Viable Mycobacterium avium ssp. paratuberculosis isolated from calf milk replacer.

When advising farmers on how to control Johne's disease in an infected herd, one of the main recommendations is to avoid feeding waste milk to calves and instead feed calf milk replacer (CMR). This advice is based on the assumption that CMR is free of viable Mycobacterium avium ssp. paratuberculosis (MAP) cells, an assumption that has not previously been challenged. We tested commercial CMR products (n = 83) obtained from dairy farms around the United States by the peptide-mediated magnetic separation (PMS)-phage assay, PMS followed by liquid culture (PMS-culture), and direct IS900 quantitative PCR (qPCR). Conventional microbiological analyses for total mesophilic bacterial counts, coliforms, Salmonella, coagulase-negative staphylococci, streptococci, nonhemolytic Corynebacterium spp., and Bacillus spp. were also performed to assess the overall microbiological quality of the CMR. Twenty-six (31.3%) of the 83 CMR samples showed evidence of the presence of MAP. Seventeen (20.5%) tested positive for viable MAP by the PMS-phage assay, with plaque counts ranging from 6 to 1,212 pfu/50 mL of reconstituted CMR (average 248.5 pfu/50 mL). Twelve (14.5%) CMR samples tested positive for viable MAP by PMS-culture; isolates from all 12 of these samples were subsequently confirmed by whole-genome sequencing to be different cattle strains of MAP. Seven (8.4%) CMR samples tested positive for MAP DNA by IS900 qPCR. Four CMR samples tested positive by both PMS-based tests and 5 CMR samples tested positive by IS900 qPCR plus one or other of the PMS-based tests, but only one CMR sample tested positive by all 3 MAP detection tests applied. All conventional microbiology results were within current standards for whole milk powders. A significant association existed between higher total bacterial counts and presence of viable MAP indicated by either of the PMS-based assays. This represents the first published report of the isolation of viable MAP from CMR. Our findings raise concerns about the potential ability of MAP to survive manufacture of dried milk-based products.

Defining colloid osmotic pressure and the relationship between blood proteins and colloid osmotic pressure in dairy cows and calves.

OBJECTIVE: To establish the reference interval for colloid osmotic pressure (COP) in neonatal and adult cattle and to investigate associations between COP and total protein, albumin, or globulin in the two populations sampled. DESIGN: Cross-sectional observational study. SETTING: Animals were sampled on commercial dairy farms in Southern Wisconsin, and samples were processed and analyzed in a clinical pathology laboratory at a university teaching hospital. ANIMALS: Forty adult lactating Holstein cows between 2 and 4 years of age and 40 healthy Holstein calves of both sexes between 2 and 7 days of age. INTERVENTIONS: Adult cows were sampled by coccygeal venipuncture into standard heparinized vacutainer tubes, calves were sampled by jugular venipuncture also into heparinized vacutainer tubes. MEASUREMENTS AND MAIN RESULTS: For adult cows, the mean COP was 22.52 mm Hg, with a standard deviation of 1.0. For calves, the mean COP was 19.6 mm Hg, with a standard deviation of 1.9. Good correlation was demonstrated in adults between COP and albumin concentrations (r(2) = 0.72) and between COP and both total protein concentration (r(2) = 0.74) and globulin (r(2) = 0.65) in calves. For adults, regression plots established best fit relationships of COP = 0.472 (albumin) + 6.49, whereas for calves, two regression equations could be described; COP = 0.305 (globulin) + 8.62, and 0.268 (total plasma protein) + 2.73. CONCLUSIONS: Suggested normal ranges (mean ± 2 standard deviations) for COP in adult lactating dairy cows and calves between 2 and 7 days of age were 21-25 mm Hg and 17-23 mm Hg, respectively.

Timely diagnosis of dairy calf respiratory disease using a standardized scoring system.

