A typical canine Ehlers-Danlos-like syndrome without collagen abnormalities: a suspected case of Tenascin-X deficiency

Abstract

Background: Ehlers-Danlos syndromes (EDS) are rare heritable connective tissue disorders, most commonly linked to collagen abnormalities. In dogs, reported cases are infrequent and typically involve skin fragility and joint laxity, with limited understanding of underlying genetic causes. This report describes an unusual, aggressive, and fatal case of an Ehlers–Danlos–like syndrome (EDlS) in a Maltese dog, with several uncommon features. Unlike most canine EDS cases, which show collagen defects, this case revealed minimal collagen alterations; instead, elastic fibers were primarily affected. Case report: A one-and-a-half-year-old male Maltese dog presented with progressive abdominal masses, skin fragility, joint deformities, and frequent bruising since early life. Clinical examination revealed hyperextensible, fragile skin, hematomas, and contractures of the hind limbs. Imaging confirmed a hernia lacking supportive connective structures. Histopathological analysis showed elastic fiber hypertrophy and fragmentation, with minimal collagen changes. Despite palliative wound management, the patient died within ten days of the initial consultation due to spontaneous evisceration and vascular rupture. Conclusion: The histological features are consistent with a possible Tenascin-X deficiency. Definitive molecular classification was beyond the scope of this case. This report expands the spectrum of EDlS in dogs.