Labeled side-view diagram of a dog rear assembly showing the croup contour, pelvis and hip socket, femur, stifle, tibia and fibula, hock and hind foot, with a 22 degree pelvic reference axis

Cold River Canine Anatomy and Working Structure · Chapter 1

The Croup in Dogs and Its Role in Rear Angulation and Working Movement

Understanding Boerboel structure from the pelvis down

By Cold River Boerboels · Updated October 19, 2026

The croup is the upper rump region between the loin and the tail base. Its outline is one part of assessing the rear assembly. Beneath it, the pelvis provides the bony foundation connecting the trunk with the hind limbs. To understand rear angulation, we start with that foundation and follow the assembly through the hip, stifle, hock and foot. [1], [2]

At Cold River Boerboels, we approach structure through the demands of working dogs. We want to know how a dog stands, moves, stabilizes itself and performs. A photograph is useful. Understanding the anatomy behind that photograph makes the conversation much more useful.

Our starting point: The pelvis is central to understanding the rear assembly. Its orientation helps establish the relationship between the trunk and hind limbs, while the rest of the skeleton, the joints, muscles and posture complete the picture.

Why we are starting an anatomy section

During a conversation with another Boerboel breeder, we were explaining the croup from a working-dog perspective. We went through diagrams, the underlying pelvis and its relationship to rear angulation. The breeder told us it was the first time they had heard of the croup and that they had not known what it was.

That conversation stayed with us. As we continued having discussions within the breed, we encountered similar gaps in understanding other important structural features. We found that concerning. When someone is making breeding decisions and presenting themselves as knowledgeable about conformation, understanding the anatomy being evaluated should be part of the foundation.

We are sharing this as our own experience, not as a survey of every breeder. The point is to explain why we believe accessible structural education matters. Everyone has something to learn. The responsibility is to keep learning before passing confident judgments or making breeding decisions.

That is why this section exists. We want owners and breeders to understand the parts, recognize their relationships and ask better questions. If we are going to discuss a working breed, we should be prepared to discuss how that breed is put together.

What is the croup on a dog

In conformation language, the croup describes the upper rump at the rear of the topline. It is a region of the dog, rather than the name of a single bone or joint. The visible contour reflects the underlying skeleton together with muscle, skin, coat and the position in which the dog is standing. A surface outline therefore needs to be distinguished from an anatomical measurement of the pelvis. [1], [2], [9], [10]

Croup: Upper rump region and its external outline. Keep separate: A region is not a joint.
Pelvis: Bony framework including the paired hip bones and their connection with the sacrum. Keep separate: Underlying bone orientation is not identical to the surface contour.
Hip joint: Articulation of the femoral head and acetabulum. Keep separate: Hip joint angle differs from croup slope.
Stifle: The hind-limb knee. Keep separate: A separate joint below the hip.
Hock: Tarsal region of the hind limb. Keep separate: Hock angle differs from pelvic inclination.

The paired hip bones are formed primarily by the ilium, ischium and pubis. These converge at the acetabulum, the socket receiving the head of the femur. The sacrum connects with the pelvis at the sacroiliac joints. These landmarks give us a more useful anatomical map than simply drawing a line down the outside of the rump. [2]

Why rear angulation starts with the pelvis

When we say the discussion of rear angulation starts at the croup, we mean that the underlying pelvic foundation must be understood first. The pelvis positions the hip sockets relative to the trunk. From there, the femur leads to the stifle, the tibia leads toward the hock, and the metatarsal region leads toward the hind foot. [2]

For teaching purposes, follow the assembly from the top down. Locate the pelvic region, identify the hip, then follow the upper thigh, lower thigh and rear pastern. This is how we prefer to begin a structural discussion at Cold River. Looking only at the bend in the hock skips much of the assembly.

There is an important limit to that shorthand: croup slope does not independently dictate every angle below it. Rear angulation describes a combination of relationships. A structural review by Zink and Schlehr discusses the pelvis and limb bones together and recommends evaluating both side and rear views. [4]

Our practical position is straightforward: evaluate the foundation, then evaluate the complete dog. We would not select a breeding dog by its croup alone, and we would not dismiss the croup because someone likes the head, size or pedigree.

Croup slope pelvic inclination and joint angles

A useful angle has three things: identifiable landmarks, a reference line and a stated convention. Ask what is being measured before accepting the number.

