Prolapsus vaginae in the IIIVO/JU rabbit.

In a specified pathogen free (SPF) breeding colony of IIIVO/JU rabbits 8 cases of prolapsus vaginae occurred in 5 years. Clinically the animals were in shock. Haematocrits ranged from 9 to 15%. The prolapses started from the submucosal layer of the proximal part of the vestibulum vaginae. The prolapsed tissue consisted of over-expanded blood-sinuses. Between the sinuses signs of an inflammatory reaction were present. All 8 animals were in a period of increasing sexual activity when the prolapse developed. The 8 rabbits were closely related, indicating a possible hereditary defect.

Histological changes in the orbital region of rats after orbital puncture.

To contribute to the assessment of the degree of discomfort in rats after orbital puncture, we have examined the histological changes in the intraorbital tissues caused by this technique of blood sampling. Orbits were studied from rats euthanized either within 1 min, 4 days, 28 days or 56 days after puncture while under diethyl-ether anaesthesia. The techniques of 2 animal technicians were compared, one using a broken haematocrit capillary and the other using an intact Pasteur's pipette. Non-punctured orbits served as controls. Microscopic slides containing the eye in situ at 2 horizontal levels in the orbital region were examined for 37 parameters; the slides were scored blind and in random order. Orbital puncture caused haemorrhages in the puncture track and, depending on the technique used, also in the periosteum. Four days after puncture, inflammatory reactions were present in the puncture track. Depending on the technique of puncture, these reactions were also seen in the eye muscles and periosteum or in the Harderian gland. Within 4 weeks after puncture, the lesions had healed without detectable scars. The different histological effects of the 2 techniques of orbital puncture are discussed in the light of the characteristics of these techniques.

Orbital bleeding in rats while under diethylether anaesthesia does not influence telemetrically determined heart rate, body temperature, locomotor and eating activity when compared with anaesthesia alone.

The question addressed was whether orbital bleeding in rats, while under diethylether anaesthesia, affects their locomotor activity body core temperature, heart rate rhythm and eating pattern. Roman High Avoidance (RHA) and Roman Low Avoidance (RLA) rats were used to enhance generalization of the results. Orbital bleeding when the rats were under diethylether anaesthesia was compared with diethylether anaesthesia alone. To take into account any effects of handling, the rats were also subjected to sham anaesthesia. The RHA rats urinated more during anaesthesia, needed more time to recover from the anaesthesia and showed a greater endocrine stress response to diethylether anaesthesia when compared with the RLA rats. During anaesthesia, the RHA rats showed a greater fall of body temperature and bradycardia than did the RLA rats. Diethylether anaesthesia reduced locomotor activity in the RHA rats, but had no effect in the RLA rats. In neither RHA nor RLA rats did anaesthesia plus orbital puncture, versus anaesthesia alone, influence body temperature, heart rate rhythm, locomotor and eating activity. The lack of effect of orbital puncture occurred both in the short term (within 2h) and long term (within 48 hours) and thus this study indicates that orbital puncture had, at least with respect to variables measured in the present study, no effect superimposed on that of diethylether anaesthesia.

Orbital sinus blood sampling in rats as performed by different animal technicians: the influence of technique and expertise.

In this study the influence of orbital sinus blood sampling on clinical signs was studied within the framework of various nutritional experiments. In order to assess the clinical signs in a random design, the rats were punctured in either the left or the right orbit. Thus, the effect of puncture within rats could be determined by comparing the left and right eye. Four animal technicians punctured a total of 303 rats, using different techniques. Orbital sinus blood sampling caused clinically visible alterations. The type, frequency and prognosis of the alterations differed with the person performing the puncture. Two experienced animal technicians were able to perform the technique without causing a statistically significant increase in alterations in punctured orbits. One less experienced animal technician caused severe abnormalities. The use of either a Pasteur pipette or a haematocrit capillary did not necessarily produce different results. Neither did puncturing the lateral vs the medial canthus of the orbit. By not applying chloramphenicol eye ointment in the conjunctival sac after puncture, the number of abnormalities in 'ocular discharge' and 'corneal alterations' in the punctured orbits was significantly decreased. Four punctures in the same orbit with 14-day intervals by a skilled animal technician did not cause a significant increase in abnormalities.

Orbital sinus blood sampling in rats: effects upon selected behavioural variables.

