Gerbils
Breeding - cont'd

The gestation period of non-lactating gerbils is 24 to 26 days on average. A fertile postpartum estrus may result in pregnancy, with a gestation length of over 30 days when the female is nursing young. Litter size averages 4 to 6 pups, which are born blind and naked.
Ears open at 3 to 7 days, hair coat develops at 7 to 10 days, incisors erupt at 12 to 14 days and eyes open at 14 to 20 days. Weaning occurs by the age of 21 days. The estrus cycle lasts 4 to 6 days with spontaneous ovulation. Monogamous pairs may produce a new litter every 30 to 40 days, for a total of 6 or 7 litters during their reproductive lives. The female gerbil is reproductively active until about 18 months of age. Males may continue to be fertile to at least 24 months of age.

Young gerbils are rarely abandoned or cannibalized. Some factors that may lead to abandonment include small litters, excessive handling of young, lack of nesting material and lack of an area for concealment of the nest. If a mother gerbil abandons a nest, fostering may be possible if the orphans and host litters were born within a few days of each other. Hand feeding of neonatal rodents is difficult and often unrewarding.

Non-Infectious Conditions
Epilepsy
The gerbil has a genetic tendency to develop epileptiform seizures. The occurrence rate for the general pet populace is 20 to 40%. These seizures may be initiated by fright, handling or exposure to a new environment. The attacks can be mild (slight shaking) to very severe (violent convulsive body jerking, erratic movements and collapse). The convulsions appear not to have any long-term effects. In some instances, however, death may result following very severe seizures, but this is rare. Anticonvulsant therapy is not indicated, and can cause more serious side effects than the seizures themselves. Frequent handling during the first few weeks of life and providing a stable environment with a complete, balanced diet can help suppress the seizures in genetically predisposed gerbils.

Tail Sloughing
Improper handling of gerbils can result in the loss of fur from the end of the tail. This occurs when the animal is grasped by the tip of the tail. The skinless tail dies off and sloughs, with the stump usually healing without complications. In some instances, the tail may need to be amputated.

Nasal Dermatitis (Bald Nose)
Gerbils commonly develop hair loss on the nose and muzzle with open lesions and crusting. This condition is often attributed to abrasions from coarse bedding or rough surfaces within the cage or environment, but the Harderian gland may also be involved. The Harderian gland is located behind the eye and produces a secretion that empties onto the globe. From the eye, this material is drained into the nose by way of the nasolacrimal duct. This secretion is mixed with saliva and spread over the hair coat during grooming. This condition can arise if this material is over produced or not used.

Nasal dermatitis tends to affect young, mature gerbils most often. It spreads from being a localized nasal hair loss to involving the face, legs and ventral body surfaces in advanced cases. Cedar shavings used as bedding tend to worsen the condition. In severe cases, secondary bacterial infections may occur. If treated early in the course of the disease with appropriate antibiotics, this condition often resolves; but if not attended to early, the treatment may be unrewarding. Surgical removal of the Harderian gland results in recovery of the condition, but the procedure is rarely performed. A veterinarian may recommend the use of sand baths to aid in removing the excessive secretions, thus resulting in partial recovery.
© 2004 Midwest Bird and Exotic Animal Hospital