How To Hold A Lab Rat To Keep It Still

Overview

Source: Kay Stewart, RVT, RLATG, CMAR; Valerie A. Schroeder, RVT, RLATG. University of Notre Matriarch, IN

Information technology has been demonstrated that even minimal handling of mice and rats is stressful to the animals. Handling for cage changing and other noninvasive procedures causes an increase in heart rate, blood pressure, and other physiological parameters, such as serum corticosterone levels. Fluctuations tin continue for up to several hours. The methods of restraint required for injections and blood withdrawals likewise cause physiological changes that can potentially affect scientific information. Training in the proper treatment of mice and rats is required to minimize the effects to the animals.^one Mice and rats can be restrained manually with restraint devices, or with chemical agents. Manual methods and the use of restraint devices are covered in this manuscript. All restraint methods include the process of lifting the animals from their home cage.

Principles

Common methods for removing either a mouse or a rat from its cage involve lifting the creature by the tail, using forceps to grab the scruff of the neck or base of the tail, using a tube or other enrichment device,ⁱⁱ grasping around the trunk, or scooping the animal into the palm.^3,iv

When lifting a mouse or rat past the tail, it is imperative that the tail be grasped at the base virtually the rump of the brute. Should the brute be lifted from the finish of the tail, the skin of the tail can deglove and be pulled off by the stress of the body weight; a degloving injury will result in the tail being amputated.³ Moving an animal from one cage to another, or to a working surface, should be done quickly and steadily. Suspending the animal in the air for whatsoever length of time will non only crusade distress, but tin also cause the fauna to twist or struggle, possibly resulting in impairment to the tail. The handler should not place their manus under the animal because-equally information technology is lifted by its tail-it is instinctive for the animal to try to grasp the hand for security, resulting in a seize with teeth.

In many mouse product facilities, forceps are used to remove animals from their cages. This is done for biosecurity, as it is believed that there is less gamble for cross-contamination from animate being to animal. The forceps tips should be stored in booze between handling of private animals, or groups of animals. There are a variety of forceps used to grasp mice. The most commonly used include long dressing forceps with atraumatic tips-or with condom, plastic, or silicone tubing placed over the ends of the forceps to provide a cushion-or tongue forceps with rubber grips.⁴

Forceps can grasp a mouse either at the scruff of the neck or at the base of the tail. Virtually mice go accepted to this method quickly and do not struggle. However, patience and practice is necessary to go expert at catching the animals. Beginners will demand to be trained on how tightly to grasp the mice, especially at the scruff, as this could interfere with breathing. When using forceps on the tail, care must be taken to place the forceps near the base of the tail to avert injury.

For animals that are anxious or showroom stereotypies, placing tubes into the muzzle may subtract handling difficulty, and reduce the flight/fright response to daily animal husbandry. A tube made of a nonporous material can be added for enrichment, and serve as a place for the animate being to shelter or seek safe refuge. Such tubes tin be open-ended or capped on one stop. Almost mice or rats volition willingly go into the tubes when their cage is opened, or they can be easily guided to the tube. In one case the animal is within the tube, the open end is covered to send the animal to the new location. When placed in a fresh cage, the tube can exist gently tipped upwards to encourage the animals to get out it. Animals are easily conditioned to this method of muzzle changing and will immediately enter the tubes, making this method every bit quick and easy equally others for moving animals from i identify to another. Although tubes do not have to exist present in the dwelling muzzle to be effective, having a tube in the primary enclosure increases recognition of a familiar prophylactic site, as well equally provides muzzle enrichment.^two

Some institutions adopt that animals be lifted by the body for routine treatment, especially for treatment rats. Animals must exist habituated to this method from an early historic period. Young rats between 2-4 weeks of age tend to spring direct up. Placing a hand over the rat'south back will crusade it to bound into the palm of the handler, assuasive information technology to be grasped. A second hand may be needed to prevent the rat from squirming out of grasp before placing it into another cage. Adult rats are gently grasped around the thorax, lifted, and quickly placed into another cage, or onto a surface.

When changing cages with neonate mice or rats, information technology is often necessary to remove them while keeping the nest intact. With the apply of ii easily to scoop the nest and neonates from the lesser of the cage, the intact nest is moved into a new cage. However, to avoid dropping pups, the fingers of each hand must be held closely together. Once moved to a new cage, information technology is important to verify that the pups are all present. Information technology is advisable to count the pups before and after moving them. A plastic scoop may be used instead of the easily. If this method is used, a hand should be placed over the top of the scoop to prevent neonates from fluctuant or jumping out of the scoop. This method of transferring pups, compared to the individual treatment of the pups, is less distressing to both the pups and the dams.

Restraint for technical procedures requires a confident and firm, merely gentle, touch. Tentative approaches can event in handler bites. If the handler recoils every bit an brute squeals, that animal apace learns how to avoid restraint. Notwithstanding, ambitious handling can result in the injury or death of rodents. A balance of an assertive notwithstanding gentle approach is the goal for rodent treatment.

