Canine Skeletal System: Axial and Appendicular Overview

By Dr. Zubair Khalid, DVM, MS, PhD · 2026-08-11

Key Takeaways

• The canine skeleton is functionally divided into the axial (skull, vertebral column, ribs, sternum) and appendicular (limbs and girdles) components, each with distinct developmental origins and primary roles in neural protection, visceral support, and locomotion.
• Palpable landmarks such as the wings of the atlas, spinous processes, olecranon, and greater trochanter are critical for accurate physical examination, radiographic positioning, and localization of lameness.
• Breed-specific skeletal variation is genetically influenced, impacting bone size and shape, which necessitates breed-appropriate interpretation of radiographic findings and clinical norms.
• Radiographic interpretation relies on orthogonal projections and understanding normal anatomical variants to accurately diagnose pathologies like fractures, luxations, and lytic lesions.
• Advanced imaging modalities like CT and MRI are indicated for complex or radiographically occult lesions, particularly in joints like the elbow and stifle, or for spinal cord evaluation.
• Accurate documentation, including structured reporting of radiographic findings and clinical observations, is essential for continuity of care and is supported by professional practice standards.

This reference article provides a systematic account of the canine skeleton, organized into its axial and appendicular divisions. It is written for veterinary students who require a working knowledge of skeletal architecture, clinically relevant landmarks, and the functional relationships between bone, muscle, and joint. The content supports palpation skills, radiographic interpretation, and the anatomical reasoning expected in clinical examinations.

The domestic dog presents a particularly instructive model for skeletal study because breed-associated variation in bone size and shape is pronounced and genetically tractable. Studies in populations such as the Portuguese Water Dog have identified quantitative trait loci that regulate pelvic size relative to limb bone dimensions and independently control pelvic shape, illustrating how discrete genetic inputs shape functionally linked skeletal suites. Understanding this variation matters clinically: what is normal for a Chihuahua is not normal for a Great Dane, and the same applies to individual bones within a single skeleton.

The skeleton is conventionally divided at the junction of the trunk and the limbs. The axial skeleton comprises the skull, vertebral column, ribs, and sternum. The appendicular skeleton comprises the bones of the thoracic and pelvic limbs, including their girdles. This division is anatomically convenient and radiographically practical, since standard positioning protocols and beam centring points differ substantially between the two regions.

At a Glance

Developmental Foundations of the Skeleton

The canine skeleton arises from three embryonic lineages. The axial skeleton derives from the paraxial mesoderm, which segments into somites, the sclerotome of each somite gives rise to the vertebrae and ribs. The appendicular skeleton derives from the lateral plate mesoderm of the limb buds, while the craniofacial skeleton is largely neural crest derived. These distinct origins explain why congenital anomalies often respect axial or appendicular boundaries instead of crossing them.

Vertebrate body asymmetry, including the directionally organized packing of viscera that the axial skeleton supports, depends on conserved molecular cascades that establish left-right identity during gastrulation. The developmental mechanism that ensures correct situs appears conserved across vertebrates, although the earliest symmetry-breaking steps remain incompletely characterized. For the clinician, the practical relevance is that severe axial malformations sometimes co-occur with visceral situs anomalies, and a thorough physical examination of a puppy with vertebral malformation should include assessment of thoracic and abdominal organ position.

Limb outgrowth follows a proximodistal sequence controlled by the apical ectodermal ridge. The stylopod (humerus or femur), zeugopod (radius-ulna or tibia-fibula), and autopod (manus or pes) form in that order, and the timing of chondrification and ossification within each segment is predictable. Interactive three-dimensional atlases of developing limb anatomy, originally generated for the mouse, demonstrate the complex spatial relationships between muscles, tendons, and skeletal elements during this period and provide a useful conceptual model for understanding how adult limb architecture is assembled.