Croup slope usually refers to the slope of the rump in a conformation discussion. Pelvic inclination describes the orientation of a defined pelvic reference relative to another axis. Joint angles describe relationships between adjoining segments. Studies may use segment coordinate systems and report flexion or extension using conventions that differ from the internal angle someone draws on a photograph. [5], [7]

Figure 2. Cold River skeletal comparison using the 40°, 22° and 10° values from a traditional “length and lay of croup” teaching illustration. Each gold axis and angle arc is constructed to the labeled value from horizontal. All three paws are shown in side profile, with the toes pointing left. Limb segment lengths are held constant to make the pelvic-reference comparison clear; this is not a reconstruction of three measured dogs. The original teaching model describes the examples as steep, favorable and flat. It does not establish a universal clinical cutoff or quantify pulling performance.

Reading the textbook comparison

A traditional conformation teaching illustration compares a steep 40° example, a moderate 22° example and a flat 10° example. In that traditional model, the middle arrangement is presented as allowing useful forward and rearward swing; the extremes illustrate potential restrictions or less favorable drive. These are explanations from a structural teaching model, rather than measured force vectors from a gait experiment.

KUSA’s Anatomy, Conformation and Movement of Dogs, pages 65–66, similarly discusses pelvic slope in relation to the rear assembly, movement and the applicable breed standard. Its skeletal examples are useful for following the relationship from pelvis to foot. [21]

Keep 22° and 23° in their own contexts. The 22° label belongs to the traditional teaching illustration. The 23° preference discussed below belongs to the WBBA Boerboel standard. A one-degree difference between two drawings is not evidence of a meaningful difference in a real dog, particularly when landmarks and measurement methods are not identical.

For example, two published pelvic-angle numbers may look contradictory while using entirely different axes. Neither should be compared directly with a breeder's surface estimate until the definitions match. The PLOS study comparing German Shepherds and Labradors provides its own methods for posture and joint measurements; those values should be interpreted within that method. [5]

Side-view diagram of a dog rear skeleton marking the pelvic reference axis and the hip, stifle and hock joint centers with their segment reference axes

Figure 3. The same skeletal framework with segment axes and joint locations. Gold identifies the pelvic reference and joint centers; teal identifies limb segment axes. These lines explain the relationships being discussed. They are not a clinical measurement protocol, and no unsupported numerical joint angles are assigned.

What Boerboel breed standards say about the croup

There is more than one Boerboel standard. Read the standard that applies to the registry or event before presenting a particular phrase or angle as a requirement for every Boerboel.

AKC: Describes a broad, flat, strong croup with defined musculature, and limits croup height relative to the withers. How to read it: Descriptive judging language; not a numerical pelvic-inclination prescription.
UKC: Calls for breadth, adequate length and a slight slope. How to read it: Assess alongside the rest of the hindquarters and movement requirements.
WBBA: Describes a firm, muscular croup and identifies 23 degrees as the preferred slope. How to read it: A stated breed-standard preference; not experimental proof of an optimum for every task.

These summaries are drawn from the respective organizations' published standards. [9], [10], [11] None of these documents, by itself, establishes which croup angle produces the greatest weight-pull performance. Nor should a side-view slope be confused with croup height, width, length or the angle of the hip joint.

Why the croup region matters in a working dog

The pelvic region includes substantial muscle attachments. Veterinary dissection resources identify the gluteal muscles and surrounding hip structures, including the sacrotuberous ligament. The apparent fullness of this region should therefore be considered alongside the anatomy beneath it, rather than treated as a decorative silhouette. [3]

Research on Greyhound pelvic-limb muscle architecture examined muscle dimensions and moment arms—the geometry affecting a muscle's ability to produce a joint moment. It supports examining how muscle and skeleton work together, while remaining specific to the animals and anatomical model studied. [12]

In a separate study of accelerating Greyhounds, the greatest increases in joint work and power occurred at the hip and hock, particularly in the lead hind limb. This is direct evidence that power production involves multiple joints. It does not identify a winning croup slope for Boerboels or measure weight-pull performance. [8]

At Cold River, this is why we ask more than whether a rear looks impressive in a stack. We want to see the dog use its body. We consider the demands of the activity, the dog's preparation and how consistently it performs. Our competition experience informs those observations; the cited studies explain specific anatomical and mechanical principles. They are different kinds of evidence.

