Fig 1.
Map of the Channel Islands (California, USA).
Distribution of foxes that are uninfected or infected with ear mites, and foxes that have ceruminous gland tumors. Island foxes do not reside on Santa Barbara or Anacapa islands.
Table 1.
Pathology terms and definitions.
Table 2.
Scoring criteria: otoscopic assessment of mites and histopathologic assessment of otitis and ceruminous gland hyperplasia (CGH).
Fig 2.
Photo of ceruminous gland tumor within ear canal of a Santa Catalina Island fox.
Fig 3.
Photo of ceruminous gland tumor after local invasion into adjacent bulla tympanica, pharynx, temporal, and occipital bones and skull of a Santa Catalina Island fox.
Fig 4.
Photo of ceruminous gland tumor after metastasis to lung, forming discrete tumors (arrow) and infiltrating pulmonary parenchyma (arrowhead) of a Santa Catalina Island fox.
Fig 5.
Photo of hematoxylin and eosin—stained histopathology slide of ceruminous gland cystadenocarcinoma in a Santa Catalina Island fox (main image scale bar = 1mm, inset = 50μm).
Fig 6.
Photo of hematoxylin and eosin—stained histopathology slide of ceruminous gland solid adenocarcinoma in a Santa Catalina Island fox (magnification same as Fig 5, inset = 50μm).
Fig 7.
Photo of hematoxylin and eosin—stained histopathology slide of ceruminous gland dysplasia in a Santa Catalina Island fox (main image scale bar = 200 μm, inset = 50μm).
Fig 8.
Scattergram developed from canonical discriminant analysis of 9 morphometric characters measured on Otodectes cyanotis mites from different hosts illustrating morphologic differentiation of mites present in island foxes from Santa Catalina (SCA), San Clemente (SCI) and San Nicolas Islands (SNI) and feral cats from SCA and the mainland.
Discriminant functions 1 (DF1; body length and outer opisthosomal setae #3 length) and 2 (DF2; outer opisthosomal setae #3 length) cumulatively accounted for 87% of the variation in group measurement means observed.
Table 3.
The prevalence of tumors (ceruminous gland carcinomas and adenomas) among live (2007–2008) and dead (2001–2008) adult island foxes examined from Santa Catalina (SCA), San Clemente (SCI) and San Nicolas (SNI) islands in the Channel Islands of southern California, USA.
Fig 9.
The frequency distribution of otitis severity scores in biopsy-sampled live adult foxes from SCA, SCI, and SNI.
Number above bar equals sample size for each subgroup.
Fig 10.
The frequency distribution of ceruminous gland hyperplasia scores in biopsy-sampled live adult foxes from SCA, SCI, and SNI.
Number above bar equals sample size for each subgroup.
Table 4.
Final logistic regression model examining risk factors associated with the presence of a ceruminous gland tumor in live-sampled Santa Catalina Island foxes.