The Axial Skeleton

The vertebral formula of the dog is C7 T13 L7 S3 Cd variable, typically 20 to 23 caudal vertebrae. The atlas (C1) lacks a vertebral body and spinous process, consisting of paired lateral masses connected by dorsal and ventral arches. Its wide transverse processes, the wings of the atlas, are readily palpable just caudal to the skull and serve as the primary landmark for locating the vertebral artery foramen. The axis (C2) possesses a prominent dens that articulates with the ventral arch of the atlas, permitting rotational movement of the head.

The thoracic vertebrae are distinguished by their tall spinous processes, which slope caudally, and by costal foveae that articulate with the ribs. The anticlinal vertebra, usually T11, marks the point where spinous process orientation changes from caudal to cranial slope. This landmark is useful radiographically for numbering thoracic vertebrae. The lumbar vertebrae have long transverse processes that project cranioventrally and provide attachment for the lumbar musculature. The sacrum is formed by fusion of three sacral vertebrae and articulates with the ilia at the sacroiliac joints, transmitting weight from the axial to the appendicular skeleton.

The ribs number 13 pairs. The first nine pairs articulate with the sternum via costal cartilages and are termed sternal ribs, the remaining four are asternal, with their cartilages joining the cartilage of the preceding rib. The last rib pair is often described as floating. The sternebrae, typically eight in number, articulate with the costal cartilages and provide attachment for the pectoral musculature.

The Appendicular Skeleton

The thoracic limb is connected to the trunk only by muscles, a suspension arrangement that provides shock absorption but renders the limb vulnerable to traction injuries. The scapula is a large flat bone whose spine divides the lateral surface into supraspinous and infraspinous fossae. The spine ends distally in the acromion, a palpable landmark at the point of the shoulder. The humerus bears the greater tubercle laterally and the lesser tubercle medially, separated by the intertubercular groove through which the biceps tendon passes. The radial fossa and olecranon fossa on the distal humerus accommodate the corresponding processes of the radius and ulna during full flexion and extension.

The radius is the principal weight-bearing bone of the antebrachium. The ulna is longer proximally, forming the olecranon, and articulates with the humerus at the elbow joint. The two bones are united by the interosseous membrane and articulate with each other at their proximal and distal ends. The carpus comprises seven or eight bones arranged in proximal and distal rows. The manus includes the metacarpals and phalanges, with five digits in the thoracic limb.

The pelvic limb attaches to the axial skeleton through the sacroiliac joint, a firm synovial articulation reinforced by strong dorsal ligaments. The pelvis is formed by the ilium, ischium, and pubis, which fuse at the acetabulum. The ilial wing is palpable as the point of the hip. The femur is the longest bone in the body, its head articulates with the acetabulum, and the greater trochanter provides the major palpable landmark of the hip. The patella, a sesamoid bone within the quadriceps tendon, articulates with the trochlear groove of the distal femur. The tibia is the principal weight-bearing bone of the crus, the fibula is slender and largely non-weight-bearing. The tarsus comprises seven bones, with the calcaneus forming the point of the hock. The pes has four weight-bearing digits.

Skeletal Variation and Its Clinical Significance

Breed-specific skeletal morphology is also cosmetic. The genetic architecture underlying pelvic size and shape in dogs involves multiple quantitative trait loci distributed across several chromosomes, with some loci regulating the pelvis relative to limb bone dimensions and others controlling pelvic shape independently. These findings imply that selection for one skeletal feature can produce correlated changes elsewhere, a consideration when evaluating conformational lameness or planning orthopedic surgery.

Radiographic interpretation requires familiarity with normal breed variation. The MSD Veterinary Manual provides peer-reviewed guidance on musculoskeletal imaging and common skeletal disorders, and veterinary students should consult such sources when encountering unfamiliar breed conformations. Similarly, professional practice resources from organizations such as the American Veterinary Medical Association offer guidance on diagnostic imaging standards and orthopedic examination technique.

