DE102017120813A1 - Apparatus and method for killing at least one small animal by means of CO2 - Google Patents

Abstract

The invention relates to a device (10) for killing at least one small animal, in particular a rodent, by introducing a CO ₂ -containing gas mixture into a cage housing the small animal. It is envisaged that the device (10) has a mixing device (14) which
a first gas connection (32) for supplying CO ₂ gas,
a second gas connection (30) for supplying a further component of the gas mixture,
a mixing chamber (40) connected to these gas connections (30, 32) for mixing the CO ₂ gas and the at least one further component and
- Having a third gas port (28) for introducing the CO ₂ -containing gas mixture in the cage, wherein the second gas port (30) and the third gas port (28) are formed and / or arranged such that these two gas ports (28, 30 ) are simultaneously fluidically connectable to the cage. The invention further relates to a corresponding method for killing at least one small animal by means of CO ₂ .

Description

The invention relates to a device and a method for killing at least one small animal, in particular a rodent, by introducing a CO ₂ -containing gas mixture into a cage housing the small animal.

The publication US 2012/0272919 A1 describes a device for killing at least one rodent by introducing CO ₂ gas or a CO ₂ -containing gas mixture into a cage enclosing the rodent. The device comprises a line system with a gas connection for introducing the CO ₂ -containing gas mixture into the cage. The corresponding cages, in turn, have (counter) connections, via which one can supply the animals located in the cages in a targeted manner with a desired gas atmosphere.

Modern animal welfare places very high demands on CO ₂ killing. For example, CO ₂ (carbon dioxide) in some countries may only be used for killing certain small animals such as the typical mouse or rat laboratory animals.

CO ₂ is a respiratory stimulant and causes dysphonia or shortness of breath very quickly in vertebrates. In addition, it can cause discomfort and pain, as carbon dioxide in conjunction with the liquid on the nasal, oral and ocular mucosa is converted to carbonic acid, which in turn activates polymodal nociceptors. If the animal notices a strong increase in CO ₂ concentration, the animal wants to avoid what is impossible in a closed cage and thus causes great stress in the animal. Therefore, CO _{2 should} only be used to kill already unconscious animals.

The publication US 4,107,818 B describes as early as 1978 a method for killing cats by introducing a CO ₂ - / O ₂ gas mixture in a small animal einhausenden cage, the cat first exposed for a certain time a gas mixture with a 40 - 70% CO ₂ concentration which is anesthetizing and then exposed to a CO ₂ - / O ₂ gas mixture with a greater than 95% CO ₂ concentration for a period of time which is lethal. Each of the two gas mixtures is kept in a separate chamber and the cat with cage first in one, then spent in the other chamber. However, such a procedure is complex in its practical implementation and associated with stress for the animal.

It is the object of the invention to provide measures for CO ₂ killing of small animals, which ensure that the animal is exposed to as little stress as possible during the entire process and has certainly lost consciousness before the actual killing.

The object is achieved by the features of the independent claims. Advantageous embodiments of the invention are specified in the subclaims.

In the device for killing at least one small animal by introducing a CO ₂ -containing gas mixture into a cage enclosing the small animal, the invention provides that it has a mixing device which in turn (i) has a first gas connection for supplying CO ₂ gas, ii) a second gas connection for supplying a further component of the gas mixture, (iii) a mixing chamber connected to these gas connections for mixing the CO ₂ gas and the further component and (iv) a third gas connection for introducing the CO ₂ -containing gas mixture into the Cage, wherein the second gas port and the third gas port are formed and / or arranged such that these two gas ports are simultaneously fluidically connected to the cage, in particular directly to the cage. Thus, the second gas port forms a gas port for introducing atmosphere from the cage as a component of the gas mixture. In other words, this arrangement allows the second and third gas connection, via the second gas port atmosphere from the cage (as a component of the gas mixture) for mixing with CO ₂ gas into the mixing chamber, while the CO ₂ -containing gas mixture via the third gas port in the cage is initiated.

By this measure, the device can be operated so that the cage is withdrawn continuously or quasi-continuously atmosphere, which is then successively added CO ₂ gas, wherein the resulting CO ₂ -containing gas mixture with ever higher CO ₂ concentration of the cage is fed again. In this cycle, the concentration of CO ₂ in the cage is automatically "ramped up". The concentration increase rate can then be selected according to the species or the animal weight.

According to a preferred embodiment of the invention it is provided that the second gas connection and the third gas connection are arranged such that these two connections enable a fluidic connection to a common cage side of the cage. For this purpose, these connections are arranged for example at a predefined distance next to each other or one above the other and aligned parallel to each other.

