A Prospective Study Of Intravenous Catheter Contamination

A one year prospective study was conducted to determine the association between intravenous catheter contamination and increased dwell time, and to identify any related risk factors. Intravenous catheters obtained from 23 cats and 98 dogs in the Intensive Care Unit at the Ontario Veterinary College with dwell times > 72 hours for the test group (n=58) and < 72 hours for a corresponding control group (n=63) were cultured between April 1991 and March 1992. One hundred and twenty one catheters were cultured, 16 jugular, 99 cephalic, and 6 saphenous. The overall contamination rate was 13 out of 121 catheters cultured (10.7%); 9/63 (14.3%) control and 4/58 (6.9%) test catheters. The bacteria isolated were E.aerogenes, S.aureus (3), P.aeruginosa, P.multocida, and Bacillus sp (7). The Bacillus sp positive catheters (5 control and 2 test) were placed during a five day period, and contaminated gauze squares were identified as the source of infection in these catheters. After these were removed from the study, the group infection rate was 6.9% control and 3.6% test. There was no significant difference between groups and no associated risk factors were identified. We conclude that intravenous dwell time need not be restricted to <72 hours.     

Effect of a new pelleting process on the level of contamination of poultry mash by Escherichia coli and Salmonella

The efficacy of a new pelleting process in eliminating naturally occurring Escherichia coli and salmonella from poultry mash was assessed by comparing the microbial load in raw and processed mash. Instead of using steam produced in a boiler, the new process conditioned mash in an Original Vertical Conditioner with steam and other hot gases generated by direct combustion in a Vaporator. E. coli was isolated from 72-100% of samples of raw mash in all trials, and the mean number of colony-forming units of E. coli/g of samples was 6.8 +/- 4.0 X 10(4). Salmonellae (S. senftenberg, S. bredeney, and S. mbandaka) were isolated from 5-10% of samples of raw mash utilized in three of the seven trials. Within limitations of the sampling and analytical tests utilized, the new pelleting process eliminated salmonella from all mash in which the organism was known to be present but eliminated E. coli in only three trials. The process appeared to be 100% effective against both organisms when mash entering the pellet mill from the conditioner had a temperature of 85.7 C and a moisture content of 14.5% and had been retained and treated with steam and hot gases for 4.1 minutes.     

Cupric oxide needles for grazing cattle consuming low-copper, high-molybdenum forage and high-sulfate water

Oxidized copper wire, commonly referred to as copper oxide needles (CuON), was evaluated using purebred Hereford cows and their calves. Thirty-seven cows were allocated to Cu treatments of 0, 25 or 50 g CuON (79.9% Cu in CuON) with 12, 12 and 13 cows per treatment, respectively; calves within cow treatments were allocated to treatment of 0 and 20 g CuON. Single oral doses of CuON were given at the start of a grazing trial that lasted 92 d. Cows and calves were weighed and blood samples were taken on d 0, 28, 63 and 92; liver biopsies were taken on d 0, 28 and 92 of the grazing trial. Cattle were consuming grass forage with mean concentrations on d 0, 28, 63 and 92 of the grazing trial ranging from 1.6 to 5.5 mg/kg DM for Cu, 2.5 to 5.5 mg/kg DM for Mo and 1.3 to 1.5 g/kg DM for total S. The water consumed by cattle contained 947 mg sulfate per liter (SE = 13.2, n = 4). Body weight of cows and calves was not influenced (P greater than .05) by CuON. Liver Cu was higher (P less than .01) in treated cows and calves but was not different (P greater than .05) between cows dosed with 25 or 50 g CuON. Treatment of cows and calves with CuON had no influence (P greater than .05) on the concentration of Fe or Mo in liver or plasma, the concentration of Cu and ceruloplasmin activity in plasma, or the concentration of Zn in liver. Plasma Zn did not differ (P greater than .05) in cows, but it was higher (P less than .05) in the calves suckling cows treated with CuON. It was concluded that dosing cows and calves with CuON resulted in a higher Cu content of liver but did not adversely influence the metabolism of Fe or Zn or modify the concentration of Mo in the plasma or liver of cows or calves.     

Evaluation of a Killed Vaccine Against Porcine Pleuropneumonia Due to Haemophilus pleuropneumoniae

A bacterin containing serotypes 1 and 5 of Haemophilus pleuropneumoniae was developed for the prevention and the control of porcine pleuropneumonia. It was injected intramuscularly into three groups of ten piglets, the first group with one dose, the second one with two doses and the third one with three doses at two-week intervals. Another group of ten piglets did not receive the vaccine. All the piglets were then challenged by an aerosol of mixed suspensions of H. pleuropneumoniae serotypes 1 and 5. Two and three injections of vaccine completely prevented mortality, whereas half of the control piglets and of those receiving only one dose of vaccine died. All surviving piglets, both control and vaccinated, had severe signs of respiratory disease for at least 36 hours after exposure to challenge. Moreover, vaccination did not induce the production of antibodies at high titers. Local reactions were not noted after vaccination and at postmortem; ten weeks after the challenge, there were no signs of abscess formation or induration.     

The effect of dose and concentration on D-xylose absorption in healthy,immature dogs

Nine combinations of dosages and concentrations of D-xylose were given orally to eight clinically normal, immature dogs. The concentrations and dosages of D-xylose consisted of 5%, 10%, and 20% at 250 mg/kg, 500 mg/kg, and 750 mg/kg. Serum samples were collected at 0, 30, 60, 90, 120, and 180 minutes. Serum xylose was quantitated using the phloroglucinol microassay technique. A peak in serum xylose concentration was seen for each treatment combination at 60 or 90 minutes after dosing. The dosage effect was important in influencing serum xylose values (P < 0.0001). As the test solution dosages increased from 250 mg/kg to 500 mg/kg and 750 mg/kg, serum xylose values (when dosage was analyzed over the length of the entire test) rose linearly (R(2) = 0.98). The treatment combinations of 5% and 20% xylose solutions dosed at 750 mg/kg produced the highest serum xylose values at the 60- and 90-minute peak intervals. The independent effect of concentration was significant (p < 0.001) but was overridden by the stronger dosage effect. Serum xylose concentrations varied little statistically (p > 0.05) when the 5%, 10%, and 20% solutions were compared at a specific dosage.     

