Introduction
Stratigraphy in veterinary anatomy is the orderly and sequential study of the anatomical layers that make up a body region, from the most superficial planes to the deepest ones. This approach allows understanding the three-dimensional arrangement of tissues and their functional relationships, being indispensable for veterinary clinical, surgical, and diagnostic practice.
Unlike the anatomical study by systems, stratigraphy analyzes the animal body by regions, considering how skin, subcutaneous tissue, muscles, vasculonervous structures, and internal organs overlap and relate to each other. This knowledge is essential for performing systematic physical examinations, interpreting medical imaging, and safely carrying out invasive procedures (Dyce et al., 2018).
Fundamentals of anatomical stratigraphy
Anatomical stratigraphy describes the arrangement in superimposed layers of the tissues that make up a specific body region. Each plane has its own histological, functional, and topographic characteristics, while maintaining a direct relationship with adjacent planes, allowing a progressive transition from the body surface to deeper structures (König & Liebich, 2020).
This method of study facilitates the spatial understanding of the animal body and constitutes the basis of topographic and applied anatomy.
Stratigraphic planes in veterinary anatomy
The cutaneous plane corresponds to the skin, the largest organ of the animal body, composed of epidermis and dermis. It acts as a physical, chemical, and biological barrier against the environment, in addition to participating in thermoregulation, sensory perception, and immunological protection.
From a stratigraphic point of view, the skin represents the first plane evaluated during clinical examination. Changes in color, texture, elasticity, or integrity may indicate systemic or local pathologies such as dehydration, inflammatory processes, parasitosis, or metabolic diseases.
In veterinary surgery, the cutaneous plane requires precise incisions and careful handling to promote proper healing and minimize postoperative infections.
The subcutaneous plane, also known as the hypodermis, is mainly composed of loose connective tissue and adipose tissue. This layer acts as a sliding plane between the skin and deeper structures, allowing the characteristic skin mobility observed in many animal species.
This plane contains superficial blood vessels, cutaneous nerves, lymphatics, and in some regions, glands and fat deposits with metabolic and thermal insulation functions. Its thickness varies notably according to species, anatomical region, age, and nutritional status of the animal (Dyce et al., 2018).
From a clinical perspective, the subcutaneous plane is relevant for the administration of medications via the subcutaneous route, detection of edema, abscesses, and emphysema, as well as for assessing body condition.
The muscular plane is composed of striated muscles organized into superficial and deep layers. These muscles are surrounded by fasciae that delimit anatomical compartments and facilitate sliding between structures during movement.
Muscular stratification allows efficient functional organization, where superficial muscles usually participate in wide movements, while deep muscles perform postural and stabilization functions.
In applied anatomy, detailed knowledge of the muscular plane is fundamental for surgical approaches, regional anesthetic blocks, and the identification of anatomical landmarks in different veterinary species.
The vasculonervous plane includes arteries, veins, nerves, and lymphatic vessels that usually run between muscular planes or in close association with them. These structures form anatomical bundles protected by connective tissue.
Accurate identification of this plane is critical during surgical and anesthetic procedures, as accidental injury may cause hemorrhage, neurological deficits, or severe functional alterations.
In veterinary practice, knowledge of vasculonervous stratigraphy allows venipuncture, catheterization, and nerve blocks to be performed with greater precision and safety (König & Liebich, 2020).
The deep plane includes bony structures, body cavities, and internal organs. At this level are located thoracic, abdominal, and pelvic viscera, as well as joints and skeletal elements.
Stratigraphic study of this plane allows understanding of visceral topography and its relationship with superficial structures, which is essential for interpreting imaging studies and surgical planning.
In invasive procedures, access to the deep plane must be performed while respecting superficial planes to minimize tissue damage and reduce postoperative complications.
Clinical importance of veterinary stratigraphy
Clinical evaluation by anatomical planes allows more precise localization of lesions, masses, pain, and structural alterations. Systematic stratigraphic palpation improves the quality of clinical diagnosis.
Respecting stratigraphic planes during surgery reduces tissue trauma, facilitates healing, and decreases the risk of complications. This principle applies to both small and large animal surgery (Fossum, 2019).
Conclusion
Stratigraphy in veterinary anatomy constitutes a fundamental tool for understanding the organization of the animal body from a regional and applied perspective. Its mastery allows the veterinarian to integrate anatomical knowledge with clinical, surgical, and diagnostic practice, ensuring safer and more effective interventions.
References
Dyce, K. M., Sack, W. O., & Wensing, C. J. G. (2018). Textbook of Veterinary Anatomy. Elsevier.
König, H. E., & Liebich, H. G. (2020). Veterinary Anatomy of Domestic Mammals. Thieme.
Fossum, T. W. (2019). Small Animal Surgery. Elsevier.