Diseases and Syndromes of Sugar Gliders

Sugar gliders are susceptible to infection with common bacteria, including Pasteurella multocida (commonly contracted from pet rabbits), staphylococci, streptococci, Mycobacterium sp (especially in skin), Klebsiella sp, and Clostridium. Clinical signs may be nonspecific, with depression, loss of appetite, and weight loss being the most readily detected. Bacterial infections in gliders may present as opportunistic skin infections associated with trauma or may result in sepsis from other underlying primary diseases. Although sugar gliders are hindgut fermenters, broad-spectrum antibiotic therapy is well tolerated, probably because diets fed in captivity are digestible without fermentation. Injectable, long-acting penicillin with clavulanic acid is an appropriate first-line antibiotic. If indicated by culture and sensitivity or by failure to respond to first-line treatment, chloramphenicol and enrofloxacin are also well tolerated in this species. Injections can be given IM into the epaxial muscles or SC over the shoulders. Palatable oral medications may also be administered.

Toxoplasmosis is a common and serious disease of marsupials, typically presenting with neurologic signs. Gliders may be infected with toxoplasmosis oocysts found in cat feces. Care should be taken to avoid cat feces coming in contact with the bedding or food of sugar gliders. Prevention is more successful than treatment. Coccidia may also cause severe, sometimes fatal diarrhea in young gliders and may be contracted via fecal-oral transmission from other species.

Internal parasites rarely cause disease in captive gliders, but giardiasis and cryptosporidiosis have been seen in captive animals. Strongyle eggs also have been seen on fecal flotation. Internal parasites reported to infect sugar gliders include nematodes of the genus Parastrongyloides and Paraustrostrongylus and a liver trematode of the genus Athesmia. Wild sugar glider nests generally contain a range of host-specific mites and fleas, but ectoparasites are uncommon in captivity. Dusting with pyrethrin or carbaryl powder (50 g/kg) has controlled fleas and mites. Both the nest and the animal should be treated. Selamectin also has been used to treat ectoparasites on sugar gliders. Ivermectin and fenbendazole have been used to treat GI parasites.

Pet sugar gliders maintained on a mainly fruit diet with few gut-loaded insects or other protein sources are very susceptible to nutritional osteodystrophy (nutritional secondary hyperparathyroidism). This condition results from an imbalance in dietary calcium, phosphorus, and vitamin D and manifests clinically as a posterior paresis progressing to hindlimb paralysis, muscle tremors, pathologic bone fractures, and sometimes, in advanced cases, seizures. Chronic malnutrition can lead to increased liver and kidney values, hypoproteinemia, and anemia. Radiography reveals osteoporosis of the vertebral column, pelvis, and long bones in particular. Measurement of ionized blood calcium typically demonstrates a low ionized calcium level. Treatment involves cage rest; administration of calcium, vitamin D₃, and fluids; assisted feeding; and correction of the diet. Seizuring gliders should be given diazepam IV, ideally, or if not possible, IM, intraosseously, or intrarectally, to stop seizures. Severely affected gliders may be given calcitonin to decrease calcium resorption from bone once calcium supplementation has normalized plasma calcium levels. Severe skeletal (especially spinal) deformities may not be reversible.

Retrobulbar abscess, sugar glider

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Courtesy of Dr. Laurie Hess.

Retrobulbar abscess, sugar glider, dorsal

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Courtesy of Dr. Laurie Hess.

Retrobulbar abscess, sugar glider, lateral

Image

Courtesy of Dr. Laurie Hess.

Unlike rodent teeth, sugar glider teeth do not grow continuously or require trimming. However, due to the frequency with which gingivitis and dental abscessation are seen in sugar gliders, prophylactic scaling and polishing have been suggested.

