Sugar Gliders: Husbandry and Common Diseases

Introduction
In recent years the sugar glider has become a popular pocket pet. However, because of their unique anatomy, natural habitat, social behaviour and highly specialised nutrition, it is extremely difficult to offer them a suitable environment, which lead often to husbandry related species-specific diseases.

I. Natural history
There are 7 subspecies of the species Pretaurus breviceps living in colonies up to 12 animals with one dominant male in the eucalyptus and acacia forest of Australia, New Guinea and Indonesia. 1835, they have also been introduced in Tasmania. As seasonally adapted omnivorous, they feed mainly on insects and arachnids during spring and summer and on plant exudates (sap, gum, nectar) during autumn and winter. To avoid their predators (e.g. birds of prey, snakes, lizards, feral cats and mulgaras) they adjust with a strictly arboreal and nocturnal way of life. Therefore, they developed a specific olfactory and vocal mode of communication.

II. Anatomy
The characteristic anatomical features: large gliding membrane (patagium), long tail, opposite thumb, sharp claws, large wide-spaced eyes, diprotodont teeth are an adaptation as highly specialised feeders and the distribution of the main components of their diet. Belonging to the interclass Marsupialia and the family Pretauridae, the female reproductive tract consists of two lateral uteri, each opening above an own cervix in the vaginal cul-de-sac, two lateral vagina and one median vagina ending in a cloaca.
The absence of the pubic bones as attachment for muscles supporting the pouch in most marsupials is probably to save weight as an adaptation to gliding.
The male reproductive tract consists of prominent visible scent glands (frontal, sternal, paracloacal), a bifurcated distal penis and pendulous scrotal sac with a strong cremaster muscle retracting the contents against the body wall while awake. In cases of severe paraphimosis or penile trauma, the distal penis can be amputated as the males urinate from the proximal portion of the penis and not the forked end.

III. Husbandry
The most common presentations are due to a poor nutrition and wrong husbandry.
• Caging:
Adult sugar gliders need a cage largest as possible due to their active nature. A cage with PVC-coated stainless bars with rectangular openings not wider than 1,25 - 2,5 cm is recommended. Nesting possibilities suspended high in the cage, as well as ropes and branches, should be offered. Due to an instinctual fear of falling, they will become significantly less active, when they cannot firmly grasp their surroundings. Regarding their nocturnal way of life, the cage should not be located in bright light and noisy rooms.

• Nutrition:
The natural diet can’t be completely replicated for domestic sugar gliders and there are several different theories how to feed a sugar glider in captivity. They are also highly sweet-selective, which can make it difficult to have a balanced diet as soon as a meal with sweet items is offered.
 30 - 50% formulated, extruded diet for sugar gliders
 30 - 40% nectar/sap/acacia gum
 15 - 30% vegetables and fresh fruits
 Small amount of insects
 Calcium-balanced multivitamin supplement for sugar gliders
 Filtered water

IV. Common diseases
• Nutritional secondary hyperparathyroidism (metabolic bone disease):
Metabolic bone disease is very common in domestic sugar gliders. Usually, the patient shows signs of weakness, ataxia, acute paresis/paralysis, pelvic or spinal deformation or tremor and seizure activity. The treatment consists in calcium supplementation, supportive treatment, pain management and correction of the diet.

• Obesity:
Sugar gliders in captivity are prone to obesity due to a lack of exercise and a diet that is too high in fats and proteins. Obesity increases the risks of cardiac, pancreatic and hepatic diseases. In females it can lead in failure to breed. Joeys can show lipid deposits within the eye. Correction of the diet and increasing exercise levels is the key for obese patient.

• Dental diseases:
It is important to remember that sugar gliders are not rodents. Therefore, their incisors do not overgrow and a trimming of those is unnecessary. Commonly seen are periodontal diseases, tartar build up or face swelling/lumpy face (mostly caused by Actinomyces spp., Fusobacterium necrophorum, which can be quite fatal in sugar glider). Depending the cause, treatment is scaling under anaesthesia, tooth extraction (incisors can be extracted with a high risk of mandibular fracture) and antibiotic treatment (cephalosporine) in case of lumpy jaw. A correction of the diet can be helpful for tartar build up.

• Diarrhea:
Mostly stress-induced, it can also be related to bacterial (E.coli, Clostridium spp., Yersinia pseudotuberculosis, Salmonella spp.), parasitic (nematodes, cestodes, coccidia, cryptosporidium, giardia, trichomonas) and viral (murine rotavirus A) infection. Like in other species, foreign bodies, metabolic disease, neoplasia or intoxication needs to be ruled out.
Sometimes, in joeys, a dam-related or joey-related “Ick” syndrome with diarrhea, anorexia, wet sticky fur and pouch exudate often leading to death related to Simplicomonas sp. is seen. Rehydration and pain management needs to be address first to stabilize the patient before establishing a specific treatment (e.g. antibiotics, anthelmintic, antiprotozoal agent or surgery).

• Pouch infection and mastitis:
It can be related to bacterial or fungal infection (Candida sp.), seldom mammary carcinoma can be the origin. Beside treating with regular cleaning of the pouch and/or a systemic treatment depending culture and antibiogram, improvement of the environment and cage hygiene is really important. In case the joeys are not nursing, a marsupial milk replacement might be necessary.

• Stress-related disorders:
Social deprivation as well as overcrowding, inappropriate diet and environment, sexual frustration and pain can lead to overgrooming and in severe cases to self-mutilation. Symptoms can vary from inappetence, coprophagy, polydipsia, cannibalism of the joeys, pulling or chewing fur or surroundings up to self-mutilation of limbs, tail or genital organs (especially in males). A thorough full history is important to find the stress or pain factor is extremely important. Furthermore, fecal, urine or blood analysis, as well as radiographs or ultrasound might be helpful.

The application of an Elizabeth collar and pain management to avoid further damage is

 Removal of potential stress factor!
 Adjust diet, environment and grouping!

Conclusion
Sugar gliders in captivity are often subject of diseases related to an inadequate environment and nutrition, as well as diseases related to stress. Therefore, client education plays a key role to provide a proper husbandry and diet, which have an important impact on the health situation of captive sugar gliders.

References

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