The Koken Rat

The Koken Rat simulator contains an anatomically correct pharynx, trachea, stomach and tail vein. The model is made of silicone and soft vinyl chloride and gives much the same feel and same sort of weight as a real rat. Laboratory rats should be spared some of the pain and injury caused by clumsy handling now that novices can practice on artificial rats. Students can see whether their efforts have been successful through a transparent silicone "window" which exposes the windpipe, gullet and stomach. Proper insertion of a hypodermic needle into the tail vein is confirmed by the flow of imitation blood. Students can open the mouth by applying pressure with the forefinger and thumb, just as they would coax open a real rat's mouth. This ensures that the mouth, gullet and stomach line up vertically, and makes dosing with pipettes swifter and less traumatic for the rat. The rat's tails have a central "vein", so that students can practice injections and blood sampling. As in real rats, the vein and skin close up after an injection. The replica tails are good for a thousand or so injections before they begin to leak, but they are detachable and can be replaced. The Koken Company of Tokyo designed the rats so that students could practise common procedures such as dosing the animals by mouth with pipettes, injecting veins in the tail and inserting feeding tubes into the throat. Kazuyoshi Maejima of the School of Medicine at Keio University in Tokyo led a team of academics that developed the Koken rat jointly with company researchers. From casts of a real rat, Maejima and his colleagues built anatomically perfect silicone replicas.

Available from The Science Bank.

Comments & References: Suitable for students in veterinary science and laboratory animal science. Also suitable for independent use. Based on casts of 9-week old male SL rats, length 21cm (tail length 19cm). Spare tails and artificial blood may be purchased. This item may be borrowed for up to 6 weeks through the Alternative Loan System of the International Network for Humane Education (InterNICHE), free of charge, but return postage must be paid by the person who has borrowed the product. Please note that there are practical limitations on where some items can be sent. Please contact loansystem@interniche.org or see http://www.interniche.org for more information.

Please also see the Natsume Rat, a more recent model, which uses the same tails as the Koken Rat.

Please also see an overview of homemade educational materials.

See also these lists of rat simulators and mouse simulators.