Sugar gliders consuming large amounts of soft, sugary foods are prone to tartar buildup and periodontal disease. Tartar may be scaled off under anesthesia. Advanced periodontal disease or traumatic tooth fracture may lead to tooth decay and exposed roots, and in severe cases, tooth root abscessation, osteomyelitis of the mandible or maxilla, and occasional extension of the abscess into the retrobulbar space. Radiographs, computed tomography scans, and endoscopic oral examination are helpful to delineate the extent of disease.

Fractured and decayed teeth must be extracted, and tooth root abscesses must be debrided and cultured (both aerobic and anaerobic). Local lidocaine blocks may aid in surgical removal of infected teeth. Care must be taken when removing affected incisor teeth not to cause mandibular symphysial fracture. Affected animals should be treated with antibiotics, analgesics, NSAIDs, and antiseptic mouthwash (either made for cats and dogs or fruit-flavored for children). Dietary modification to provide softer, more easily chewed foods may be necessary after surgery. Affected animals that do not eat postoperatively must be syringe fed until they eat on their own.

Potential causes of diarrhea in sugar gliders include:

• bacterial infection by Escherichia coli, Clostridium sp, and others

• GI parasites

• malnutrition

• stress

• metabolic disease, such as liver or kidney disorders

Sugar gliders with diarrhea should have a fecal analysis for parasites, fecal bacterial culture and Gram stain, blood testing (CBC and chemistry panel), and possibly radiographs. Gliders with diarrhea should be given supportive care with fluids, supplemental feeding, and drug therapy, as dictated by the cause of the GI signs. Rectal and cloacal prolapse can occur in gliders secondary to diarrhea and straining and is more common in malnourished animals. The prolapsed tissue must be cleaned, checked for necrotic areas (which must be removed), and replaced under anesthesia. Vertical mattress sutures may be placed next to the vent to help prevent recurrence, and the glider should be given postoperative analgesics, antibiotics, and NSAIDs.

Occasionally, pouch prolapse occurs. This commonly occurs secondary to infection of the pouch with yeast or bacteria, as a result of mastitis or from excessive grooming. Culture and sensitivity as well as cytology of exudate in the pouch should be performed to try to identify the cause and guide treatment. The pouch should be cleaned gently with chlorhexidine solution diluted with warm water, inverted, and replaced back into its normal anatomic position. Temporary stay sutures should be placed until infection and inflammation have resolved. Improved environmental sanitation to reduce the chance of infection, as well as decreasing behavioral stress by eliminating overcrowding or separating incompatible cagemates, may also be warranted

Sugar gliders can develop cystitis, crystalluria, and urolithiasis. They may show hematuria, stranguria, and dysuria. Affected gliders should have a urinalysis and urine culture and sensitivity testing and should be properly hydrated. Antibiotics should be administered based on results of culture and sensitivity testing. Cystotomy may be required to remove uroliths. Male gliders may develop urinary tract obstruction from uroliths and require urethrostomy if cystocentesis and flushing of the distal urethra do not relieve the obstruction. These gliders should receive analgesics, antibiotics, fluids, and NSAIDs. Sugar gliders with renal failure may show weakness, polyuria, and polydypsia and should be given standard treatment used for renal disease in other mammals.

An intact, adult male sugar glider was diagnosed with bilateral hydronephrosis and hydroureter secondary to functional urinary tract obstruction from inflammation/hyperplasia of the urinary bladder and ureteral epithelium of unknown cause.

Both sexes have paracloacal glands (similar to anal glands in mammals) that may become infected or impacted. Expression of impacted glands may produce a thick, mucoid discharge that should be cultured to guide antibiotic therapy. Chronically or recurrently infected or impacted glands should be removed. Lidocaine is injected into the skin over each gland, where a single skin incision is made. Each gland is bluntly dissected free of surrounding connective tissue and then removed without rupturing it. Associated blood vessels may be ligated with absorbable suture or cautery. The incisions are closed with a single absorbable suture in a subcuticular pattern with or without tissue glue.

