Journal of Threatened
Taxa | www.threatenedtaxa.org | 26 April 2026 | 18(4): 28668–28672
ISSN 0974-7907 (Online) | ISSN 0974-7893 (Print)
https://doi.org/10.11609/jott.9477.18.4.28668-28672
#9477 | Received 04 November 2024 | Final received 27 February 2026|
Finally accepted 28 March 2026
Report of phimosis in an Andean
Bear Tremarctos ornatus
(Mammalia: Carnivora: Ursidae) and ultrasonographic
description of the male genitourinary system
Aléxia Pimenta
Bom-Conselho 1, Agatha Campinho
Belsito 2 ,
Arthur Carlos Trindade 3 ,
Ciro Alexandre Teixeira Cruvinel 4 , Pedro Nacib Jorge-Neto 5 &
Cristiane Schilbach Pizzutto
6
1,5,6 Faculty of Veterinary Medicine
and Animal Science, University of São Paulo, Av. Prof. Dr. Orlando Marques de
Paiva, 87, São Paulo, SP 05508-270, Brazil.
1,5,6 Reprocon Institute, Rua
Joao Vieira de Meneses, 1064, Campo Grande, MS
79052-280, Brazil.
2,3 Veterinary Institute, Federal
Rural University of Rio de Janeiro, BR-465, Km 7, Seropédica,
RJ 23890-000, Brazil.
3,4 Bioparque do Rio, Parque da Quinta da Boa
Vista s/n, Rio de Janeiro, RJ 20940-040, Brazil.
6 Laboratory of Ecology and
Evolution, Instituto Butantan, Av. Dr. Vital Brasil 1500, São Paulo, SP 05503-900, Brazil.
1 alexiapbc@gmail.com, 2 agathacampinho@gmail.com,
3 arthur.trindade@bioparquedorio.com.br, 4 ciro.cruvinel@grupocataratas.com,
5 pepovet@gmail.com, 6 cspizzutto@yahoo.com.br
(corresponding author)
Editor: Rajeshkumar G. Jani, Anand Agricultural University,
Anand, Gujarat, India. Date of
publication: 26 April 2026 (online & print)
Citation: Bom-Conselho, A.P., A.C. Belsito, A.C. Trindade, C.A.T. Cruvinel, P.N. Jorge-Neto &
C.S. Pizzutto (2026). Report of
phimosis in an Andean Bear Tremarctos ornatus (Mammalia: Carnivora: Ursidae)
and ultrasonographic description of the male genitourinary system. Journal of Threatened Taxa 18(4): 28668–28672. https://doi.org/10.11609/jott.9477.18.4.28668-28672
Copyright: © Bom-Conselho et al. 2026. Creative Commons Attribution 4.0
International License. JoTT allows unrestricted use,
reproduction, and distribution of this article in any medium by providing
adequate credit to the author(s) and the source of publication.
Funding: This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
- Brasil (CAPES)
- Finance Code 001; This study was financed in part by Reprocon Institute.
Competing interests: The authors declare no competing interests.
Author details: Aléxia Pimenta Bom-Conselho, DVM, MSc in Wildlife Reproduction (FMVZ-USP), currently a PhD candidate in Animal Reproduction at the University of São Paulo. Field veterinarian responsible for free-ranging Andean Bear capture operations in Cusco, Peru. Works in clinical practice, reproduction, and management of Andean bears in Brazil and Peru. Member of the Reprocon Institute. Agatha Campinho Belsito, DVM with a residency in Diagnostic Imaging (UFRRJ), postgraduate in Computed Tomography (Anclivepa-SP) and Veterinary Radiology (UNIRADIO). Works as an independent practitioner in veterinary ultrasonography, radiology, and computed tomography. Arthur Carlos
Trindade, DVM, MSc in Veterinary Sciences (UFRRJ), specialized in wildlife medicine and currently pursuing a postgraduate degree in Veterinary Orthopedics. Supervising Veterinarian at BioParque do Rio, with experience in clinical care and management of wild animals in captive settings. Ciro Alexandre Teixeira Cruvinel, DVM and Technical Manager at the Bioparque do Rio, responsible for overseeing the institution’s departments of veterinary medicine, biology, animal behavior and welfare, as well as research and conservation programs. Pedro Nacib Jorge-Neto, DVM and PhD specializing in animal reproduction. He currently serves as the Technical-Commercial Director for IMV Technologies Brazil and leads the Reprocon Institute. He is also developing the ReproSense ecosystem, integrating AI and deep learning into reproductive biotechnologies for livestock and wildlife conservation. Cristiane Schilbach Pizzutto
researcher and technical manager of the Ecology and Evolution Laboratory at the Butantan Institute; Supervisor in the Postgraduate Program in Animal Reproduction at the School of Veterinary Medicine and Animal Science of University of São Paulo.
