H. van Herck

Recommendations for the health monitoring of mouse, rat, hamster, guineapig and rabbit breeding colonies: Report of the Federation of European Laboratory Animal Science Associations (FELASA) Working Group on Animal Health accepted by the FELASA Board of Management November 1992

Preamble 1. General considerations 2. Frequency of monitoring and sample size 3. Viral infections 3.1 Mice 3.2 Rats 3.3 Hamsters 3.4 Guineapigs 3.5 Rabbits 4. Bacterial, mycoplasmas and fungal infections 4.1 Methodology 4.2 Samples to be investigated 4.3 Mice and rats 4.4 Hamsters 4.5 Guineapigs 4.6 Rabbits 5. Parasitology 5.1 Methodology 5.2 Report of results 5.3 Test schedule in mouse, rat, hamster and guineapig breeding units 5.4 Test schedule in rabbit breeding units 6. Pathology 7. Appendix I-Necropsy procedures 8. Appendix II-Guidelines for the Use of the FELASA Approved Health Monitoring Report 9. Appendix IIIAbbreviations 2 2 3 3 3 4 5 5 6 6 6 6 6 7 8 8 9 9 9 9 10 10 10

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-N 2O-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 LABORASTM 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-N 2O-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.

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 intra-orbital 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 Pasteurs 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.

Endocrine stress response in rats subjected to singular orbital puncture while under diethyl-ether anaesthesia.

In an attempt to assess possible discomfort in rats subjected to orbital puncture while under diethylether anaesthesia, their endocrine stress response was determined. Concentrations of corticosterone, adrenaline and noradrenaline were measured in plasma obtained via a jugular catheter from rats subjected to diethyl-ether anaesthesia with or without orbital puncture. No statistically significant differences were found between the punctured and non-punctured rats as to peak levels of plasma corticosterone and adrenaline as well as for the times required by the increased concentrations to return to baseline values. The rate by which the plasma noradrenaline level returned to baseline values was somewhat decreased by orbital puncture. Diethyl-ether anaesthesia alone produced a marked endocrine response when compared with handling and novelty stress associated with the induction of anaesthesia. It is concluded that diethyl-ether anaesthesia causes pronounced increases in the plasma levels of the selected stress hormones and that orbital puncture does not amplify this response. It is suggested that diethyl-ether anaesthesia masks any effects of orbital puncture.

A bacterial proventriculitis in canaries (Serinus canaria)

A description is given of the pathomorphology and pathomorphogenesis of a bacterial infection of the proventriculus of canaries. The cause appeared to be a large, rod-shaped, Grampositive bacterium, in which no spore formation could be observed. Cultivation in vitro has not as yet been achieved. Thirty % of the 30 canaries examined contained this bacterium in the proventriculus. In the rest of the digestive tract much smaller numbers were found. The bacteria were associated with a proliferative inflammatory reaction in the proventriculus. The infected proventriculi had an increased pH and an altered synthesis of mucopolysaccharides. The coilin layer of the gizzard was thinner in the infected canaries than in the control group, possibly as a result of the increased pH in the proventriculus.

FELASA recommendations for the health monitoring of breeding colonies and experimental units of cats, dogs and pigs: Report of the Federation of European Laboratory Animal Science Associations (FELASA) Working Group on Animal Health

The health of an animal is always at risk from a variety of infections. Infections in animals, whether clinically manifest or subclinical may, when the animals are used in biomedical research, produce effects that change the outcome of the experiments undertaken. Depending upon the specific infection a variety of biological parameters may be affected such as behaviour, growth rate, relative organ weights, immune response, tumour development etc. Subclinical infections can also lead to contamination of

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.

Endocrine stress response in jugular-vein cannulated rats upon multiple exposure to either diethyl-ether, halothane/O2/N2O or sham anaesthesia.

The main objective of this study was to assess the endocrine stress response to multiple anaesthesia followed by sham anaesthesia in order to detect any memory effects. For this purpose, jugular-vein cannulated rats were subjected to either sham, diethyl-ether or halothane/O2/N2O anaesthesia, and their plasma ACTH, corticosterone, glucose, adrenaline and noradrenaline levels measured. The study had three separate experiments, each consisting of a control and treatment group. In two experiments, the rats were exposed to high or low concentrations (40-15%) of diethyl ether, using either a jar containing cotton soaked in diethyl ether or a vaporizer. In the third experiment, rats were exposed to halothane/O2/N2O. Control animals underwent sham anaesthesia. Blood samples were taken 6 min before and at 5, 15 and 55 min after starting the exposure (t = 0 min). For each variable, the dt5 (level at t = 5 min minus that at t = -6 min) and the cumulative levels over the one-hour period as determined by the area under the curve (AUC) were calculated. Further, the peak levels (Cmax) were determined. The mean time needed to induce anaesthesia was 68, 121 and 55 s for exposure to high and low concentrations of diethyl ether and to halothane/O2/N2O, respectively. Increased noradrenaline and adrenaline dt5 levels were observed only after the first exposure to the high concentration of diethyl ether. Multiple anaesthesia sessions using either diethyl ether or halothane/O2/N2O did not clearly influence adrenaline and noradrenaline levels. Diethyl ether induced a sharp rise in plasma ACTH and glucose levels, irrespective of the concentration used. The response of the ACTH and glucose was similar for single and multiple exposure. An increased response of ACTH, corticosterone and glucose to sham anaesthesia following multiple induction of anaesthesia was observed for the high concentration of diethyl ether only. Halothane/O2/N2O raised plasma glucose without differences between single and multiple anaesthesia sessions. Upon sham anaesthesia following multiple exposures to halothane/O2/N2O, glucose levels were significantly increased. This study indicates that repeated anaesthesia in rats can elicit an increased stress response during subsequent handling and change of environment.

The effectiveness of Ivomec and Neguvon in the control of murine mites

The effectiveness of different methods of external applications of Neguvon and Ivomec for treating infestations with Myobia musculi and Myocoptes spp. in conventional colonies of laboratory mice was investigated. Ivomec appeared to be effective over a longer period of time than Neguvon. There was no difference in the results obtained with different methods of application, but spraying seems to be more practical for large colonies of mice than individual dipping.

The use of repeated treatment with Ivomec and Neguvon spray in the control of murine fur mites and oxyurid worms

In a previous study, a single external treatment with Ivomec appeared to be more effective than Neguvon treatment. In this study the anti-endoparasitic qualities of external application of Ivomec were investigated, together with the effectiveness of a combined Neguvon and Ivomec treatment. After 3 treatments, all mice were mite- and worm-free: they remained free of ectoparasites until 18 weeks after the last treatment; eggs of endoparasites reappeared 9 weeks after the last treatment.