Unusual Paget's?

Here we explore interesting and unusual reports of possible Paget's disease.

Paget’s disease in an extinct monkey?

In 1992, the discovery of a nearly complete skeleton of a large platyrrhine (New World monkey) in the Toca da Boa Vista cave, Northeastern Brazil, led to researchers exploring the potential presence of metabolic bone disease. Although a precise age of the skeletal elements is unknown, the Late Pleistocene (Ice Age) is suggested. This species, weighing around 25 kg, is the largest known platyrrhine and was discovered in the Toca da Boa Vista cave in Northeastern Brazil. The specimen appears to be the only case of metabolic bone disease in an extinct New World monkey.

The researchers documented various pathological changes found using radiographic and CT images of the affected bones. The lesions noted include cortical thickening, sclerosis and coarse trabeculae in the skull and long bones. The features observed support the diagnosis of metabolic bone disease with lesions comparable to those seen in Paget’s disease.

In their paper, the authors considered other diagnoses but concluded that this represents the closest relative of humans in the fossil record to be diagnosed with a disease closely resembling Paget’s disease. They noted that the absence of other skeletal materials for comparison from the same species and period makes differential diagnosis challenging and conclusions must be drawn with caution. They stress the need for further studies using broader comparative samples of extinct and extant platyrrhines to refine the diagnosis and assess the evolutionary implications of such diseases in primates. Despite these limitations, the findings represent a significant contribution to understanding the paleobiology and health conditions of extinct New World monkeys.

This work adds to the ongoing debate about the natural history of Paget's disease, an area of research that the Paget's Association has promoted and supported.

Reference

Araújo AV, Dantas MAT, Liparini A, Cozzuol MA, Halenar-Price LB, Ribeiro RM, Barbosa FHS, Bandeira F, Araújo Júnior HI. Metabolic bone disease in an extinct neotropical primate. Int J Paleopathol. 2024 Nov 19;48:1-12. doi: 10.1016/j.ijpp.2024.11.003. Epub ahead of print. PMID: 39566418.

Rare Paget-like bone disease reported in a boa constrictor

Veterinary researchers in South Korea reported an unusual case of a Paget-like bone remodelling disorder in a snake, highlighting that diseases resembling Paget’s disease may also occur in animals.

Boa constrictors are widely recognised snakes that typically grow to around two to three metres in length and because their active ground movement depends heavily on spinal flexibility, good vertebral health is essential to their mobility and overall wellbeing. The case, reported in the Journal of Veterinary Science, described a 23‑year‑old male red‑tailed boa constrictor (relatively old for such a snake) that developed severe skeletal abnormalities and showed a marked decline in its overall health.

The snake was taken for veterinary care after showing several concerning symptoms, including loss of appetite, difficulty shedding its skin properly, stiffness of the spine and reduced movement. X-rays and CT scans, similar to those that would be performed in humans, revealed widespread deformities in the spine. Blood tests showed very high levels of alkaline phosphatase (ALP 1,512 U/L) which exceeded previously reported reference values (96 to 116 U/L) for snakes. ALP is an enzyme often linked to increased bone activity in Paget’s disease. In addition, blood cultures detected Escherichia coli, suggesting a bacterial infection was also present.

The snake was treated with antibiotics (enrofloxacin) and steroids (dexamethasone) which led to some temporary improvement, with appetite partially returning, ALP levels falling and general comfort improving. The snake’s living conditions were changed by moving it to an enclosure twice as large as its previous habitat. Within the new enclosure, the temperature gradient was maintained with a hot zone at 30°C and a cool zone at 25°C. The enclosure was adapted to meet the snake’s reduced mobility: there were no climbing structures due to severe spinal rigidity and the floor was lined with soft, moisture‑retaining materials to improve comfort and support shedding. The 2‑metre‑long space allowed the snake to stretch fully and move with less strain.

With continued treatment, food intake gradually resumed, reaching 30% of baseline and subsequently improving to 50%–60%. The snake’s mobility and quality of life appeared to improve for a time. After two months, the snake’s ALP level had more than halved, falling to 473 U/L and no further bacterial growth was detected. However, the vertebral deformities remained and the snake was unable to bend, maintaining an increasingly extended posture.

Symptoms later returned, including loss of appetite and shedding problems. Due to the snake’s ongoing decline in health and wellbeing and following a zoo‑based quality‑of‑life assessment, the decision was made to proceed with humane euthanasia. Examination after death found extensive spinal deformities, while microscopic analysis revealed thickened trabeculae, mosaic lamellar bone and osteoclast proliferation, consistent with a Paget-like bone remodelling disorder.

Of course, Paget’s disease is best known as a human condition, where bone is broken down and rebuilt in a disorganised way, leading to enlarged and weakened bones. It is rarely described in animals but this report in an old snake adds to occasional past mentions of Paget-like changes in non-human species, such as dogs, rodents and reptiles, though confirmed cases remain extremely uncommon. As so few animal cases have been documented, vets still know little about the causes, progression or best treatment options.

The researchers say this case highlights the importance of imaging, blood tests, microscopic tissue examination (histopathology) and welfare-centred care. Although no cure was possible, changes to the snake’s environment appeared to provide temporary comfort and improved mobility.

While rare, Paget-like bone disease may occur in reptiles and other animals, and this unusual boa constrictor case may help veterinarians recognise similar disorders earlier and improve care for affected animals.

The authors noted that ‘Animal care and clinical management were conducted under the oversight of the zoo’s animal care and welfare committee’.

Reference

Youn SH, Lee NY, Shin KY, Shin HJ, Yang JY, Kim DY. Paget-like bone remodelling disorder in a red-tailed boa (Boa constrictor constrictor): diagnosis and management. J Vet Sci. 2026 Mar;27(2):e22.