Author contribution: AP Bom-Conselho: Conceptualization, data curation, formal analysis, investigation, methodology, project administration, resources, writing – original draft, writing – review & editing. AC Belsitoc: Investigation, writing – original draft; AC Trindade & CAT Cruvinel: Investigation. PN Jorge-Neto: Writing – review & editing; CS Pizzutto: Investigation, methodology, supervision, visualization, writing – review & editing.
Acknowledgments: The authors thank Bioparque do Rio for their collaboration and partnership in favor of the health and conservation of the Andean Bear, and the Coordination for the Improvement of Higher Education Personnel (CAPES).
Abstract: The Andean Bear is classified as
‘Vulnerable’ by the IUCN Red List of Threatened Species. Unfortunately, there
is still a lack of data on the species’ reproduction and reproductive
pathologies. General anesthesia was administered to assess the health of a
16-year-old male individual weighing 161 kg, housed in a zoological
institution. Anesthesia was induced using ketamine (7 mg/kg; im), butorphanol (0.2 mg/kg; im),
midazolam (0.3 mg/kg; im), and dexmedetomidine (0.007
mg/kg; im). It was maintained with 1% isoflurane.
During the clinical evaluation, a phimosis condition, secondary to a traumatic
injury, was observed for the first time in this species. Ultrasonography of the
reproductive system revealed the left testicle measured 3.87 x 2.27 cm and the
right testicle measured 3.66 x 2.16 cm. Both testicles exhibited irregular
hyperechoic areas. The prostate measured 1.77 x 3.11 cm. The penile urethra
measured approximately 0.5 cm, and the penile bone, an elongated structure,
measured 4 x 0.8 cm.
Keywords: Accessory glands, animal
welfare, captive management, conservation medicine, one conservation, preputial
trauma, reproductive pathology, Spectacled Bear, testicular parenchyma.
Introduction
The Andean
Bear Tremarctos ornatus
is a species in the Ursidae family, classified as
‘Vulnerable’, regarding its risk of global extinction (Velez-Liendo, X. & S. García-Rangel 2017) .
Endemic to South America (Ruiz-Garcia 2003; Cueva et al. 2018, 2024), the Andean Bear measures
approximately 1.5–1.8 m in height, with females weighing up to 60 kg and males
up to 140 kg (Hohendorff & Giacomini 2014;
Collins 2015). However, these weight ranges may vary in both wild and captive
individuals without compromising their health parameters or biochemical
evaluations. This species is commonly kept in zoological institutions
worldwide, with records dating back to the 19th century (New York
N.Y. Board of Commissioners of the Central Park 1867; Gould 1871). There is a
lack of information, however, especially regarding reproduction and
reproductive pathologies in this species.
Phimosis is
a reproductive pathology that typically affects juveniles and, less frequently,
adult animals (De Vlaming et al. 2019). Characterized
by the inability to expose the penis through the prepuce due to a reduced
preputial orifice (Volkmann 2023), there are reports of phimosis in various
mammalian species, both domestic and wild (Ali et al. 2016; Martel-Arquette
& Mans 2016; Kane et al. 2021). However, to date, there are no reports of
phimosis in Andean Bears.
Ultrasonography
is a highly useful imaging technique for the reproductive evaluation of
domestic and exotic animals. Its applications include assessing the
reproductive system of males and females, monitoring gestation, confirming
reproductive pathologies, tracking ovulation and the estrous cycle in females,
and aiding in semen collection, artificial insemination, ovum pick-up, and
embryo transfer (Hildebrandt et al. 2000; Pugliesi et
al. 2018; Silvatti et al. 2020; Araújo et al. 2022; Gazendam et al. 2023; Requena et
al. 2023). This examination has enormous potential for use in zoological
institutions and free-ranging animals, not only as a tool for general health
assessment but also for the application of reproductive biotechnologies for
conservation purposes (Pizzutto et al. 2021). For
this, it is essential to understand the normal reproductive system patterns of
the Andean Bear.