Mice and small rats can be restrained by grasping the skin at the nape of the neck, referred to as scruffing. Precautions for this method include both grasping the peel also firmly or as well loosely. If the skin is grasped too tightly, the airway can get constricted, which can lead to decease. If grasped too loosely, the animal will be able to plough its head and potentially bite the handler.

Animals that are agitated or extremely fearful are much more than likely to bite. It is best to calm the creature prior to handling. There are diverse calming techniques that accept been tried with varying success. The near reliable method is to use some sort of chemical restraint, almost ofttimes an inhalation anesthetic. Isoflurane or sevoflurane are brusk-acting inhalation anesthetics that can exist delivered with only the handling required to transfer the animal from its muzzle to an induction sleeping room. Once the animal is anesthetized, they tin can exist manipulated or manually restrained for the process.

A method for calming a rat is to wrap it in a thick terry towel, allowing it to hide under the towel. Placing it on a lab coat sleeve so that they can bury their head in the folds at the elbow may as well provide a sense of safety security to the animate being. This same result can be accomplished by placing the animal in a night area for a few minutes.

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one. Scruffing

Mice are nigh often restrained using the scruffing technique, but immature rats can also be restrained with this method. Adult rats are more hard to restrain with this technique due to a more than muscular neck, a reduced amount of loose skin, and an aversion to this method.

The one-handed restraint method is utilized most oftentimes in mouse strains that are very calm, such every bit the athymic nude, SCID, and some GEM strains. However, at that place is a greater chance for being bitten with this method. Novice brute handlers should become comfortable with the 2-handed restraint technique before attempting the i-handed method.
1. Place the creature on a surface that they can grip, such every bit a wire bar muzzle top or a mat.
2. Hold the tail between the third and fourth fingers of the nondominant hand, and employ gentle backward traction. This causes the animal to agree onto the surface, and results in the body being stretched and elongated.
3. Plow the paw so that the palm is facing the body of the animal.
4. With the index finger and thumb, pin the rodent over the shoulders.
5. Gently slide the thumb and index finger forrad, and position them at the base of the skull. Grasp the loose skin at the neck and lift the creature.
6. Use the middle finger to stabilize the animal along the dorsum past pinning the dorsal peel against the base of the pollex.
Two-handed restraint
1. Place the creature on a surface that they tin grip.
2. Hold the tail at the base (within 1-two cm of the body) with the dominant mitt, and use gentle astern traction. This causes the animal to hold onto the surface, and results in the body existence stretched and elongated.
3. With the alphabetize finger and thumb of the other paw, pivot the rodent over the shoulders.
4. Gently slide the pollex and index finger forward, and position them at the base of the skull. Grasp the loose pare at the neck and elevator the animal.
5. Employ the remaining fingers to stabilize the beast along the back past pinning the dorsal skin against the base of the pollex.
6. Secure the hindquarters by pinning the tail against the palm with the fourth finger, or by allowing the hind limbs to rest on a solid surface.

Effigy ane: One-handed and two-handed restraint method for mice

two. Gloves

There are a diversity of gloves available for handlers to wear for protection from rat bites. They are generally unsuitable for work with mice due to the loss of dexterity. Often, the disadvantages of many glove types outweigh the advantages.

Cotton wool sheet work gloves are not seize with teeth resistant, simply provide a modest amount of protection from teeth and nails. They do not provide proficient grip as they slide easily over the fur.
Skilful quality leather gloves are bite resistant. However, their stiffness causes a reduction in dexterity. The thickness of the leather, though protective, reduces tactile acuity and mitt mobility.
Chain mail gloves provide a psychological sense of security for the creature handler. Still, they are heavy and most rats' teeth can penetrate between the links. In addition, these gloves decrease manual dexterity, and if used improperly are more unsafe for both the animal and the handler.
Rubber-insulated gloves that are commonly used in homes for washing dishes provide a textured palmar surface, and let for a secure grip on the hair glaze of rodents. The stretchy latex surface is thick enough to resist puncture by rodent incisors, and thin enough to be able to feel and command the animal. The major disadvantage is that they are made of latex, which is a business concern for persons with latex allergies. Furthermore, these gloves deteriorate in light, and need to be replaced regularly.