Palpable Landmarks and Surface Anatomy

Palpation remains the first imaging modality in musculoskeletal examination. A systematic approach proceeds from axial to appendicular structures, comparing contralateral sides for symmetry, temperature, and crepitus. The clinician who can reliably identify bony prominences will localize lameness more efficiently and position radiographic projections with greater accuracy.

The dorsal spinous processes of the thoracic vertebrae are palpable through the epaxial musculature from the withers to the lumbosacral junction. The first thoracic vertebra is often the most prominent, though this varies with body condition and breed conformation. The wings of the atlas are readily palpable immediately caudal to the skull base, and the transverse processes of the sixth and seventh cervical vertebrae are identifiable in thin-coated patients. The lumbosacral space is located by sliding a finger caudally along the dorsal midline until the last lumbar spinous process gives way to the sacral prominence.

On the thoracic limb, the spine of the scapula runs obliquely across the lateral thorax and terminates at the acromion, a reliable landmark for the shoulder joint. The greater tubercle of the humerus projects cranially and is covered by the acromial head of the deltoideus muscle. The olecranon forms the palpable point of the elbow, and the lateral epicondyle of the humerus lies just distal to it. The styloid processes of the radius and ulna flank the carpus medially and laterally, with the accessory carpal bone projecting caudolaterally and serving as a key landmark for the carpal joint and for regional nerve blocks.

On the pelvic limb, the wing of the ilium forms the palpable point of the hip, and the greater trochanter of the femur is felt as a firm prominence just distal to it. The ischiatic tuberosity is palpable caudal to the hip, and the patella glides within the trochlear groove during stifle flexion and extension. The tibial tuberosity is the prominent crest on the proximal craniomedial tibia, and the lateral malleolus of the fibula and medial malleolus of the tibia flank the tarsocrural joint. The calcaneal tuber, or point of the hock, is the prominent proximal projection of the calcaneus.

Table 1. Major Bones and Palpable Landmarks

Radiographic Positioning and Projection Selection

Radiographic evaluation of the canine skeleton follows a standardized sequence that balances diagnostic yield against radiation exposure and patient comfort. The orthogonal principle governs all skeletal imaging: a minimum of two projections at right angles is required to characterize a fracture, luxation, or lytic lesion. Additional oblique projections are indicated when a structure is obscured by superimposition, such as the carpus and tarsus, or when a specific lesion is suspected, such as a fragmented medial coronoid process.

For the axial skeleton, lateral projections of the spine are obtained with the patient in true lateral recumbency, ensuring that the sternum and spine are superimposed in the thoracic region. Ventrodorsal projections of the spine require careful positioning to avoid rotation, which can mimic or obscure vertebral lesions. The skull is imaged with lateral, dorsoventral, and rostrocaudal projections, with open-mouth oblique views reserved for the tympanic bullae and dental arcades.

The thoracic limb is positioned with the joint of interest centerd in the primary beam. The shoulder is imaged with the limb in a neutral stance position, and the elbow requires a flexed lateral projection to separate the humeral condyles from the olecranon. The carpus is imaged in lateral and dorsopalmar projections, with stress views reserved for suspected collateral ligament injury. The digits require dorsopalmar and lateral projections, often with sedation to achieve the necessary positioning.

The pelvic limb follows a similar logic. The hip is imaged in ventrodorsal projection with the femurs extended and parallel, the standard view for hip dysplasia screening. The stifle requires lateral and craniocaudal projections, with the lateral view obtained in a flexed position to assess the patellar ligament and fabellae. The tarsus is imaged in lateral and dorsoplantar projections, and the calcaneus is best assessed on the lateral view.

Patient size and temperament alter the approach. Brachycephalic breeds with respiratory compromise tolerate dorsal recumbency poorly and may require shorter examination times or supplemental oxygen. Obese patients require higher exposure factors, and heavy sedation or general anesthesia is often necessary to achieve diagnostic positioning in fractious animals. The MSD Veterinary Manual provides species-specific guidance on positioning and technique that should be consulted before unfamiliar projections are attempted.

