An Anatomical Study of the Thoracic Limb of the Giant Anteater (Myrmecophaga tridactyla) Compared to the Domestic Dog: A Surgical Guide for Approaching the Humerus and Radius

Introduction: An increased demand for veterinary care of the giant anteater, a vulnerable species in South America, has aroused interest in anatomical studies of this animal. Traumatic long bone fractures have been the most common morbidity in these animals when they survive road traffic accidents. The objective was to study the anatomy of the thoracic limb of the giant anteater with reference to the domestic dog.

Materials and Methods: Cadavers of three giant anteaters and three adult dogs were selected for the study. During the evaluation of the anatomical structures, the species were compared, to identify peculiarities in the giant anteater that may be relevant in the consideration of surgical approaches. The remaining specimens were used to study surgical approaches to the humerus and radius in both limbs.

Results: The humerus of the giant anteater can be approached from lateral or medial aspect. The short head of the biceps brachii divides into two branches, one of which is joined to the long head. This insertion must be incised to expose the humeral diaphysis. In the giant anteater, the lateral approach to the radius must be performed through an incision in the forearm fascia, and later dissection between the extensor carpi radialis and extensor digitalis communis muscles.

Discussion/Conclusion: The authors’ found a greater number of muscle divisions, crests and bony prominences needed to support the traction of larger muscle groups and tendons of the giant anteater compared to the dog. Although similar to the dog in many ways, the long bones and limb muscles of the giant anteater also have distinct features that affect the surgical approach and implant placement. The fracture repair can be potentially guided by these similarities and differences.

Acknowledgments: FAPESP - São Paulo State Research Support Foundation.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
11 September 2023