Présence de la maladie bactérienne du rein chez les salmonidés au Québec

Presence of the bacterial kidney disease in salmonid fish in Quebec During the summers of 1979 and 1980, wild and hatchery fish were analysed for the presence of the bacterial kidney disease (BKD) agent in salmonid fish in Quebec by the indirect immunofluorescence technique. The causative agent of BKD was detected in all hatcheries tested. Ten to 25% of the fish were positive. The presence of this agent was independent of age and species. We were unable to detect the BKD in fish from the rivers in the northern part of Quebec (over the 50th parallel).     

Analyse de la composition du liquide céphalo-rachidien chez le porcelet nouveau-né.

Cerebrospinal fluid composition has been studied in low and normal birthweight piglets. Values for urea, Ca, K, Cl and P did not differ between the two groups. However, glucose concentration was lower in low birthweight subjects and Mg and Na values were higher. Total leukocytes were also higher in low birthweight piglets. These differences may suggest that blood-brain-barrier is not at the same stage of maturation in low birthweight as in normal birthweight subjects.     

Une étude expérimentale sur la variation du taux d'anticorps sériques suivant le cycle évolutif des oestres du cheval

The changes of antibody titers in the sera of colts infested naturally or artificially with Gasterophilus have been determined in relation to the life cycle of this arthropod using passive hemagglutination, complement fixation, double diffusion techniques and saline extracts of antigens from the third larval stages of Gasterophilus intestinalis and G. nasalis.

In the sera of the infected animals the hemagglutinating antibodies were present at low titers at the third week post-infestation by using somatic extract of G. intestinalis and at the seventh week in case of G. nasalis. At eight weeks post-infestation the antibody titers reached their maximum 1:8192 (G. intestinalis) and 1:4096 (G. nasalis), then dropped at 12 weeks post-infestation.

The complement fixing antibodies were present occasionally between the seventh and 11th weeks after infestation. Precipitating antibodies were absent in all sera.

     

Utilisation du mélange lidocaïne-butorphanol en anesthésie épidurale caudale chez la jument.

Loss of rear motor control is the main limiting factor in the use of caudal epidural anesthesia in the horse. In man and laboratory animals, a small dose of an opiate combined with a local anesthetic enhances analgesia without impairing motor function. Thus, the amount of local anesthetic administered may be reduced. Butorphanol is an opiate widely used in horses. It has a good margin of safety and few cardiorespiratory effects. The effects of lidocaine (0.25 mg/kg) and lidocaine-butorphanol (0.25 mg/kg, and 0.04 mg/kg, respectively) were compared in 2 groups of 5 healthy unsedated mares. Horses in each group received either lidocaine or lidocaine-butorphanol in saline solution for a total volume of 0.0165 mg/kg. Epidural injection was performed at the first coccygeal interspace. Each mare was used only once. Cutaneous analgesia was assessed by a response to a pin prick; and visceral analgesia was assessed by response to a noxious stimulus applied to the urethra. Heart rate, respiratory rate, and arterial blood pressure were also measured. Analysis of the results showed an increase in duration of both cutaneous and visceral analgesia in the mares given lidocaine-butorphanol. Cutaneous analgesia increased from 36 +/- 13 to 150 +/- 21 min and visceral analgesia increased from 22 +/- 10 to 162 +/- 16 min. A cranial extension of the cutaneous analgesia was also observed. Cardiorespiratory depression or signs of excitation were not observed. However, these mares demonstrated peculiar walking in the hind limbs, not associated with signs of ataxia or hyperkinesia.     

Concentrations sériques et biodisponibilité sanguine du chloramphénicol chez les bovins

Serum concentrations and factors affecting the blood bioavailability of chloramphenicol in bovine

The authors have compared the serum concentrations and the factors affecting blood bioavailability of chloramphenicol after intramuscular administration of canadian commercial preparations containing 500 mg/mL of antibiotic.

The animals (dairy cows and heifers) received each drug (20 mg/kg) in one or two injection sites. The serum samples, analysed by colorimetric or microbiological methods, showed that considerable differences in concentration exist between the two methods.