Interpreting Common Radiographic Findings

The radiographic appearance of bone reflects the balance between osteoblastic and osteoclastic activity. Periosteal new bone formation appears as smooth, lamellar, or spiculated opacity along the cortical surface, and its character narrows the differential list. Smooth, well-marginated periosteal reaction is typical of chronic, low-grade processes such as hypertrophic osteopathy or healing fractures. Irregular, aggressive periosteal reaction with sunburst or Codman triangle patterns raises concern for neoplasia, though infection can produce a similar appearance.

Lytic lesions appear as areas of reduced bone opacity and are classified as geographic, moth-eaten, or permeative. Geographic lysis with a well-defined margin suggests a slow-growing process such as a bone cyst or benign tumor. Moth-eaten and permeative patterns indicate rapid, aggressive destruction and are more typical of osteosarcoma or fungal osteomyelitis. The distribution of lesions is equally informative: osteosarcoma preferentially affects the metaphyseal regions of the appendicular skeleton, particularly the distal radius and proximal humerus, while multiple lytic lesions raise suspicion for metastatic disease or multiple myeloma.

Fracture description follows a standardized nomenclature that includes the bone, the location within the bone, the fracture configuration, and the degree of comminution. The Salter-Harris classification applies to physeal fractures in immature patients and guides both prognosis and treatment decisions. A Salter-Harris type I fracture through the physis carries a good prognosis with appropriate stabilization, while a type IV fracture that crosses the physis into the epiphysis risks growth disturbance and requires anatomic reduction.

The clinician must correlate radiographic findings with the clinical examination. A radiographically apparent lesion that does not match the patient's lameness localization warrants further investigation, including additional projections, advanced imaging, or arthrocentesis. Conversely, a normal radiograph does not exclude significant pathology, particularly in the early stages of osteomyelitis or in stress fractures of the pelvic limb, where the genetic regulation of pelvic size and shape may predispose certain breeds to specific injury patterns.

Advanced Imaging and When to Use It

Computed tomography (CT) provides cross-sectional imaging of bone with superior spatial resolution and eliminates the superimposition that limits radiography. CT is the imaging modality of choice for the elbow, where fragmented medial coronoid process and other developmental abnormalities are often radiographically occult. CT is also indicated for complex fractures of the skull, spine, and pelvis, where three-dimensional reconstruction aids surgical planning. The availability of CT has expanded in general practice, and its use is now standard for preoperative planning of articular fractures.

Magnetic resonance imaging (MRI) offers superior soft tissue contrast and is indicated when the clinical signs localize to the joint but radiographs and CT are unremarkable. MRI is the modality of choice for evaluating the menisci, cruciate ligaments, and collateral ligaments of the stifle, and for assessing the intervertebral discs and spinal cord in patients with suspected disc disease. MRI requires general anesthesia and is more expensive than CT, so its use is reserved for cases where the information will change the treatment plan.

Ultrasonography has a limited role in skeletal imaging but is valuable for assessing the soft tissue structures adjacent to bone, including tendons, ligaments, and joint effusion. The biceps tendon and supraspinatus tendon of the shoulder are readily assessed with ultrasound, and the technique is useful for guiding arthrocentesis and joint injections. Nuclear scintigraphy detects areas of increased bone turnover and is highly sensitive for occult lesions, though its specificity is low and its availability is limited to referral institutions.

The choice of imaging modality depends on the clinical question, the patient's stability, and the available equipment. A patient with a suspected simple radial fracture requires radiographs alone, while a patient with persistent thoracic limb lameness and normal radiographs warrants CT of the elbow. The NCBI Bookshelf provides comparative anatomy and imaging references that support modality selection in ambiguous cases.

Documentation and Reporting Standards

Accurate documentation of skeletal findings is essential for continuity of care, medicolegal protection, and monitoring disease progression. The radiographic report should follow a structured format that includes the patient identification, the date of the study, the projections obtained, and a description of the findings. The description should be objective and use standard terminology, avoiding interpretive statements that belong in the conclusion section.

