. BLV+ cows produced significantly lower titers of IgM against BHV1, L. hardjo and L. pomona and produced lower titers of IgG2 against BHV1. γδ T cells from BLV+ cows displayed a hyper reactive response to stimulation in vitro, although no differences were observed in CD4+ or CD8+ T cell activation. Finally, B cells from BLV+ cows exhibited higher CD25 expression and reduced MHCII expression in response to stimulation in vitro. All together, data from this study support the hypothesis that BLV+ cows fail to respond to vaccination as strongly as BLV- cows and, consequently, may have reduced protective immunity when compared to healthy BLV- cows.


Asunto(s)
Leucosis Bovina Enzoótica/inmunología , Leucosis Bovina Enzoótica/prevención & control , Virus de la Leucemia Bovina/inmunología , Animales , Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , Linfocitos B/inmunología , Vacunas Bacterianas/uso terapéutico , Bovinos , Femenino , Inmunidad Celular , Inmunidad Humoral , Inmunoglobulina M/sangre , Activación de Linfocitos , Subgrupos de Linfocitos T/inmunología , Factores de Tiempo , Vacunación/veterinaria , Vacunas Virales/uso terapéutico
8.
Appl Environ Microbiol ; 82(16): 5049-56, 2016 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-27342555

RESUMEN

UNLABELLED: Shiga toxin-producing Escherichia coli (STEC) is an important foodborne pathogen that can cause hemorrhagic colitis and hemolytic-uremic syndrome. Cattle are the primary reservoir for STEC, and food or water contaminated with cattle feces is the most common source of infections in humans. Consequently, we conducted a cross-sectional study of 1,096 cattle in six dairy herds (n = 718 animals) and five beef herds (n = 378 animals) in the summers of 2011 and 2012 to identify epidemiological factors associated with shedding. Fecal samples were obtained from each animal and cultured for STEC. Multivariate analyses were performed to identify risk factors associated with STEC positivity. The prevalence of STEC was higher in beef cattle (21%) than dairy cattle (13%) (odds ratio [OR], 1.76; 95% confidence interval [CI], 1.25, 2.47), with considerable variation occurring across herds (range, 6% to 54%). Dairy cattle were significantly more likely to shed STEC when the average temperature was >28.9°C 1 to 5 days prior to sampling (OR, 2.5; 95% CI, 1.25, 4.91), during their first lactation (OR, 1.8; 95% CI, 1.1, 2.8), and when they were <30 days in milk (OR, 3.9; 95% CI, 2.1, 7.2). These data suggest that the stress or the negative energy balance associated with lactation may result in increased STEC shedding frequencies in Michigan during the warm summer months. Future prevention strategies aimed at reducing stress during lactation or isolating high-risk animals could be implemented to reduce herd-level shedding levels and avoid transmission of STEC to susceptible animals and people. IMPORTANCE: STEC shedding frequencies vary considerably across cattle herds in Michigan, and the shedding frequency of strains belonging to non-O157 serotypes far exceeds the shedding frequency of O157 strains, which is congruent with human infections in the state. Dairy cattle sampled at higher temperatures, in their first lactation, and early in the milk production stage were significantly more likely to shed STEC, which could be due to stress or a negative energy balance. Future studies should focus on the isolation of high-risk animals to decrease herd shedding levels and the potential for contamination of the food supply.


Asunto(s)
Derrame de Bacterias , Enfermedades de los Bovinos/epidemiología , Infecciones por Escherichia coli/veterinaria , Síndrome Hemolítico-Urémico/veterinaria , Escherichia coli Shiga-Toxigénica/fisiología , Animales , Bovinos , Enfermedades de los Bovinos/microbiología , Estudios Transversales , Industria Lechera , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/microbiología , Femenino , Síndrome Hemolítico-Urémico/epidemiología , Síndrome Hemolítico-Urémico/microbiología , Michigan/epidemiología , Prevalencia
9.
J Am Vet Med Assoc ; 244(8): 914-22, 2014 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-24697767

