Dairy management practices associated with multi-drug resistant fecal commensals and in cull cows: a machine learning approach.

Background: Understanding the effects of herd management practices on the prevalence of multidrug-resistant pathogenic and commensals spp. in dairy cattle is key in reducing antibacterial resistant infections in humans originating from food animals. Our objective was to explore the herd and cow level features associated with the multi-drug resistant, and resistance phenotypes shared between , and spp.

Bayesian estimation of diagnostic accuracy of fecal culture and PCR-based tests for the detection of in California cull dairy cattle.

Epidemiological studies of low prevalence disease problems are often hindered by the high cost of diagnostic testing. The objective of this study was to evaluate PCR screening of both individual and pooled fecal samples from culled dairy cows for the A gene of followed by culture to determine if the sensitivity and specificity were comparable to the results from traditional culture methods applied to individual samples. Cows from six different dairies were sampled in all four seasons.

Bovine cardiac mesothelial hyperplasia: a common incidental finding in adult cattle.

Cardiac mesothelial hyperplasia forming pale plaque lesions on the epicardial surface is a common incidental finding in the hearts of aged humans. A similar phenomenon with a more papillary appearance has also been reported as an incidental finding in dogs and mice. These lesions are believed to occur in response to friction between the epicardium and overlying pericardium.

Environmental sampling to assess the bioburden of subspecies in drylot pens on California dairies.

subspecies (MAP) is a bacterium that can cause substantial economic losses in infected dairy herds due to reduced milk production and increased cow-replacement costs. In order to control MAP in dairies with drylot pens, a standardized environmental sampling protocol to quantify MAP in fecal slurry was developed based on an existing protocol for freestall pens. Specifically, following a 24 h hold of the flush, a grab sample of approximately 10 ml of fecal slurry was collected every 1 m along the flush lane of the drylot pens, avoiding individual cow fecal pats.

Association between herd management practices and antimicrobial resistance in spp. from cull dairy cattle in Central California.

Background: In this study cull dairy cows from six California dairy herds were sampled seasonally over the course of a year. The objectives were to determine the prevalence of antimicrobial resistant (AMR) spp. shed in cull cow feces, and the factors associated with fecal shedding of AMR and multidrug resistant (MDR) .

Avian pulmonary proteinosis: six cases and a review of the literature.

Pulmonary alveolar proteinosis (PAP) is a disease of surfactant clearance in which functional abnormalities in alveolar macrophages lead to accumulation of surfactant within alveoli in mammals. Histologic examination of 6 avian autopsies, including 4 chickens, a turkey, and a cockatiel, revealed accumulation of hypereosinophilic densely arrayed lamellar material in the lungs that was magenta by periodic acid-Schiff stain and diastase resistant. Transmission electron microscopy of the proteinaceous material in 2 cases demonstrated alternating electron-dense and electron-lucent lamellae that formed whorls and had a regular periodicity of 6-14 nm, consistent with pulmonary surfactant.

Polycystic liver in two adult llamas.

Polycystic liver is usually considered an incidental finding in human and veterinary medicine. Two unrelated adult llamas ( Lama glama) with a history of marked anorexia and weight loss were received for autopsy and diagnostic workup. The main gross change in the liver of both animals was multiple variably sized cysts randomly distributed throughout the parenchyma.

Pathology of blackleg in cattle in California, 1991-2015.

Blackleg is an infectious disease of cattle and rarely other ruminants, produced by Clostridium chauvoei and characterized by necrotizing myositis. In most cases of blackleg, the large muscles of the pectoral and pelvic girdles are affected, with other skeletal muscles and the heart involved less frequently. We studied 29 blackleg cases selected from the archives of the California Animal Health and Food Safety Laboratory, 1991-2015.

Multiple episodes of 1080 (sodium monofluoroacetate) intoxication in a California calf-raising operation.

Over a 1-y period, a California calf-raising operation experienced 4 separate episodes of sudden death in 4-6-mo-old steers. Each episode occurred in 1-3 contiguous pens on 1 of 3 properties owned by the operation, but eventually all 3 properties were involved. In each episode, animals appeared normal at the evening feeding but at the subsequent morning feeding were found dead or dying.

Parapoxviral vulvovaginitis in Holstein cows.

A group of Holstein first-calved heifers developed small pustules and ulcers on the vulva and in the vagina during the first 1-4 wk postpartum. The lesions varied from small red pinpoint foci to pustules and ulcers, 3-5 mm diameter. Some ulcers coalesced to form large ulcerated areas up to 15 mm diameter.

Cecal infarction in neonatal calves.

Cecal infarction is an uncommon lesion in calves that results in localized peritonitis and, on occasion, perforation with secondary diffuse peritonitis and death. This lesion in calves has not been described previously. We reviewed the postmortem cases of cecal infarction in dairy calves ≤30 d of age that had been submitted over the course of 5 y to the Tulare branch of the California Animal Health and Food Safety Laboratory System.

Epidemiology of Salmonella sp. in California cull dairy cattle: prevalence of fecal shedding and diagnostic accuracy of pooled enriched broth culture of fecal samples.

Background: The primary objective of this cross-sectional study was to estimate the crude, seasonal and cull-reason stratified prevalence of Salmonella fecal shedding in cull dairy cattle on seven California dairies. A secondary objective was to estimate and compare the relative sensitivity (Se) and specificity (Sp) for pools of 5 and 10 enriched broth cultures of fecal samples for Salmonella sp. detection.