This study
aims to report the first case of phimosis in an Andean Bear and describe the
ultrasonographic findings of the genitourinary system in this species.
Materials and Methods
The study
details the results of clinical assessments conducted by veterinary professionals.
These assessments fall under zootechnical practices and, therefore, did not
necessitate approval from an animal use ethics committee (MCTIC 2023). Adhering
to ethical standards for the assisted reproduction of wild animals (Pizzutto & Jorge-Neto 2023),
the treatment and use of experimental animals were in full compliance with
Brazilian laws, guidelines, and policies regarding animal welfare.
A
16-year-old male Andean Bear, weighing 161 kg, housed at a zoological
institution (Rio de Janeiro, RJ, Brazil; lat. -22.904o
, long. -43.229o), underwent an annual medical check-up for
health assessment. The animal was fasted for 12 hours before anesthesia. An
anesthetic dart gun was used, containing ketamine (7 mg/kg), butorphanol (0.2
mg/kg), midazolam (0.3 mg/kg), and dexmedetomidine (0.007 mg/kg). Anesthesia
was maintained with 1% isoflurane.
A
complementary examination of the abdominal and pelvic regions was performed
using a GE Logiq E R8 ultrasound machine in
two-dimensional mode, with high-frequency linear and microconvex
multifrequency transducers ranging from 7–13 MHz, to assess the animal’s
general health and reproductive status. A breeding soundness examination was
also performed.
Results
Clinical
evaluation revealed a narrowing of the preputial ostium, characterized as
phimosis, preventing penile exposure (Image 1A,B).
Based on the clinical history, the phimosis was secondary to preputial trauma.
Clinical pathology tests showed values within the normal range for the Andean
Bear. The animal did not present other clinical abnormalities; however, semen
collection was not possible.
On
palpation, the testicles were firm, and ultrasonography showed regular contours
and symmetrical sizes, measuring 3.87 x 2.27 cm for the left testicle (LT)
(Image 2A) and 3.66 x 2.16 cm for the right testicle (RT) (Image 2B). The
mediastinum testis was poorly defined, and the parenchyma was hypoechoic and
slightly heterogeneous due to the presence of small, irregular hyperechoic
areas in both testicles, with the largest measuring 0.35 x 0.18 cm in the left
testicle (Image 2C). In the pelvic region, at the topography of the accessory
glands, in close contact with the caudal bladder wall, a hypoechoic structure
with regular contours and an oval shape in the longitudinal section was
observed, measuring 1.77 x 3.11 cm (Image 2D). The penile bone (Image 2E,F) is an elongated structure measuring approximately 4.0 x
0.8 cm, it is almost completely inside the gland and has a ventral groove that
houses the urethra.
The urinary
bladder was filled with anechoic liquid content, with a normoechoic,
slightly irregular, and normothickened wall for the
Andean Bear, measuring 0.45 cm. The penile urethra was empty and measured
approximately 0.5 cm (Image 2E). The kidneys were symmetrical, measuring 9.41
cm on the left and 9.83 cm on the right, elongated and multilobed, with regular
contours and typical architecture. Diffuse echogenic points were observed in
the renal parenchyma.
Discussion
Phimosis in
adults is reported as secondary to trauma, lacerations, inflammatory processes,
scarring, neoplastic conditions, excessive cleaning, licking, and other factors
(De Vlaming et al. 2019; Madhesh
et al. 2019), leading to inflammation, ostium narrowing, and phimosis. Andean
bears have a strong tendency towards stereotypy in captivity (Lima et al.
2022), including excessive masturbation, which, according to the animal’s
history, possibly caused the lesion leading to the current condition. Despite
the phimosis, the animal did not present other clinical abnormalities, such as stranguria, which is common in these cases. The bladder
wall irregularity was related to insufficient filling at the time of the examination,
as clinical pathology tests were within the normal range for the Andean Bear.
Surgical intervention was not performed during the check-up, and clinical
follow-up was planned for the following days, without ruling out the
possibility of surgery, which is generally recommended for phimosis reversal in
small animals.
In
ultrasonography, the left testicle measured 3.87 x 2.27 cm and the right 3.66 x
2.16 cm, consistent with the literature, with the left averaging 3.16 x 2.44 cm
and the right 3.19 x 2.55 cm (Talavera et al. 2021). As previously reported,
the mediastinum testis in the Andean Bear is poorly defined (Talavera et al.