What the movement research actually shows

Different breeds can stand and move differently

Humphries and colleagues compared 12 healthy German Shepherd Dogs with 12 healthy Labrador Retrievers using motion capture and a pressure walkway. They found differences in pelvic tilt, joint positioning and aspects of movement. The authors called for further research before connecting these biomechanical differences to clinical disorders. This study supports examining the whole posture; it does not prove that one breed's geometry is an ideal for another. [5]

Conformation varies within a breed too

A second 2020 study examined 60 German Shepherd Dogs. It investigated relationships between conformation, standing posture and movement, finding associations particularly involving back inclination. A study of the back and overall conformation should not be relabeled as a controlled experiment on croup angle alone. [6]

The pelvis is moving in three dimensions

Schaub and colleagues examined four clinically sound working-line German Shepherd Dogs with moving X-rays and three-dimensional reconstruction. Pelvic and caudal lumbar movement varied between dogs and strides. The small study helps show why one static side-view angle cannot describe all of a dog's movement. [7]

Expert structural guidance is useful when its limits are clear

Zink and Schlehr's working-dog review discusses the tradeoff between mobility and stability at extremes of rear angulation. It also explicitly acknowledges gaps in the research and draws on experienced breeders' and judges' observations. We find that a useful model for this section: name the evidence, explain the interpretation and avoid presenting experience as a controlled trial. [4]

What we can responsibly say: pelvic anatomy belongs in a serious discussion of working structure. The sources here do not establish a single scientifically proven croup angle for maximum Boerboel pulling ability, lifetime soundness or injury prevention.

Does croup angulation cause C sections in dogs

One of the most persistent misconceptions we encounter is the claim that an angled croup causes difficult births and that a flat croup prevents the need for a C-section. Frequently, the conversation shifts between croup slope and croup width as though they were the same thing. They are different measurements, and neither should be substituted for an assessment of the internal birth canal.

At Cold River, our question is simple: what exactly was measured, and where is the evidence connecting that measurement to the outcome? Repeating a claim does not answer either question.

Croup slope external width and the pelvic canal are different

Visible croup slope: The side-view inclination of the upper rump contour. Cannot establish by itself: The dimensions of the birth canal or whether a particular female will need surgery.
External croup width: Breadth across the rump, including the contribution of muscle and other tissues. Cannot establish by itself: The internal clearance available to a particular puppy.
Internal pelvic dimensions and shape: Measurements of the bony canal, including its height, width, length and anatomical relationships. Cannot establish by itself: The entire outcome of labor; fetal factors and uterine function also matter.

Pelvimetry studies examine the bony pelvis using imaging. They do not simply judge whether the rump looks broad or flat in a photograph. In a 1999 study of 20 Boston Terriers and 14 Scottish Terriers, radiographic measurements identified smaller pelvic size in females with a history of obstructive dystocia compared with normally whelping females. These are breed-specific findings about pelvic anatomy and difficult birth, not proof that the outside slope of a Boerboel's croup predicts a C-section.

A later conference report by Linde-Forsberg gives an important additional detail: in Scottish Terriers, a combination of internal measurements, including a radiographic angle labeled k, distinguished the groups. That angle belongs to the study's skeletal measurement system. It is not a measurement of the visible croup contour. The report also describes differences in pelvic height-to-width relationships in some of the breeds studied.

This is why we do not replace one oversimplification with another. We cannot say that every pelvic angle is irrelevant to birth. We can say that a study of internal pelvic geometry does not validate a claim about external croup slope.

What the research supports

A CT study comparing 40 English Bulldogs with 30 non-brachycephalic controls found differences in pelvic dimensions and shape, including a shorter pelvic canal and narrower outlet in Bulldogs. It was a cross-sectional anatomical comparison, not a trial showing that changing croup slope prevents difficult births.

C-section research also considers factors such as litter size and previous C-sections. A 2022 breeder-questionnaire study found associations involving both. A C-section outcome cannot therefore be treated as a pure measurement of croup structure, and elective procedures need to be distinguished from emergency surgery for obstruction.

The evidence-based conclusion: In the canine literature reviewed for this article, we did not identify a study establishing visible croup slope as an independent predictor of C-section need, or showing that selecting for a flatter visible croup prevents C-sections. Internal pelvic dimensions and shape can matter in obstructive dystocia. That is a different claim.

Failure to find direct evidence is not proof that a relationship is impossible. It does mean that “a flat croup prevents C-sections” should not be presented as an established scientific fact. We would ask anyone making that claim to identify the canine study, its landmarks, its breed population and what it actually found.

