Computed Tomographic Analysis of Calvarial Hyperostosis in Captive Lions

Gross-Tsubery, Ruth; Chai, Orit; Shilo, Yael; Miara, Limor; Horowitz, Igal; Shmueli, Ayelet; Aizenberg, Itzhak; Hoffman, Chen; Reifen, Ram; Shamir, Merav H.

doi:10.1111/j.1740-8261.2009.01617.x

Cited by 17 publications

(20 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A possible genetic basis for the malformation has not yet been investigated, although in some reports affected lions came from the same litter ([10], [17], [38]; Shamir et al unpublished data), thus suggesting possible genetic, in utero , or postpartum factors. This may be related to a possible small founder population and subsequent inbreeding of lions in captivity.…”

Section: Discussionmentioning

confidence: 99%

Comparative Skull Analysis Suggests Species-Specific Captivity-Related Malformation in Lions (Panthera leo)

et al. 2014

Self Cite

View full text Add to dashboard Cite

Lion (Panthera leo) populations have dramatically decreased worldwide with a surviving population estimated at 32,000 across the African savannah. Lions have been kept in captivity for centuries and, although they reproduce well, high rates of stillbirths as well as morbidity and mortality of neonate and young lions are reported. Many of these cases are associated with bone malformations, including foramen magnum (FM) stenosis and thickened tentorium cerebelli. The precise causes of these malformations and whether they are unique to captive lions remain unclear. To test whether captivity is associated with FM stenosis, we evaluated 575 lion skulls of wild (N = 512) and captive (N = 63) origin. Tiger skulls (N = 276; 56 captive, 220 wild) were measured for comparison. While no differences were found between males and females or between subadults and adults in FM height (FMH), FMH of captive lions (17.36±3.20 mm) was significantly smaller and with greater variability when compared to that in wild lions (19.77±2.11 mm). There was no difference between wild (18.47±1.26 mm) and captive (18.56±1.64 mm) tigers in FMH. Birth origin (wild vs. captive) as a factor for FMH remained significant in lions even after controlling for age and sex. Whereas only 20/473 wild lions (4.2%) had FMH equal to or smaller than the 5th percentile of the wild population (16.60 mm), this was evident in 40.4% (23/57) of captive lion skulls. Similar comparison for tigers found no differences between the captive and wild populations. Lions with FMH equal to or smaller than the 5th percentile had wider skulls with smaller cranial volume. Cranial volume remained smaller in both male and female captive lions when controlled for skull size. These findings suggest species- and captivity-related predisposition for the pathology in lions.

show abstract

Section: Discussionmentioning

confidence: 99%

Comparative Skull Analysis Suggests Species-Specific Captivity-Related Malformation in Lions (Panthera leo)

et al. 2014

Self Cite

View full text Add to dashboard Cite

show abstract

“…While several studies have examined specific aspects of captive pantherine cranial morphology, this research has generally focused on relatively few variables [45] , [49] with a specific interest, most recently on a peculiar foramen magnum stenosis found in captive lions [3] , [24] , [42] , [45] , [50] – [52] (but, interestingly, not tigers; [45] ) that almost certainly has nothing to do with the mechanical properties of their diet.…”

Section: Introductionmentioning

confidence: 99%

The Three-Dimensional Morphological Effects of Captivity

et al. 2014

View full text Add to dashboard Cite

Many captive animals are fed diets that are drastically different in mechanical properties than their wild diet. Most captive pantherines are fed a nutritionally supplemented diet consisting almost entirely of ground meat. While many zoos supplement this diet with bones, the fact remains that large captive felids are fed diets that require substantially less masticatory effort than those of their wild counterparts. The osteological effects of this dietary difference have not been fully evaluated. To this end, we compared linear measurements and 3D geometric morphometric landmarks of captive and wild lions and tigers. Using Principal Component (PC) analysis of the linear measurements, not only were the sexes and species statistically distinct, but so too was the population clearly divisible in terms of captivity status. The 3D analysis supported these findings: although the most influential variable in the sample (PC1, 21.5% of the variation) separates the two species, the second most influential contributor (PC2) to the overall skull shape is driven not by the sex differences in these highly dimorphic species, but rather by their captivity status. In fact, captivity status drives nearly twice as much of the 3D variation as sexual dimorphism (14.8% vs. 8.0% for PC2 vs. PC3). Thus the shape is influenced nearly twice as much by whether the animal was captive or wild than by whether it was male or female. If a causal relationship can be demonstrated between dietary mechanical properties and morphology, people who oversee the diets of captive carnivores should consider modifying these diets to account for not only nutritional but also the mechanical properties of a carcass-based diet as well. In addition to the husbandry implications, our analyses show the ways in which captive specimens are different than their wild counterparts – findings that have implications for morphologists when considering anatomical samples.

