Form follows Function
Evaluating structure in this context phrase
answers a multitude of questions.
What is the primary purpose of the Xolo- survival.
It must be built to survive.
And what
guarantees survival-
versatility.
What is the basis of structural versatility- moderation.
Specialization in one skill always comes at the expense of another.
A
good Xolo possesses all purpose construction-
to efficiently:
trot
run
sprint
jump
climb
dig
stalk
swim
fight
etc.
If we really wanted to assess Xolo conformation we
would have them doing all these things in the show ring. Since we can’t do that, we must concentrate on evaluating moderation
which means structural balance.
Balance results when all anatomical features
combine perfectly. We can usually sense when something about a dog is out of balance but cannot always identify precisely
what the problem is.
All parts of dog’s anatomy are interrelated like pieces
of a puzzle. Subtle changes in one piece work as a domino effect, they resound through the entire dog.
n Excess in one area inevitably creates a deficiency in another.
n Weakness in one area
will cause other parts of the body to compensate.
Never make the mistake of thinking
your dog has a single structural fault. Your job as a breeder is to trace and rate the weaknesses in order to correct them.
The Xolo
has remained a fairly natural breed that has not been greatly modified by selective breeding. Even so, we find many structural
variations in our breed. These are naturally occurring due to normal genetic variation. Every dog has them and every breeder
must determine how much each particular structural failing might compromise the dog’s
survival ability. That must
always be the basis of selective xolo breeding- Not who is a champion or won the most shows.
When
evaluating Xolo conformation, begom with the
overall dog. The fact that certain pieces are fantastic will never redeem
an unbalanced, unsound dog.
Size: proportional differences in size between toy
mini and standard
Substance: Relative thickness of bone, size of muscles and their relative areas of attachment
Angulation:
The length of various bones and angulation of joints
Size
Toy, mini and
standard Xolos should be identical in type, temperament, structure, substance and proportion. Ideally, looking at a picture
of a well made Xolo, it should be
impossible to tell the size of the dog. Unfortunately, this rarely happens.
Size-related faults can be the most difficult to correct
because they occur in response to natural
laws. Correcting this is not impossible but it requires vigilance.
Substance
Substance is the relative amount of bone and muscle which will vary depending on the breed, function and size of the dog.
It should not to be confused with fat. Bone is usually evaluated in foreleg, size equals strength to a certain point.
Wolff’s Law: Light bone is denser and harder than heavy bone
Round bone gives a dramatic
impression of strength but in reality, it is not as sturdy as oval shaped bone which is strong AND flexible.
One more point about substance:
Insufficient angulation
reduces the area available for muscles to attach to bones- this is why well angulated dogs appear comparably substantial and
sturdy regardless of size
Proportions
Ideal Xolo proportions are describes
as a 9:10 ratio- slightly rectangular, not long but definitely not short backed.
This
body shape is the tried and true canine prototype, serviceable and adaptable for many uses.
In
general, a rectangular body shape is best for trotting and galloping, and a square body shape enhances endurance at the expense
of agility. A Xolo needs both but determining
proportion can be tricky.
How
do we measure proportions?
A dog’s height is measured from the highest
point of withers (shoulder blade) to the floor with dog stacked on a
level surface.
Body
length is measured from the tip of the breastbone to the end of the pelvis.
these measurement points vary by breed.
Leg Length is critcal to proportion. Sometimes it’s hard to decide if
a dog is short on leg or long in back. Xolo leg length is ideally equal to body depth. Body depth is measured from the highest
point of the withers to bottom of ribcage.
Longer legs are good for speed the
dog will have a bigger stride IF it is properly angulated.
Shorter legs are better for endurance,
However; extreme leg length in either direction compromises rather than enhances speed or strength.
In order to survive a Xolo must have both- so a 50/50 ratio of leg length to body depth is ideal.
Why are balanced proportions so important?
When a dog moves
it needs to do a lot of things. Its bones and muscles must create and maintain forward momentum, recycle energy and
absorb shock. The bones and muscles work as a lever system to accomplish this., meaning they should provide a mechanical advantage
by multiplying
the initial force of the operation. The better the dog is put together the more efficiently this works.
Balanced structure produces perfectly synchronized front and rear movement resulting in continuous recycling
of energy from the rear to the front. In other words- effortless gait.
Effortless
means that energy is recycled rather than
constantly wasted and regenerated as the dog moves.
Balanced structure provides another crucial survival
advantage: it gives the dog continuous support
as it moves- in other words, smooth gait
Smooth means that shock is absorbed
rather than reverberating through the dog
The dog’s center of gravity is
not located in the middle of the dog
The heaviest components are up front,
skull, brain, ribcage, major organs. Is it built to optimally support this weight?
The front legs
are meant to provide a straight column of support from the center of shoulder blade, through elbow, forearm, wrist, to foot.