3. Body Restraint

The "T. king grip" is a two-handed restraint method for rats.
1. Identify a rat on a surface that can be gripped.
2. Holding the base of the tail with 1 hand, bring the other hand upwards and over the dorsum with the index and middle fingers divide.
3. Identify the hand over the shoulder with the index finger on i side of the head, and the middle finger on the other side. The fingers on each side of the head restrict side-to-side movement of the head.
4. Encircle the torso behind the forelegs with the tertiary finger, the 4th finger, and the thumb. Intendance must exist taken to avoid compressing the chest and compromising respirations. This grip prevents the rat from moving frontwards or backward out of the hand.
5. Stabilize the tail and hindquarters by grasping the base of the tail with or without holding onto the hind feet.
6. This restraint works well with larger rats, and when admission to the head is needed.
The forelimb crisscross method is a two-handed restraint method.
1. Place the animal on a surface that they tin can grip.
2. Hold the tail at the base (within ane-ii cm of the trunk) with the dominant hand and apply gentle backward traction. This causes the animal to grip onto the surface, and results in the body being stretched and elongated.
3. Bring the other hand from behind over the back.
4. Grasp the rat direct behind the shoulders, with the fingers on one side and the thumb on the other side of the chest, and slide the hand forwards, thus forcing the forelegs forward.
5. The forelegs will cross under the rat's mentum, creating a physical bulwark and preventing the rat from moving its head down toward the fingers.
6. Accept care to avoid compressing the breast and compromising respirations.

Figure ii: T-rex grip and forelimb crisscross method for restraining rats

4. Restraint devices

Effigy 3: Broome-fashion restraining device

Figure 4: Apartment-bottomed rodent restrainer

Rigid devices come in a variety of types, and are generally made of nonporous material that is hands disinfected.
1. The Broome-style restraint is designed to provide admission to the tail for intravenous injections. It is constructed with a slot that runs forth the full length of the device, which allows the animal to be pulled into the restrainer hindquarters first. A plastic nosepiece is inserted to hold the animal in place.
  1. Remove the nosepiece from the body of the restraint tube past loosening the screw.
  2. Grasp the animate being at the base of operations of the tail, and orient the restraint tube then that the slit that runs the length of the tube is facing up. Gently pull the creature into the restraint device hindquarters first.
  3. It is often advantageous to place the animal on a smooth surface to facilitate its placement into the tube.
  4. One time the animal is fully in the tube-and has been fatigued to the airtight end-slide the plastic nosepiece into the tube to occlude the opening.
  5. Place the nosepiece associates and so that the animal's olfactory organ is in the eye opening. Do not position the nosepiece so tightly that the animal cannot exhale.
2. The flat-bottomed rodent restrainer is a half cylinder with openings that allow admission from the elevation and the lesser of the restraint device. A rigid plastic gate is inserted into one of several graduated slots to hold the animal inside the device.
  1. Hold the beast by the base of the tail with the dominant hand on a smooth surface, or on a muzzle tiptop.
  2. Hold the flat-bottomed restraint tube in the other mitt, and angle information technology and then that the open terminate is at the animal'south head at a 45° angle to the table/cage acme surface.
  3. Some animals volition immediately enter the tube, while others are reluctant and require the handler to steer them into the tube.
  4. Place the tube over the animal's caput. Immediately tap the animal's rump and maintain pressure to prevent the beast from backing up.
  5. Once the animal is in the restraint device, slide the plastic gate into the appropriate slot to hold the animal in the restraint device.
3. Tube restraints are Plexiglass cylinders with ane closed end containing holes or slits for air circulation. Some are modified with a broad slothalf the length of the cylinderto accommodate exposure of a hind limb for intramuscular injections, saphenous and femoral claret collection, or admission to the dorsal surface for subcutaneous injections.
  1. Grasp the animal by the base of operations of the tail with the dominant paw on a smooth surface, or on a muzzle top.
  2. Concur the restraint tube in the other hand and angle information technology so that the open up stop is at the animal'due south caput at a 45° angle to the tabular array/cage top surface.
  3. Some animals volition immediately enter the tube. Other animals are reluctant and require the handler to steer them into the tube.
  4. Place the tube over the animal's caput. Immediately tap the brute's rump and maintain pressure to prevent the beast from backing up.
  5. Scruff and manually guide unmanageable animals into the tube, allowing the skin beingness held to slide through the slit in the tube.
  6. Once the animal is in the restraint device, it is necessary to occlude the opening to forbid the beast from backing upward.
  7. Depending on the process, several fingers are placed across the opening.
  8. Stuff a large latex glove into the opening. The gloves are usually textured and will grip the Plexiglass surface.
  9. Some restraint tubes will have closures specific to that style or size.

Figure five: Tube restraining device

Flexible restrainers are disposable flexible plastic cones. They are bachelor in either transparent or opaque plastic. The plastic is thin enough to allow penetration past a needle to accomplish injections without removing the brute from the restraint device. They come in a diversity of sizes to fit mice and rats, both adult and weanling.
1. Cut the plastic with scissors to allow access to the limbs, the tail, and other injection sites.
2. Select a cone size advisable for the animate being. The cone should exist long enough to extend two-3 inches across the animal'due south rump.
3. Insert the beast into the cone
  1. Open the cone and grasp it around the upper half.
  2. Grasp the beast by the base of operations of the tail with the dominant mitt, placing information technology on a polish surface or a cage top.
  3. Concur the restraint cone in the other mitt, and angle information technology so that the open end is at the beast's caput at a 45° angle to the tabular array/muzzle top surface.
  4. Some animals volition immediately enter the cone. Other animals are reluctant and require the handler to steer them into the restraint cone.
  5. Identify the cone over the animal's head. Immediately tap the creature'due south rump and maintain pressure to prevent the animal from backing up. Due to the larger diameter of the cone opening, animals are much more likely to turn effectually to go out the cone.
  6. Every bit soon as the creature enters the cone, grasp the open end and seal it to force the creature to the end.
  7. Secure the opening past folding the plastic to one side of the tail and applying the binder clip to the folded plastic, being careful to avoid clamping the tail or skin. Alternatively, gather the plastic effectually the tail evenly, and place the twist tie as close to the body as possible to secure the opening.