In this case, each of the two connections is preferably designed in the form of a plug contact for direct fluidic connection to a respective socket-like mating contact of the cage. Preferably, each of the terminals in the form of a plug contact has a seal on its outer circumference. This is in particular designed as an O-ring.

According to a further preferred embodiment of the invention, the mixing device further comprises a further mixing chamber downstream of the mixing chamber for further mixing of the mixed in a mixing chamber components, wherein the third gas connection of the further mixing chamber is downstream of flow. Through this two-stage mixture, a very homogeneous CO ₂ -containing gas mixture can be introduced into the cage.

It is advantageously provided that the two mixing chambers are connected to each other via a channel in which a fan or compressor is arranged. In general, a fan rather than a compressor is provided, since a mass flow and less a pressure difference to be built. The fan is in particular a fan. In addition to the mass flow into the further mixing chamber, this also ensures turbulence of the gas mixture, which ensures faster / additional mixing.

According to a further preferred embodiment of the invention, the device further comprises a control and / or regulating device. This controls or regulates the said cycle. Since in this cycle process, the concentration of CO ₂ gas in the cage is automatically "romped", can be dispensed with a regulation well. The control and / or regulating device can therefore be operated as a pure control device. The corresponding control variables are then, for example: the CO ₂ mass flow, the mass conversion of the fan and the total process duration. The corresponding fixed sizes are then the volumes of cage and mixing chamber (s).

In a configuration with two mixing chambers is advantageously provided that the control and / or regulating device is arranged between the two mixing chambers. In this way, it is particularly close to the components to be controlled, such as the fan or compressor or other components such as a switching valve for switching on or off a corresponding source of CO ₂ gas.

According to a preferred embodiment of the invention, the device has a button or other sensor for registering a defined mounting position of the cage on the device, in which the second gas connection and the third gas connection contact the cage fluidly.

According to a further preferred embodiment of the invention, the device has a rail system for mounting the cage on the device. Such a rail system is widely used. The initially mentioned document US 2012/0272919 A1 shows, for example, such a rail system with two rails on which the cage can be precisely brought to the one or more connections of the corresponding device. In the same way it is possible in the case of the device described here to introduce a cage with corresponding counter connections / contacts to the second and the third gas connection. If said connections (second and third gas connection) are each in the form of a plug contact for direct fluidic connection to a respective socket-like mating contact of the cage, they are aligned with their respective longitudinal axis parallel to the longitudinal axes of the rails.

According to yet another preferred embodiment of the invention, it is finally provided that the device has a base element, in particular a bottom plate, on which the mixing device is mounted. In a device with a rail system, the rails of the system are preferably also mounted on this base element.

In the method according to the invention for killing at least one small animal by introducing a CO ₂ -containing gas mixture into a cage enclosing the small animal, it is provided that in a continuous or quasi-continuous process (a) the cage is deprived of atmosphere, (b) this withdrawn Atmosphere CO ₂ gas is mixed and (c) the resulting CO ₂ -containing gas mixture is fed back to the cage. In this cycle, the concentration of CO ₂ in the cage is automatically "ramped up". The concentration increase rate can then be selected according to the species or animal weight.

The admixing of CO ₂ gas is preferably carried out in two stages. About this two-stage mixture, a particularly homogeneous CO ₂ -containing gas mixture can be introduced into the cage.

The aforementioned embodiments of the device apply analogously to relevant embodiments of the method.

According to a preferred embodiment of the method according to the invention this is performed by means of the above-mentioned device.

• 1 eine Vorrichtung zum Töten von zumindest einem Kleintier durch Einleiten eines CO₂-haltigen Gasgemischs in einen das Kleintier einhausenden Käfig gemäß einer bevorzugten Ausführungsform der Erfindung,
• 2 die Vorrichtung aus einer anderen Perspektive,
• 3 die Vorrichtung mit geöffneter Mischeinrichtung,
• 4 die geöffnete Mischeinrichtung aus einer anderen Perspektive,
• 5 die geöffnete Mischeinrichtung mit dem Innenleben eines Funktionsmoduls der Mischeinrichtung,
• 6 der in 5 gezeigte Teil der Vorrichtung aus einer anderen Perspektive,
• 7 die Mischeinrichtung in Explosionsdarstellung und
• 8 den Gasfluss in der Mischeinrichtung.