Trout mortalities as a result of Streptococcus infection.

Excessive mortalities were experienced in the bigger rainbow trout (Salmo gairdneri) at an efficiently managed trout farm. All tests for known toxins in the feed and water proved to be negative. A faecal Streptococcus which belongs to the Lancefield group D but which could not be identified as belonging to any of the recognized species within this group, was isolated from the spleens, livers and kidneys of affected fish. Pathogenicity studies with this organism proved it to be highly fatal to trout but not to Mozambique bream (Sarotherodon mossambicus), banded bream (Tilapia sparrmenii), carp (Cyprinus carpio) or largemouth bass (Micropterus salmoides). The isolation and biochemical characteristics of the organism are described. The symptoms, gross- and histopathology of this disease are described and discussed. The disease resembles a haemorrhagic septicaemia and appears to be associated with intensification and conditions of stress.     

Relationship between energy and protein intakes and laying characteristics in individually‐caged broiler breeder hens

1. Individually‐caged broiler hens, which had been reared on an advised rationing programme, were fed allowances of 1.88, 1.61, 1.32 or 1.13 MJ apparent metabolisable energy/bird d at four different protein intakes (27, 23, 19.5 or 16.5 g crude protein per bird d) from 21 to 60 weeks of age.

2. Age at first egg, body‐weight gain and egg production were affected by energy allowance. Birds on the lower energy allowances came into lay later than birds on the higher energy allowances and at a lower body weight.

3. Body‐weight gain decreased with decreasing energy allowance. The decrease in egg output in response to decreasing energy allowance resulted from more birds ceasing to lay and fewer birds laying on more than 3 d per week. Similar changes in the distribution of rates of lay were observed on each treatment as the flock aged.

4. The relationship between body‐weight gain and egg number on each treatment was negative from 21 to 36 weeks, but became less consistent with age.

5. Protein intake had little effect on body weight. At the lowest energy allowance, egg number and egg weight decreased with increasing protein allowance. This effect was not observed on the higher energy allowances.     

Effects of energy and protein allowances during lay on the reproductive performance of broiler breeder hens

1. Broiler parent stock were fed daily allowances of 1.88, 1.73 or 1.52 MJ apparent metabolisable energy (AME) per bird at two different daily protein intakes (27, 21.3 g crude protein (CP) per bird) or daily protein intakes of 24.6 and 19.4 g CP per bird at a daily energy intake of 1.88 MJ AME per bird from 21 to 64 weeks of age.

2. Body‐weight gain and carcass fat and water content increased and fertility decreased with increasing energy allowance. Maximum egg production occurred at an energy intake of 1.73 MJ AME/bird d.

3. Differences in egg weight and hatchability were related to differences in both energy and protein intake. The highest egg weight occurred at the highest allowance of energy and protein. Hatchability was depressed where the daily allowances of protein and energy were in a ratio of more than 15 g protein: 1 MJ AME.

4. Apart from egg size no significant effects on reproductive performance were observed when dietary protein intake was varied from 27 to 19.5 g/bird d.

5. Requirements of broiler breeder hens for protein during lay may be lower than previously thought. For the strain used a protein intake of 19.5 g/bird d appeared adequate provided essential amino acid concentrations were maintained.

6. The close relationships between body weight and energy allowance and the latter and egg production make body‐weight gain a useful guide to management. A body‐weight gain of about 1.1 kg from 21 to 36 weeks of age was associated with optimum performance in this study.     

Feeding standards during lay and reproductive performance of broiler breeders

1. Broiler parent stock (Marshall) were supplied with energy and protein from diets in amounts defined as percentages of an allowance such that nutrient intake increased or decreased in three consecutive periods from 23 to 63 weeks of age.

2. A 20% reduction in energy allowance from 23 to 34 weeks was associated with reduced body‐weight gain, egg weight and carcass constituents except ash, but had no significant effect on egg production or hatchability.

3. Increases in nutrient intake after 34 weeks were associated with an increase in body‐weight gain and carcass fat.

4. Moderate decreases in energy intake after 34 weeks were associated with reduced body‐weight gain, and a 15% reduction in nutrient intake resulted in a decrease in body weight and egg weight.

5. It is suggested that a feeding allowance which controls body‐weight gain during early lay, and then allows for a gradual increase in body weight over the breeding period may be the most efficient way of feeding the broiler breeder hen.     

PERINATAL FOAL MORTALITY ASSOCIATED WITH A HERPESVIRUS

An outbreak of perinatal foal mortality associated with a herpesvirus is described. Twenty two foals either were still-born, or died soon after birth, or were weak and soon developed severe respiratory signs, or were normal at birth and developed respiratory symptoms 18 to 24 hours later. Elevated temperatures, heart and respiratory rates were constant features. The animals were severely leucopaenic, and showed an absolute neutropaenia. At autopsy the lungs were enlarged, and showed varying degrees of aeration and moderate to severe oedema and congestion. Histopathology showed an acute focal necrotising bronchiolitis with the presence of intranuclear eosinophilic inclusion bodies. Herpesvirus was recovered from 9 foals in cell culture and identified by electron microscopy.