Figure 6: Flexible restrainer

five. Restraint methods for specific technical procedures

Ventral exposure is required for intraperitoneal injections.
1. Scruffing
  1. Scruff the creature and plough the manus so that the belly is exposed.
  2. Tilt the animal so that the head is pointing downwardly at a thirty° bending.
  3. Secure the hindquarters by pinning the tail against the palm using the fourth finger.
  4. Alternatively, the hindquarters can exist immobilized by pinning the backlog skin forth the back betwixt the fingers and the base of the thumb.
2. T. rex grip and forelimb crisscross restraint methods
  1. Grasp the animal (rats but) using either of the above techniques.
  2. With the costless paw, grasp both hind legs above the hock, and extend them caudally.
  3. Support the weight of the animal with the palm of the hand on the back.
  4. Tilt the beast and so that the head is pointing downward at a 30° angle.
  5. A second person performs the injection.
3. Rigid restrainer
  1. About rigid restraint devices cannot preclude the fauna from instinctively rolling to remain upright.
  2. If a rigid restrainer is employed, plow the brute so that its head is pointed down and is perpendicular to the tabletop.
4. Flexible restrainer
  1. When placed properly in a flexible plastic cone, the animal is unable to turn over or effectually.
  2. Care must be taken to position the beast such that the hind limbs are sufficiently separated to allow admission to the abdomen.
  3. As the fauna is compressed, it is imperative that the injection be low enough on the ventral surface to avoid puncture of the spleen, liver, kidney, or tummy.
Dorsal exposure is required for injections into the subcutaneous space.
1. Scruffing
  1. Scruff the fauna and permit its hind legs to rest on a solid, flat surface.
  2. Elevator the scruff to create a tent of skin over the neck and shoulders.
  3. Place the weight of the hand on the tabular array when injecting mice. Placing weight on the mouse can cause suffocation.
  4. Concur rats in place with weight on the hindquarters, but never the chest.
  5. Inject the substance into the space below the fingers on the body of the animal.
2. Rigid restrainers
  1. Place the brute in a restraint device with an opening large plenty to pull the peel up.
  2. It may exist necessary to use forceps to grasp the skin.
  3. Most animals remain in the proper posture unless the restraint is rotated.
  4. Do not inject a volume that prevents the skin from receding from the opening once the injection is complete.
The restraint of the hind limb is necessary for intramuscular injection; blood withdrawal from the saphenous vein, femoral vein, or femoral artery; and injection into the footpad.
1. Scruffing of mice and small rats (under 200 thou)
  1. Scruff the animal and turn the paw so that the belly is exposed.
  2. Access the hind foot by placing the foot between the fingers.
  3. This method is best used only for footpad injections.
2. T. rex grip or forelimb crisscross
  1. This method requires 2 people: one for restraint of the body, and ane for restraint of the limb and the functioning of the injection.
  2. Extend the rat's hind leg by grasping the foot for admission to the saphenous vein, femoral vein or artery, or the muscle for injection.
  3. Hold the leg just above the hock for injection of the footpad.
3. Rigid restrainers
  1. Place the animal in a restraint tube head first.
  2. Expose the tail and hindquarters past gently pulling them backward from the tube.
  3. Immobilize the leg past grasping the skin of the flank and locking the genu straight. This provides admission to the quadriceps musculus for injection in the mouse or rat, and prevents the animate being from exiting the restraint device.
  4. In devices with large slots, position the leg outside the tube for access to the blood vessels for sampling or footpad injection.
  5. Those restraint tubes with flat terminate pieces allow the tube to rest on the table and stabilize the device during the procedure.
  6. Because the creature is secured in this manner, it is possible to perform injections or blood sampling of rats by a single technician.
4. Flexible restraint
  1. Flexible plastic restraints tin can exist modified by cutting openings to accommodate the exposure of limbs.
  2. The openings fabricated can be customized for each fauna, or for specific procedures.
  3. As the brute is secured in this manner, it is possible for a single technician to perform injections or blood sampling of rats.

Rodents are widely used model organisms to investigate various scientific questions, and it has been demonstrated that fifty-fifty minimal handling is stressful for these animals.

Handling for simple tasks such as cage changing may cause an increase in heart rate, blood force per unit area, and serum corticosterone levels, and these fluctuations tin can continue for several hours. The methods of restraint required for common injection and blood withdrawal procedures tin too cause physiological changes, which tin can potentially affect the scientific data. Therefore, training for proper treatment of mice and rats is required to minimize these effects on animals.