For breeding decisions, we take a female's reproductive history and veterinary assessment seriously. External width may prompt questions about underlying anatomy, but it is not a validated substitute for measuring the internal pelvis. A broad-looking rump is not a guarantee of an uncomplicated delivery.

Does dietary protein change a puppy's croup angle

Another claim we have encountered is that feeding more protein causes a puppy's croup or rear angulation to develop a particular way, and that reducing protein will correct it. We did not identify controlled canine evidence demonstrating that dietary protein percentage can be used to steepen, flatten or correct croup angulation.

That claim should be distinguished from the broader fact that adequate nutrition supports growth. Protein supplies essential building material. Saying that a puppy needs protein is not evidence that protein percentage acts as a control for the angle of its pelvis.

The controlled Great Dane protein study

Nap and colleagues studied 17 Great Dane puppies beginning at seven weeks of age. For 18 weeks, the groups received diets of the same energy density containing 14.6%, 23.1% or 31.6% protein on a dry-matter basis. The investigators found no differences in shoulder height between groups and no demonstrable consequences of protein intake itself for calcium metabolism or skeletal development. Body weight and some blood measurements did differ. They considered a causative role for dietary protein in osteochondrosis unlikely.

This is useful evidence against blaming protein level alone for abnormal skeletal development. However, the trial did not report croup-angle measurements. It supports challenging the protein explanation; it does not justify claiming that researchers directly tested and disproved every possible effect on croup geometry. These experimental protein levels are also not a feeding prescription.

Protein calories and mineral balance are separate variables

Two foods can differ in protein percentage and also differ in energy density, calcium, phosphorus and feeding amount. If several things change at once, a change in appearance cannot automatically be attributed to protein.

In a separate Great Dane study, varying dietary calcium and phosphorus concentrations at a fixed ratio affected tissue accretion and bone mineral measurements. This illustrates why the ratio alone does not describe the entire mineral supply.

A further Great Dane feeding study compared freely available food with restricted food supply and examined skeletal development. It is evidence about energy supply and growth conditions, not a demonstration that protein sets croup angle.

A nutrition review by Nap and Hazewinkel likewise treats energy, protein and calcium as important to growth. Protein is biologically important; its importance should not be confused with evidence for the specific claim that an otherwise adequately nourished puppy's croup angle is dictated by the protein percentage on its food bag.

The Cold River position: Feed to support appropriate growth and condition. Evaluate structure with comparable photographs, movement and qualified examination. Do not diagnose a protein problem from a puppy's rump, and do not promise to correct croup angulation by lowering protein.

For the broader feeding discussion, visit our Boerboel nutrition page. The structural question and the nutritional question both deserve an explanation grounded in what was actually observed or measured.

The Cold River perspective on competition and structure

Our background comes from breeding, raising, training, conditioning and competing with working dogs. That perspective shapes the questions we ask about conformation. We care about how a dog uses what it has, how it responds to preparation and whether its structure deserves closer evaluation.

Our documented 22,039-pound competition performances are part of our program's history. You can also explore Cold River's Sun Wukong and Cold River's Mr. Wednesday. Those results document what those dogs achieved. We are not using them as an experiment proving that a particular croup angle caused the result.

For us, the value of competition is that it puts performance into the conversation. The responsibility of the breeder is to keep asking questions afterward. Which observations are repeatable? What changed with conditioning? What might warrant veterinary assessment? What should be considered in future breeding decisions?

For a sport introduction, read our dog weight pulling guide. For equipment, see our Cold River Supplies weight pulling harnesses. Neither equipment nor a competition result replaces an anatomical evaluation.

How to begin evaluating the rear assembly

We recommend treating this as a process of observation, documentation and discussion. These questions help organize that process; they are not a home diagnostic test.

Identify the region. Know where the loin ends, where the croup lies and where the tail begins. Separate the surface outline from assumptions about the underlying bones.
Use comparable views. Photograph on level ground, at the dog's height and perpendicular to its side. Record a natural standing position as well as any deliberately arranged stack. Record what you changed.
Follow the full rear. Consider the pelvic region, thigh segments, joint positions and feet together. Do not let a single attractive angle end the evaluation.
Look from behind. Include rear-view standing and movement footage. A side photograph cannot answer every question about limb alignment.
Watch comfortable movement. Record the walk and trot from the side, coming and going. Keep the surface, speed and camera position comparable when reviewing the same dog over time.
Keep a history. Note age, body condition, training stage and any discomfort. Compare observations with actual veterinary findings when they exist.
Ask a specific question. Instead of “Does this rear look good?” ask which landmark, segment, movement or standard requirement is being evaluated.