2021). The amorphous hyperechoic points found may be related to fibrosis or
dystrophic mineralization, subject to histopathology for confirmation.
The
prostate’s function is to produce fluids for the first and third fractions of
the ejaculate. It is important to know the normal dimensions of the prostate in
Andean bear to monitor the animal’s health, as affections in the accessory
glands, such as hyperplasias, neoplasias,
and prostatitis, are common in other mammals, especially humans and dogs,
potentially compromising the individual’s quality of life and health (Alves et
al. 2010; Christensen 2018). For pharmacological semen collection, it is
important to know the depth at which the urethral catheter should be inserted
to reach the prostate, promoting semen recovery and avoiding urine
contamination by reaching the bladder (Jeong et al.
2019; Araújo et al. 2020, 2021; da Silva et al. 2022; Deco-Souza et al. 2024).
Ultrasonographic visualization of the urethral probe could confirm the prostate
image; however, the individual’s phimosis prevented urethral catheterization.
According to
the ultrasonographic examination, it is possible that the prostate of Andean
bears has an oval shape in the longitudinal section and is located at the neck
of the urinary bladder, surrounding the caudal urethra, similar to dogs,
measuring 1.77 x 3.11 cm in the evaluated Andean Bear. Transrectal ultrasonographic
images of the prostate of a bear of the species Ursus
thibetanus (Jeong et
al. 2019) coincide with the images found for the species T. ornatus; however, the study does not provide gland
measurements for interspecific comparison. Although there are studies
describing the ultrasonographic topography of the abdominal and pelvic organs
in T. ornatus (Cahua
& Sato 2012; Talavera et al. 2021), no description of the prostate was
found, which may be related to the difficulty of visualizing the gland due to
its proximity to the pelvis or bladder filling, hindering visualization.
Conclusion
Phimosis can
affect Andean Bears, as it does other mammals, and this is the first report.
The testicular measurements (LT 3.87 x 2.27 cm and RT 3.66 x 2.16 cm) obtained
by ultrasonography are consistent with the literature (LT 3.16 x 2.44 cm and RT
3.19 x 2.55 cm). The accessory gland in the pelvic region is located caudal to
the bladder wall, with a hypoechoic appearance, regular contour, and oval shape
in the longitudinal section, measuring 1.77 x 3.11 cm. Further studies are
needed for comparison and determination of prostate normality.
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References
Ali, A., D. Derar, F.A. Al-Sobyil,
M.M. Zeitoun, K.M.A. Hassanein
& A. Al-Howas (2016). Phimosis in
male dromedary camels: Clinical findings and changes in the hemogram, nitric
oxide metabolites, and testosterone concentrations. Theriogenology
85(9): 1576–1581. https://doi.org/10.1016/j.theriogenology.2016.01.011
Alves, C.E.F., M.B.R. Faleiro, R.L. Amorim
& V.M.B.D. De Moura (2010). Avaliação histológica da próstata de cães adultos sexualmente
intactos. Arquivo
Brasileiro de Medicina Veterinária e Zootecnia
62(3): 596–602. https://doi.org/10.1590/S0102-09352010000300014
Araújo, G.R. de, P.N. Jorge-Neto, A.C. Csermak-Jr, C.S. Pizzutto, T.C. Luczinski & T. de Deco-Souza (2021). Avanços na andrologia de grandes felinos neotropicais. Revista Brasileira de Reprodução Animal 45(4): 219–228. https://doi.org/10.21451/1809-3000.RBRA2021.028
Araújo, G.R., A.F. Moraes-Ferreira, T.C. Luczinski, A.C. Csermak-Junior,
T. Deco-Souza, C.S. Pizzutto & P.N. Jorge-Neto (2022). Ultrasound pregnancy diagnosis in
a free-living jaguar (Panthera onca) with subsequent birth: First case report. Animal
Reproduction 19(1): Abstracts ISABR 2020/2021.