In this video, we volition first review the bones techniques for handling rodents, and then we'll discuss the rodent restraint procedures including manual techniques and methods involving usage of restraining devices.

Let's begin past discussing the basics of rodent treatment. One of the most mutual methods for moving either an adult mouse or rat is by lifting the animal past its tail. While doing this, information technology is imperative that the tail be grasped at the base of operations near the rump. If the creature is lifted by the terminate of its tail, the skin tin exist pulled off due to the body weight and may lead to an injury resulting in tail amputation. Chiefly, moving an animal from one place to some other should be done speedily and steadily. Suspending the animal in air for any length time will not only crusade distress, but will also cause the animal to twist or struggle, possibly causing harm to the tail. Also, the handler should not identify a paw under the animal, considering it may try to grasp it for security, resulting in a bite.

Another method for handling adult rodents is to use forceps. Types of forceps unremarkably used are long-dressing forceps or tongue forceps with rubber, plastic, or silicone tubing placed over the ends to provide a cushion. The forceps tin grasp the mouse either at the scruff of the neck or at the base of the tail. The use of forceps minimizes cross contamination from animal to animal, and it is quicker and less expensive than irresolute gloves between each animal cage. Beginners will need to be trained on how tightly to grasp the mice with forceps, peculiarly at the scruff as information technology could interfere with breathing. When using the forceps on the tail, intendance must be taken to place the forceps near the base of the tail to avoid injury. Remember to store them facedown in 70% ethanol between handling of unlike groups of animals.

Also, one can use tubes made of a non-porous material to transfer animals. These tubes can be added to a cage as a identify for the animal to shelter or seek safe refuge. Most mice or rats would willingly enter the tubes when their muzzle is opened, or they can be easily guided into the tube. When the animal is inside, embrace the open ends with your palm and fingers. Next, to encourage the animal to get out, gently tip the tube upward in the new cage. Animals are easily conditioned to this method of cage changing, making this a quick and easy process for moving animals from i place to another.

Some institutions prefer that animals-especially rats-be lifted by their body, even while routine handling. Developed rats are gently grasped around the thorax, lifted, and speedily placed into another cage. It is of import that animals are habituated to this method of handling from an early age. When working with immature rats, placing a paw over the rat'south dorsum will cause it to leap into the palm of the handler allowing it to exist grasped. A second mitt may be needed to forestall the rat from squirming from the grasp.

When changing cages with neonate mice or rats, it is often necessary to remove them while keeping the nest intact. Utilise two hands to scoop the nest and pups from the bottom of the muzzle into a new muzzle. Hold your fingers close together to avert dropping the pups. Once the nest has been moved to a new cage, information technology is important to verify that all the pups are nowadays. Alternatively, a plastic scoop may be used to move neonate rodents in their nests. While doing this, information technology is of import that you lot place your hand over the superlative of the scoop to preclude neonates from wiggling or jumping out. Compared to the private handling of the pups, scooping the entire nest is less distressing to both the pups and the dams.

Now that we have discussed the nuts of rodent handling, permit's delve into detailed procedures for rodent restraint. Outset we will outline how to restrain these animals manually. Mice and young rats can be restrained using the one handed or the two-handed technique. However, for adult rats, total body restraint using the T-rex grip or the forelimb crisscross method, are the preferred techniques.

Let'due south begin by learning the two-handed restraint method. First, place the animal on a surface they can grip, such as the wire bar lid. With your dominant hand, hold the tail at the base of operations and gently tug the mouse backwards. This causes the animate being to concur onto the surface and let its body to be stretched. Side by side, gently pin the rodent with your non-dominant index finger and thumb positioned at the base of the skull, and grasp the loose skin on the cervix to lift up the animal. Utilise your remaining fingers to stabilize the animal with its back against the base of your thumb. You lot can secure the hindquarters by pinning the tail with your band finger against the palm of your hand.

For the 1-handed restraint method, again place the animal on a surface that it can grip. Hold the tail between the third and fourth fingers of your non-dominant mitt and apply gentle backward traction. With your alphabetize finger and thumb of the same manus, pin the rodent over the shoulders. Gently slide your pollex and alphabetize finger forward and grasp the loose skin at the cervix and lift the animal. Utilize your middle finger to stabilize the animate being along the dorsum by pinning the dorsal skin confronting the base of the thumb.

The third restraint method we will talk over is the T-rex grip- a 2-handed restraint method for rats. First, place the rat on a solid surface, similar a mat, that it can grip. While holding the base of the tail with one hand, place your other hand over the rat's shoulder with your index and middle finger carve up on either side. This is to restrict the side-to-side head move. Once the head is stabilized, encircle the body behind the forelegs with the eye and ring fingers and the thumb. Avoid compressing the breast so that information technology does not compromise the animal'southward breathing. Finally, stabilize the tail and hindquarters by grasping the base of the tail WITHOUT holding onto the hind feet, if you plan to administrate an oral gavage; or WITH property onto the hind feet, if the intention is to inject the animal.

