Initial steps in defining the environment of the prepuce of the bull by measuring pH and temperature.

OBJECTIVE: To determine the baseline pH and temperature of the preputial cavity of bulls. METHODS: We enrolled 55 bulls ranging in age from 15 to 84 months. The preputial temperature and pH were measured by insertion of temperature and pH probes, respectively, into the preputial orifice prior to routine breeding soundness examinations. Information was obtained from owners regarding the diet of each bull and categorised as one of three categories: forage only, grain supplemented or silage supplemented. RESULTS: The average temperature of the prepuce was 37.81°C ± 1.76 and the median pH of the prepuce was 8.45 (6.35-9.46). Preputial temperatures of the bull weakly correlated with ambient temperatures (rs = -0.29, P = 0.028). The preputial pH of silage-fed bulls was significantly lower than that of bulls fed forage only (P = 0.025) or grain-supplemented diets (P = 0.002). The median preputial pH of bulls fed a silage-based diet was 7.6 (6.3-8.9) compared with a median pH 8.7 (7.8-9.1) for bulls fed forage-based diets or a median of 8.5 (7.7-9.4) for those given grain-supplemented diets. CONCLUSION: Diet and ambient temperature can, respectively, affect pH and the temperature in the prepuce. Further studies to describe and understand the microbiota of the prepuce and penis may assist in developing treatments for diseases of the genital tract in bulls.

Double-outlet right ventricle with an intact interventricular septum and concurrent hypoplastic left ventricle in a calf.

A 3-day-old Hereford heifer calf presented for evaluation of lethargy and dyspnea, with persistent hypoxia despite supplemental oxygen therapy. A grade III/VI right apical systolic murmur was noted during cardiac auscultation. Echocardiography revealed a double-outlet right ventricle with an intact interventricular septum and concurrent hypoplastic left ventricle and tricuspid valve dysplasia. Post-mortem examination revealed additional congenital anomalies of ductus arteriosus, patent foramen ovale, and persistent left cranial vena cava. This report illustrates the use of echocardiographic images to diagnose a double-outlet right ventricle with an intact interventricular septum and a hypoplastic left ventricle in a calf.

Comparison of reproductive performance of primiparous dairy cattle following revaccination with either modified-live or killed multivalent viral vaccines in early lactation.

The objective of this randomized clinical trial was to compare the effect of revaccination in primiparous dairy cows with modified live viral (MLV) or killed viral (KV) vaccines containing bovine viral diarrhea virus (BVDV) and bovine herpesvirus-1 (BoHV-1) on (1) pregnancy rate following estrus synchronization-timed artificial insemination (TAI), (2) serum progesterone concentrations, and (3) serum neutralizing antibody titers at revaccination and at TAI. Primiparous dairy cows (n=692) that had been previously vaccinated with 4 doses of MLV vaccine as calves or heifers were randomized to receive either an MLV or a KV vaccine between 21 and 28 d in milk and 17 d before initiation of a double-Ovsynch-TAI protocol. Serum was collected within the double-Ovsynch protocol for determination of progesterone concentrations, and at vaccination and TAI for serum neutralizing antibody titers. Ultrasound pregnancy determinations were made at 30 and 60 d after TAI. No differences in pregnancy rates were observed between cows receiving MLV vaccine (44%; n=326) or KV vaccine (43%; n=336). No differences were observed in serum progesterone concentrations during a double-Ovsynch-TAI protocol between cows receiving MLV and KV vaccines. No differences were observed in BVDV 1 or BVDV 2 antibody titers at vaccination and TAI between cows receiving MLV or KV vaccine; however, BoHV-1 antibody titers were greater at TAI in cows receiving KV vaccine. Overall response to vaccination-defined as the percent of all individual cows that had any detectable increase in antibody titer from vaccination to TAI-was 39% for BVDV 1, 45% for BVDV 2, and 61% for BoHV-1. In this research, use of an MLV vaccine did not impede reproduction when revaccination was performed between 21 and 28 DIM and just before enrollment in an estrus synchronization-TAI program in primiparous dairy cows; however, response to vaccination as defined by increases in virus-specific antibody titers could be considered less than ideal for this population of cattle.

Experimental transmission of Corynebacterium pseudotuberculosis biovar equi in horses by house flies.

BACKGROUND: The route of Corynebacterium pseudotuberculosis infection in horses remains undetermined, but transmission by insects is suspected. OBJECTIVES: To investigate house flies (Musca domestica L.) as vectors of C. pseudotuberculosis transmission in horses. ANIMALS: Eight healthy, adult ponies. METHODS: Randomized, controlled, blinded prospective study. Ten wounds were created in the pectoral region where cages for flies were attached. Three ponies were directly inoculated with C. pseudotuberculosis. Four ponies were exposed for 24 hours to 20 hours C. pseudotuberculosis-inoculated flies. One negative control pony was exposed to noninoculated flies. Ponies were examined daily for swelling, heat, pain, and drainage at the inoculation site. Blood was collected weekly for CBC and biochemical analysis, and twice weekly for synergistic hemolysis inhibition titers. RESULTS: Clinical signs of local infection and positive cultures were observed in 7/7 exposed ponies and were absent in the negative control. In exposed ponies, peak serologic titers (1:512 to 1:2,048) were obtained between days 17 and 21. Seroconversion was not observed in the negative control. Neutrophil counts were higher in the positive and fly-exposed groups than in the negative control (P = .002 and P = .005) on day 3 postinoculation. Serum amyloid A concentrations were higher in the positive control than in the negative control and fly-exposed ponies on days 3 (P < .0001) and 7 (P = .0004 and P = .0001). No differences were detected for other biochemical variables. CONCLUSIONS AND CLINICAL IMPORTANCE: House flies can serve as mechanical vectors of C. pseudotuberculosis and can transmit the bacterium to ponies.

