Cold River Canine Anatomy and Working Structure · Chapter 3
Boerboel Topline: Rear-High Structure, Swaybacks, and the Back of a Working Dog
Why extreme toplines deserve a serious conversation in the Boerboel breed.
By Cold River Boerboels · Updated October 28, 2026
A Boerboel’s topline is the upper outline of the dog; in breed evaluation, the conversation usually centers on the withers, back, loin and croup. A rear-high Boerboel has a rump that stands higher than the withers in a comparable, level-ground stance. That is different from a back that sags through the middle or arches upward. Those distinctions matter before we discuss soundness, movement or breeding decisions.
The Cold River position, as of 2026: In our opinion, extreme topline faults—especially markedly rear-high dogs—have become an epidemic in the Boerboel breed. We are talking about the exaggerated outlines we keep seeing, not a tiny variation in an otherwise balanced dog.
“Epidemic” is our description of the seriousness and frequency of what we observe. It is not a prevalence statistic from a breed-wide scientific survey. We have not identified a representative study measuring how many Boerboels have these faults. The breed standard, published canine research and our experience answer different questions; we will identify which one we are using.
No dog is perfect. That does not make every fault acceptable.
At Cold River, we do not expect a flawless dog. Every dog has strengths, weaknesses and details we would like to improve. We also recognize that slight variations in outline can be acceptable to us when we evaluate the complete animal. A small departure and a major exaggeration do not deserve the same reaction.
What concerns us is the adult dog whose back looks like a ski slope because the rear towers over the front, or whose outline resembles an upside-down banana because of a pronounced upward arch. Some dogs instead have a deep sag between the front and rear. Those are different shapes, but none should be casually excused because the dog has a large head, a fashionable pedigree or an impressive weight.
We are not assigning a diagnosis to every unusual outline. We are saying that an obvious, persistent structural concern deserves honest evaluation. Calling every fault “just a little variation” eventually makes it difficult to recognize the exaggeration standing in front of us.
What is a dog’s topline? The anatomy beneath the outline
Terminology varies. Zink and Schlehr use topline for the upper profile from the head to the tail base and backline for the portion from the withers rearward. In this chapter, “Boerboel topline” primarily means the body outline from the withers through the back and loin to the croup. The visible contour includes soft tissue; it is not a tracing of the vertebral bodies. [2]
The dog normally has seven cervical, thirteen thoracic and seven lumbar vertebrae, followed by three sacral vertebrae and a variable tail series. The thoracic region relates to the ribcage; the lumbar region underlies the loin; the sacrum sits within the pelvic assembly. The vertebral column provides support, protects the spinal cord and gives muscles attachment sites. [3]
Figure 1. Original Cold River regional schematic. The croup is an external region; its outline and the orientation of underlying bones are related but distinct. Anatomy background: [2,3].
What does the UKC Boerboel standard say about topline?
The United Kennel Club’s South African Boerboel standard describes a “level, straight-appearing topline”. Its body section also calls for a broad, muscular back and a short, substantial loin. Its hindquarters section describes a broad croup with a slight slope. These are compatible features: a local slope at the rump does not require a rear-high body. [1]
The gait section expects the topline to stay steady during movement, without a raised arch, a sagging middle or excessive rolling. It also emphasizes unrestricted, sound movement. That makes the moving dog part of the evaluation, alongside the standing profile. [1]
At Cold River, we read that as a practical expectation: the front, trunk and rear should work together. We do not read it as permission to exaggerate one region because another feature looks impressive. Nor are we inventing a UKC numerical allowance for rump height; the cited sections do not provide one.
Rear-high, swayback and roach back: three different topline concerns
Rear-high / high in the rear: The rump stands above the withers on level ground in a comparable stance. What it cannot establish by itself: the exact skeletal cause, whether pain is present, or whether a young dog will retain the outline.
Sagging / swayback outline: A conspicuous downward dip through the middle of the back. What it cannot establish by itself: whether the cause is conditioning, posture, an underlying spinal abnormality or another problem.