A stacked posture is an examination position, not a permanent property of the dog. Research comparing square and stacked positions illustrates why stance must be documented when interpreting measurements. [6] If a dog develops pain, lameness or a change in movement, obtain a veterinary assessment instead of assigning the problem to croup shape from a photograph.

Common mistakes in croup discussions

Using “croup” and “pelvis” as interchangeable words. One names an external region; the other names underlying skeletal anatomy.
Arguing about degrees without defining the lines. A number cannot resolve a disagreement about different measurements.
Calling an entire rear good or bad from the rump outline. A complete evaluation requires more information.
Applying another breed's study as a Boerboel prescription. Explain what transfers anatomically and what has not been tested.
Confusing croup slope with the internal birth canal. A side-view outline does not establish clearance for a puppy.
Blaming protein for an angle without a measurement. A dietary change, a growth phase and a new photograph are not a controlled experiment.
Treating a registry preference as a performance experiment. Standards and biomechanics research answer different questions.
Using an impressive photograph as the whole case. Ask to see the movement, history and supporting information.

Questions about the croup and Boerboel rear angulation

Where is the croup on a dog

It is the upper rump region behind the loin and toward the tail base. It is evaluated as part of the topline and hindquarters.

Does rear angulation begin at the croup

It is a useful teaching starting point when we mean the underlying pelvic foundation. A complete explanation then follows the hip, stifle, hock and foot. Croup slope alone does not describe the entire rear.

Is a 23 degree croup correct for every Boerboel

WBBA identifies 23 degrees in its standard. Other organizations use different descriptive language. Name the applicable standard and measurement before applying a number.

Does a flat croup mean a straight rear

That conclusion cannot be drawn from the phrase alone. Croup contour and the relationships of the limb segments need to be evaluated separately.

Can you measure the pelvis accurately from a phone picture

A photograph can document an outline and help explain visible relationships. It cannot automatically reveal obscured skeletal landmarks or substitute for calibrated anatomical measurement.

Does more rear angulation mean more power

There is no simple rule that more is always better. Working-dog structural guidance considers stability as well as the available movement. The full assembly and task matter.

Does a powerful pull prove ideal anatomy

It proves the recorded performance under that event's conditions. It does not isolate the contribution of croup shape or answer every question about the dog's structure or health.

Can training fix the croup

We would not promise to correct an underlying skeletal configuration through conditioning. A change in muscular appearance or standing posture should not be presented as proof that the bones have been redesigned.

Does an angled croup mean a female will need a C section

No such conclusion can be made from visible slope alone. The reviewed literature does not establish that a flatter external croup prevents C-sections. Internal pelvic shape and dimensions are a separate issue, and they are only part of evaluating reproductive risk.

Is a broad croup the same as a wide birth canal

No. External breadth includes soft tissue. Internal pelvic measurements are more directly relevant to possible obstruction, but neither appearance nor a single width measurement guarantees an easy birth.

Can too much protein make a puppy's croup steep

We did not find controlled canine research demonstrating that claim. A Great Dane trial found no demonstrable effect of protein level itself on skeletal development within its study conditions, but did not measure croup angles.

Learning the dog behind the outline

We started this section because an important anatomical conversation revealed how easily structural terminology can be repeated without being understood. Our response is to put the explanation, diagrams and sources in one place.

At Cold River, understanding the croup is a starting point for understanding the working dog. We encourage owners to learn the landmarks, compare the standards and watch the dog move. The better the questions become, the more useful the discussion of breeding and conformation becomes.

Next in the series: Chapter 2: Boerboel rear angulation and stifle anatomy, which follows the assembly from the hip through the stifle and hock.

Continue exploring the Performance Dog Journal and our Boerboel strength and performance questions.

Sources and further reading

Sources checked October 19, 2026. The anatomy schematics are newly drawn teaching graphics guided by standard textbook anatomy and the cited anatomical resources. They are not radiographs, tracings of a named dog or validated measuring tools.