RESUMEN

The subclinical impact of bovine leukemia virus (BLV) on the sustainability of the US dairy industry is only now being fully recognized. Findings of recent longitudinal studies conducted in Michigan dairy herds were consistent with the results of previous studies in showing that within-herd prevalence of BLV-infected cattle was negatively associated with milk production and cow longevity. Risk factors relating to routes of hematogenous transmission such as the use of shared hypodermic needles, shared reproductive examination sleeves, and natural breeding were associated with BLV within-herd prevalence. Few US dairy producers know the prevalence of BLV-infected cattle in their herds or are aware of the insidious economic impact of BLV or the options for BLV control. As an increasing number of countries eradicate BLV from their cattle populations, restrictions on the movement of US cattle and cattle products will likely increase. Veterinarians should be aware of recent developments for screening serum and milk samples for antibodies against BLV and the results of research regarding the economic impact of BLV so they can advise their dairy clients of available alternatives for monitoring and controlling BLV infection.


Asunto(s)
Anticuerpos Antivirales/aislamiento & purificación , Leucosis Bovina Enzoótica/prevención & control , Virus de la Leucemia Bovina/fisiología , Bienestar del Animal , Animales , Anticuerpos Antivirales/sangre , Bovinos , Industria Lechera , Leucosis Bovina Enzoótica/epidemiología , Femenino , Inocuidad de los Alimentos , Longevidad , Masculino , Michigan , Leche/química , Factores de Riesgo
10.
J Am Vet Med Assoc ; 243(1): 131-5, 2013 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-23786202

RESUMEN

OBJECTIVE: To determine the effect of bovine leukemia virus (BLV) infection on absolute neutrophil and lymphocyte concentrations in healthy lactating Holstein dairy cattle. DESIGN: Observational cross-sectional survey. ANIMALS: 311 healthy lactating Holstein dairy cattle from herds in Michigan (n = 2), Wisconsin (1), Iowa (1), and Pennsylvania (1). PROCEDURES: Whole and anticoagulated (EDTA) blood samples were collected. Serum samples were tested for antibody against BLV by use of an ELISA. Absolute neutrophil and lymphocyte concentrations were measured in EDTA blood samples with an automated hematology analyzer and manual differential cell counts. RESULTS: 208 cows tested positive and 103 cows tested negative for anti-BLV antibodies. Neutrophil concentration was not significantly different between BLV-positive versus BLV-negative cattle. The distribution of lymphocyte concentration was positively skewed for the entire cow population (n = 311) and the BLV-positive subset (208). In contrast, lymphocyte concentration distribution was approximately normal for BLV-negative cows (n = 103). Consequently, the presence or absence of BLV infection strongly influenced the calculated neutrophil-to-lymphocyte concentration ratio. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that absolute lymphocyte concentration is significantly affected by BLV infection in dairy cattle. Accordingly, hematologic reference intervals should be derived from healthy animals that are not infected with BLV and patient BLV status must be considered for meaningful interpretation of lymphocyte concentration. We recommend that the calculated neutrophil-to-lymphocyte ratio be abandoned because it does not provide more information than direct comparison of patient absolute leukocyte concentration with updated reference intervals from healthy BLV-negative cattle.


Asunto(s)
Leucosis Bovina Enzoótica/sangre , Virus de la Leucemia Bovina , Linfocitos/fisiología , Neutrófilos/fisiología , Animales , Bovinos , Estudios Transversales , Industria Lechera , Leucosis Bovina Enzoótica/epidemiología , Leucosis Bovina Enzoótica/patología , Estados Unidos/epidemiología
11.
J Dairy Res ; 79(4): 445-50, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22963749

