Spontaneous Tumors and Non-Neoplastic Proliferative Lesions in Pet Degus (Octodon degus)

Our plain-English summary of Spontaneous Tumors and Non-Neoplastic Proliferative Lesions in Pet Degus (Octodon degus), by T. Švara, M. Gombač, A. Poli, et al (Veterinary Sciences, 2020).

The study

• Authors: T. Švara, M. Gombač, A. Poli, J. Račnik, M. Zadravec
• Journal: Veterinary Sciences
• Published: 2020;7(1)
• Cited by: 9 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

In recent years, degus (Octodon degus), rodents native to South America, have been becoming increasingly popular as pet animals. Data about neoplastic diseases in this species are still sparse and mainly limited to single-case reports. The aim of this study was to present neoplastic and non-neoplastic proliferative changes in 16/100 pet degus examined at the Veterinary Faculty University of Ljubljana from 2010 to 2015 and to describe the clinic-pathological features of these lesions. Twenty different lesions of the integumentary, musculoskeletal, genitourinary and gastrointestinal systems were diagnosed: amongst these were 13 malignant tumors, six benign tumors, and one non-neoplastic lesion. Cutaneous fibrosarcoma was the most common tumor (7/16 degus). It was detected more often in females (6/7 degus) and lesions were located mainly in hind limbs. The gastrointestinal tract was frequently affected, namely with two malignant neoplasms - an intestinal lymphoma and a mesenteric mesothelioma, four benign tumors - two biliary cystadenomas, an oral squamous papilloma and a hepatocellular adenoma, and a single non-neoplastic proliferative lesion. In one animal, two organic systems were involved in neoplastic lesions.

In plain English

This veterinary study, which does not concern asbestos, described tumors and other growths in pet degus, a South American rodent, examined at the Veterinary Faculty of the University of Ljubljana, Slovenia. Of 100 pet degus referred between 2010 and 2015, 16 (ten females, five males, one of unrecorded sex), aged 3 to 9 years, had such lesions. Twelve had a full necropsy and four had biopsies. Twenty lesions were found, in the skin, the bones, the genital and urinary organs, and the digestive system. The most common tumor was skin fibrosarcoma, in seven degus (six females, one male), mostly on the hind limbs (4 of 7). No spread of these fibrosarcomas to lymph nodes or other organs was seen at necropsy. One 8-year-old female had a mesothelioma of the mesentery, the tissue holding the intestines. The article does not discuss its cause. Digestive-system tumors were found in six animals. The authors concluded that tumors in degus, especially older ones, can be very frequent. They suggested the 16% rate of such lesions might reflect the animals' older age or referral for surgery.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Case series of pathology findings (necropsy or biopsy) in pet degus seen at a university veterinary clinic
• Who was studied: 100 pet degus (Octodon degus) referred to the Veterinary Faculty, University of Ljubljana, Slovenia, between 2010 and 2015. Sixteen had tumors or non-neoplastic proliferative lesions: ten females, five males and one of unrecorded sex, aged 3 to 9 years (mean 6, plus or minus 1.9 years).
• Main results:
  • Twenty different lesions were found in the 16 affected degus, in the integumentary, musculoskeletal, genitourinary and gastrointestinal systems. The musculoskeletal lesions were two bone tumors.
  • The two bone tumors were a chordoma of the tail and a femoral osteosarcoma, both in 5-year-old degus.
  • Cutaneous fibrosarcoma was found in seven degus (six females and one male).
  • The fibrosarcomas were most often on the hind limbs (4 of 7). For these fibrosarcomas, no metastases were found at necropsy in regional lymph nodes or other organs.
  • Of the seven fibrosarcomas, four were graded intermediate grade, two high grade and one low grade.
  • Some of the degus with fibrosarcoma were related: two mothers and three of their female offspring.
  • An 8-year-old female (degu number 11) had a mesenteric mesothelioma, together with a kidney hemangioma and nodular hyperplasia of the liver. It was euthanized because of persistent weight loss.
  • The mesothelioma cells stained positive for cytokeratin AE1/AE3 and vimentin, and negative for desmin and c-kit (CD117).
  • A female degu with femoral osteosarcoma had lung lesions consistent with metastases.
  • Neoplastic lesions of the gastrointestinal tract were found in 6 degus, which the article gives as 37.5% of animals.
  • The prevalence of neoplastic and non-neoplastic proliferative disorders among the referred degus was 16%.
• The authors' conclusion: The authors concluded that neoplastic lesions in degus, especially in older animals, can be very frequent. They found integumentary (skin) lesions the most common, and cutaneous fibrosarcoma the most common tumor type in their study.
• Limitations the authors state:
  • The authors suggested the higher prevalence than in earlier studies might reflect the older age of their animals, or the fact that some were referred to the university clinic for surgery.
  • The authors stated that their preliminary results on fibrosarcoma in related animals cannot support definitive conclusions about genetic predisposition.

Topics

Medical terms in this study, explained in our Lexicon: Neoplasm, Mesothelioma.

Related studies

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• Reduced tumor necrosis factor-alpha and transforming growth factor-beta1 expression in the lungs of inbred mice that fail to develop fibroproliferative lesions consequent to asbestos exposure — D.M. Brass, G.W. Hoyle, et al. (1999)
• Observer variability in mesothelioma tumor thickness measurements: defining minimally measurable lesions — S.G. Armato, A.K. Nowak, et al. (2014)
• Microcystic variant of localized malignant mesothelioma accompanying an adenomatoid tumor-like lesion — H. Umezu, K. Kuwata, et al. (2002)
• Primary lesions that may imitate metastatic tumors histologically: A selective review — M.R. Wick (2018)

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