Respiratory disease of young dairy calves is a significant cause of morbidity, mortality, economic loss, and animal welfare concern but there is no gold standard diagnostic test for antemortem diagnosis. Clinical signs typically used to make a diagnosis of respiratory disease of calves are fever, cough, ocular or nasal discharge, abnormal breathing, and auscultation of abnormal lung sounds. Unfortunately, routine screening of calves for respiratory disease on the farm is rarely performed and until more comprehensive, practical and affordable respiratory disease-screening tools such as accelerometers, pedometers, appetite monitors, feed consumption detection systems, remote temperature recording devices, radiant heat detectors, electronic stethoscopes, and thoracic ultrasound are validated, timely diagnosis of respiratory disease can be facilitated using a standardized scoring system. We have developed a scoring system that attributes severity scores to each of four clinical parameters; rectal temperature, cough, nasal discharge, ocular discharge or ear position. A total respiratory score of five points or higher (provided that at least two abnormal parameters are observed) can be used to distinguish affected from unaffected calves. This can be applied as a screening tool twice-weekly to identify pre-weaned calves with respiratory disease thereby facilitating early detection. Coupled with effective treatment protocols, this scoring system will reduce post-weaning pneumonia, chronic pneumonia, and otitis media.

Comparison of passive transfer of immunity in neonatal dairy calves fed colostrum or bovine serum-based colostrum replacement and colostrum supplement products.

OBJECTIVE: To compare serum total protein (sTP) and serum IgG (sIgG) concentrations In neonatal calves administered colostrum or a bovine serum-based colostrum replacement (CR) product followed by a bovine serum-based colostrum supplement (CS) product. DESIGN: Randomized controlled clinical trial. ANIMALS: 18 Jersey and 269 Holstein neonatal heifer calves. PROCEDURES: 141 calves were given 4 L of colostrum in 1 or 2 feedings (first or only feeding was provided≤2 hours after birth; when applicable, a second feeding was provided between 2 and 12 hours after birth). Other calves (n=146) were fed 2 L of a CR product≤2 hours after birth and then 2 L of a CS product between 2 and 12 hours after birth. Concentrations of sTP and sIgG were measured 1 to 7 days after birth. Data from cohorts on individual farms and for all farms were analyzed. RESULTS: Mean sTP and sIgG concentrations differed significantly between feeding groups. In calves fed colostrum and calves fed CR and CS products, mean±SD sTP concentration was 5.58±0.67 g/dL and 5.26±0.54 g/dL, respectively, and mean sIgG concentration was 1,868±854 mg/dL and 1,320±620 mg/dL, respectively. The percentage of calves that had failure of passive transfer of immunity (ie, sIgG concentrations<1,000 mg/dL) was not significantly different between groups. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that sequential feeding of bovine serum-based CR and CS products to neonatal calves is an alternative to feeding colostrum for achieving passive transfer of immunity.

Urogenital leiomyosarcoma in an alpaca.

A mass in the pelvic canal of a 4-year-old pregnant alpaca hembra diagnosed as leiomyosarcoma of the urogenital tract was confirmed by biopsy. Following a tube cystotomy, the alpaca was presented 33 d later, 2 d after the tube cystotomy had been dislodged. A dead cria was delivered by caesarean section.

Surgical findings and outcome for dairy cattle with jejunal hemorrhage syndrome: 31 cases (2000-2007).

OBJECTIVE: To describe signalment; surgical findings; short-, medium-, and long-term outcome; and recurrence rate for cattle undergoing celiotomy because of jejunal hemorrhage syndrome (JHS) and to analyze risk factors associated with outcome and recurrence. DESIGN: Retrospective case series. ANIMALS: 31 dairy cattle with JHS. PROCEDURES: Medical records were analyzed. Follow-up information was obtained from owners of cattle surviving until discharge. RESULTS: 18 of 31 (58%) cattle undergoing celiotomy survived to initial discharge. Fifteen (48%) and 13 (42%) were alive 6 and 12 months after discharge, respectively. All 5 deaths within 12 months after discharge were attributed to JHS recurrence. Survival time was 12 to 85 months for the 13 long-term survivors. Six of 7 that died > 12 months after celiotomy did so for reasons unrelated to JHS. Recurrence rate among short-term survivors was 7 of 18; 1 of these survived long-term. A significant proportion of affected cattle were Brown Swiss, compared with proportions for other breeds. Manual massage of the bowel to break down clots was associated with a significantly higher short-term survival rate than was enterectomy or enterotomy. Medium- and long-term survival rate was higher in cattle referred 24 to 48 hours after onset of signs. Length of obstructing blood clots was not associated with outcome. Other factors were not significantly associated with recurrence. CONCLUSIONS AND CLINICAL RELEVANCE: Survival rates were higher than those in other reports. Prompt celiotomy and resolution by use of manual massage were associated with higher survival rates. In this population, JHS recurred in 7 of 18 short-term survivors.

Nocardia arthritidis infection in the distal metaphysis of the metatarsal III and IV bone of a heifer.