RESUMEN

The prevalence of bovine leukaemia virus (BLV) was determined in 113 Michigan dairy herds by ELISA testing for anti-BLV antibodies in milk. Additionally, an interview regarding management practices with cooperating herd managers identified farm-level variables thought to be associated with prevalence of BLV. Twenty-three risk factors (P ≤ 0·1) were identified on one-way ANOVA or simple linear regression. Multivariate analysis identified several management practices whose predictive value for increased prevalence of BLV may relate to transmission among herd mates, e.g. reuse of hypodermic needles, lack of fly control, gouge dehorning and increased use of injections in dry cows. Additionally, exclusive breeding of heifers with artificial insemination was associated with decreased BLV prevalence, as compared with at least some use of natural service by a bull. Although intervention studies are needed before causal relationships can be concluded, and unaccounted variables related to transmission exist among dairy herds, these findings suggest management practices that may help dairy producers reduce the transmission of BLV within their herds.


Asunto(s)
Anticuerpos Antivirales/sangre , Leucosis Bovina Enzoótica/transmisión , Leucosis Bovina Enzoótica/virología , Virus de la Leucemia Bovina/inmunología , Animales , Cruzamiento , Bovinos , Industria Lechera/métodos , Leucosis Bovina Enzoótica/epidemiología , Ensayo de Inmunoadsorción Enzimática/veterinaria , Femenino , Inseminación Artificial/veterinaria , Factores de Riesgo
12.
Vet Med Int ; 2012: 350374, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22577607

RESUMEN

Enzootic bovine leukosis is a contagious disease of cattle caused by the retrovirus, bovine leukemia virus (BLV) and is the most common cause of malignant neoplasm in cattle. In order to facilitate surveillance of this disease in dairy herds, we developed a method to combine ELISA of milk collected during routine production testing with a prescribed sampling of cows that is independent of the proportion of cows within each lactation. In 113 Michigan dairy herds, milk samples from ten cows in each of the 1st, 2nd, 3rd, and ≥4th lactations were analyzed for anti-Bovine Leukemia Virus (BLV) antibodies by milk ELISA. For each herd, a BLV herd profile (BHP) was calculated as the simple average of the percent of BLV-positive cows within each of the four lactation groups. The mean BHP for all herds was 32.8%, with means of 18.5, 28.8, 39.2, and 44.8% of 1st, 2nd, 3rd, and ≥4th lactation animals infected, respectively. In eight herds, we determined the correlation between the BHP, and true herd prevalence by testing the entire lactating herd (r = 0.988, P < 0.0001). The BHP allows discrimination of lactation-specific BLV prevalence within a dairy herd, to help identify risk factors and management plans that may be important in transmission of BLV.

13.
J Vet Med Educ ; 38(4): 404-7, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-22130416

RESUMEN

Recognizing the crucial role of veterinarians in mitigating antimicrobial resistance (AMR), the Centers for Disease Control and Prevention (CDC) has funded the development of a suite of educational materials to promote the responsible veterinary medical use of antimicrobials. An open-access, Web-based multimedia curriculum regarding antimicrobial resistance in veterinary practice was thus created. The antimicrobial-resistance learning site (AMRLS) for veterinary medical students was completed and made available for use in January 2011 (http://amrls.cvm.msu.edu/). Designed for integration into existing veterinary medical courses, the AMRLS is also a resource for continuing education for practicing veterinarians, animal scientists, and food-animal industry specialists. This Web site emphasizes the mechanisms by which AMR emerges and spreads, the significant role of veterinarians in mitigating AMR, and the need to preserve the efficacy of antibiotics for future generations.


Asunto(s)
Antibacterianos/farmacología , Farmacorresistencia Microbiana , Educación en Veterinaria/métodos , Internet , Animales , Curriculum , Humanos , Práctica de Salud Pública , Facultades de Medicina Veterinaria , Estudiantes del Área de la Salud , Estados Unidos
14.
Vet Med Int ; 2011: 915747, 2011 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-21547233