This support column becomes displaced every time the dog takes a step. The dog’s center
of gravity shifts laterally -called lateral displacemen. In the case of breeds with very wide chests (Peke, Bulldog)
this side to side sway is more obvious, creating a rolling movement. It should be barely noticeable in a well made Xolo.
A dog’s hind legs are not designed to efficiently support its weight. The sturdiest rear assembly
is not nearly as strong as the front assembly. Correctly built, the rear assembly obviously does support a fair amount of
body weight but it is mainly designed to generate power.
In order to smoothly
transfer support from one set of legs to the other all legs must lift and hit the ground
simultaneously.
Although it is not true for all breeds, a Xolo’s topline should stay level when moving. A slight
amount of movement in the topline is inevitable as energy is transferred and balance shifted. But this should be nearly imperceptible
if the dog is well constructed - Because the dog’s structure absorbs the shock.
Forward
movement always produces some shock to the front assembly, but if the dog is correctly constructed- most importantly if the
shoulders are correctly placed, this shock passes through the column of the front assembly with a minimum effect, and is absorbed
by the muscles. It causes very little visible rise and fall to the withers and top line.
Toplines
Structural problems that cause bad toplines become
increasingly obvious as the dog speeds up and the power generated by the rear assembly transfers weight from one diagonal
pair if legs to the other. Energy is transferred from the rear to the front much faster. And balance must be maintained
by forward momentum with only two feet on the ground. For this to work with smoothness and efficiency, all four legs must
be doing exactly the same amount of work at the same speed at the same time.
For
instance, when the dog is galloping the rear legs need to lift the front assembly right off the ground. This is where a shorter
back becomes an asset. The further the front happens to be from the rear, the more energy is needed to accomplish this maneuver,
therefore shorter back requires less energy, making it better for endurance, but this is a trade off. It also
compromises a dog’s ability to sprint.
Why?
The
topline is made of five sections:
Neck
withers
back
loin
croup
These
terms were appropriated from horse anatomy, which as led to some misconceptions.
Generally,
lighter weight dogs have more flexible backs. Flexibility is imperative for a multipurpose breed like the Xolo.
n A flexible back offers a far greater potential range of motion.
n
It provides agility and speed – the dog will be capable of a much longer stride for maximum forward propulsion. But
it eats up energy- which is why the underline is equally important.
The area
between withers and loin (back) is sometimes called the coupling. This is the spot where muscles join the front to rear with
No skeletal support. It is the least supported area of the topline. It is no coincidence it is also a prime location for structural
problems to raise their red flag. It is also a very difficult spot to evaluate in puppies.
Many
puppies have a dip at this spot but it fills in with muscle as they mature ultimately creating a level topline. But don’t
hope for a miracle cure for bad toplines. if the dog is very long in loin, or improperly angulated, this might not happen.
Every dog possesses exactly the same pieces- the difference is the way they
are assembled.
Regardless of its overall back length, a short coupled dog possesses
a combination of a long ribcage and a short loin. This is one of the traits that can be evaluated accurately at birth and
it is VERY important. Every dog has 13 pairs of ribs- Dachshunds, Pugs and Xolos and ribcage length will not change.
Shorter coupling is stronger. It provides better support and more efficiently
transmits energy from the front to rear assemblies. But if the coupling is too short it will impede agility. Flexibility is
a survival tool.
Nor does a short back ensure short coupling.
What is the Underline?
The underline is created
from combination of a deep long ribcage and strong loin muscles-
both are essential for survival.
The muscles creating the tuck up aid the flexing ability of the back as the dog moves faster.
But that is just part of the story.
The ribcage protects vital organs, lungs
positioned against sides of ribcage, heart positioned at elbow.
The space allotted to the critical items is determined
by the size and shape of the ribcage. It needs to be as big as possible without interfering with movement.
What is ribspring?
All dogs have the same number of ribs.
The slant of the ribs determines the length of ribcage. The curvature of ribs ranges from flat, to oval, to round.
The Xolo should have deep oval ribcage which provides
maximum lung capacity and efficient
movement.
A flat ribcage compromises heart and lung room
(shallow chest)
A round ribcage produces a
wide chest, out at elbows,
toeing in (bulldog front)
How does it
affect movement?
The shape of the ribcage influences the position of shoulder
blade over it. There is no bony attachment between shoulder joint and ribcage. The shoulder blades should come together like
a tent over the highest point of the thoracic vertebrae. As the dog moves, the shoulders glide and pivot along the sides of
the ribcage.
For a Xolo the ribcage should be deep enough to reach the elbows.
They should be positioned level with the bottom of the brisket for maximum elbow stability. The elbow is a hinge joint.
It should not have lateral movement.
If the dog has a shallow brisket that does
not reach the elbow it will lack of front fill. This produces pigeon breast-narrow chest- tuck up begins too far forward (herring
gut)
Fronts will widen with age and the dog will develop front fill IF it has
good shoulder layback.
