GB2320174A - Animal holder for tests - Google Patents

Abstract

A device for holding an animal in a laboratory test, the device comprising a chamber 10 adapted to enclose the animal and having an exposure orifice and a stocks facility 12 at the exposure orifice for holding the animal by its neck. The device enables the animal to be presented for tests employing its respiratory system and to that end the device can readily incorporate plethysmographic instrumentation connections 17.

Description

ANIMAL INHALATION TEST APPARATUS The present invention relates to devices for holding animals employed in laboratory tests, in particular inhalation tests carried out with small animals such as rats, ferrets and guinea pigs.

In a known such device a tube the bore of which is just sufficient to enclose the animal has an exposure end which is tapered down to an exposure orifice and which taper is adapted to fit closely and snugly to the animal's snout, with the snout protruding from the orifice, and a closure end and bung therefor, the closure and and bung being adapted to urge the animal to keep its snout tightly within the taper.

This known device has the disadvantage that the end bung arrangement is practically never capable of ensuring that the animal's snout is held tightly in the taper or protrudes from the orifice, and accordingly the experimenter cannot be certain of the extent to which the animal has participated in an inhalation test.

The present invention provides an animal holding device with which the experimenter can have a high degree of certainty that the animal has participated in the test. Not only that but the device can be adapted for plethysmography, and thus to provide for a reasonably accurate determination of the quantity of the animal's inhalation.

According to the present invention a device for holding an animal in a laboratory test comprises a chamber adapted to enclose a test animal and having an exposure orifice and a stocks facility at the exposure orifice adapted for holding the animal snugly around the neck to prevent it from withdrawing its head therethrough.

According to a feature of the invention the stocks facility may additionally comprise a sheet of flexible elastic material, such as latex, having a perforation therethough adapted to fit closely around the neck of the animal.

According to another feature of the invention the device may have a bleed, preferably passing through the chamber wall, adapted for connection to plethysmographic instrumentation for measuring changes of volume within the chamber. By this means an experimenter can determine the rate and volume of the animal's inhalation. Ideally the bleed is sited approximate, or just ahead of, where in use the animal's thorax will be situated. If the tube were to have a top and a bottom the plethysmographic bleed (as distinct from any ducting body fluids) should not be at the bottom.

Devices in accordance with the invention are particularly useful in gauging the toxicity of gases and/or gas borne particles, and are accordingly readily adapted for use in sealed inhalation test apparatus. Preferably the chamber is a tube, ideally right cylindrical, with a bore and length just sufficient to enclose the animal, having a closure end and a closure therefor. The device may also have attachment means whereby it can be fitted gas-tight into a supply of gas or aerosol under test - it being appreciated that in the context of the present invention the word "gas" includes a gas as such as well as a vapour or gas borne particles. Clearly where it is likely that different animals may be tested in the same apparatus, while the tube may have a bore to suit the particular animal the attachment means may be adapted for fitting in the one location. A flange on the tube may readily provide for this.

An animal holding device in accordance with the invention will now be described by way of example with reference to the accompanying drawings, of which: Figure 1 is a longitudinal section of the device; and Figure 2 is an exposure end view of the device.

As shewn in the drawings the animal holding device comprises a tube 10 having at an exposure end thereof a fitment flange 11. The fitment flange 11 is adapted for mounting both the device into an inhalation test apparatus and animal stocks 12 onto the tube 10, held in place by inner and outer plates 13, 14. A neck seal 15 is adapted to be held against the outer plate 14 by an outer cover 16 when the device is held in place on a supply manifold of an inhalation test apparatus 20 by clips 21.

The tube 10 is cylindrical and in bore and length is adapted to be a snug fit around the animal. The stocks 12 comprise two halves 12a, 12b of a toroidal plate, the bore of which is adapted to fit firmly around the animal's neck so that when fitted the animal can neither withdraw or advance its head through it. The neck seal 15 is a latex toroid also adapted to seal around the animal's neck without strangulating discomfort.

The tube 10 has a bleed 17 located at a position approximate where in use the animal's thorax would be. The bleed is adapted for fitment of flexible piping (not shewn) by which the interior of the tube 10 can be connected to a micromanometer or pressure transducer (not shewn) for plethysmography. Screws 18 are used to mount the plates to the tube flange 11.

At a closure end thereof the tube 10 has a closure bung 19 made of rubber. There is an O-ring seal between the flange 11 and the inner plate 14.

The tube 10 is made of an aluminium alloy. The stocks 12 and the plates 13, 14 are made of a rigid plastics material. The cover 16 is formed of polyvinylchloride.

The device is prepared for use by mounting the inner and outer plates 13, 14 to the tube flange 11, with the lower half 12b of the stocks 12 interposed between the plates. With the upper half 12a of the stocks 12 offered to the slot between the plates 13, 14 the animal is introduced to the tube via the closure end. When its neck is at the stocks 12 these are closed and, after ensuring that the animal's neck is not pinched, the upper stock 12a is fastened in place with screws 18. The bung 19 is then fitted to the tube closure end, after having tucked the animal's tail inside, and the neck seal 15 is fitted to the animal's neck.

The cover 16 is placed over the neck seal and plate assembly and the device can then be offered to the supply manifold 20 of an inhalation tests apparatus and clipped in place with the clips 21.

The tube 10 is chosen with a bore into which the animal can just crawl, this being snug and apparently a comfortable arrangement for the animal under test, as well as facilitating accurate plesymography. Accordingly tubes 10 which are particularly suitable for use with rats, ferrets and guinea pigs have bores and lengths respectively of 51mm by 188mm, 70mm by 350mm and 70mm by 178mm. As it is convenient for the supply manifold 20 to have a certain fixed internal and external diameter, the flange 11 has the same external diameter regardless of the outer diameter of the tube 10.

A particular advantage of devices according to the invention in combination with inhalation tests apparatus rests in the fact that it is readily possible to construct an apparatus supply manifold with a flange 20 such that whichever animal is under test its snout will protrude well into the supply manifold and hence into the gas under test.

Claims (6)

What I claim is:

1. A device for holding an animal in a laboratory test and comprising a chamber adapted to enclose a test animal and having an exposure orifice and a stocks facility at the exposure orifice adapted for holding the animal snugly around the neck to prevent it from withdrawing its head therethrough.

2. A device as claimed in claim 1 and wherein the stocks facility additionally comprises a sheet of flexible elastic material having a perforation therethough adapted to fit closely around the neck of the animal.

3. A device as claimed in claim 1 or claim 2 and wherein the chamber is a tube having a closure end and the device has a closure therefor.

4. A device as claimed in any one of claims 1 to 3 and having a bleed adapted for connection to plethysmographic instrumentation for measuring changes of volume within the chamber.

5. A device as claimed in claim 4 and wherein the bleed is sited approximate where in use the animal's thorax will be situated.

6. An animal holding device substantially as hereinbefore described with reference to the accompanying drawings.