Lastly, to restrain a rat using the forelimb crisscross method, identify the fauna on a surface it can grip. Then with your dominant hand, hold the tail at the base and apply gentle backward traction and then that the animal'due south body elongates. Next, with your other hand, grasp the animal directly backside the shoulders, with your fingers on one side and thumb on the other side of the chest, and slide the hand forward. This motion will strength the animal's forelegs to cantankerous under its chin, creating a concrete barrier that prevents the beast from moving its head downwardly. Have care to avoid compressing the chest, which will lead to difficulty in breathing.

Now that nosotros take reviewed the manual restraint techniques, let's learn how to restrain rodents using specialized devices.

The first device that nosotros'll learn nigh is the Broome-fashion restraint device. It has a slot that runs along the total length of the device and a plastic nosepiece, which is inserted to hold the animal in place. Beginning past loosening the screw to remove the nosepiece. And then, orient the restraint tube such that the slit is facing up. Grasp the brute at the base of the tail and gently pull the creature into the restraint device, hindquarters beginning. Once the brute is inside, slide the plastic nosepiece dorsum into the tube to preclude it from opening. Identify the nosepiece such that the animal's nose is centered in the opening. Do not position it and then tightly that the fauna cannot breathe.

Another example of a restraint device is the apartment-bottomed rodent restrainer, which is a half cylinder with openings that let access from the top and the bottom of the device. Information technology likewise has slots in which a rigid plastic gate can be inserted to hold the animal in place. To utilize this restrainer, grasp the rodent by the base of the tail with your dominant hand and place it on a smooth surface. Using your other mitt, concur the flat-bottomed restraint tube so that the open terminate is at the animal'due south head at a 45° angle to the surface. Place the tube over the animal's caput, and immediately tap the rump to prevent the brute from bankroll up. Once it is in the device, slide the plastic gate into the advisable slot to secure the animal's position.

The third blazon of device that nosotros'll talk over is tube restraints. These are Plexiglass cylinders with one airtight end containing holes for air apportionment, and a slit at the open up cease. To employ a tube restraint, grasp the animal and identify information technology on a smooth surface. Side by side, place the open stop of the tube at the creature'due south head at a 45° angle. As shortly as the rodent enters the tube, tap the rump to prevent it from backing up. Finally, occlude the opening by stuffing a large latex glove, which volition grip the Plexiglass surface and prevent the beast from exiting the tube.

Lastly, we will discuss how to use flexible restrainers, which are dispensable flexible plastic cones available in different sizes. Pick of a cone depends on the animal size. Ideally, it should be long enough to extend two-3 inches beyond the animal's rump. Like previous methods, place the animal on a smooth surface and place restraint cone at a 45° angle over the animate being's head. As soon equally the beast enters the cone, grasp the open end and seal it to force the animal to the end. Secure the opening by folding the plastic to one side of the tail and applying a binder prune to the folded plastic being careful to avert clamping the tail or skin.

Afterward discussing the basics of handling and different restraining techniques, let's review why having an understanding of these procedures is necessary for whatever in vivo scientist.

The knowledge and rationale behind these bones handling procedures is at the cadre of maintaining creature's wellness. From the time the animals are built-in, they are handled for elementary, solar day-to-day activities like weighing, inspection and cage changing, which ought to be performed irrespective of the scientific objective.

The restraining procedures are also useful for marking purposes. For case, in club to perform procedures like ear punching the animal need to exist restrained past scruffing. On the other hand, a restraint device should be used when inserting a microchip in rats so that they can be tagged permanently.

Lastly, the manual restraining methods are used for mutual injection procedures similar subcutaneous and intraperitoneal administration. And the cognition of restrain devices is useful when performing intravenous assistants, which demands minimal fauna movement during the injection.

You've just watched JoVE's introduction to basic handling and restraint techniques for rodents. These procedures require a confident and house, but gentle touch. Tentative approaches tin can effect in handler bites, while aggressive handling tin cause injury to the rodent. Therefore, it is of import to acquire these techniques thoroughly and find a balance of an assertive notwithstanding gentle grip. As ever, thanks for watching!

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Applications and Summary

Routine treatment for muzzle changing and technical procedures is a crusade of stress for experimental animals. Although this type of stress is not a threat to the overall wellbeing of the beast, it can crusade fluctuations in physiologic parameters that can take an agin effect on the research data. The use of skilled personnel, proper techniques, and equipment can mitigate some of the stress.

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References

Balcombe, J.P., Barnard, N.D., and Sandusky, C. 2004. Laboratory routines cause animate being stress. Contemporary Topics. 43:6. 42-51
Gouveia, Chiliad. and Hurst, J.L. 2022. Reducing mouse anxiety during handling: issue of experience with treatment tubes.
AALAS Learning Library*. Animal handling and restraint in: Working with the laboratory rat. https://world wide web.aalaslearninglibrary.org/Pages/Courses/CourseAllPages.aspx?intLessonID=27691
AALAS Learning Library*. Animal handling and restraint in: Working with the laboratory mouse. https://www.aalaslearninglibrary.org/Pages/Courses/course.aspx?intCourseID=2451&intPageID=94993

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Rodents are widely used model organisms to investigate various scientific questions, and information technology has been demonstrated that even minimal handling is stressful for these animals.