University of Calgary — Dog and Cat Anatomy Veterinary teaching resource; vertebral regions and skeletal orientation.
University of Veterinary Medicine Budapest — Bones of the Hindlimb Veterinary osteology teaching slides; hip bones, acetabulum and pelvic limb landmarks.
University of Minnesota — Proximal Pelvic Limb Dissection teaching guide; gluteal muscles, hip region and sacrotuberous ligament.
Zink and Schlehr 2020 — Working Dog Structure Evaluation and Relationship to Function Peer-reviewed review; useful expert synthesis, including observations where experimental evidence is limited.
Humphries et al 2020 — German Shepherd and Labrador Posture and Trot Primary study; 12 healthy German Shepherd Dogs and 12 healthy Labrador Retrievers.
Humphries et al 2020 — Different German Shepherd Conformations Primary study; 60 German Shepherd Dogs, conformation, standing posture and movement.
Schaub et al 2021 — Three Dimensional Pelvic and Lumbar Kinematics Primary study; four clinically sound working-line German Shepherd Dogs, moving X-rays and 3D reconstruction.
Williams et al 2009 — Pelvic Limb Function During Greyhound Acceleration Primary biomechanics study; acceleration mechanics rather than Boerboel weight pulling.
AKC — Official Standard of the Boerboel Official breed standard; descriptive judging criteria rather than a performance experiment.
UKC — South African Boerboel Breed Standard Official breed standard; croup, hindquarters and movement.
WBBA — Boerboel Breed Standard Association standard; includes a 23-degree croup slope preference.
Williams et al 2008 — Greyhound Pelvic Limb Anatomy and Muscle Moment Arms Primary anatomical study; muscle architecture and estimated moment-generating capacity.
Eneroth et al 1999 — Radiographic Pelvimetry and Dystocia in Two Terrier Breeds Primary clinical study; internal pelvic anatomy and obstructive dystocia in Boston and Scottish Terriers. Not a visible croup-slope study.
Linde Forsberg 2002 — Pelvimetry to Diagnose Dystocia in the Bitch Conference report with radiographic diagrams; includes a skeletal angle among combined discriminating measurements in Scottish Terriers. Overlaps the earlier research and should not be counted as independent replication.
Computed Tomographic Pelvimetry in English Bulldogs 2018 Primary cross-sectional study; 40 Bulldogs and 30 controls. Anatomical comparison, not prospective validation of croup slope as a birth predictor.
Schrank Contiero and Mollo 2022 — Incidence and Concomitant Factors of Cesarean Sections in the Bitch Primary breeder-questionnaire study; associations involving litter size and previous C-sections, among other recorded variables.
Nap et al 1991 — Growth and Skeletal Development in Great Dane Pups Fed Different Levels of Protein Intake Controlled primary study; 17 puppies, 18 weeks and three dry-matter protein concentrations. Skeletal development was assessed; croup angulation was not reported as an outcome.
Lauten et al 2002 — Dietary Calcium and Phosphorus in a Fixed Ratio and Great Dane Development Primary nutrition study; mineral concentrations, bone mineral measurements and growth. Not a protein or croup-angle experiment.
Energy Supply and Skeletal Development in Growing Great Danes 1995 Primary feeding study; ad libitum versus restricted supply, including an additional-load subgroup. Not a protein-level experiment.
Nap and Hazewinkel 1994 — Growth and Skeletal Development in the Dog in Relation to Nutrition Review distinguishing the roles of energy, protein and calcium in growth; does not establish protein percentage as a means of changing croup angulation.
Joy McFarlane 2019 — KUSA Anatomy Conformation and Movement of Dogs Written and illustrated by Joy McFarlane for the KUSA Breed Judges Learning Programme, September 2019 edition, especially pages 65–66 on the hind assembly and pelvic angle. Used as a visual reference for the hind assembly. The 40°, 22° and 10° comparison values come from a traditional teaching illustration whose original illustrator we could not identify.

World-Record Performance Boerboels: Bred to Work, Proven to Win.

Three side-view skeletal diagrams comparing croup slope: a steep 40 degree example, a moderate 22 degree reference and a flat 10 degree example, each measured from horizontal

Figure 1. Cold River illustration based on standard textbook anatomy. The femur, tibia, fibula, hock and foot are proportioned as a connected hind assembly inside the body outline. The 22° pelvic reference is a geometric teaching overlay, not an X-ray measurement or a universal breed requirement. The paw is shown in lateral profile, with overlapping digits pointing forward to the left. Fine anatomy and depth relationships are simplified.