Roached outline: A conspicuous upward arch through the back or loin. What it cannot establish by itself: whether the appearance is persistent conformation or a posture associated with discomfort.
Lordosis and kyphosis are terms used for abnormal spinal curvatures and also appear in structural discussions of sagging and roached outlines. A photograph cannot establish the internal vertebral alignment. The structural review by Zink and Schlehr discusses muscular weakness or vertebral abnormalities with sagging outlines, and pain as a possible explanation for roaching. These are reasons to investigate, not diagnoses for a dog seen online. [2]
Figure 2. Original Cold River outline comparison. These traces separate height difference from curvature. They do not depict vertebrae, define acceptable degrees, or diagnose individual dogs.
High in the rear: the problem Cold River wants breeders to confront
Our concern is the adult Boerboel that repeatedly stands markedly higher behind than in front, across ordinary positions, on a level surface. A single awkward moment is not the same evidence as a consistent outline. We want to know whether the shape persists, how pronounced it is, and what the dog does when it moves.
A taller-looking rear does not automatically tell us that the pelvis is too steep, the femur is too long or the stifles are too straight. Those are separate relationships that require assessment. The same outward label can hide different combinations of proportions, joint positions and posture.
Chapter 1 discussed the croup. Chapter 2 followed the rear assembly through the stifle and hock. Chapter 3 joins those discussions to the trunk. We do not want to replace one oversimplification with another by pretending that the topline independently explains every joint below it.
Cold River’s breeding view: A small imperfection can be weighed against the complete dog. A major exaggeration should be recognized as a major exaggeration. We should not keep moving the definition of acceptable to fit the dogs we already own.
What science tells us about back structure and movement
Back slope and loading: a study of 60 German Shepherd Dogs
Humphries, Shaheen and Gómez Álvarez studied 60 German Shepherd Dogs using motion capture and a pressure walkway. Greater back slope was associated with differences in forelimb loading and posture, and some measures of movement asymmetry. The study did not establish that those differences caused orthopedic disease. [4]
Crucially, these were German Shepherds with a different conformation context—not a controlled trial of rear-high Boerboels. We cannot reverse the direction of the slope and assume identical effects. The useful lesson is that back geometry can relate to measurable movement differences; the specific consequences in Boerboels remain unquantified.
Figure 3. Square versus stacked stance. Reproduced from Humphries, Shaheen & Gómez Álvarez (2020), original Figure 2 [4], CC BY 4.0. Figure unchanged. These are German Shepherds, not Boerboel ideals.
Figure 4. Back curvature measured separately by region. Humphries et al. (2020), original Figure 3 [4], CC BY 4.0. Figure unchanged; caption rewritten. Curvature and overall slope are different measurements.
A steady topline still contains a moving spine
Wachs, Fischer and Schilling used X-ray motion reconstruction in three dogs walking and trotting. Their study documented small intervertebral movements, with greater motion toward the caudal lumbar and lumbosacral region, and coordination between the pelvis and hind limbs. It supports the importance of controlled spinal motion rather than a rigid, motionless back. Its small sample limits generalization. [5]
Schaub and colleagues examined four healthy German Shepherds with biplanar X-ray video and three-dimensional reconstruction. They documented coupled pelvic and lumbar movement, with small vertebral rotations and translations. This was descriptive research on healthy movement, not a Boerboel fault-grading system or proof that a particular outline causes spinal disease. [6]
Figure 5. Directions of pelvic and spinal motion. Schaub, Kelleners, Schmidt, Eley & Fischer (2021), original Figure 2 [6], CC BY 4.0. Figure unchanged. A side profile captures only part of a three-dimensional system.
Figure 6. Coupled motion at the lumbosacral junction. Schaub et al. (2021), original Figure 6 [6], CC BY 4.0. Panels A and B are stacked vertically for easier viewing on phones; the content is unchanged and the caption is rewritten. This illustrates motion mechanics, not a rear-high Boerboel diagnosis.
