2002

The application of traditional behavioural and physiological methods for monitoring of the welfare impact of different flooring in rodents
Krohn, T.C., Hansen, A.K.
Scandinavian Journal of Laboratory Animal Science, 29, pp. 79-89, 2002
Abstract:
In this study, observations on traditional methods, such as open field test, corticosterone assays and monitoring of barbiturate sleeping time were performed to validate the impact of housing conditions on the welfare of rats and mice in order to compare the outcome with observations previously achieved by preference tests and telemetry. These traditional methods failed to demonstrate the impact on the animals caused by grid housing previously shown by telemetry and preference studies, and it is, therefore, concluded that these traditional tests may be less sensitive for monitoring subtle small environmental impacts on laboratory rodents.
Although the methods were not able to reveal any differences in corticosterone level and open field test between housing conditions, there were significant differences between mouse strains and sexes. These differences between strains should be taken into account when choosing the best suitable strain for a study.

 

Carbon Dioxide Concentrations in Unventilated IVC Cages
Krohn, T.C., Hansen A.K.
Laboratory Animals, 36, pp. 209-12, 2002
Abstract:
The use of individually ventilated cage (IVC) systems has become more common worldwide. The various systems are becoming more and more sealed in order to protect the animals against infections and the staff against allergens; which, however, may lead to problematic CO2 concentrations, if the cages are left unventilated. In this study it is shown that, depending on how tight the cage is and the number of animals housed in each cage, CO2 inside the cage within 2h will increase to levels of between 2 and 8%.

 

Assessment of the postoperative discomfort of intra-auricularly hypophysectomized rats
Hansen AK, Christoffersen LB, Hejgaard KC, Thon R, Velschow S
Laboratory Animals 36 (2): 144-152 APR 2002
Abstract:
Rats subjected to hypophysectomy make up one of the largest groups of experimental animals in Europe, since there is a legal demand for batch testing of industrially produced growth hormones. To describe the clinical performance of rats having undergone hypophysectomy, animals were examined postoperatively by monitoring behaviour, body temperature and food intake. Behavioural changes were observed in rats that had only been anaesthetized, as well as in sham-operated rats, while no behavioural deviations could be shown in hypophysectomized rats. On the first day after surgery all rats had declining body temperature and food intake; and this change was not reversed by treatment with carprofen, buprenorphine or oxytetracycline. The mortality rate in rats treated with buprenorphine was increased, as was the mortality rate in rats hypophysectomized when weighing more than 100 g. As there seemed to be no differences whether methohexital or a combination of fentanyl, fluanison and midazolam was used, the latter anaesthesia is recommended due to its analgesic potential. For post-surgical analgesic treatment, carprofen is recommended rather than buprenorphine. At best, the use of hypophysectomized rats should be replaced in industrial batch testing by an existing in vitro method.