Rabbits, belonging to the small animal category of experimental animals but considerably larger than rats and mice, offer many advantages in experimental research (Mapara et al., 2012). Given their docile and non-aggressive nature, rabbits are easily handled. Their larger size presents many possibilities in the observation, examination and other procedures. In addition, rabbits also have short vital cycles such as gestation, lactation, and puberty, an advantage to longitudinal research paradigms.
A necessity in the use of rabbits for experimental research is the rabbit restrainer, an enclosure which limits movement and immobilizes the animal for a number of purposes. The rabbit restrainer can be used for easier handling and transport, as well as keeping the animal immobile during experimental and surgical procedures while lessening apparent stress or the need for anesthetics (Braverman et al., 1989). Rabbits can become dangerous when nervous, and must, therefore, be carefully handled and properly restrained (Mapara et al., 2012).
The use of rabbit models, however, also come with some disadvantages, such as a lack of well-designed animal cages, expert handlers, and a considerable scarcity of experimental literature. The rabbit restrainer aims to address some of these disadvantages by providing a standardized tool for easy animal handling and observation.
Apparatus and Equipment
Rabbit restrainers are usually made of stainless steel, or plexiglass and other transparent material.
The rabbit is laid flat and positioned inside the restrainer with only its head and neck exposed outside of the restrainer. The typical restrainer consists of padded ear clamps, an adjustable neckpiece, a sturdy backplate, and a grid floor located above a removable collection pan for waste.
Rabbits can be particularly obedient creatures by nature, and thus an important first step to rabbit handling is allowing them to get acclimated to one’s scent before beginning the experimental procedures. All small animals must be handled gently but firmly, approached slowly but purposefully, handled with clean and odorless hands while wearing disposable gloves and a clean laboratory coat (“Handling and Restraint of Small Laboratory Animals”).
Just as important as following appropriate experimental methods are the tools with which they are implemented, such as the rabbit restrainer. Rabbit restrainers are used for transporting and restraining rabbits during experimental protocols. These devices are particularly useful as they provide access to the rabbit’s ears for blood collection or IV injections as well as to the rabbit’s back for subcutaneous or intramuscular injections. The rabbit restrainer keeps the animal immobile during experimental or surgical methods, which works to lessen the animal’s apparent stress or even to deem anesthetic procedures unnecessary. The restrainers must be cleaned and thoroughly disinfected in order to avoid the spread of disease among animals.
Even with the use of the rabbit restrainer, guidelines for the appropriate handling of rabbits must still be observed in order to avoid accidental injuries to the animal, such as common back or spinal damage. If transported without their cages or restrainers, rabbits must be grasped by their excess skin around the dorsal neck or cervical region, and their hind legs must be sufficiently supported.
Rabbit models for wound healing make use of restrainers for their capacity to immobilize rabbits for observation during extended periods of time, without apparent stress or the need for anesthetics (Braverman et al., 1989). Additionally, rabbit models have also been used in the examination of the effects of certain substances on the development of experimental sinusitis (Brown et al., 2004).
A number of studies also look at the extraneous effects of rabbit restrainers on experimental animals, particularly in the form of immobilization stress (Lata et al., 2004). Rabbit restrainers may also be modified to address certain variables, such as shocks treatments and the insertion of electrocardiogram recording electrodes (Gallagher et al., 1987), as well as optokinetic stimulation (Barmack and Young., 1990).
Strengths and Limitations
The effectiveness of rabbit restrainers in limiting movement and immobilizing the animal for a variety of purposes makes it a necessity in the use of rabbits as experimental animals. Rabbit restrainers can be used to transport and restrain rabbits in following key experimental protocols. One documented limitation that must be considered, however, is forced immobilization stress. Stress can come from many sources, and it is imperative that researchers should control possible extraneous influences.
- The rabbit restrainer is an apparatus that limits movement and immobilizes rabbits during experimental procedures.
- Rabbit restrainers may be used for easy handling and transport, as well as keeping the animal restrained during experimental and surgical procedures.
- Rabbit restrainers are usually made of stainless steel, and consist of ear clamps, adjustable neck piece, sturdy backplate, and grid floor elevated over a removable collection pan for waste.
Barmack, N. H., & Young, W. S. (1990). Optokinetic stimulation increases corticotropin-releasing factor mRNA in inferior olivary neurons of rabbits. Journal of Neuroscience, 10(2), 631-640.
Braverman, B., McCarthy, R. J., Ivankovich, A. D., Forde, D. E., Overfield, M., & Bapna, M. S. (1989). Effect of helium‐neon and infrared laser irradiation on wound healing in rabbits. Lasers in surgery and medicine, 9(1), 50-58.
Brown, C. L., Graham, S. M., Cable, B. B., Ozer, E. A., Taft, P. J., & Zabner, J. (2004). Xylitol enhances bacterial killing in the rabbit maxillary sinus. The Laryngoscope, 114(11), 2021-2024.
Gallagher, M., Meagher, M. W., & Bostock, E. (1987). Effects of opiate manipulations on latent inhibition in rabbits: Sensitivity of the medial septal region to intracranial treatments. Behavioral Neuroscience, 101(3), 315.
Lata, H., Ahuja, G. K., Narang, A. P. S., & Walia, L. (2004). Effect of immobilisation stress on lipid peroxidation and lipid profile in rabbits. Indian Journal of Clinical Biochemistry, 19(2), 1.
Mapara, M., Thomas, B. S., & Bhat, K. M. (2012). Rabbit as an animal model for experimental research. Dental research journal, 9(1), 111.
Handling and Restraint of Small Laboratory Animals. Thiel College Institutional Animal Care and Utilization Committee. Retrieved from: https://www.thiel.edu/assets/documents/academics/iacuc/IACUC-handling-and-restraint-of-small-laboratory-animals.pdf