The evolution of biodisponibility factors proved identical in both cases. It appears that therapeutic levels of chloramphenicol are reached only by drug A for four to five hours.

The usual dosage (2-10 mg/kg), by intramuscular route, is not sufficient to attain these active concentrations using the other drugs. However, the important variability obtained during the experiment and reflected in the standard deviation values, has not proved that drug A has a better bioavailability based on the criteria of the only microbiological analysis.

     

Effects de deux glucorticoïdes synthétiques sur le glucose du sang et des sécrétions endométriales chez la vache

Twelve normal cows were injected with 9_αFFAC and with 9_αF, 16_αmF. A marked increase of blood glucose and endometrial secretions glucose was noted up to the postestrus period. A more constant but lower glucose concentration was obtained with 9_αFFAC.     

Les électrolytes du sang et des sécrétions endométriales de la vache à la suite d'une glucocorticothérapie

The effect of two synthetic glucocorticoids, 9_α-fluoroprednisolone acetate and dexamethasone (9_α-fluoro, 16_α-methylprednisolone) was studied on 12 normally breeding cows. Na, Mg, K, Ca and P concentrations were evaluated in the serum and in the uterine fluid at four stages of the estrous cycle.

No significant changes were noted in Na and Ca concentration in either serum or uterine fluid. On the other hand, significant changes in the Mg, K and P were observed. Both drugs have caused a decrease in the content of Mg in the serum (P<0.05) during diestrus, a fall in the level of uterine K (P<0.01) during proestrus and a decrease of P during proestrus both in serum (P<0.001 after dexamethasone treatment) and in uterine fluid (P<0.001 for both drugs).

It is obvious that the two drugs change the chemical composition of blood and endometrial secretions. This could jeopardize the survival of the spermatozoids and of the ovum as well as the fertilization and the implantation processes.

     

Toxicité et effet immunosuppresseur de la sulfaquinoxaline chez la poule

Secondary effects of sulfaquinoxaline have been studied by comparing specific antibody titres of treated birds with the titres of those birds which were not treated.

Previously these birds had been immunized by intramuscular injections of a killed antigen of S. pullorum, standard strain, and S. pullorum, variant strain. This experiment demonstrated that this drug possesses an immuno-suppressing action. This secondary effect was confirmed by an experimental infection with the GB strain of Newcastle disease virus.

     

Détermination de la courbe de dissociation standard de l''oxyhémoglobine du cheval et influence, sur cette courbe, de la température, du pH et du diphosphoglycérate.

The equine blood oxyhemoglobin dissociation curve has been traced in its entirety in standard conditions and the effects of temperature, pH and 2,3-diphosphoglycerate on this curve have been measured. When compared to that of human blood, the curve showed a higher oxygen affinity of hemoglobin (23.8 +/- 0.8 versus 26.6 mm Hg). The effect of the pH, expressed by d log P50/dpH, was found to be identical in man and horse (-0.47). The effect of temperature, however, expressed by d log P50/dT, proved to be lower in the horse (0.016 versus 0.024). The P50 showed an increase of 1 mm Hg each time 2,3-diphosphoglycerate was experiencing an elevation of 4 mumol/gHb in the horse. The results obtained from this experiment are intended for the replacement of the values related to the human blood which have been found to be somewhat inadequate for the horse blood, when the data of blood gases are given in algorithms.     

Césarienne chez la vache laitière: 159 cas.

A retrospective study on 159 cesareans on dairy cows referred between 1985 and 1989 to the veterinary teaching hospital is reported. The objective of the study was to evaluate the probability and the factors associated with survival and subsequent calving. The risk of dying for the cows was 24% following surgery. The risk of dying differed if the cow had an emphysematous, dead, or live calf; it was 63%, 21%, and 14%, respectively. Of all the cows returned to the farm and for which there was a breeding recorded, 64% calved again. But only 28% of all the cows returned home and, therefore, only 17% of all the referred cases calved again. We used multivariate analysis to obtain a predictive model on prognosis following surgery. The prognosis was only influenced by the calf condition at admission.