Coinfection with bovine viral diarrhea virus and Mycoplasma bovis in feedlot cattle with chronic pneumonia

Chronic, antibiotic-resistant pneumonia, sometimes with concurrent polyarthritis, occurs in feedlot cattle in western Canada. The prevalence of Mycoplasma bovis, bovine viral diarrhea virus, and Haemophilus somnus was determined by using immunohistochemical staining of lung and heart tissue from 2 groups of animals with this history. Mycoplasma bovis antigen was present in 44/48 cases submitted between 1995 and 1998 (retrospective group) and 15/16 of cases from 1999 (prospective group), and was associated with pulmonary necrosis. Bovine viral diarrhea virus antigen was present in association with microscopic vascular lesions in 31/48 retrospective and 9/16 of prospective cases. Types Ib and II bovine viral diarrhea virus were isolated from 4/16 prospective cases. Haemophilus somnus antigen was present in heart, lung, or both of 15/48 retrospective and 8/16 prospective cases. The results suggest that there may be synergism between bovine viral diarrhea virus and M. bovis in this pneumonia with arthritis syndrome.     

Angiostrongylus vasorum infection in 2 dogs from Newfoundland

Described are the first antemortem diagnosis made via fecal examination using the Baermann technique and the first postmortem recovery of endemic Angiostrongylus vasorum in dogs from North America, specifically the Avalon peninsula of Newfoundland. In one dog, A. vasorum was recovered and identified at postmortem; gross and histologic lesions are described.     

Increase in milk yield following eprinomectin treatment at calving in pastured dairy cattle

Gastrointestinal nematodes rarely cause signs of clinical disease in adult cattle. However, they have been shown to exert a negative impact on production in lactating animals, as seen by improved production following elimination of the worms using anthelmintics. A double blind, randomized clinical trial was performed in 28 dairy herds in Canada. The objective of the study was to evaluate the effect of treatment with eprinomectin pour-on solution (IVOMEC EPRINEX) at calving on production, in cattle that have had some exposure to pasture. Cows were randomly allocated to treatment or placebo in blocks of 10, based on calving date, and treated with eprinomectin or placebo on the day of calving.Information on milk production was obtained from all animals, as well as recorded cases of selected diseases. Milk production results from the Canadian dairy herd management system database were analysed using a mixed model with herd as a random effect and test within-cow as a repeated measurement. Test day milk yields from the first six tests after treatment were included in the model, representing a period of between 180 and 200 days in milk (dim). Treated cows produced an additional 0.94 kg of milk per day when compared to the controls over this period. The production effect was independent of calving season, age of the animal and geographical location. No effect of treatment was seen on milk composition, somatic cell count (scc) or on the selected health parameters that were recorded for all included animals.Monthly fecal egg counts (FEC) were performed for eight randomly selected animals in each herd. The observed FEC were low in this study, with a range from 0 to 419 trichostrongyle type eggs per 5g (ep5g) of feces in animals not yet treated with the anthelmintic. The average count was 9.8 and the median was 1.0. FECs dropped immediately after calving and stayed lower for at least 100 days in treated animals when compared to controls.In conclusion, gastrointestinal nematodes appear to have an effect on milk production in Canadian dairy cows that have had some degree of pasture exposure. Eliminating the present subclinical parasite burdens produced a consistent increase in milk production that can yield economic benefits for the dairy producer.     

The Interaction of Endochitinase, A Synthetic Peptide and Resveratrol in Controlling Fungi in vitro

The efficacy of two-way combinations of Trichoderma endochitinase (CHIT42), synthetic peptide ESF12 and resveratrol upon the control of growth of Botrytis cinerea and Penicillium digitatum were evaluated in vitro. CHIT42 had effective concentration for 50% growth inhibition (EC₅₀) values of 1.5 and 0.5 µM against B. cinerea and P. digitatum, respectively. CHIT42 also caused swelling, hyperbranching and bursting of P. digitatum at concentrations as low as 0.003 µM. The EC₅₀ values of ESF12 were 30.9 and 29.2 µM against B. cinerea and P. digitatum, respectively. Resveratrol had EC₅₀ values of 178.6 and 343.2 µM against B. cinerea and P. digitatum, respectively. Combinations of CHIT42 + ESF12, CHIT42 + resveratrol and ESF12 + resveratrol showed additive activity (interaction ratios between 0.5 and 1.5) against B. cinerea and P. digitatum.     