Evaluation of methods to improve the diagnosis of systemic inflammation in alpacas.

BACKGROUND: The stoic nature of alpacas and limitations of current diagnostic tests make early recognition of inflammatory diseases in this species challenging. OBJECTIVES: In a model of mild systemic inflammation, this study evaluated the utility of different clinical and clinicopathologic variables as accurate predictors of inflammation in alpacas. ANIMALS: Twelve clinically healthy alpacas were randomly assigned to equal-sized treatment (TG) and control (CG) groups. After collection of initial blood samples (0 hour), lipopolysaccharide (LPS; 20 µg/kg/24 h) or saline was administered by SC osmotic mini-pumps (OMP) for 96 hours. Additional blood samples were collected at 12, 18, 24, 36, 48, 72, 96, 120, 144, and 240 hours and differential leukocyte counts and concentrations of globulin, albumin, iron, haptoglobin, and serum amyloid A were measured. RESULTS: Mild swelling was observed at OMP implantation sites in both groups. Other clinical signs of systemic inflammation were not observed. Total leukocytes, neutrophils, albumin, and globulin concentrations were not significantly different between groups. Compared with CG-alpacas, TG-alpacas had fewer lymphocytes (P = .0322), more band neutrophils (P = .0087), and higher neutrophil/lymphocyte ratios (P = .0295) during the first 96 hours of the study. During LPS administration, serum iron concentrations were significantly decreased in TG-alpacas (P < .0001). Haptoglobin concentrations of TG-animals exceeded those of CG-animals after removal of OMP (P = .0056). Serum amyloid A was not detectable in alpacas in this study. CONCLUSION AND CLINICAL IMPORTANCE: These results indicated that neutrophil/lymphocyte ratios and serum iron concentrations are early indicators of inflammation in alpacas. Additional research is needed to evaluate the acute phase protein responses of alpacas.

Distribution of bovine viral diarrhoea virus antigen in persistently infected white-tailed deer (Odocoileus virginianus).

Infection with bovine viral diarrhoea virus (BVDV), analogous to that occurring in cattle, is reported rarely in white-tailed deer (Odocoileus virginianus). This study evaluated the distribution of BVDV antigen in persistently infected (PI) white-tailed deer and compared the findings with those from PI cattle. Six PI fawns (four live-born and two stillborn) from does exposed experimentally to either BVDV-1 or BVDV-2 were evaluated. Distribution and intensity of antigen expression in tissues was evaluated by immunohistochemistry. Data were analyzed in binary fashion with a proportional odds model. Viral antigen was distributed widely and was present in all 11 organ systems. Hepatobiliary, integumentary and reproductive systems were respectively 11.8, 15.4 and 21.6 times more likely to have higher antigen scores than the musculoskeletal system. Pronounced labelling occurred in epithelial tissues, which were 1.9-3.0 times likelier than other tissues to contain BVDV antigen. Antigen was present in >90% of samples of liver and skin, suggesting that skin biopsy samples are appropriate for BVDV diagnosis. Moderate to severe lymphoid depletion was detected and may hamper reliable detection of BVDV in lymphoid organs. Muscle tissue contained little antigen, except for in the cardiovascular system. Antigen was present infrequently in connective tissues. In nervous tissues, antigen expression frequency was 0.3-0.67. In the central nervous system (CNS), antigen was present in neurons and non-neuronal cells, including microglia, emphasizing that the CNS is a primary target for fetal BVDV infection. BVDV antigen distribution in PI white-tailed deer is similar to that in PI cattle.

Safety and efficacy of vaccination of seronegative bulls with modified-live, cytopathic bovine viral diarrhea viruses.

The objectives were to vaccinate peri-pubertal bulls with a modified-live vaccine consisting of cytopathic BVDV strains Singer and 296 and evaluate the resulting: (a) transient shed of modified-live, cytopathic BVDV in semen; (b) risk of prolonged testicular infection; and (c) protection against subsequent testicular infection due to viral challenge. Seronegative, peri-pubertal bulls were vaccinated subcutaneously with a standard dose of vaccine (n=11) or were maintained as unvaccinated controls (n=11). Forty-nine days after vaccination, all bulls were intranasally inoculated with a noncytopathic field strain of BVDV. Semen and testicular biopsies collected after vaccination and challenge were assayed for BVDV using virus isolation, reverse transcription-nested PCR, or immunohistochemistry, and the identity of viral strains was determined by nucleotide sequencing of PCR products. Vaccination of peri-pubertal bulls with this vaccine caused a short-term, transient shed of only the type 1a strain of modified-live, cytopathic BVDV in semen for up to 10d after vaccination. The vaccine did not cause prolonged testicular infection. Vaccination with this product prevented development of prolonged testicular infections after subsequent exposure to a field strain of BVDV.