- Veterinary View Box
- Posts
- Should keep Calvarial Hyperostosis Syndrome on your list for differential of exophthalmia....
Should keep Calvarial Hyperostosis Syndrome on your list for differential of exophthalmia....
Veterinary Ophthalmology 2025
Obi Veterinary Education
October 14, 2025
Steinmetz, A.; Kohl, S.
Background:
Calvarial Hyperostosis Syndrome (CHS) is a non-neoplastic bone proliferation affecting the flat bones of the skull, previously reported in several dog breeds but not well-documented in Labrador Retrievers. CHS has been associated with skull swelling, pain, and, in rare cases, ophthalmological signs such as exophthalmos. This case report describes CHS as a potential cause of exophthalmos and epiphora in two young Labrador Retrievers.
Methods:
Two Labrador Retrievers (a 9-month-old female and a 2-year-old male) were examined for ophthalmological signs. Both underwent clinical and ophthalmic examinations, computed tomography (CT), and histopathological analysis. Additional dacryocystorhinography (DCR) was performed in one case.
Results:
Case 1 presented with lateral exophthalmos of the left eye, with CT revealing thickened and sclerotic frontal, parietal, temporal, and occipital bones, extending into the orbit. Case 2 exhibited chronic serous lacrimal discharge due to nasolacrimal duct narrowing from hyperostotic changes in the right lacrimal and maxillary bones. Histopathology in case 1 indicated active bone remodeling, while case 2 displayed trabecular lamellar bone without neoplastic or infectious features. CHS was diagnosed in both cases. The exophthalmos in case 1 partially regressed over six months, while epiphora in case 2 persisted without progression.
Limitations:
This report describes only two cases, limiting broader conclusions about CHS in Labrador Retrievers. The lack of genetic analysis means a hereditary component cannot be ruled out. Additionally, long-term outcomes beyond six months remain unknown.
Conclusions:
CHS should be considered as a differential diagnosis for exophthalmos or epiphora in young dogs, particularly when skull thickening is detected. Diagnostic imaging and histopathology are essential for confirmation. Further studies are needed to determine breed predisposition and disease progression.
Imaging findings. (A) Transverse CT image showing marked thickening of the orbital lamina of the left frontal bone with smoothly marginated bone proliferation and sclerosis (solid arrows), as well as moderate bilateral thickening of the squama frontalis (arrowheads). (B) Transverse CT image showing marked bilateral thickening of the parietal bone with smoothly marginated bone proliferation and sclerosis (arrowheads). (C) Dorsal CT image showing marked thickening of the orbital lamina of the left frontal bone with smoothly marginated bone proliferation and sclerosis (solid arrows). (D) 3D volume-rendered image illustrating the extent of left frontal bone thickening and bone proliferation (solid arrows).
How did we do? |
Disclaimer: The summary generated in this email was created by an AI large language model. Therefore errors may occur. Reading the article is the best way to understand the scholarly work. The figure presented here remains the property of the publisher or author and subject to the applicable copyright agreement. It is reproduced here as an educational work. If you have any questions or concerns about the work presented here, reply to this email.