Causes of neurologic signs in pet sugar gliders include nutritional secondary hyperparathyroidism, bacterial meningitis, toxoplasmosis, traumatic brain injury, otitis media/interna, encephalitis from aberrant CNS migration of Baylisascaris procyonis, and encephalomalacia from hypovitaminosis E. Gliders exhibiting neurologic signs should undergo a full evaluation, including blood testing (CBC and chemistry), fecal testing for parasites, radiographs, and CT scanning plus CSF analysis, if indicated. Prognosis in many of these cases is poor.

Gliders are prone to neoplastic disease in old age. Hepatocellular tumors and lymphoid neoplasia are common, as is mammary gland adenocarcinoma. Cutaneous melanoma, scent gland tumors, bronchogenic carcinoma, and chondrosarcoma of the jaw also have been reported. Hepatocellular carcinoma has been reported simultaneously with adrenocortical carcinoma in a 15-year-old female sugar glider. Dermal hemangiosarcoma was diagnosed in an 11-year-old female glider at the margin of the patagium. A soft-tissue carcinoma associated with a microchip implant was reported in a mahogany glider (Petaurus gracilis). A malignant testicular interstitial cell tumor in a mahogany glider was managed by hemicastration. Transitional cell carcinoma with squamous differentiation was noted pericloacally in a 10-year-old male sugar glider. Paracloacal gland carcinoma was diagnosed in a male sugar glider that was self-mutilating its cloacal region, and a 9-year-old female sugar glider was found to have mammary adenocarcinoma that metastasized to sublumbar, axillary, and pouch lymph nodes, as well as to the lungs,

Sugar gliders may develop cardiomyopathy/myocarditis, cataracts in juveniles (possibly associated with nutritionally imbalanced handfeeding formula, hyperglycemia, and hypovitaminosis A), cloacitis/vaginitis (females), irregularity of ear margins/crusting of pinnae from ear mite infections, and retrobulbar abscesses associated with facial bite wounds in competing males. Gastric dilatation and volvulus from unknown causes may also occur in sugar gliders presented with acute abdominal distension These syndromes are treated with medications and surgery , when indicated, similarly to those used in other mammals with these conditions. In addition, six adult sugar gliders with lethargy, tachypnea, and dyspnea were found to have pulmonary hyalinosis at necropsy, similar to lesions documented in the lungs of old dogs postmortem.

Sugar gliders live in colonies in the wild and are very social. Thus, they should be kept in captivity in groups of two or more. Gliders love to crawl into pockets or pouches, where they feel safe and more relaxed. Behavioral disorders can develop in sugar gliders housed alone, with incompatible mates, or in inappropriate cages. When housed singly, not given enough social stimulation, or not provided with a nest box or pouch in which to hide or enough room to exercise, they may self-mutilate their fur and skin, develop stereotypic behaviors, or become aggressive. Anxious gliders will overgroom, causing fur loss, particularly at the tail base. Anorexia, polyphagia, polydipsia, coprophagia, cannibalism, and pacing are also seen in stressed gliders.

Sexually mature male sugar gliders without access to females may self-mutilate the tail base, limbs, scrotum, penis, or perineum and may develop paraphimosis, in which the penis remains extruded from the cloaca and becomes traumatized and devitalized, necessitating amputation. These gliders should receive pain relievers, antibiotics, and possibly antidepressants, plus an Elizabethan collar, to enable healing. At least 2 hours per day, preferentially at night, when they are awake, must be spent with other pet gliders for proper socialization.

Diseases that may infect sugar gliders, such as salmonellosis, giardiasis, leptospirosis, clostridiosis, and toxoplasmosis, are potentially zoonotic. Sugar gliders are best handled wrapped in a small towel, because they may bite and scratch, and although they are small, their lower incisors, which are designed to bite through tree bark, may inflict significant damage. Biting and scratching can be avoided by gentle handling and proper socialization. All ocular, nasal, GI, and genitourinary discharges should be treated as potentially infectious.

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