Abstract
The sugar glider, (Petaurus breviceps), is a small (95–160 g) arboreal marsupial native to Australia and New Guinea. Although held by no fewer than 43 North American zoos, and having become a popular pet in recent years, little concerning them has been published in the veterinary literature.1,5,6
In August 2001, at the Albuquerque Biological Park (ABP), a 7-year-old male sugar glider was reported to have an alopecic spot on one of its legs. Physical exam found the alopecic spot to be associated with a subcutaneous mass on the left lateral thigh. A second subcutaneous mass was also found in the right axillary region. Both masses were surgically removed and submitted for histopathology. Both excised masses, one an axillary lymph node, contained neoplastic lymphocytes with a high mitotic index of 4–8 mitotic figures per hpf, consistent with a diagnosis of lymphosarcoma. A recheck examination 2 weeks post-surgery found two additional subcutaneous masses. Euthanasia was elected and postmortem histopathology confirmed that these additional masses were also lymphosarcoma.
A review of pathology records at ABP revealed that, between 1997 and 1998, neoplasia was diagnosed in all six members of a group of sugar gliders received as a group from another institution in 1993. An investigation into the history of this group of sugar gliders and similar groups of sugar gliders was initiated. In addition to ABP records, medical records of sugar gliders that died and had a complete necropsy examination at the Metropolitan Toronto Zoo and the Gladys Porter Zoo were reviewed, and a search of the Australian Registry of Wildlife Pathology was conducted.
The results of this preliminary investigation are listed in Table 1. Males were affected roughly twice as commonly as females. Gliders as young as 1 year of age were affected. Many different systems are affected, but the more common types included lymphosarcoma, leukemia, and adenocarcinoma. Among the marsupials, the dasyurids are disproportionately represented in their susceptibility to neoplasia.4 Neoplasia has been described in nearly all tissue types in dasyurids and are well documented in the literature. In contrast, previous documented reports of neoplasia in sugar gliders are limited to a single case report3 and a smattering of cases included in a large survey of neoplasia in native Australian marsupials2. Neoplasia has been reported in other gliders, such as squirrel gliders and greater gliders.1 The true incidence of neoplasia in the Petauridae may be common, as in the Dasyuridae.
Table 1. Cases of neoplasia in sugar gliders
Case #
|
ID
|
Sex
|
Age
|
Source
|
Diagnosis
|
1
|
D8
|
M
|
A
|
Canfield et al.
|
Splenic erythroid leukemia
|
2
|
D25
|
M
|
A
|
Canfield et al.
|
Splenic erythroid leukemia
|
3
|
D54
|
M
|
–
|
Canfield et al.
|
Splenic erythroid leukemia/duodenal adenocarcinoma
|
4
|
D107
|
–
|
–
|
Canfield et al.
|
Subcutaneous fibroma
|
5
|
D140
|
–
|
–
|
Canfield et al.
|
Subcutaneous fibroma
|
6
|
–
|
M
|
–
|
Canfield et al.
|
Lymphoid or myeloid leukemia
|
7
|
–
|
M
|
4
|
Hough et al.
|
Cutaneous lymphosarcoma
|
8
|
N97035
|
M
|
12
|
ABP3
|
Cutaneous lymphosarcoma
|
9
|
N97036
|
M
|
1
|
ABP
|
Spindle cell tumor
|
10
|
N97073
|
M
|
7
|
ABP
|
Pericloacal tumor
|
11
|
N97077
|
F
|
6
|
ABP
|
Mammary carcinoma
|
12
|
N98034
|
M
|
8
|
ABP
|
Lymphosarcoma
|
13
|
N98047
|
F
|
12
|
ABP
|
Lymphosarcoma
|
14
|
N01050
|
M
|
7
|
ABP
|
Lymphosarcoma
|
15
|
2042-90
|
F
|
A
|
MT2b
|
Adrenal cortical carcinoma
|
16
|
2250-91
|
F
|
4
|
MT2
|
Mammary carcinoma
|
17
|
2010-93
|
M
|
11
|
MT2
|
Intestinal carcinoma
|
18
|
2040-93
|
F
|
5
|
MT2
|
Pheochromocytoma
|
19
|
2215-93
|
F
|
7
|
MT2
|
Vaginal squamous cell carcinoma
|
20
|
3297
|
M
|
11
|
GP2c
|
Fibroma
|
21
|
3299
|
M
|
11
|
GP2
|
Myxosarcoma
|
22
|
3302
|
M
|
11
|
GP2
|
Lymphosarcoma/fibrosarcoma
|
23
|
4065
|
M
|
4
|
GP2
|
Sebaceous epithelioma
|
24
|
4066
|
F
|
A
|
GP2
|
Adenocarcinoma
|
25
|
4067
|
F
|
7
|
GP2
|
Adenocarcinoma (lung)
|
26
|
4590
|
F
|
1
|
GP2
|
Dysgerminoma
|
27
|
7588
|
M
|
1
|
GP2
|
Fibrosarcoma (incidental)
|
28
|
D251
|
F
|
7
|
ARWPd
|
Histiocytoma, subcutaneous
|
29
|
D366
|
–
|
–
|
ARWP
|
Adenocarcinoma (chest gland)
|
30
|
D396
|
–
|
–
|
ARWP(N2)
|
Mammary adenocarcinoma
|
31
|
D399
|
–
|
–
|
ARWP(N2)
|
Adenocarcinoma-metastatic
|
32
|
D400
|
–
|
–
|
ARWP(N2)
|
Splenic erythroid leukemia
|
33
|
D1498.1
|
M
|
10
|
ARWP
|
Adenocarcinoma (abdominal)
|
aAlbuquerque Biological Park.
bMetro Toronto Zoo.
cGladys Porter Zoo.
dAustralian Registry of Wildlife Pathology.
Acknowledgments
Thanks to Ms. Gwen Dragoo, RVT, for formatting Table 1.
Literature Cited
1. Booth, R.J. 2000. General husbandry and medical care of sugar gliders. In: Bonagura, J.B. (ed.). Kirk’s Current Veterinary Therapy XIII: Small Animal Practice. W.B. Saunders Company, Philadelphia, Pennsylvania, Pp. 1157:1163.
2. Canfield, P.J., W.J. Hartley and G.L. Reddacliff. 1990. Spontaneous proliferations in Australian marsupials—a survey and review. 1. Macropods, koalas, wombats, possums, and gliders. J. Comp. Path. 103:135–146.
3. Hough, I., R.E. Reuter, R. S. Rahaley, C. Belford, R. Miller, and G. Mitchell. 1992. Cutaneous lymphosarcoma in a sugar glider. Aust. Vet. J. 69: 93–94.
4. Jakob-Hoff, R.M. 1993. Diseases of free-living marsupials. In: Fowler, M.E. (ed.). Zoo and Wild Animal Medicine: Current Therapy 3. W.B. Saunders Company, Philadelphia, Pennsylvania, Pp. 276–281.
5. Johnson-Delaney, C.A. 1998. The marsupial pet: sugar gliders, exotic possums, and wallabies. Proc. Assoc. Avian Vet., St. Paul, Minnesota, August 26–28. Pp. 329–339.
6. Pye, G.W. and J.W. Carpenter. 1999. A guide to medicine and surgery in sugar gliders. Vet. Med. (Oct.):891–905.