BELOW IS STRAIGHT FROM MY NOTES, ON DISEASES, DIFFERENT AGES FOR DIFFERENT THINGS, AND REPRODUCTION!

Diseases

Epilepsy
The gerbil has a genetic tendency to develop epileptiform seizures. The occurrence rate for the general pet population 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 porphyrin 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 cleaning and 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.

Renal Disease
Old gerbils, 21/2 to 4 years of age, often present with a history of weight loss, loss of muscle mass, poor appetite, and lethargy. In addition, an increase in water consumption may be observed. These are all signs consistent with renal disease in old gerbils. Treatment is only supportive in rodents, with emphasis on providing ample fresh, clean water and food at all times to prevent stress that may trigger full renal failure.

Neoplasia
Gerbils have a relatively high incidence of cancer after they reach 2 years of age. The organ most affected is the ovary. Ovarian tumors are common in female gerbils with poor reproductive performance. They may present with early cessation of reproduction, decreased litter size, or distended abdomens. All of these signs may also be present with cystic ovaries as well.

The skin is the second most affected site for tumors in the gerbil. Squamous cell carcinomas and melanomas are most frequently encountered. Melanomas have a tendency to develop around the ear, foot, or base of the tail.

The ventral marking scent gland is the third most common site of neoplasia. This gland is located in the mid-abdominal area. It is a hairless, oval tan structure, which tends to be more prominent in males. The gland produces an orange-colored secretion which is used to mark territory. Tumors of this gland appear as 'abscesses' on the abdomen. Usually the tumor is not malignant, but may have a secondary bacterial infection.

Many other organs may be affected by cancer, but much less often. Where possible, surgical intervention as early as possible is the treatment of choice.

Tyzzer's Disease
The most commonly reported infectious disease of gerbils is Tyzzer's disease, caused by Bacillus piliformis, a gram-negative bacteria that infects living cells. The disease causes a high death rate especially in young male gerbils. Clinical signs are nonspecific, primarily consisting of ruffled fur, lethargy, hunched posture and poor appetite. Diarrhea may also be present. The disease causes changes in the heart, liver, lymph nodes and digestive tract which can be observed at necropsy. Special stains of tissue samples from dead rodents can confirm the diagnosis.

Treatment of affected colonies with tetracycline antibiotics in the drinking water may be of some benefit in an epidemic. Supportive care with fluid therapy is often necessary in affected animals.

Prevention is the key to this disease. High level sanitation and minimal stress greatly reduces the occurrence of this disease in colony situations. Tyzzer's disease typically affects gerbils that are stressed by weaning, shipping, and adjusting to new environments. Strict sanitation prior to introduction of new animals is important in preventing outbreaks.

Reproduction

Gerbils should be paired by the time they reach sexual maturity, at 7 to 8 weeks of age. Life long, monogamous pairs typically form. The first mating typically occurs at about 10 to 12 weeks of age. Loss of or separation from a mate can make it difficult to rebreed a gerbil. Harem breeding of two females to one male have also been successful, but may lead to some fighting. The male gerbil participates in the care of the young. In fact, if a male is removed from the cage for an extended length of time after birth, fighting may ensue when reintroduced only a few weeks later.

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 estrous 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 which 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.