Handling for simple tasks such as cage changing may cause an increment in eye rate, blood force per unit area, and serum corticosterone levels, and these fluctuations can keep for several hours. The methods of restraint required for common injection and blood withdrawal procedures can as well cause physiological changes, which can potentially affect the scientific data. Therefore, preparation for proper handling of mice and rats is required to minimize these effects on animals.

In this video, nosotros will first review the basic techniques for treatment rodents, and then nosotros'll discuss the rodent restraint procedures including manual techniques and methods involving usage of restraining devices.

Let's begin by discussing the nuts of rodent handling. One of the almost mutual methods for moving either an adult mouse or rat is by lifting the animate being by its tail. While doing this, information technology is imperative that the tail be grasped at the base of operations near the rump. If the animate being is lifted by the end of its tail, the skin can be pulled off due to the trunk weight and may lead to an injury resulting in tail amputation. Importantly, moving an animal from one identify to another should be done rapidly and steadily. Suspending the animate being in air for any length fourth dimension will not just crusade distress, just will too cause the animal to twist or struggle, possibly causing harm to the tail. Likewise, the handler should not place a hand under the fauna, considering it may try to grasp it for security, resulting in a seize with teeth.

Another method for handling adult rodents is to use forceps. Types of forceps commonly used are long-dressing forceps or natural language forceps with condom, plastic, or silicone tubing placed over the ends to provide a absorber. The forceps can grasp the mouse either at the scruff of the cervix or at the base of the tail. The apply of forceps minimizes cross contamination from animal to animal, and it is quicker and less expensive than changing gloves between each animate being cage. Beginners volition demand to be trained on how tightly to grasp the mice with forceps, especially at the scruff every bit it could interfere with animate. When using the forceps on the tail, care must be taken to place the forceps near the base of the tail to avoid injury. Call up to store them facedown in 70% ethanol between handling of different groups of animals.

Also, one tin use tubes fabricated of a non-porous material to transfer animals. These tubes can exist added to a cage as a place for the animal to shelter or seek condom refuge. Most mice or rats would willingly enter the tubes when their cage is opened, or they can be easily guided into the tube. When the animal is inside, cover the open ends with your palm and fingers. Side by side, to encourage the animal to go out, gently tip the tube upwards in the new cage. Animals are easily conditioned to this method of muzzle changing, making this a quick and easy process for moving animals from i place to another.

Some institutions prefer that animals-especially rats-exist lifted by their body, even while routine handling. Adult rats are gently grasped around the thorax, lifted, and quickly placed into another cage. It is of import that animals are habituated to this method of handling from an early age. When working with young rats, placing a manus over the rat's back volition crusade it to jump into the palm of the handler allowing it to exist grasped. A second hand may exist needed to prevent the rat from squirming from the grasp.

When changing cages with neonate mice or rats, it is often necessary to remove them while keeping the nest intact. Use two easily to scoop the nest and pups from the bottom of the cage into a new cage. Concur your fingers close together to avert dropping the pups. In one case the nest has been moved to a new cage, it is important to verify that all the pups are present. Alternatively, a plastic scoop may exist used to move neonate rodents in their nests. While doing this, it is important that you place your hand over the top of the scoop to forestall neonates from wiggling or jumping out. Compared to the individual treatment of the pups, scooping the entire nest is less distressing to both the pups and the dams.

Now that nosotros have discussed the basics of rodent handling, permit'southward delve into detailed procedures for rodent restraint. Get-go nosotros will outline how to restrain these animals manually. Mice and young rats can be restrained using the one handed or the ii-handed technique. Even so, for adult rats, full body restraint using the T-rex grip or the forelimb crisscross method, are the preferred techniques.

Let'due south begin by learning the two-handed restraint method. Commencement, identify the animal on a surface they can grip, such every bit the wire bar chapeau. With your dominant manus, concord the tail at the base and gently tug the mouse backwards. This causes the animal to hold onto the surface and allow its trunk to be stretched. Side by side, gently pivot the rodent with your non-dominant index finger and thumb positioned at the base of the skull, and grasp the loose skin on the neck to lift up the animal. Utilise your remaining fingers to stabilize the animal with its back confronting the base of your thumb. Y'all can secure the hindquarters by pinning the tail with your ring finger against the palm of your hand.

For the one-handed restraint method, again place the brute on a surface that it tin can grip. Hold the tail betwixt the 3rd and fourth fingers of your non-ascendant hand and employ gentle backward traction. With your index finger and pollex of the aforementioned hand, pin the rodent over the shoulders. Gently slide your thumb and alphabetize finger forrard and grasp the loose skin at the neck and elevator the animal. Use your middle finger to stabilize the animal along the back by pinning the dorsal pare against the base of operations of the thumb.