The invention will now be described by way of example with reference to the accompanying drawings with reference to preferred embodiments, wherein the features shown below may represent an aspect of the invention both individually and in combination. It shows:

• 1 a device for killing at least one small animal by introducing a CO ₂ -containing gas mixture into a cage housing the small animal according to a preferred embodiment of the invention,
• 2 the device from a different perspective,
• 3 the device with opened mixing device,
• 4 the opened mixing device from another perspective,
• 5 the opened mixing device with the inner workings of a functional module of the mixing device,
• 6 the in 5 shown part of the device from a different perspective,
• 7 the mixing device in exploded view and
• 8th the gas flow in the mixing device.

The 1 shows a device 10 for killing at least one small animal kept in a cage (not shown) by means of CO ₂ . These small animals are especially rodents like rats and mice. The device 10 has the following assemblies 12 . 14 . 16 on: designed as a base plate base element 12 , a mixing device 14 for mixing gases and a rail system 16 with two rails 18 which is a recording room 20 for the cage and about which the cage to the mixing device 14 can be introduced. The mixing device 14 has a substantially rectangular housing 22 on. At the rail system 16 facing front wall 24 this case 22 has the mixing device 14 a trained as a button sensor 26 as well as two gas connections 28 . 30 on. These are matched to corresponding (counter) connections on the cage. The sensor 26 recognizes the presence of one in the recording room 20 inserted cage. The two connections 28 . 30 serve the fluidic connection of the mixing device 14 to the cage. Here are the two connections 28 . 30 not the only gas connections of the mixing device 14 , On the back of the mixer 14 is located below as the first gas connection 32 designated gas port for supplying CO ₂ gas, which in 2 is recognizable. The first mentioned gas connections 28 . 30 are hereinafter referred to as the second gas connection 30 and third gas connection 28 designated. The second gas connection 30 serves for supplying a further gas component of the CO ₂ -containing gas mixture to be mixed via the mixing device and the third gas connection 28 serves to introduce this CO ₂ -containing gas mixture into the cage. The further component of the CO ₂ -containing gas mixture is gas or a gas mixture which is withdrawn from the cage. This gas is the atmosphere surrounding the animal in the cage.

The 2 now shows the device 10 from the back. At one of the front wall 24 opposite rear wall 34 of the housing 22 is next to the said first gas connection 32 , which is designed as a pluggable gas connection, also an electrical fuse 36 and a socket 38 to power the device 10 recognizable.

The back wall 34 is designed removable. The 3 shows the device 10 with removed rear wall 34 of the housing 22 the mixing device 14 , The interior of the housing 22 is roughly divided into three areas: a mixing chamber 40 , which is also referred to as a return chamber in terms of their function, another mixing chamber 42 , which is referred to in terms of their function as a flow chamber and arranged between the two mixing chambers and this while separating function module 44 which will be discussed in detail below.

The 4 shows the mixing device 14 with the housing open 22 again in detail. It can be seen that the functional module 44 from a channel 46 is traversed, the two mixing chambers 40 . 42 fluidically connects. In other words, this channel extends 46 from the one mixing chamber 40 to the further mixing chamber 42 ,

In the presentation of the 4 is now also recognizable that the second gas connection 30 fluidically to the mixing chamber 40 is connected while the third gas connection 28 is connected to the other mixing chamber.

The 5 shows, among other components of the device 10 now especially the inside of the module 44 , There, the components of a in the example shown as a pure control unit formed control and / or regulating device 48 , These are:

A control module 50 with time relay, a distribution terminal 52 , LEDs 54 , as well as the sensor designed as a button 26 , In addition, the module houses 44 continue a solenoid valve 56 , a gas throttle valve 58 and a fan designed as a fan 60 whose housing is the channel 46 (co-) forms and whose rotor is in the channel 46 located. An existing CO ₂ supply via the first gas connection 32 , the solenoid valve 56 and the throttle valve 58 into the mixing chamber 40 is not shown in detail.

The 6 shows the in 5 shown part of the device 10 again from a slightly different perspective. The control module 50 the control unit 48 controls the parameters with which the device 10 dictates the gas flow over the sensor 26 , which dictates the start time of the process, the solenoid valve 56 , which controls the CO ₂ supply and the fan 60 which drives the circulating gas stream.

The 7 shows the mixing device 14 with at the side with opened housing 22 in a kind of exploded view, in which some of the walls are shown semitransparent.

The 8th shows the device 10 Finally, in a presentation that depicts the representation of 4 corresponds, wherein now the circulating flow path from the cage via the second gas connection 30 into the mixing chamber 40 (first arrow), from there - powered by the fan 60 - over the canal 46 into the further mixing chamber 42 (second half-hidden arrow) and from there via the third gas connection 28 (third arrow) leads back into the cage.