The question addressed was whether the behaviour of rats is changed after orbital sinus blood sampling while they are under diethyl-ether anaesthesia. Twelve rats were subjected to sham anaesthesia, diethyl-ether anaesthesia and anaesthesia plus orbital puncture according to a Latin square. After each treatment, the behaviour of the rats was automatically monitored using the so-called LABORAS method, which discriminates between grooming, locomotion and inactivity. Treatment ended, and behaviour monitoring began, when the light period changed over to the dark period. The various behaviours were quantified as relative duration and frequency. Anaesthesia versus sham anaesthesia reduced the relative duration of grooming during the first 5 h after treatment. Anaesthesia plus orbital puncture versus anaesthesia alone did not significantly influence grooming, but orbital puncture did reduce the relative duration and the frequency of locomotion during the entire 20 h period, which was mainly due to a decrease in the dark period. After orbital puncture, the animals were also less frequently inactive. It is concluded that orbital puncture has an effect on behaviour superimposed on that of diethyl-ether anaesthesia. This observation may contribute new arguments to the debate on the acceptability of the orbital puncture technique.

Blood sampling from the retro-orbital plexus, the saphenous vein and the tail vein in rats: comparative effects on selected behavioural and blood variables.

We compared the behaviours of rats, and measured various blood parameters, after three blood sampling techniques: orbital puncture while they were under diethyl-ether anaesthesia, blood collection by tail vein puncture under O2-N2O-halothane anaesthesia and puncture of the saphenous vein without anaesthesia. Twelve rats were subjected to the three treatments according to a Latin square design. After each treatment, the behaviour of the rats was automatically monitored using the so-called LABORAS method, which discriminates between grooming, locomotion and inactivity in rats. Based on excitation scores and urine production, it was found that induction of diethyl-ether anaesthesia combined with orbital puncture caused more distress than did the other two blood sampling techniques. The three techniques had no differential effects on the behaviours of grooming, locomotion and inactivity. Collecting 0.5 ml of blood by orbital puncture was +/-7 times faster than doing so by saphenous vein puncture and +/- 15 times faster than collecting blood by tail vein puncture while the rats were under O2-N2O-halothane anaesthesia. The levels of some haematological and plasma variables differed significantly between the three blood collection techniques. These observations may help to select the most appropriate technique of blood sampling with respect to anticipated discomfort in the animals.

Assessment of discomfort in gallstone-bearing mice: a practical example of the problems encountered in an attempt to recognize discomfort in laboratory animals.

In order to obtain practical experience on the recognition, assessment and evaluation of discomfort in laboratory animals, the degree of discomfort was studied in gallstone-free and gallstone-bearing mice. Out of nine parameters to which scores were assigned per individual mouse, only the response to palpation of the right hypochondrium was found to score significantly higher in gallstone-bearing mice. That is, the incidence of squeaking and the magnitude of muscular contractions were significantly higher in these animals compared with the gallstone-free mice. The stance of the gallstone-bearing mice also tended to be abnormal, although the difference between gallstone-free and gallstone-bearing animals did not reach statistical significance. Although this study does not prove unequivocally that the induction of gallstones per se causes discomfort or pain in mice, we tentatively conclude that it does. We feel that this should be taken into account in any projected work in which gallstone induction in animals may occur. There was considerable between-assessor variation in the assignment of scores to the variables used to assess discomfort, including the response to palpation. It is concluded that the selection of parameters and the experience and/or attitude of the assessor are critically important when the magnitude of discomfort, if any, is assessed in experimental animals.

Effects of group size and gentling on behaviour, selected organ masses and blood constituents in female Rivm: TOX rats.

The effects of group size (individually versus 3 in a cage) and gentling on behaviour and blood constituents were studied in female rats. Gentled rats showed less freezing and/or escaping when approached in an objective handling test than non-gentled rats; the type of caging had no significant influence. In a small field, gentled rats displayed significantly more turning and standing upright, whereas these parameters did not differ between rats housed either individually or three in a cage. In both tests, gentled rats produced significantly less urine than did control rats. Neither caging nor gentling significantly influenced the group mean values and variance of masses of adrenals, spleen and thymus and plasma concentrations of glucose, cholesterol, triglycerides and corticosterone. Removal of a cage from the rack and getting out a rat caused increase in plasma concentrations of corticosterone in its remaining cage mates.