CASE DESCRIPTION: A 19-month-old 536.4-kg (1,180-lb) Brown Swiss heifer was referred for evaluation of a firm swelling over the distal aspect of the right metatarsal region and chronic lameness in the right hind limb. CLINICAL FINDINGS: Examination of radiographs of the right metatarsophalangeal joints revealed an expansile, smoothly marginated, cyst-like lesion within the distal metaphysis of the metatarsal III and IV bone. Differential diagnoses included bone abscess, bone cyst, aneurysmal bone cyst, neoplasia, osteomyelitis, and metabolic bone disease. Aerobic microbial culture of the aspirate yielded moderate growth of branching, gram-positive, rod-shaped bacteria, which were presumptively identified as Nocardia spp. The isolate was subsequently identified as Nocardia arthritidis by 16S rRNA gene sequence analysis. TREATMENT AND OUTCOME: The lesion was surgically debrided, lavaged, and bandaged. Exercise was restricted, and systemic and local administration of antimicrobials was instituted. After a communication between the abscess and the metatarsophalangeal joints was iatrogenically created, the extralabel use of aminoglycosides was initiated. The heifer had noticeable clinical improvement within 2 weeks after initial evaluation and reportedly had no evidence of lameness and minimal external blemishes 3 months after the second evaluation. CLINICAL RELEVANCE: To our knowledge, this is the first report on the diagnosis and management of a long-bone abscess attributable to N arthritidis infection in cattle. Complications encountered during treatment and the decision to engage in extralabel use of antimicrobial agents in the heifer described here may serve as a guide for food animal practitioners faced with the treatment of valuable cattle.

Respiratory disease of the bovine neonate.

Respiratory disease is an important problem in bovine neonates. Early detection of clinical disease is challenging. In the newborn calf, mucous membrane color, character and frequency of the respiratory effort, thoracic auscultation, and ability to oxygenate are critical elements of the examination to determine whether or not respiratory disease is present. Within a few days of birth, screening calves for fever, abnormal nasal or ocular discharge, or an inducible cough finds many calves with early respiratory disease. This article describes respiratory conditions in newborn calves that veterinarians are most likely to encounter, along with diagnostic and treatment options that can be applied to both herd investigations and individual animals.

Disease management of dairy calves and heifers.

This article focuses on the most important diseases of dairy calves and heifers and presents clinical approaches that can improve detection, diagnosis, and treatment of herd-based problems. A systematic herd investigation strategy is pivotal to define the problems, understand important risk factors, develop a plan, and make recommendations for disease management accurately. A review of records, colostrum and feeding routines, housing and bedding management, routine procedures, vaccination, and treatment protocols begins the investigation and determines which diagnostic procedures and testing strategies are most useful. Disease management is most effective when the problem source is well defined and the exposure can be limited, calf immunity can be enhanced, or a combination of both. Screening examinations performed regularly or done at strategic time points improves detection of disease, can be used to monitor treatment outcomes, and can avoid disease outbreaks.

Prognostic value of clinicopathologic variables obtained at admission and effect of antiendotoxin plasma on survival in septic and critically ill foals.

This prospective study compared survival rates of critically ill and septic foals receiving 1 of 2 different types of commercial equine plasma and analyzed admission variables as possible predictors of survival. Standardized clinical, hematologic, biochemical, and hemostatic admission data were collected and foals received either conventional commercially available hyperimmune equine plasma or equine plasma specifically rich in antiendotoxin antibodies in a double-blinded, coded fashion. Sepsis was defined as true bacteremia or sepsis score >11. Overall survival rate to discharge was 72% (49/68). Foals that were nonbacteremic and demonstrated a sepsis score of < or = 11 at admission had a 95% (18/19) survival rate. The survival rate to discharge for septic foals was 28/49 (57%), with truly bacteremic foals having a survival rate of 58% (14/24), whereas that for nonbacteremic, septic foals was 56% (14/25). Sensitivity and specificity for sepsis score >11 as a predictor of bacteremia were 74 and 52%, respectively. For the entire study population, a higher survival rate to discharge was documented for those foals receiving hyperimmune plasma rich in antiendotoxin antibodies (P = .012, odds ratio [OR] 6.763, 95% confidence interval [CI]: 1.311, 34.903). Administration of plasma rich in antiendotoxin antibodies also was associated with greater survival in septic foals (P = .019, OR 6.267, 95% CI: 1.186, 33.109). Statistical analyses demonstrated that, among 53 clinical and clinicopathologic admission variables, high sepsis score (P < .001), low measured IgG concentration (P = .01), high fibrinogen concentration (P = .018), low segmented neutrophil count (P = .028), and low total red blood cell numbers (P = .048) were the most significant predictors of overall mortality.

