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MRI Images

foramen magnum

MRI foramen magnum 1

CT images of healthy lions

axial CT of healthy lion at the tentorium level

A Global Survey of Neurological Diseases among
Captive Lions (Panthera leo) in Zoological Gardens

Please note that the numbers at this file represent zoological gardens and not individual lions. That is, the disease is more prevalent than shown in the figures.

The survey was sent to 300 zoological gardens across the world, and to whom 46  zoological gardens’ veterinarian have currently responded. Among those who have responded, 12 veterinarian have seen neurological problems among lions under the age of 5 in their zoo (Fig. 1).

A world survey of neurological diseases among captive lions in zoological gardens; aiming to better understand the association between the lion’s lineage, breeding strategies and other husbandry parameters and neurological abnormalities, stillbirths and other reproduction problems.

Lion behavioral predation patterns in the wild

Biodiversity genetic survey; comparing between healthy and affected lions in captivity and to those in the wild

Conservative treatment

Upon diagnosis, medical treatment should be initiated. Based on previously reported cases [14], this is achieved through the administration of steroids (1 mg/kg/day prednisone administered for 3 weeks) and vitamin A.

A tentative diagnosis of Clavarial Hyperosteosis can be based on:

1. The occurrence of the above clinical signs in lion cubs and young adults from captivity
2. Normal CBC and blood chemistry
3. Negative titers for infectious diseases

Definitive diagnosis

Computed Tomographic (CT) scan or MRI performed under general anesthesia, detecting excessive bone formation around the caudal fossa.

Bone abnormality indicating Clavarial Hyperosteoses include:

Signalment

• young to young adult captive lions

History

• progressive neurologic abnormalities
• blood work, ultrasound usually normal
• delayed growth
• death of young cubs and stillbirth

Initial presentation

• ataxia
• weakness
• moderate dementia or depression
• reluctance to move
• reduced appetite
• seizures

Findings on neurological examination

• 1. Bauer, H, Nowell K. & Packer C. Panthera leo, In: IUCN Red List of Threatened Species, Version 2013
  http://www.iucnredlist.org/details/15951/0
• 2. Shamir, H.M., Horowitz, I.H., Yakobson, B., Ofri, R., (1998) Arnold-Chiari malformation in a captive African lion cub. J Wildl Dis.; 34:661-6

Lions are known to reproduce well in captivity but high incidence of morbidity and mortality has been reported in young captive lions [4].

Wildlife Veterinarian and PhD student

Our interest in Clavarial Hyperostosis in captive lions (Panthera leo) began in 1998, when we first encountered a 5-months old lion cub with severe whole body ataxia, which deteriorated and eventually died, without us being able to help. (2). When a similar situation occurred once more in the same zoological garden , 10 years later, we had already suspected what the 14-month old male lion suffers from a bone malformation which compresses his cerebellum and spinal cord, and so we knew what needed to be done.

Clavarial Hyperostosis in Lions (Panthera leo) Research Group