Back muscles do more than create an impressive outline
Ritter and colleagues combined muscle activity recordings, force measurements and video in trotting dogs. Their findings supported a role for the epaxial muscles in resisting the trunk’s tendency to rebound into flexion during part of the stride. That is more specific than simply saying that “a strong back matters.” [7]
Schilling and Carrier subsequently examined epaxial activity during walking, trotting and galloping. Their results show that muscle function changes with gait and location along the spine: stabilizing and producing movement are both part of the job. A back that looks steady at a trot still needs appropriate flexibility during other activities. [8]
Webster, Hudson and Channon compared epaxial muscle anatomy in nine racing Greyhounds and six Staffordshire Bull Terriers. They found differences in muscle architecture between breeds and along spinal regions. This reinforces the need to consider the muscular system and the task, rather than treating one silhouette as a complete measure of strength. It does not establish an optimal Boerboel topline angle. [9]
Why topline matters to a working Boerboel
At Cold River, our working question is straightforward: can the dog coordinate the front, trunk and rear while performing its task? In weight pull, we want the dog to establish traction, maintain an organized position and apply effort repeatedly. We evaluate the whole animal doing the work, including how it manages its body between efforts.
That is our practical interpretation of what we want from working structure. The studies cited here did not compare rear-high Boerboels pulling competitive loads. They do not allow us to assign a percentage of lost pulling power to a slope, predict a dog’s lifetime soundness from a photograph, or claim that every dog with an imperfect back will fail.
Performance is valuable evidence about the individual dog on that task, on that day. Our breeding assessment also considers movement, maturity, health information, relatives and what the dog produces. We do not want a record, a title or a show result to become an excuse to stop evaluating structure.
How Cold River evaluates a Boerboel’s topline fairly
Start with level ground. Photograph the dog from the side with the camera level and roughly at body height. Include all four feet and enough ground to judge the surface.
Let the dog stand naturally, then compare a consistent stance. Document more than one position. Record head position and foot placement rather than forcing one flattering outline.
Separate height from shape. Ask whether the rump is higher than the withers, whether the middle sags or arches, or whether several features coexist.
Watch several passes at a walk and comfortable trot. Look from the side, front and rear. Observe steadiness, symmetry, tracking and ease of movement without assuming a cause for every irregularity.
Repeat over time. Use dated photographs and videos, especially for young dogs. An adult breeding decision deserves more than a puppy snapshot.
Investigate discomfort. A new hunched posture, pain, weakness, altered gait or reluctance to move calls for veterinary assessment. Do not assume that every change is a breeding fault.
These are our documentation practices, not a validated diagnostic scoring system. The aim is to make comparisons more honest and useful.
Can a rear-high Boerboel puppy grow out of it?
A young dog is still developing, so we do not treat one rear-high photograph as a final adult verdict. Equally, “he will grow out of it” is a prediction, not a finding. We want a dated series showing what actually happens as that individual matures.
We have not identified a Boerboel study establishing how often rear-high puppies become level adults, or an age after which every outline is permanent. Our practical position is to document development and reassess the mature dog rather than promise correction.
Diet is another explanation people offer for a rear-high puppy. We address the protein claim directly in the questions below.
Can conditioning fix a poor topline?
Conditioning can change muscle development and how a dog manages its posture. It should not be presented as a guaranteed way to correct an underlying skeletal problem. First establish what is being evaluated: muscle, stance, pain, proportions or a combination. A veterinary examination may be needed to distinguish them.
At Cold River, we want conditioning to develop the dog’s abilities. We do not want a training plan, a different stack or a better camera angle to become a substitute for acknowledging a persistent structural concern.
Boerboel topline questions and answers
Should a Boerboel have a level topline?
Under the UKC standard discussed here, yes: the body should present a level outline and the topline should remain steady in motion. Evaluate the whole dog and the severity of any departure. [1]
Is a slightly sloping croup the same as being high in the rear?