The third restraint method we will discuss is the T-male monarch grip- a two-handed restraint method for rats. First, place the rat on a solid surface, like a mat, that it can grip. While holding the base of operations of the tail with one hand, place your other paw over the rat'southward shoulder with your index and middle finger split up on either side. This is to restrict the side-to-side head movement. Once the caput is stabilized, encircle the body behind the forelegs with the centre and ring fingers and the thumb. Avoid compressing the chest so that it does not compromise the animal'due south breathing. Finally, stabilize the tail and hindquarters by grasping the base of operations of the tail WITHOUT property onto the hind feet, if you plan to administrate an oral gavage; or WITH holding onto the hind anxiety, if the intention is to inject the animal.

Lastly, to restrain a rat using the forelimb crisscross method, place the animal on a surface it can grip. And then with your dominant mitt, hold the tail at the base of operations and utilise gentle backward traction so that the beast's body elongates. Next, with your other hand, grasp the animal directly behind the shoulders, with your fingers on ane side and thumb on the other side of the chest, and slide the hand frontward. This motion will force the animal'due south forelegs to cantankerous nether its chin, creating a concrete barrier that prevents the animal from moving its caput down. Take care to avoid compressing the breast, which will atomic number 82 to difficulty in breathing.

At present that we have reviewed the manual restraint techniques, allow'due south learn how to restrain rodents using specialized devices.

The starting time device that we'll learn near is the Broome-mode restraint device. It has a slot that runs forth the total length of the device and a plastic nosepiece, which is inserted to agree the animate being in identify. Outset by loosening the spiral to remove the nosepiece. Then, orient the restraint tube such that the slit is facing up. Grasp the animal at the base of the tail and gently pull the animal into the restraint device, hindquarters get-go. Once the animal is within, slide the plastic nosepiece dorsum into the tube to preclude it from opening. Identify the nosepiece such that the animate being'due south nose is centered in the opening. Do not position it so tightly that the creature cannot breathe.

Another example of a restraint device is the flat-bottomed rodent restrainer, which is a half cylinder with openings that allow admission from the meridian and the bottom of the device. Information technology also has slots in which a rigid plastic gate tin can be inserted to hold the animal in place. To use this restrainer, grasp the rodent by the base of operations of the tail with your dominant hand and place it on a shine surface. Using your other manus, hold the flat-bottomed restraint tube then that the open finish is at the animal's head at a 45° angle to the surface. Place the tube over the animal's head, and immediately tap the rump to forbid the animal from bankroll up. Once it is in the device, slide the plastic gate into the appropriate slot to secure the animal's position.

The 3rd type of device that we'll discuss is tube restraints. These are Plexiglass cylinders with one closed end containing holes for air circulation, and a slit at the open up stop. To use a tube restraint, grasp the fauna and place it on a smooth surface. Adjacent, place the open cease of the tube at the creature'south head at a 45° angle. As before long as the rodent enters the tube, tap the rump to forbid information technology from backing up. Finally, occlude the opening past stuffing a large latex glove, which will grip the Plexiglass surface and prevent the animal from exiting the tube.

Lastly, nosotros will discuss how to apply flexible restrainers, which are disposable flexible plastic cones available in different sizes. Selection of a cone depends on the animal size. Ideally, information technology should exist long enough to extend 2-3 inches beyond the animal'south rump. Similar previous methods, place the creature on a smooth surface and place restraint cone at a 45° angle over the animal's head. As soon every bit the animate being enters the cone, grasp the open end and seal it to force the animate being to the end. Secure the opening by folding the plastic to one side of the tail and applying a folder clip to the folded plastic being careful to avert clamping the tail or skin.

After discussing the basics of handling and different restraining techniques, allow'southward review why having an understanding of these procedures is necessary for any in vivo scientist.

The knowledge and rationale backside these bones handling procedures is at the cadre of maintaining animal's wellness. From the time the animals are born, they are handled for simple, day-to-day activities similar weighing, inspection and cage changing, which ought to be performed irrespective of the scientific objective.

The restraining procedures are besides useful for marking purposes. For example, in order to perform procedures like ear punching the animal need to be restrained by scruffing. On the other hand, a restraint device should be used when inserting a microchip in rats and then that they can exist tagged permanently.

Lastly, the transmission restraining methods are used for common injection procedures similar subcutaneous and intraperitoneal assistants. And the knowledge of restrain devices is useful when performing intravenous assistants, which demands minimal animal movement during the injection.

You've simply watched JoVE'southward introduction to basic treatment and restraint techniques for rodents. These procedures require a confident and firm, but gentle touch. Tentative approaches can result in handler bites, while ambitious handling can cause injury to the rodent. Therefore, it is important to learn these techniques thoroughly and find a balance of an believing even so gentle grip. As always, thanks for watching!