Araújo, G.R., T.A.R. Paula, T. Deco-Souza, R.G. Morato,
L.C.F. Bergo, L.C. Silva, P.N. Jorge-Neto & B.F.B. Sampaio (2020). Colheita farmacológica de sêmen de onças-pardas (Puma concolor: Mammalia: Carnivora: Felidae). Arquivo Brasileiro de Medicina Veterinária e Zootecnia 72(2): 437–442. https://doi.org/10.1590/1678-4162-11030
Cahua U.J. &
A.S. Sato (2012). Reporte ultrasonográfico postmortem de órganos
abdominales del oso de anteojos (Tremarctos ornatus). Revista
de Investigaciones Veterinarias
Del Perú 23(2): 235–239. https://doi.org/10.15381/rivep.v23i2.904
Christensen, B.W. (2018). Canine Prostate Disease. Veterinary
Clinics of North America: Small Animal Practice 48(4): 701–719. https://doi.org/10.1016/j.cvsm.2018.02.012
Collins, D.M. (2015). Ursidae, pp.
498–508. In: Fowler’s Zoo and Wild Animal Medicine, Volume 8. Elsevier.
Cueva, D.F., B. Gutierrez, G. Bruque, S.
Molina & M.L. Torres (2018). Mitochondrial DNA reveals low
genetic diversity in Ecuadorian Andean Bears. Ursus
29(1): 43. https://doi.org/10.2192/URSUS-D-17-00020.2
Cueva, D.F., R. Zug, M.J. Pozo, S. Molina, R.
Cisneros, M.R. Bustamante & M.D.L. Torres (2024). Evidence of
population genetic structure in Ecuadorian Andean bears. Scientific Reports
14(1): 2834. https://doi.org/10.1038/s41598-024-53003-5
De Vlaming, A., M.L. Wallace & G.W.
Ellison (2019). Clinical characteristics, classification, and surgical outcome for
kittens with phimosis: 8 cases (2009–2017). Journal of the American
Veterinary Medical Association 255(9): 1039–1046. https://doi.org/10.2460/javma.255.9.1039
Deco-Souza, T., G.R. Araújo, C.S. Pizzutto,
L.A. Requena, & P.N. Jorge-Neto
(2024). In situ and ex situ Jaguar (Panthera
onca) reproduction: what do we have so far? Theriogenology
Wild 100070. https://doi.org/10.1016/j.therwi.2024.100070
Gazendam, B.A.T., A.
Avenant, A. Kitshoff, C.J. Blignaut, A.S.W. Tordiffe, S.N. Hoepner, E.H. Hooijberg &
M.L. Schulman (2023). The first report of the clinical diagnosis and
surgical management of pyometra in two cheetahs (Acinonyx
jubatus). Theriogenology Wild 3: 100046. https://doi.org/10.1016/j.therwi.2023.100046
Gould, J. (1871). December 5, 1871 pp. 699–766. In: Proceedings
of the Zoological Society of London. Zoological Society of London, London.
Hildebrandt, T.B., R. Hermes, K. Jewgenow
& F. Göritz (2000). Ultrasonography
as an important tool for the development and application of reproductive
technologies in non-domestic species. Theriogenology 53(1): 73–84. https://doi.org/10.1016/S0093-691X(99)00241-1
Hohendorff, R. von
& C. Giacomini (2014). Carnivora – Ursidae (Ursos) pp. 880–892. In: Tratado
de animais selvagens: medicina veterinária. Roca,
São Paulo.
Jeong, D.H., J.J.
Yang, M.K. Seo, A.N. Lee & Y.K. Lim (2019). Effectiveness
of urethral catheterization under ultrasound guidance for semen collection from
Asiatic Black Bears (Ursus thibetanus). Theriogenology 129: 154–159. https://doi.org/10.1016/j.theriogenology.2019.02.032
Kane, L.P., J.N. Langan & M.J. Adkesson (2021). Successful
surgical correction of phimosis in Amur Leopards (Panthera
pardus orientalis)
using a carbon dioxide laser: case series. Journal of Zoo and Wildlife
Medicine 52(4): 1280–1285. https://doi.org/10.1638/2021-0027
Lima, E.G., R. dos S. Teixeira, C.F. da Cruz, S.R.S. de Alcântara & C.M. Pigozzo
(2022). Descrição comportamental do urso de óculos - Tremarctos ornatus em cativeiro
no zoológico de Salvador-BA. Candombá
8(1): 37–52.
Madhesh, E., Y.