• - dem jeweiligen Käfig über den zweiten Gasanschluss 30 Atmosphäre entzogen,
• - dieser entzogenen Atmosphäre in der Mischkammer 40 ein über den ersten Gasanschluss 32 eingeleitetes CO₂-Gas zugemischt und
• - das dabei entstehende CO₂-haltige Gasgemisch dem Käfig über den dritten Gasanschluss 30 wieder zugeführt.

By means of this device 10 Now caged small animals can be killed fully automatically by introducing a CO ₂ -containing gas mixture in their cages. This is done in a continuous or quasi-continuous process

• - The respective cage via the second gas connection 30 Withdrawn atmosphere,
• - This withdrawn atmosphere in the mixing chamber 40 on via the first gas connection 32 introduced CO ₂ gas admixed and
• - The resulting CO ₂ -containing gas mixture to the cage via the third gas connection 30 fed again.

The admixing of CO ₂ gas takes place in the example shown via the two mixing chambers 40 . 42 two stages. Through this two-stage mixture, a very homogeneous CO ₂ -containing gas mixture can be introduced into the cage.

In this cycle, the concentration of CO ₂ in the cage is automatically "ramped up". The concentration increase rate can then be selected according to the species or the animal weight.

In the process, to kill said rodents, the CO ₂ concentration will be from a starting value, which is usually less than 1%, to a final value of 70% or more than 70% at a rate of 10% -30% per minute booted. Preferably, the rate is about 20% per minute.

LIST OF REFERENCE NUMBERS

10

contraption

12

base element

14

mixing device

16

rail system

18

rail

20

accommodation space

22

Housing (mixing device)

24

front wall

26

sensor

28

third gas connection

30

second gas connection

32

first gas connection

34

rear wall

36

fuse

38

Socket power supply

40

mixing chamber

42

another mixing chamber

44

function module

46

channel

48

Control and / or regulating device

50

control module

52

distributor terminal

54

LED

56

magnetic valve

58

Gas throttle valve

60

fan

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 2012/0272919 A1 [0002, 0017]
• US 4107818 [0005]

Claims (11)

Device (10) for killing at least one small animal, in particular a rodent, by introducing a CO ₂ -containing gas mixture into a cage housing the small animal, having a mixing device (14), which has - a first gas connection (32) for supplying CO ₂ Gas, - a second gas connection (30) for supplying a further component of the gas mixture, - a mixing chamber (40) connected to these gas connections (30, 32) for mixing the CO ₂ gas and the further component, and - a third gas connection ( 28) for introducing the CO ₂ -containing gas mixture into the cage, wherein the second gas connection (30) and the third gas connection (28) are designed and / or arranged such that these two gas connections (28, 30) simultaneously flow-related to the Cage are connectable. Device after Claim 1 , characterized in that the second gas connection (30) and the third gas connection (28) are arranged such that these two connections (28, 30) enable a fluidic connection to a common cage side of the cage. Device after Claim 1 or 2 , characterized in that each of the two terminals (28, 30) is preferably in the form of a plug contact for direct fluidic connection to a respective female counter-contact of the cage. Device according to one of the preceding claims, characterized in that the mixing device (14) further comprises one of the mixing chamber (40) fluidly downstream further mixing chamber (42) for further mixing the mixed in the one mixing chamber (40) components, wherein the third gas connection ( 28) downstream of the further mixing chamber (42). Device after Claim 4 , characterized in that the two mixing chambers (40, 42) via a channel (46) are interconnected, in which a fan (60) or compressor is arranged. Device according to one of the preceding claims, characterized by a control and / or regulating device (48). Device after Claim 6 , characterized in that the control and / or regulating device (48) between the two mixing chambers (40, 42) is arranged. Device according to one of the preceding claims, characterized by a button or other sensor (26) for registering a defined mounting position of the cage on the device (10), wherein the second gas port (28) and the third gas port (30) fluidly contact the cage , Device according to one of the preceding claims, characterized by a rail system (16) for mounting the cage to the device (10). Device according to one of the preceding claims, characterized by a base element (12), in particular a bottom plate, on which the mixing device (14) is attached. A method for killing at least one small animal, in particular a rodent, by introducing a CO ₂ -containing gas mixture into a cage housing the small animal, wherein in a continuous or quasi-continuous process - the cage is deprived of atmosphere, - this withdrawn atmosphere CO ₂ - Gas is mixed and - the resulting CO ₂ -containing gas mixture is fed back into the cage.

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