show abstract

“…9 In another study, MpEs were not present on the CT scans of 5 live captive African lions: 3 normal animals and 2 affected by calvarial hyperostosis. 5 Although MpEs can be easily identified macroscopically, their prevalence may also be underestimated if middle ear examination is not routinely performed during necropsy, unless clinical history includes signs of middle ear disease.…”

Section: Microscopic Findingsmentioning

confidence: 99%

Mucoperiosteal Exostoses in the Tympanic Bulla of African Lions (Panthera leo)

et al. 2014

View full text Add to dashboard Cite

Mucoperiosteal exostoses (MpEs) of the tympanic bulla (TB), also referred as middle-ear otoliths, have been occasionally described in dogs and cats in association with clinical signs of otitis media or as an incidental finding, but they have not been recorded in other species. In this report, we describe the radiographic, gross, and histopathologic features of MpEs in 8 African lions (Panthera leo). All animals (5 males and 3 females) were adults that had been kept in captivity and had their skeletons conserved as part of an anatomic academic collection. A radiographic study revealed mineralized structures in the TB consistent with MpEs in 7 of the 16 examined TB; a computed tomography study identified MpEs in 12 of the 16 TB. Six TB from 4 lions were sectioned, and several MpEs were demineralized for histopathologic analysis. Grossly, MpEs appeared variable in number and shape. Some were globular structures that were loosely attached to the mucosal surface of the TB; others were isolated to coalescent bone spicules extending from the mucoperiosteum. Position was also variable, but MpEs frequently developed in the hypotympanum, especially on the ventromedial aspect of the TB wall. Microscopically, MpEs were composed of osteonal bone growing from the periosteum and not by dystrophic calcification of necrotic tissue debris, as is hypothesized in dogs. KeywordsAfrican lion, computed tomography, mucoperiosteal exostoses, middle ear, Panthera leo, pathology, tympanic bullaThe middle ear structure is well known in domestic animals, but it has only been occasionally studied in lions.6 Threedimensional anatomic reconstructions show that the middle ear of the lion and cat are similarly arranged but have large differences in absolute and relative size. 6,12 In mammals, the middle ear is lined by respiratory epithelium that is contiguous with the nasopharynx via the auditory tube; however, portions of the middle ear are lined by squamous to cuboidal epithelium, especially the petrous portion of the temporal and tympanic membrane. 1,12 In a recent exhaustive study on the histology and histopathology of the cat middle ear, Sula et al 12 introduced the term auricular mucoperiosteum to name this unique mucosal membrane lining the middle ear, which is characterized by the direct apposition of epithelia and submucosa with periosteal connective tissues.Little is known about the pathology of the middle ear in the majority of animal species. Infectious (bacterial) otitis media has been more frequently described in dogs, cats, and cows.7,12,13 Sula et al 12 recently described the histologic characteristics of diseased ears in a series of 50 cats and concluded that middle ear diseases in cats are far more common than gross lesions or clinical literature suggests.

show abstract

Computed Tomographic Analysis of Calvarial Hyperostosis in Captive Lions

Cited by 17 publications

References 7 publications

Comparative Skull Analysis Suggests Species-Specific Captivity-Related Malformation in Lions (Panthera leo)

Comparative Skull Analysis Suggests Species-Specific Captivity-Related Malformation in Lions (Panthera leo)

The Three-Dimensional Morphological Effects of Captivity

Mucoperiosteal Exostoses in the Tympanic Bulla of African Lions (Panthera leo)

Contact Info

Product

Resources

About