Ajith, U. Dimri, S. Shanmuganathan,
P. Sivasankar & R. Karthikeyan (2019). Medical
management of phimosis associated with generalized Sticker’s sarcoma in an
intact mongrel dog. Comparative Clinical Pathology 28(6): 1851–1854. https://doi.org/10.1007/s00580-019-03031-9
Martel-Arquette, A. & C. Mans (2016). Management
of Phimosis and Balanoposthitis in a Pet Chinchilla
(Chinchilla lanigera). Journal of Exotic Pet
Medicine 25(1): 60–64. https://doi.org/10.1053/j.jepm.2015.12.001
MCTIC (2023). Perguntas frequentes ao Concea
https://antigo.mctic.gov.br/mctic/opencms/institucional/concea/paginas/FAQs.html
(accessed on 26 September 2023).
New York (N.Y.). Board of Commissioners of the Central Park (1867). Eleventh
Annual Report of the Board of Commissioners of the Central Park, Vol. 11th. Board of
Commissioners of the Central Park, New York, 200 pp.
Pizzutto, C.S., H. Colbachini, & P.N. Jorge-Neto
(2021). One Conservation: the integrated view of biodiversity conservation. Animal
Reproduction 18(2): e20210024. https://doi.org/10.1590/1984-3143-ar2021-0024
Pizzutto, C.S. &
P.N. Jorge-Neto (2023). Ética e condicionamento de animais
selvagens para a aplicação de técnicas de reprodução assistida. Revista Brasileira de Reprodução Animal 47(3): 530–535. https://doi.org/10.21451/1809-3000.RBRA2023.054
Pugliesi, G., G.D.
de Melo, G.A. Ataíde, C.A.G. Pellegrino, J.B. Silva,
C.C. Rocha, I.G. Motta, J.L.M. Vasconcelos & M. Binelli
(2018). Use of Doppler ultrasonography in embryo transfer programs: feasibility
and field results. Animal Reproduction 15(3): 239–246. https://doi.org/10.21451/1984-3143-AR2018-0059
Requena, L.A., P.N.
Jorge-Neto, G.R. de Araújo, L. Silveira, A.T.A. Jácomo, A. Echegaray, T. Deco-Souza & S. Pizzutto (2023). From
livestock production to conservation: innovation for evaluating testicular
parenchyma echotexture, and seminal quality in jaguars. Revista
Brasileira de Reprodução
Animal 47(2): 438.
Ruiz-Garcia, M. (2003). Molecular population genetic
analysis of the spectacled Bear (Tremarctos ornatus) in the northern Andean area. Hereditas
138(2): 81–93. https://doi.org/10.1034/j.1601-5223.2003.01578.x
da Silva, M.C.C., P.N. Jorge-Neto, G.M.
Miranda, A.C. Csermak-Jr, R. Zanella,
C.S. Pizzutto, H. Colbachini,
A.R. Silva, G.R. de Araújo & T. de Deco-Souza (2022). Reproductive
parameters of male crab-eating foxes (Cerdocyon
thous) subjected to pharmacological semen
collection by urethral catheterization. Theriogenology Wild 1: 100004. https://doi.org/10.1016/j.therwi.2022.100004
Silvatti, B., T.M. Granato, P.N. Jorge-Neto,
M.M.C.P. Luppi, L.C. Reisfeld,
P.C. Henrique, F.L.A. Padilha, R.F. Leite, J.D. de Agostini Losano,
G.K.V. Kawai & M. Nichi & C.S. Pizzutto (2020). Sperm
evaluation and morphological description of male genitalia of meerkats (Suricata suricatta).
Animal Reproduction Science 221: 106585.
https://doi.org/10.1016/j.anireprosci.2020.106585
Talavera C., K. Muñoz, C. Hermoza & R. Grandez (2021). Caracterización ultrasonográfica de los órganos abdominales y pélvicos del oso de anteojos (Tremarctos ornatus) en cautiverio.
Revista de Investigaciones
Veterinarias Del Perú 32(6): e21693.
https://doi.org/10.15381/rivep.v32i6.21693
Velez-Liendo, X. & S. García-Rangel
(2017). Tremarctos ornatus
(errata version published in 2018). The IUCN Red List of Threatened Species
2017: e.T22066A123792952. https://doi.org/10.2305/IUCN.UK.2017-3.RLTS.T22066A45034047.en.
Accessed on 17 April 2026.
Volkmann, D.
(2023). Phimosis pp. 736–739. In: Monnet, E. (ed.). Small Animal Soft Tissue
Surgery. Wiley, 1025 pp. https://doi.org/10.1002/9781119693741