RESUMEN

Thirteen bovine leukemia virus- (BLV-) negative and 22 BLV-positive Holstein cows were immunized with J5 Escherichia coli bacterin at dry off, three weeks before calving, during the second week after calving, and three weeks after the third immunization. Serum was collected before the initial immunization, immediately before the third and fourth immunizations, and 21 days after the fourth immunization. Anti-J5 E. coli IgM, IgG1, and IgG2 titers were determined by ELISA. Anti-J5 E. coli IgM titers did not differ significantly (P = .98) between groups. Increases in anti-J5 E. coli IgG1 titers were higher in the BLV-negative cows (P = .057). Geometric mean anti-J5 E. coli IgG2 titers increased fourfold in the BLV-negative cows, which was significantly higher (P = .007) than the twofold increase in the BLV-positive cows. Cattle infected with BLV may have impaired serologic responses following immunization with J5 bacterin, and response may differ according to antibody isotype.

15.
Vet Med Int ; 20102010 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-20885927

RESUMEN

An age-matched case-control study was initiated to determine the major risk factors associated with CKD in cats and dogs and to determine what clinical signs cat and dog owners observed before their veterinarian diagnosed their pet with CKD. When compared to controls, the feline cases were more likely to have had polydipsia and polyuria in the year before the owners' cats were diagnosed with CKD. In the dogs, increased water intake, increased urination, small size and a recent history of weight loss and bad breath were noticed by the dog owners before veterinary CKD diagnosis. Dog owners recognized abnormal drinking and urination behavior over half a year before their pet's veterinary diagnosis with CKD, and they recognized weight loss almost 4 months before CKD diagnosis. Bad breath was noticed 1.2 years before recognition of CKD by a veterinarian. Given that earlier CKD diagnosis should have been possible in most cases, clinical trials should proceed to measure the efficacy of early interventions.

16.
Prev Vet Med ; 94(3-4): 264-71, 2010 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-20129684

RESUMEN

The Veterinary Medical Database (VMDB) is a summary of veterinary medical records from North American veterinary schools, and is a potential source of disease surveillance information for companion animals. A retrospective record search from four U.S. university veterinary teaching hospitals was used to calculate crude disease rates. Our objectives were to evaluate the utility of the database for disease surveillance purposes by comparing the utility of two methodologies for creating disease categories, and to evaluate the database for evidence of referral bias. Summaries of the medical records from November 2006 to October 2007 for 9577 dogs and 4445 cats were retrieved from VMDB for all canines and felines treated at Kansas State University, Colorado State University, Purdue University and Ohio State University. Disease frequency, computed as apparent period-prevalence and as the percentage of veterinary visits, was compiled for 30 disease categories that were formulated by one of two methods. To assess the possible impact of referral bias, disease rates were compared between animals residing in zip codes within 5 miles of the hospitals (zone 1) and those animals living at more distant locations (zone 2). When compared to zone 1 animals, disease conditions commonly associated with primary veterinary care were reduced by 29-76% within zone 2, and selected diseases generally associated with more specialized care were increased from 46 to 80% among zone 2 animals. The major differences in disease prevalence seen between zones suggests that substantial referral bias may exist, and that adjustment on the basis of geographical proximity to the university teaching hospitals may be useful in reducing this type of selection bias in the VMDB, thereby improve the accuracy of prevalence estimates and enhancing the utility of this database for purposes of disease surveillance.


Asunto(s)
Enfermedades de los Gatos/epidemiología , Enfermedades de los Perros/epidemiología , Hospitales Veterinarios/estadística & datos numéricos , Derivación y Consulta/estadística & datos numéricos , Vigilancia de Guardia/veterinaria , Medicina Veterinaria/estadística & datos numéricos , Animales , Gatos , Perros , Femenino , Masculino , Vigilancia de la Población , Prevalencia , Estudios Retrospectivos , Estados Unidos/epidemiología , Veterinarios/psicología
17.
J Am Vet Med Assoc ; 236(2): 201-10, 2010 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-20074013