Off-site rearing of heifers reduces the risk of Mycobacterium avium ssp. paratuberculosis ELISA seroconversion and fecal shedding in a California dairy herd.

The objective of this cohort study was to evaluate whether rearing dairy heifers at different premises than the dairy of origin (off-site) reduced the risk of Mycobacterium avium ssp. paratuberculosis (MAP) infection more effectively than rearing on the dairy of origin (on-site). From 2003 to 2005, 3 cohorts of Jersey heifers were born on a single California dairy, with heifers in the first cohort raised on-site until first calving (n=797); heifers in the second cohort raised on-site until approximately 5 mo of age and off-site until about 1 to 2 mo precalving (n=791); and heifers in the third cohort raised off-site from d 1 until about 1 to 2 mo before first calving (n=797).

Congenital portosystemic shunts and hepatic encephalopathy in goat kids in California: 11 cases (1999-2012).

Between 1999 and 2012, 11 cases of congenital portosystemic shunts (cPSS) resulting in hepatic encephalopathy were diagnosed in goat kids necropsied at the California Animal Health and Food Safety Laboratory System and at the Department of Pathology, Immunology & Microbiology, School of Veterinary Medicine, University of California-Davis. Affected animals included 6 females and 5 males of various breeds including Boer (5/11), Nigerian Dwarf (1/11), Saanen (1/11), Toggenburg (1/11), and mixed-breed (3/11) aged between 1.5 months and 11 months, submitted live (2/11) or dead (9/11) for necropsy.

Jejunal hematoma in cattle: a retrospective case analysis.

Sixteen years of adult cattle submissions to the California Animal Health and Food Safety Laboratory System were examined and data captured from cases with anaerobic cultures of intestinal content. Analysis was performed to determine if there were statistical differences between case submission types (nonbloody intestinal content [129 cases], bloody intestinal content [134 cases], and jejunal hematoma [JH; 51 cases]) for the presence of Clostridium perfringens (314 cases), C. perfringens toxinotypes (35 cases), and C.

Systemic Bovine herpesvirus 1 infections in neonatal dairy calves.

During a 6-year period, 62 out of 2,980 calves examined (2.08%) between 1-30 days of age had lesions consistent with Bovine herpesvirus 1 infection. The mean and median age of affected calves was 14 days of age.

Cost-effectiveness of diagnostic strategies to identify Mycobacterium avium subspecies paratuberculosis super-shedder cows in a large dairy herd using antibody enzyme-linked immunosorbent assays, quantitative real-time polymerase chain reaction, and bacterial culture.

Diagnostic strategies to detect Mycobacterium avium subsp. paratuberculosis (MAP) super-shedder cows in dairy herds have been minimally studied. The objective of the current study was to compare the cost-effectiveness of strategies for identification of MAP super-shedders on a California dairy herd of 3,577 cows housed in free-stall pens.

Low rate of detectable in utero transmission of Mycobacterium avium subspecies paratuberculosis in a dairy herd with a low prevalence of Johne's disease.

In an effort to correlate the likelihood of in utero transmission of Mycobacterium avium subsp. paratuberculosis (MAP), the causal organism of Johne's disease, with the test status of the dam, tissues from neonatal calves borne to known test status cows were cultured for the presence of MAP. Tissues from a single calf borne to a test-positive cow shedding large numbers of organisms in the feces were positive for MAP.

Malignant edema in postpartum dairy cattle.

Five cases of postparturient vulvovaginitis and metritis in cattle caused by Clostridium septicum (malignant edema) are described in the current report. The diagnosis was established based on detection of C. septicum by culture and fluorescent antibody test.

Isolation of Mycobacterium avium subsp. paratuberculosis from waste milk delivered to California calf ranches.

The objective of this study was to determine if viable Mycobacterium avium subsp. paratuberculosis (MAP) was present in waste milk delivered and fed to calves on California calf ranches. Four calf-raising facilities in the Central Valley of California that fed pasteurized waste milk to calves were enrolled.

Antimicrobial resistance in Salmonella enterica subspecies enterica serovar Dublin from dairy source calves in the central San Joaquin Valley, California (1998-2002).

The present study describes antimicrobial resistance patterns of Salmonella enterica subspecies enterica serovar Dublin (S. Dublin) in clinical submissions from calves and temporal and farm-type trends in antimicrobial resistance patterns of the isolates. A total of 300 isolates of S.

Use of age and milk production data to improve the ability of enzyme-linked immunosorbent assay test results to predict Mycobacterium avium ssp. paratuberculosis fecal culture status.

Cows from 2 California dairies were tested for paratuberculosis at the end of lactation by using fecal culture and a commercially available serum enzyme-linked immunosorbent assay (ELISA) test kit. Individual cow characteristics and production variables were evaluated along with ELISA testing results as predictors of fecal culture status. In multivariable logistic regression analysis, age and a herd-standardized version of 305-day mature equivalent (305 ME) milk production were significant predictors of fecal culture status after adjusting for herd, quarter of the study year, and ELISA sample-to-positive (S/P) ratio.

Evaluation of microbial culture of pooled fecal samples for detection of Mycobacterium avium subsp paratuberculosis in large dairy herds.

Objective: To evaluate sensitivity of microbial culture of pooled fecal samples for detection of Mycobacterium avium subsp paratuberculosis (MAP) in large dairy herds and assess the use of the method for estimation of MAP prevalence.

Animals: 1,740 lactating cows from 29 dairy herds in California.

Procedure: Serum from each cow was tested by use of a commercial ELISA kit.