No. Croup slope describes the local rump outline. Rear-high describes the height relationship between the rump and withers. A dog can have a slight croup slope without being rear-high.
Is every imperfect topline a health problem?
An outline alone cannot establish health status. A persistent deviation deserves evaluation; pain or altered movement deserves veterinary attention. Small variations and marked exaggerations should not be treated as equivalent.
Does a rear-high Boerboel automatically have hip dysplasia?
No. A rear-high outline is not a hip dysplasia diagnosis. Assessing hip health requires the appropriate veterinary examination and imaging; a side photograph cannot replace that process.
What degree of rear-high structure is acceptable?
The UKC passages cited here do not give a numerical tolerance. Cold River’s acceptance of a slight variation is a whole-dog breeding judgment, not a scientific cutoff or a rewritten registry rule.
Does high protein make a growing Boerboel high in the rear?
No. We have found no published scientific study showing that dietary protein makes a growing dog high in the rear, or that it changes how a topline develops. The claim gets repeated often in the Boerboel community. Repetition is not evidence.
The most direct test comes from Nap and colleagues. Great Dane puppies were fed diets with the same energy content but 31.6%, 23.1% or 14.6% protein on a dry-matter basis, from 7 weeks of age for 18 weeks. Shoulder height did not differ among the groups, and the differences in protein intake had no demonstrable consequences for skeletal development. The researchers concluded that a causative role for dietary protein in osteochondrosis was unlikely. The study used Great Danes and did not score topline, but it is the controlled experiment that isolated protein, and it found no skeletal effect. [10]
A follow-up study of the same three diets found the low-protein diet was marginal during part of early growth. Adequate protein supports normal growth. It is not the thing to cut from a growing Boerboel’s bowl. [11]
Reviews reach the same conclusion. A review of canine hip dysplasia reported that variations in dietary protein and carbohydrate levels do not affect the development of hip dysplasia. A 2025 veterinary review states that high-protein diets balanced for large-breed puppies do not negatively affect skeletal development, though they can mildly affect growth rate. [12], [13]
What does matter in feeding is total energy and calcium. Unrestricted feeding, overfeeding high-energy foods and excess calcium from foods, treats or supplements are recognized risks for developmental orthopedic disease in large-breed puppies. That is why a complete large-breed growth diet and a lean body condition are the practical goals. [13]
Cold River’s answer: Whether a puppy’s rear-high outline persists is a question of structure and maturity, documented over time. The feed bag does not answer it. For more on feeding, see our Boerboel nutrition page and the protein section of Chapter 2.
Is Cold River saying every other breeder has this problem?
No. We are describing a pattern that concerns us in the breed as of 2026. This chapter is an argument for honest evaluation, including of our own dogs, rather than a diagnosis of unnamed programs.
The Cold River standard: recognize the fault and work to improve it
We believe extreme rear-high structure has become far too normalized in Boerboels. A dog should not need a perfect camera angle for us to discuss its back honestly. There is room to acknowledge ordinary variation without pretending that a ski-slope outline is the same thing.
No program produces perfection. Our responsibility is to recognize what needs improvement and make deliberate decisions about it. A Boerboel deserves to be evaluated as a complete working dog—from the front assembly, across the topline, through the rear and down to the ground.
Continue the series
Next in the series: Chapter 4: Boerboel movement and gait
Read Chapter 1: the croup and rear angulation and Chapter 2: rear angulation and stifle anatomy. For the work this structure has to do, see our dog weight pulling guide, the documented 22,039-pound world-record pull and our Boerboel strength and performance questions. Learn more about the Cold River Boerboels program, and find new chapters in the Performance Dog Journal.
References and illustration credits
Figures 1–2 are original explanatory schematics, not medical images. Figures 3–6 are reproduced from the credited open-access papers under CC BY 4.0, with figures unchanged and new explanatory captions. Research in other breeds is used to explain principles, not to claim Boerboel-specific effect sizes. This educational chapter does not diagnose an individual dog.
World-Record Performance Boerboels: Bred to Work, Proven to Win.