The report should describe the alignment, the cortical margins, the medullary opacity, and the periosteal reaction of each bone examined. Fractures are described by location, configuration, and comminution, and the degree of displacement is quantified in terms of bone width or percentage. Joint spaces are assessed for widening or narrowing, and the presence of effusion or intra-articular gas is noted. The conclusion should state the most likely diagnosis, the differential diagnoses, and any recommendations for further imaging or treatment.

Serial radiographs are essential for monitoring fracture healing and detecting complications. The expected timeline for healing varies with the patient's age, the fracture location, and the method of stabilization. Immature patients heal more rapidly than adults, and metaphyseal fractures heal faster than diaphyseal fractures. The clinician should compare current radiographs with previous studies to assess the progression of callus formation and the maintenance of reduction. The WOAH terrestrial animal health standards provide guidance on documentation practices that support traceability and quality assurance in veterinary practice.

Recognized Complications and Failure Modes

Skeletal pathology in dogs presents with a limited repertoire of clinical signs, and the same radiographic pattern can arise from distinct disease processes. The most frequently missed complications in axial and appendicular disease are pathologic fracture through an occult bone lesion, cervical vertebral instability with spinal cord compression, and aggressive bone lesions mistaken for traumatic or degenerative change.

Pathologic fracture should be suspected when a fracture occurs with minimal trauma, when the fracture line traverses a region of abnormal bone density, or when periosteal reaction is present at a site distant from the fracture. The discriminating finding is the character of the bone itself. A fracture through a primary bone tumor shows an ill-defined transition zone, Codman triangle formation, or sunburst periosteal reaction, whereas a traumatic fracture in otherwise normal bone shows sharp margins and a narrow transition zone. Early detection depends on comparing the affected bone with the contralateral limb and on scrutinising the medullary cavity for subtle endosteal scalloping or cortical thinning.

Cervical vertebral instability, particularly in young large-breed dogs, presents with progressive ataxia and proprioceptive deficits that can be mistaken for orthopedic disease. The failure mode is delayed diagnosis because thoracic limb lameness and cervical pain are attributed to shoulder or elbow pathology. The discriminating check is a complete neurologic examination, including postural reactions and spinal reflexes, before imaging is planned. Radiographic signs include vertebral canal stenosis, articular facet subluxation, and malalignment of the dorsal laminae on a lateral projection.

Aggressive bone lesions, including osteomyelitis and neoplasia, share radiographic features with each other and with healing fractures. The early detection strategy is temporal. A healing fracture shows progressive callus maturation over weeks, whereas an aggressive lesion shows progressive lysis and periosteal destruction. Serial radiography at two to four week intervals is the most practical discriminator when the initial study is equivocal.

Common Errors and Corrective Action

Less experienced clinicians frequently misidentify normal anatomic variants as pathology. The nutrient foramen of the femur and humerus appears as an oblique radiolucent line that can be mistaken for a fissure fracture. The physis of the proximal humerus in a growing dog can mimic a fracture line. The key discriminator is location and contour. Nutrient foramina have smooth, corticated margins and a consistent oblique orientation, while fractures have irregular, non-corticated edges.

Positioning errors are the most common technical fault. Oblique positioning of the pelvis creates apparent asymmetry of the coxofemoral joints and can simulate subluxation. The corrective action is to verify symmetry of the obturator foramina and iliac wings before interpreting the study. Similarly, a slightly rotated lateral thoracic radiograph superimposes the ribs over the vertebral bodies and can obscure a vertebral lesion. Repeat the projection instead of attempting to interpret a non-diagnostic study.

A second common error is overinterpreting the significance of a single radiographic finding without clinical correlation. Spondylosis deformans is common in older dogs and is often an incidental finding. The error is attributing pelvic limb weakness to spondylosis when the neurologic examination points to a different localization. The corrective action is to establish a neuroanatomic localization before imaging and to treat imaging findings that do not match the clinical examination with caution.