RESUMEN

OBJECTIVE: To compare apparent prevalence and patterns of antimicrobial resistance in Campylobacter spp in feces collected from pigs reared with antimicrobial-free versus conventional production methods in 8 states in the Midwestern United States. DESIGN: Cross-sectional study. SAMPLE POPULATION: 95 swine farms that used antimicrobial-free (n = 35) or conventional (60) production methods. PROCEDURES: Fecal samples from 15 pigs/farm were collected. Biochemical and multiplex-PCR analyses were used to identify Campylobacter spp. The minimal inhibitory concentrations of erythromycin, azithromycin, ciprofloxacin, nalidixic acid, gentamicin, and tetracycline for these organisms were determined by use of a commercially available antimicrobial gradient strip. The data were analyzed by use of population-averaged statistical models. RESULTS: Campylobacter spp were isolated from 512 of 1,422 pigs. A subset (n = 464) of the 512 isolates was available for antimicrobial susceptibility testing. The apparent prevalence of Campylobacter spp isolates from pigs on conventional farms (35.8%) and antimicrobial-free farms (36.4%) did not differ significantly. Resistances to azithromycin, erythromycin, and tetracycline were significantly higher on conventional farms (70.0%, 68.3%, and 74.5%, respectively) than antimicrobial-free farms (20.1%, 21.3%, and 48.8%, respectively). Resistances to azithromycin, erythromycin, and tetracycline declined as the number of years that a farm was antimicrobial-free increased. CONCLUSIONS AND CLINICAL RELEVANCE: Production method did not affect the apparent prevalence of Campylobacter spp on swine farms. However, antimicrobial-free farms had a significantly lower prevalence of antimicrobial resistance. Although cessation of antimicrobial drug use will lower resistance over time, investigation of other interventions designed to reduce resistance levels is warranted.


Asunto(s)
Antibacterianos/administración & dosificación , Infecciones por Campylobacter/veterinaria , Campylobacter/efectos de los fármacos , Farmacorresistencia Bacteriana , Enfermedades de los Porcinos/microbiología , Animales , Antibacterianos/farmacología , Infecciones por Campylobacter/epidemiología , Infecciones por Campylobacter/microbiología , Pruebas de Sensibilidad Microbiana , Medio Oeste de Estados Unidos/epidemiología , Prevalencia , Porcinos , Enfermedades de los Porcinos/epidemiología
18.
Am J Vet Res ; 71(1): 120-4, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20043791

RESUMEN

OBJECTIVE: To determine effects of injection site on antibody response to J5 Escherichia coli bacterin. ANIMALS: 28 adult Holstein cows. PROCEDURES: Cows were randomly assigned as control cattle (n = 4 cows), not administered J5 E coli bacterin; 3X (8), administered 3 doses of bacterin SC in the left side of the neck; 5XN (8), administered 5 doses of bacterin SC in the left side of the neck; or 5XSR (8), administered 5 doses of bacterin SC sequentially in the left side of the neck, right side of the neck, right side of the thorax, left side of the thorax, and left side of the neck. Blood samples were collected from the cows to determine anti-J5 E coli IgG1 and IgG2 concentrations. RESULTS: Vaccinated cows had higher mean serum anti-J5 E coli IgG1 concentrations than did control cows. The 5XN and 5XSR cows had higher mean serum anti-J5 E coli IgG1 concentrations than did 3X cows. Additionally, 5XSR cows had higher mean serum anti-J5 E coli IgG1 concentrations than did 5XN cows. Vaccinated cows had higher mean serum anti-J5 E coli IgG2 concentrations than did control cows. The 5XN and 5XSR cows had higher mean serum anti-J5 E coli IgG2 concentrations than did 3X cows. The 5XSR cows had higher mean serum anti-J5 E coli IgG2 concentrations than did all other groups at 84 days after the fifth vaccination. CONCLUSIONS AND CLINICAL RELEVANCE: Sequential doses of core-antigen bacterins administered at different anatomic locations may improve antibody response in dairy cattle.