Use of a commercial methylcellulose medium with and without recombinant bovine granulocyte colony-stimulating factor for culturing bovine bone marrow cells

A commercial methylcellulose culture medium, with and without the addition of recombinant bovine granulocyte colony-stimulating factor (rbG-CSF), was utilized for culturing bovine bone marrow cells in a colony-forming unit assay. Bone marrow mononuclear cells were isolated and cultured in a commercial methylcellulose-based medium containing several recombinant human cytokines. Cultures were prepared with and without 100 ng/mL of rbG-CSF. The size and mean number of colonies per plate from culture days 3 to 9 were compared. We concluded that bovine bone marrow colony growth was supported by this culture medium. The addition of rbG-CSF yielded larger and more numerous colonies. There were significantly more colonies on day 3 (P < 0.001), day 4 (P < 0.001), and day 5 (P = 0.03) with rbG-CSF. Both culture media had the highest colony counts on day 5.     

Wound healing in the veterinary rehabilitation patient.

Wound healing is a biologically complex cascade of predictable overlap-ping events and is a natural restorative response to tissue injury. The biologic process for wound healing is the same for all wounds, although the specific mechanisms may vary. This article reviews the wound heal-ing process, discussing factors that may delay normal healing progression and potential modalities and treatments to aid healing.     

Management of complicated wounds.

Most injuries, including those with significant tissue loss, can be successfully managed with proper therapy. With delayed healing, potential causes for the delay, such as sequestra, foreign bodies, and excessive motion,should be determined and treated to permit complete wound resolution.Horses have the innate ability to heal rapidly; however, minor injuries can quickly turn into complicated wounds, given the severity of the inciting trauma and the less than ideal environment in which the horses are housed.Wound management must focus on a combination of timely surgical and medical intervention to ensure the best potential outcome.     

Effects of noncytopathic type 2 Bovine viral diarrhea virus on the proliferation of bone marrow progenitor cells

The purpose of this study was to investigate the effects of isolates of noncytopathic type 2 Bovine viral diarrhea virus (ncpBVDV-2) of high and low virulence on the proliferation of bone marrow progenitor cells. Holstein calves 6 to 7 mo old and BVDV-na?ve were inoculated intranasally with a BVDV isolate of high virulence (HV24515), a BVDV isolate of low virulence (LV11Q), or uninfected cell culture medium. Serial bone marrow and peripheral blood samples were collected before and after inoculation. Bone marrow mononuclear cells (BMMCs) were isolated and cultured for 5 d, and the mean number of colony-forming unit-granulocyte-macrophage (CFU-GM) colonies was determined. Tritiated (3H)-thymidine uptake by BMMCs was determined to indicate overall proliferative capacity. Virus isolation was done on concurrent samples of BMMCs and peripheral blood. Virus was isolated from BMMCs and peripheral blood buffy-coat cells as early as day 2 or 3 after inoculation. Neutropenia developed in both groups inoculated with a BVDV isolate. However, in the calves given LV11Q, neutrophil counts rebounded earlier in response to increased proliferation of BMMCs, whereas the response was delayed in calves given HV24515. Thymidine uptake was significantly increased (P = 0.0047) in BMMCs after inoculation compared with before inoculation in the calves given LV11Q but not in those given HV24515 or in the control calves. The median number of CFU-GM colonies was significantly decreased (P = 0.0164) after inoculation compared with before inoculation in the calves given HV24515, whereas there was no significant difference in the calves given LV11Q or in the control calves. The data support the hypothesis that the prolonged neutropenia observed in calves given HV24515 results at least in part from decreased proliferative capacity of bone marrow progenitor cells.     

COMPARATIVE GROWTH OF Isochrysis galbana PARKE AND Isochrysis aff. galbana,CLONE T-ISO AT POUR TEMPERATURES AND THREE LIGHT INTENSITIES

The growth of a temperate and a tropical strain of Isochrysis was studied at four temperatures and three light intensity levels. All algal cultures were grown in an enriched artificial seawater medium under constant illumination and were bubbled with air enriched with 0.1% CO₂. Culture density (cells/ml) was measured periodically during exponential growth. Average growth rates for each combination of temperature and light intensity are presented as doublings/day. Observations of growth under the various culture conditions indicate that T-ISO (tropical strain) grows rapidly over a much broader range of temperatures than does I. galbana. Variations in growth at different light intensity levels suggest that the optimum light level increases as a function of temperature for T-ISO and that the growth of I. galbana is inhibited by high levels of light (1500 μW/cm²). The relative value of both strains as food for larval and juvenile oysters and the advantages and limitations of large scale culture are discussed.     

RADIOTHERAPY OF THE EXPREMITIES

Physical and patient factors relative to orthovoltage and supervoltage radiotherapy treatment planning for extremity lesions are described. The radiation tolerance of the limb and the pathogenesis of radiation injury are reviewed. Prevention of radiotherapy injury by modification of physical and patient factors in the treatment protocol is discussed. The treatment of radiotherapy complications encountered in the extremities is sumarized.