Limitations of Current Evidence

The genetic architecture of canine skeletal variation is incompletely characterized. Studies in Portuguese Water Dogs have identified quantitative trait loci for pelvic size and shape on multiple chromosomes, but these findings have not been replicated across breeds, and the functional variants remain unknown. Breed-specific reference values for skeletal dimensions and joint angles are largely absent from the literature, and clinicians should be cautious when applying measurements derived from one breed to another.

The developmental mechanisms that produce the vertebrate body plan, including left-right asymmetry and limb patterning, are understood primarily from mouse and chick models. Whether these mechanisms are fully conserved in dogs is not established. The turtle shell provides a striking example of how axial and appendicular elements can be reorganised during evolution, but the relevance of such comparative developmental data to clinical canine anatomy is indirect.

Expert opinion still differs on the clinical significance of certain radiographic findings, particularly the degree of lumbosacral stenosis that warrants surgical intervention and the role of prophylactic fixation of the contralateral limb in dogs with unilateral cruciate disease. These areas lack prospective outcome data, and management decisions should be individualised.

Referral and Escalation Criteria

Referral to a specialist is warranted when a suspected bone tumor requires biopsy or limb-sparing surgery, when spinal cord compression is suspected on the basis of neurologic examination, and when a fracture is intra-articular, comminuted, or open. Specialist consultation is also appropriate when the radiographic findings are equivocal but the clinical suspicion of aggressive disease remains high.

Laboratory involvement is indicated when osteomyelitis is suspected. Aerobic and anaerobic culture of bone or joint fluid, together with histopathology, is required to distinguish infection from neoplasia. Hematology and serum biochemistry are supportive but not diagnostic.

Regulatory reporting obligations vary by jurisdiction. Fractures and other skeletal injuries that may result from non-accidental injury should be reported according to local legal requirements. The AVMA professional practice resources provide guidance on professional obligations, and the WOAH terrestrial animal health standards address notifiable conditions that may present with skeletal signs, such as brucellosis.

Frequently Asked Questions

How do I distinguish a normal skeletal variant from a pathologic lesion on survey radiographs?

Compare the finding with the contralateral limb whenever possible, since many variants are bilaterally symmetrical. Assess whether the margin is smooth and cortical bone is continuous. Normal variants such as accessory carpal bone ossification centers, ununited anconeal processes in early maturity, and sesamoid bones have characteriztic locations and predictable radiographic appearances. Breed-specific differences in vertebral formula and pelvic morphology are well documented, and the genetic basis for pelvic size and shape variation has been mapped to specific quantitative trait loci in dogs genetic analysis of canid pelvic variation. When uncertainty persists, repeat radiographs in four to six weeks to document progression or stability, or advance to computed tomography for cross-sectional assessment of cortical and trabecular architecture.

What can I do when ideal orthogonal radiographic projections are not feasible in a fractious or unstable patient?

Sedation or anesthesia is often the safest solution and should be pursued before accepting a single oblique projection. When restraint is genuinely impossible, obtain the lateral projection first because it provides the most information about the axial skeleton and major long bones. For the appendicular skeleton, a straight craniocaudal view of the affected limb can be acquired with manual restraint and minimal patient movement. Document the actual positioning used and note the limitations in the record. The MSD Veterinary Manual professional edition provides guidance on patient positioning and safety during diagnostic imaging. If the study is inadequate for the clinical question, state that explicitly and recommend re-imaging under anesthesia instead of interpreting a non-diagnostic study.

How does the canine skeleton differ from the feline skeleton in ways that affect my clinical approach?