Asunto(s)
Anticuerpos Antibacterianos/sangre , Vacunas Bacterianas/administración & dosificación , Vacunas Bacterianas/inmunología , Infecciones por Escherichia coli/veterinaria , Escherichia coli/inmunología , Inmunoglobulina G/sangre , Animales , Bovinos , Esquema de Medicación , Infecciones por Escherichia coli/prevención & control , Femenino
19.
J Vet Med Educ ; 35(2): 199-202, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18723803

RESUMEN

Many reports have highlighted the need for the veterinary profession to fill critical shortages of veterinarians in public health and food safety. Michigan State University's College of Veterinary Medicine offers educational programs within the professional veterinary curriculum, as well as graduate degree programs, to meet these societal needs. Within the scope of the professional veterinary curriculum, educational opportunities in public health include clerkships in veterinary public health and an innovative Web-based curriculum on judicious use of antimicrobials. For graduate degree programs, Michigan State University has a memorandum of understanding with the University of Minnesota for the Master of Public Health degree and an innovative Online Professional Master of Science in Food Safety degree program. A new option available is the opportunity for veterinary students to pursue the Master of Science in Food Safety concurrently with the DVM (DVM/MS in Food Safety). These educational programs will prepare graduates to meet societal needs in public health and food safety.


Asunto(s)
Educación de Postgrado/métodos , Educación en Salud Pública Profesional , Educación en Veterinaria/métodos , Industria de Alimentos/educación , Conducta Cooperativa , Curriculum , Microbiología de Alimentos , Humanos , Internet , Michigan , Minnesota , Preceptoría , Escuelas de Salud Pública , Facultades de Medicina Veterinaria , Universidades
20.
J Am Vet Med Assoc ; 232(10): 1521-9, 2008 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-18479243

RESUMEN

OBJECTIVE: To determine factors that influenced culling or death of cows with left displaced abomasum (LDA) subsequent to correction by a roll-and-toggle (R&T) procedure or via laparotomy. DESIGN: Cohort study. ANIMALS: 810 Holstein dairy cows with LDA. PROCEDURES: Data regarding method of repair and risk factors for survival after correction of LDA were collected during a 1-year period. Outcomes were compared at days 14 and 60 after LDA correction for 3 groups of cattle (veterinarians performed R&T [V-R&T], herd personnel performed R&T [H-R&T], and veterinarians performed surgical repair via laparotomy [V-Surg]). RESULTS: Survival rates 14 days after LDA correction for the V-R&T, H-R&T, and V-Surg groups were 87% (286/329), 81% (327/403), and 85% (66/78), respectively. At 60 days after LDA correction, survival rates for the V-R&T, H-R&T, and V-Surg groups were 79% (260/329), 71% (286/403), and 73% (57/78), respectively. Multivariable analysis indicated that factors positively associated with failure to remain in the herd at 60 days after LDA correction included current mastitis status, history of a previous LDA, high preoperative risk, and correction of LDA by herd personnel rather than by a veterinarian. CONCLUSIONS AND CLINICAL RELEVANCE: Correction of LDA by veterinarians via an R&T procedure yielded results that were generally comparable to those for correction by veterinarians via laparotomy. Although survival rates at days 14 and 60 after surgery differed significantly between the V-R&T and H-R&T groups, herd personnel in this study used the R&T procedure to correct LDA and achieved survival rates within the range for those of practicing veterinarians.


Asunto(s)
Abomaso/anomalías , Enfermedades de los Bovinos/mortalidad , Laparotomía/veterinaria , Gastropatías/veterinaria , Medicina Veterinaria/métodos , Abomaso/cirugía , Animales , Bovinos , Enfermedades de los Bovinos/cirugía , Estudios de Cohortes , Femenino , Laparotomía/métodos , Laparotomía/mortalidad , Análisis Multivariante , Complicaciones Posoperatorias/mortalidad , Complicaciones Posoperatorias/veterinaria , Factores de Riesgo , Gastropatías/mortalidad , Gastropatías/cirugía , Tasa de Supervivencia , Resultado del Tratamiento
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