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Oral, Cloacal, and Hemipenal Actinomycosis in Captive Ball Pythons (Python regius)

By Steven B. Tillis, Marley E. Iredale, April L. Childress, Erin A. Graham, James F. X. Wellehan, Ramiro Isaza, Robert J. Ossiboff

Category Journal Articles

Ball pythons (Python regius) are one of the most commonly kept and bred reptiles in
captivity. In a large ball python breeding colony, a unique syndrome characterized by
granulomatous inflammation of the cloaca and hemipenes (phalli) was observed in 140
of 481 (29.1%) breeding males, but only one of 1,446 breeding females. Lesions were
absent in virginmales (n=201) and virgin females (n=293). On postmortemexamination
(n = 13, 12 males, 1 female), numerous well-defined mucosal and submucosal
granulomas were present in the hemipenes (males) and cloaca (males and female).
Extension into the coelomic cavity and liver was noted in a subset of these animals.
An additional small subset of breeder animals (6/2027; 0.3%) presented with oral and
mandibular swellings. Postmortem examination (n = 4, all female) showed oral lesions
histologically indistinguishable from the cloacal/hemipenal lesions. Aerobic bacterial
culture of a hepatic granuloma of one snake resulted in the isolation of filamentous, Grampositive
bacilli; amplification, and sequencing of the 16S rRNA gene and subsequent
phylogenetic analysis of the isolate identified the bacterium as a novel species of
Actinomyces. Screening of cloacal and oral granulomas using a specific, heminested
16S rRNA PCR assay confirmed the presence of the agent in all 17 snakes, as well as in
cloacal swabs taken at the time of necropsy in 11/13 snakes. The Actinomyces sp. was
also identified by PCR of cloacal swabs of unaffected snakes (n = 94) from the affected
colony and two unrelated, grossly unaffected breeding colonies. In the affected colony,
65.5% of breeding animals (n = 23) but only 11.9% of virgin animals (n = 42) tested
PCR positive, with breeding status being a significant predictor of bacterium presence
(P < 0.00001). This study characterizes a granulomatous mucosal disease syndrome
of breeding male ball pythons associated with a novel Actinomyces. In stark contrast to
male snakes, the presence of the bacterium in both breeding and virgin females was very
rarely associated with clinical disease. Though additional studies are necessary, these
data suggest a role for the novel bacterium in the disease process, a predilection for
clinical disease in male snakes, and the potential for sexual transmission of the disease.


Marcy Wilhelm-South

Purdue University

Date 2021
Publication Title Frontiers in Veterinary Science
Volume 7
Pages 11
DOI 10.3389/fvets.2020.594600
Language English
Additional Language English
Cite this work

Researchers should cite this work as follows:

  1. Animal roles
  2. open access
  3. Reptiles
  4. Snakes
  5. Zoo and captive wild animals
  1. open access