Assistant Laboratory Animal Technician (ALAT) Practice Exam

Why is cervical dislocation less commonly used with rats compared to mice?

1. Rats are younger

2. Rats are larger in size

3. Rats have more weight restrictions

4. Rats are more agile

The correct answer is: Rats are larger in size

Cervical dislocation is a method of euthanasia that relies on the rapid displacement of the cervical vertebrae, which can be more challenging to perform effectively on larger animals due to their size and muscle mass. Rats are significantly larger and heavier than mice, making the technique more difficult to execute accurately. The increased mass requires more force and precision, which may lead to difficulties in achieving the desired outcome quickly and humanely. Additionally, larger animals like rats have a greater potential for injury when this method is improperly administered, which underscores the importance of using euthanasia techniques that are appropriate for the size of the animal. Therefore, the larger size and weight of rats compared to mice is a fundamental reason that cervical dislocation is used less commonly with them. This aspect highlights the need for practitioners to select euthanasia methods that are specifically suited to the species and size of the animal to ensure humane treatment and compliance with ethical standards in laboratory settings.