U5Ch21 : Gerbils

Question 1

Gerbil nicknames

Answer 1

Jirds / desert rats

Question 2

native environment of gerbils

Answer 2

regions of Mongolia, northeastern China, and other semi-arid parts of the world.

Question 3

Important charateristics of Gerbils and research purposes

Answer 3

Gerbils are well-known for their ease in handling, mild temperament, adaptability to environmental changes, and low occurrence of natural diseases. Gerbils are often used in research to study stroke and epilepsy. Since they are prone to dental caries (cavities) and periodontal disease as they age, gerbils are also used in dental research. 1,2

Question 4

Physical characteristics of gerbils

Answer 4

Gerbils are longer and more slender than hamsters. They have strong hind legs and a tendency to jump. They also have a very long furred tail with a tufted end. Gerbils of both sexes have a large sebaceous gland on their abdomen called the ventral marking gland

Question 5

Ventral marking gland

Answer 5

large sebaceous gland on their abdomen called the ventral marking gland. This gland is controlled by reproductive hormones. It is covered by a distinct mid-ventral abdominal pad, and is larger in males. Secretions from this gland are used in territorial marking, and pup identification, and may also serve as a sexual attractant.

Question 6

Gerbils and seizures

Answer 6

Spontaneous seizures are hereditary in gerbils. The incidence of seizures is reported in 20% to 50% or more of the gerbil population, depending on the strain. The seizures begin at about 2 months of age and may be induced by sudden noises or handling.

Question 7

Which of the following statements is FALSE?

The ventral marking gland is controlled by insulin and blood glucose levels.
Both male and female gerbils have a ventral marking gland.
The ventral marking gland is larger in males than in females.
Secretions from the ventral marking gland are used in territorial marking and pup identification.

Answer 7

The ventral marking gland is controlled by insulin and blood glucose levels.

Question 8

An unusual behavior that may be noticed in approximately 20% of gerbils is:

Answer 8

seizures

Question 9

The most common species of gerbil studied in biomedical research is

Answer 9

Mongolian gerbil, Meriones unguiculatus. Other species are also studied, but less commonly (for example, Meriones libycus, Meriones crassus).

Question 10

What is the scientific name of the Mongolian gerbil?

Answer 10

Meriones unguiculatus

Question 11

Male gerbils reach sexual maturity at:

Answer 11

70-85 days.

Question 12

The average life span of a gerbil is:

Answer 12

2-4 years

Question 13

Handling and restraint of gerbils

Answer 13

A gerbil may be grasped by the base of the tail and the scruff of the neck; however, extra care must be taken not to pull too hard on the tail. If the tail is grasped tightly or if the animal is held along the length of its tail, the skin will slough off if the animal moves against the restraint, resulting in permanent damage known as degloving or tail-slip. Surgical amputation may be necessary if the tail is injured. Since tail degloving injuries can occur easily in gerbils, it is recommended to use handling methods that are gentle and only hold the base of the tail.

Most gerbils are nonaggressive, easy to work with, and rarely bite. They may be picked up by simply scooping them up with both hands. A secure hold may also be obtained with the V-hold. This method involves grasping the animal with the index and middle fingers around its neck and the thumb and ring fingers around the body. Gerbils can also be restrained by wrapping them in a towel or using a restraint box.4

Question 14

What is it called when the skin sloughs off of a gerbil�s tail while handling?

Answer 14

Degloving

Question 15

What is an appropriate handling method for gerbils?

Answer 15

Wrapping the gerbil in a towel.
Scooping the animal up with both hands
V-hold

Question 16

Methods of identification in gerbils

Answer 16

As for other rodents, cage cards are typically used to identify gerbils. Subcutaneous microchips, ear tags, ear notching, and colored markers may also be used for individual identification.

Question 17

Which identification methods are usually NOT used on gerbils?

Answer 17

ear tattoo

Question 18

Gerbil caging requirements

Answer 18

Gerbils are a USDA-regulated species, so their housing, husbandry, and record-keeping requirements are governed by the Animal Welfare Act and Regulations. Gerbils often stand erect on their hind legs (Figure 21.2). Therefore, it is important to use tall cages with a solid bottom. The use of wire-bottom cages should be avoided. Gerbils need escape-proof cages with secure lids because of their tendency to jump. Being desert rodents, gerbils excrete little urine and very dry feces. Even in nonventilated caging, cage changes may be needed as seldom as every other week. Depth of bedding should be about 3-5 cm to permit burrowing behavior. Environmental temperature recommendations are similar to that for mice and rats, with the exception of humidity. Humidity levels greater than 50% may be associated with rough hair coats and occasional skin problems (nasal dermatitis). Noise levels from human activity in housing areas should be kept to a minimum, and handling during cage changes should be performed gently to avoid inducing seizures.

Question 19

What is a characteristic of gerbils ?

urinary output

Answer 19

produce small amounts of urine

Question 20

Which statement is TRUE?

Answer 20

Gerbil cages may be changed as little as once per month.
Gerbils must be fed feed fortified with vitamin C.
Gerbils should be kept at humidity lower than 50%.
Gerbils may be housed in standard mouse caging.

Question 21

Gerbil environmental enrichment

Answer 21

Enrichment items for gerbils are generally similar to those for rats and mice. Gerbils are avid chewers and anything placed in their cage needs to be either durable or safe to be chewed and ingested. Some enrichment items are made of paper materials which can be safely chewed, whereas others are made of hard materials, like PVC, which need to be regularly inspected for damage or sharp edges and replaced regularly to avoid safety concerns. Fruit tree branches and wood blocks for gnawing are excellent enrichment items for gerbils. Gerbils may also benefit from the addition of shelters to the home cage as these can provide a hiding place, and assist with thermoregulation. Because of their tendency to burrow, gerbils benefit from deep bedding.6 Both deep bedding and nesting materials should be provided to allow for expression of normal behaviors.

Question 22

Which type of environmental enrichment promotes species specific behaviors in gerbils?

Answer 22

Deep bedding

Question 23

signs of pain, distress or illness in gerbils

Answer 23

Sick or injured gerbils often display similar clinical signs to other laboratory rodent species, regardless of what is causing their illness. Common clinical signs include ruffled fur, hunched posture, decreased activity, and weight loss.

Question 24

What would NOT be a sign of pain or distress in a gerbil?

Answer 24

Weight loss
Ruffled fur
Hunched posture
Sleeping during the day

Question 25

Euthanasia methods used in gerbils

Answer 25

Euthanasia methods for gerbils include cervical dislocation and exposure to high levels of inhalant gases, such as carbon dioxide or isoflurane. An overdose of barbiturates administered intraperitoneally is also a commonly used method. As with other laboratory animal species, death must be verified. Your institution�s SOPs may require an additional procedure to be performed for this verification. Carcass disposal should be according to the facility�s guidelines.

Question 26

What is NOT a common method of euthanasia for gerbils?

Answer 26

Exposure to high levels of inhalant anesthetic Injection of overdose of barbiturates Carbon dioxide asphyxiation ***Intracardiac injection of potassium chloride***

Question 27

The normal gestation length for the gerbil is ________ days.

Answer 27

24-26 days