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).

Fig. 1. Zoological gardens who had encountered neurologically affected lions under the age of 5 Vs zoological gardens that had not.

The breeding policy among the 46 zoological gardens is described in Fig. 2. Among those zoological gardens that breed their lions (column1,2&3 – n =27) , 8 (8/27) encountered neurological problems among lions under the age of 5, while 19 (19/27) have not (Fig.3).

Fig. 2. Breeding policy among the participating zoological gardens.

Fig. 3. Neurologically affected lions under the age of 5.
This Figure present the ratio of affected lions in zoological gardens that breed their lions only (n=8).
While the total number of zoological gardens in which affected lions were reported was 12.

Lion’s diet in zoological gardens with neurologically affected animals consists of red meat, commercial large feline diet, chicken and rabbits, whole carcass of large herbivores and various combinations of the above (Fig.4). In addition, most of the zoological gardens who possess neurologically affected lions also provide vitamin supplementation including vitamin A on a regular basis (Fig.5).

Fig. 4. Dietary menu at zoological gardens that had encountered neurologically affected lions under the age of 5.

Fig. 5. Vitamin A supplementation at zoological gardens that had encountered neurologically affected lions under the age of 5.

Among the 12 zoological gardens that reported to have neurological problems in lions under the age of 5, two zoological gardens encountered neurological problems in lions in two different age categories (Fig. 6).

Fig. 6. Numbers of zoological gardens that had encountered neurological problems among lions at different age categories:
0-3 months, 3-6 months, 6-12 months and 2-5 years.

In two parks, neurologically affected lions (n=4) older than 5 years of age were also reported. These lions were not included in the study assuming they suffer from a different disease than clavairal hyperosteosis that only affect cubs or young adult lions.

Summary

1. These are the preliminary result from 46 responders only, the strength of this preliminary survey will increase as more veterinarian will cooperate and send us their responses.

2. About quarter of the veterinarian that responded to our first questionnaire have reported on neurologically affected lions in their zoo under the age of 5 years (12/46).

3. Neurologically affected lions were observed in zoological gardens with different dietary regimes.

4. We are aware of the fact that not all of these lions suffered from clavarial hyperosteosis and definitive diagnosis is not available in most of these cases, therefore a second questionnaire is now sent to veterinarians who have responded to the first questionnaire in which more specific questions are asked regarding the nature of the neurological abnormality.

We wish to thank all of you that took the time to participate and will update these results soon.