The canine vertebral formula is typically C7 T13 L7 S3, while cats commonly have T13 L7 but show more variation in lumbar vertebral numbers. The feline clavicle is a vestigial floating bone, whereas the canine clavicle is absent or rudimentary. Feline pelvic morphology is narrower and more elongated than canine, and the feline tail has more variable vertebral counts. These differences matter for surgical approaches and for interpreting radiographs, since a structure that is normal in one species may appear anomalous in the other. Comparative developmental studies show that rib and vertebral patterning arises from conserved axial mechanisms, but species-specific folding of the body wall produces distinct topologies body plan and shell evolution in turtles. Always confirm the species-specific normal before calling a finding abnormal.

What documentation should accompany skeletal radiographs and physical examination findings?

Record the patient signalment, the reason for the study, the projections obtained, and the radiographic technique used. Describe each finding using standard anatomic terminology and note whether it is new, static, or progressive relative to prior studies. Include a statement about radiographic quality and any limitations. For palpatory findings, record the location, symmetry, presence of pain, crepitus, or swelling, and the patient's response to manipulation. This documentation supports longitudinal comparison and defensible medical records. Professional practice standards for record keeping and diagnostic imaging are available through AVMA practice resources. If images are sent for external review, include the complete study and the relevant clinical history.

How should I explain an incidental skeletal finding to a client without causing unnecessary alarm?

Use the client's own words when possible. State that the finding is common, that it was not causing the presenting problem, and that it does not require treatment in most cases. Show the image and point out the finding directly. Explain what monitoring is needed, for example annual palpation or repeat radiographs only if lameness develops. Avoid speculative language about future arthritis or neoplasia unless the imaging features genuinely support that risk. If you are uncertain about the clinical significance, say so and offer a referral for a second opinion. The NCBI Bookshelf veterinary and comparative biomedical sciences collection contains background material that can help you frame explanations in accessible terms.

When should I refer a skeletal case for advanced imaging or specialist assessment?

Refer when the survey radiographs are non-diagnostic, when the findings do not explain the clinical signs, or when the suspected condition requires surgical planning that exceeds your imaging capability. Examples include suspected osteosarcoma needing staging and limb-sparing planning, complex elbow or stifle fractures, and suspected spinal cord compression where magnetic resonance imaging is required. Refer also when you have identified a lesion you cannot characterize confidently. Timely referral is preferable to repeated inconclusive imaging. The WOAH terrestrial animal health standards address broader expectations for diagnostic quality in animal health practice, though they do not set referral thresholds. Communicate directly with the receiving specialist and send all prior images and reports.

Related Clinical & Scientific Guides

• Canine Respiratory System: Anatomy and Physiology
• Comparative Anatomy of the Mammalian Kidney
• Feline Cardiopulmonary Physiology: Heart-Lung Interactions

References and Further Reading

• Developmental mechanism and evolutionary origin of vertebrate left/right asymmetries.. 2004.
• The control of human motor units.. 1994.
• Body plan of turtles: an anatomical, developmental and evolutionary perspective.. 2012.
• Genetics of canid skeletal variation: size and shape of the pelvis.. 2005.
• The Mouse Limb Anatomy Atlas: an interactive 3D tool for studying embryonic limb patterning.. 2008.
• Tailored Pig Models for Preclinical Efficacy and Safety Testing of Targeted Therapies.. 2016.
• NCBI Bookshelf: Veterinary and Comparative Biomedical Sciences. NCBI Bookshelf.
• MSD Veterinary Manual, Professional Edition. MSD Veterinary Manual.
• American Veterinary Medical Association Practice Resources. American Veterinary Medical Association.

Related Articles

• Canine Lymphatic System: Anatomy and Function
• Canine Respiratory System: Anatomy and Physiology
• Canine Endocrine System: Glands and Hormonal Regulation
• Canine Heart Anatomy: Chambers, Valves, and Conduction System
• Canine Integumentary System: Skin Layers and Adnexal Structures

This article is educational professional reference material for veterinary audiences. It is not a substitute for veterinary diagnosis, individual clinical judgment, current product labeling, or applicable regulatory requirements.