Changes of blood biochemical values in ponies recovering from hyperlipemia in Japan.

Hyperlipemia in horses is a disorder of lipid metabolism peculiar to ponies. This study reports changes of blood biochemical values from the acute to the postconvalescent phases in 3 Shetland ponies with hyperlipemia in Japan. Diseased ponies (all 7 to 9 years old, in late pregnancy, and obese) were fed in the same farm. The periods of their hospitalizations ranged from 30 to 45 days. Twelve well-conditioned ponies (3 to 13 years old) around parturition were used to establish baseline values for blood test results. Main clinical findings in the affected ponies were depression, dysphagia, anorexia, ventral edema and milky-appearing plasma. Hypertriglyceridemia (40- to 70-fold rise of controls) was found in the acute phase of the disease in the affected ponies, and was derived from increased very-low density lipoproteins. Aspartate transaminase and gamma-glutamyl transpeptidase activities, blood urea nitrogen, and creatinin concentrations were increased in acute ponies compared to controls, suggesting impairment of liver and kidney functions. However, these values gradually recovered until the end of postconvalescent phase. Hyperinsulinemia was observed in the acute phase of the hyperlipemia of all affected ponies. And an exaggerated insulin response to intravenous glucose was observed in the 2 ponies given intravenous glucose tolerance tests. These findings suggest decreased insulin sensitivity in hyperlipemic ponies.

Biochemical markers of cardiac injury in normal, surviving septic, or nonsurviving septic neonatal foals.

The cardiac biomarkers cardiac troponin T (cTnT) and I (cTnI) and the cardiac isoenzyme of creatine kinase (CKMB) are used extensively in human medicine to diagnose and provide valuable prognostic information in patients with ischemic, traumatic, and septic myocardial injury. We designed a study to establish normal values for these markers in healthy, neonatal foals and to compare them with values obtained from septic neonates in a referral hospital population. The 25th, 50th, 75th, and 95th percentiles for cTnI and CKMB in the healthy-foal population were 0.08, 0.14, 0.25, 0.49 ng/mL and 1.4, 2.3, 4.0, 7.4 ng/mL, respectively. The values obtained for cTnT were frequently (43/52 foals; 83%) below the lower limit of detection of the assay (0.009 ng/mL), but the median and range were 0.009 and 0.009-0.041 ng/mL, respectively. In the septic foal population, the 25th, 50th, 75th, and 95th percentile values for cTnI and CKMB were 0.05, 0.12, 0.22, and 1.10 ng/mL and 2.0, 4.4, 7.8, and 24 ng/mL, respectively. The values obtained for cTnT were less frequently below the lower limit of detection (23/38 foals; 60%) compared with the healthy foal population, and the median and range were 0.009 and 0.009-0.20 ng/mL, respectively. Significantly higher values were observed for cTnT and CKMB in septic foals compared with the healthy neonatal foal population, but there were no differences among septic foals in survivors compared with nonsurvivors. These findings suggest that myocardial injury occurs during septicemia in neonatal foals but that the injury is not associated with survival among septic foals.

A coordinated teaching program for future dairy practitioners at the university of Wisconsin-Madison, School of Veterinary Medicine.

The University of Wisconsin School of Veterinary Medicine (UW-SVM) has implemented a variety of strategies to optimize teaching in dairy herd medicine. These include the provision of opportunities for dairy cow handling and management using a dairy teaching herd for veterinary students throughout the four-year curriculum, exposure for all students in their final year to a substantial first-opinion dairy case load using a private practice-based ambulatory clinic rotation, and, finally, the teaching of dairy herd health management and problem solving in a group of four final-year elective production medicine clinical rotations. On average, since 1986, 32.6% of each graduating class attended at least one elective production medicine rotation, with a range from 19.0% to 43.4%. For those University of Wisconsin students who could be traced, 65% were still actively involved in some aspect of dairy practice, representing a range of between seven and 17 students per year since the start of the program. The advantages and disadvantages of operating a "regional center of excellence" for training students from out-of-state institutions are discussed.