Front reach
The
validity of 45-degree shoulder angulation is a
continuing topic of debate. However, there is not much
debate that
for most breeds it’s desirable for the forearm to be longer than shoulder blade, and obliquely placed to slope down
and back to the elbow. Length of shoulder blade and forearm are often approximately the same. A drastic difference in
length is a major structural problem.
The shoulder assembly
n Fold the
foreleg in half to evaluate the relative length of the bones.
n Locate the raised ridge of bone (the spine) running along
center of the shoulder blade. Locate the notch at the point where the forearm meets the shoulder. Measure angle
The angle between shoulder blade and forearm dictates the length of the dog’s stride and generates
the power to lift the body’s center of gravity as the dog moves forward. The forearm provides the critical leverage
to lift the body and pivot the shoulder blade back.
The muscles that pull
the front legs forward are attached to the shoulder blade and the forearm. The muscles for follow through are attached only
to forearm. A short forearm is going to compromise reach AND follow through.
Indications
of a steep shoulder:
n no forechest
n short neck
n wrinkles over withers
Straight shoulder placement creates an abrupt transition at the point where the neck meets the shoulder. This dip at is
clearly visible on a hairless dog and often highlighted by an obvious crease or wrinkle at this juncture. It also creates
the characteristic short, choppy steps that often accessorize a bouncy topline.
A
short, straight forearm deprives the dog of needed
leverage forcing it to waste a lot of energy trying to lift its center
of gravity rather than moving itself forward. Many dogs try to compensate by using their loin muscles to produce this needed
lift. The cumulative effect of this compensating action is the classic “dipping and roaching” topline of a poorly
constructed dog on the move.
If the dog has a short straight forearm and straight
shoulder the entire front assembly will be placed too far forward on the dog. It will lack forechest. Its center of
gravity will not be properly supported. Any movement will be inefficient and exhausting
The
forearm plays another crucial role in producing smooth gait by absorbing and recycling shock. The length of the forearm has
a direct bearing on the shock absorbing capacity of front assembly. Properly constructed, there should be minimal impact as
the front absorbs and recycles energy from the rear at a trotting pace. Ideally, the footpad should hit the ground when the
leg is fully extended approximately level with the ear. The shock of impact passes straight up through the column of bones
through the shoulder blade to coincide with its arc of movement.
A slight
bend of pastern also absorb shock and providesmaximum endurance
Too much length
or bend of pastern is caused by loose
tendons. Movement is characterized by floppy wrists, which wastes a tremendous
amount of energy.
The Rear Assembly
A long pelvis allows for good leverage to create drive
To
measure the length and slope of the pelvis:
run your hand along front of thigh to find front edge of pelvis and measure
angle from top to back.
There is a slight indentation between croup and tail
A long croup allows the broadest possible base for muscles to attach- this produces width of thigh-
a trait desirable in all breeds.
A short croup provides less space for muscle
attachment, resulting in narrow thighs,a tucked under rear and restricted drive. It is commonly found in combination
with luxated patella and/or extreme arch of topline
The croup should be long
but the angle of the pelvis will vary by breed and function
A flat croup allows
for more rear extension
A rounded croup provides more agility at the expense
of rear extension. The hind legs can get up under the dog more easily.
Bend
of Stifle
The hind leg is made up of the thigh bone and second thigh which should
be approximately equal in length, and the hock.
The angle between upper and lower
thigh is called the bend of stifle
A Xolo should have moderate bend of stifle,
meaning the front edge of the toes should like up directly under the butt.
Less
angulation will place the foot under rather than behind the body, and limit driving power
More
angulation is not always better- overangulated rear is often the result of excessive length of the second thigh
Too much creates instability, wastes energy. In general, dogs with lots of angulation are more likely
to have joint
instability which will become obvious coming and going.
The Hock
The
hock is a major source of movement problems. Horse breeders obsess about this anatomical feature for good
reason.
It should be substantially shorter than the thigh bones, straight and sturdy for propulsion, leverage and stability
Short hocks produce better leverage and better endurance.
Longer hocks are better
for and jumping power
Therefore, in the Xolo we want something moderate. Not
too long, not too short. More importantly the joint must be strong and stable, which is produced by the tendons
and
ligaments supporting it.
Instability at the hock causes the joint to twist rather
than push when the leg is flexed. The hock will not be able to exert enough thrust when foot is on the ground OR extend the
hind leg back for follow through.
To compensate, many dogs resort to excessive
lift of the hind leg with each step or use its back muscles try and pull the rear up and forward. Major muscle groups attached
to the back of pelvis pull the leg backwards and straighten stifle to produce thrust. Either of these compensating actions
can cause a high in the rear” topline.
Feet
Front
feet are always larger than back feet.
Smaller feet are better for speed and agile footing
Big feet good
for soft surfaces
The Xolo has a hare foot characterized by a longer oval shape which maximizes speed, agility, and leverage
