DHLPP - These initials stand for Distemper, Hepatitis, Leptospirosis, Para-influenza and Parvo Virus. This vaccination is a combination vaccination, which protects against:
Canine Distemper: A common viral disease that causes severe respiratory symptoms and/or central nervous system disturbances.
Hepatitis: A viral disease affecting the liver.
Leptospirosis: A bacterial disease spread by wild rodents causing liver and kidney disease
Para-influenza: One cause of canine cough or kennel cough, a contagious non-productive, dry cough.
Parvo: A severe viral gastrocenteritis passed in the stools for infected dogs. The disease is especially serious in young puppies. Symptoms are vomiting, bloody diarrhea, dehydration, and collapse. Dobermans and Rottweilers seem especially sensitive to this virus and care should be taken to vaccinate properly.
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Other vaccinations and procedures:
Corona Virus: This virus consists of viral gastrocenteritis and is very similar to Parvo virus. The virus is passed in the stools of infected dogs. Severe vomiting, bloody diarrhea, collapse, dehydration, and death are its presenting sign. Initial vaccination requires two vaccinations three weeks apart. A yearly booster vaccination is required.
Fecal Analysis: This is a test for intestinal parasites. It is a recommended test for all puppies for intestinal parasites. This requires that you bring a small bowel movement sample or one can be taken from the puppy. Appropriate medication will be dispensed based on the results of the laboratory test. Intestinal parasites are parasites that live in the intestinal tract. Dogs can be affected by as many as five different types of intestinal parasites at the same time without any indication of sickness. New guidelines indicate deworming puppies every 3-4 weeks until the age of 16 weeks. Testing for intestinal parasites should be performed at least once yearly.
Naramune (Bordetella): There are many causes of Canine Cough or Kennel Cough. Bordetella is the major cause of this disease and can be effectively prevented with this vaccine. It is administered once and it is good for one year. Protection requires yearly boosters.
Lyme Disease: Lyme disease is a tick born disease caused by a type of bacteria called a spirochete. Symptoms of this illness are fever, loss of appetite, and acute onset of lameness or pain. In some pets several joints may be swollen. Pets that are prone to tick exposure should be vaccinated. Examples are hunting dogs and dogs that live in or near the woods. Initial Lyme vaccination requires two vaccinations 2-3 weeks apart followed by a yearly booster.
Rabies: Rabies vaccinations are required by Law. Rabies is a fatal viral disease of domestic and wild animals as well as man. Rabies causes nervous system disturbances. Rabies virus is transferred in the saliva and urine of infected animals. In recent years there has been an epidemic of Rabies in the United States. The first Rabies vaccination is good for one year. A booster is required and this one is good for three years.
Heartworms: Heartworms are parasites that live in the heart and blood vessels of the lungs of dogs. The parasite is transferred by mosquitoes. All puppies under six months of age should be placed on heartworm preventative. Dogs over six months of age should be tested for heartworms with a blood test before being placed on heartworm preventative. Heartworm preventative should be given year round with yearly blood checks to screen for infection. There is an effective treatment for heartworm disease if it is detected in its early stages. All puppies and dogs can get heartworms even if they are only housedogs. It only takes one mosquito!
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Characteristics that are common to Chihuahuas:
( This explanation of the molera in Chihuahuas was taken from the Chihuahua Club of America handbook)
THE MOLERA
The Chihuahua as developed in Mexico and the United States has displayed a "soft spot" on the top of the head. In the Chihuahua this spot, or fontanel, is known as a MOLERA; and is the same as that found in human babies. In the past, this molera was accepted as a mark of purity in the breed, and it is still mentioned in most Chihuahua breed standards the world over.It is important to note that while many Chihuahua puppies are born without the molera, there are probably just as many with one and its presence is nothing to become alarmed over.
As shown in the illustration below, the molera in a Chihuahua will occur on the top of the head and may vary in shape and size when present.
FROM THE OFFICIAL AMERICAN KENNEL
CLUB
Chihuahua, Toy Group, Breed Standard
Luxating Patellas
This condition basically means a dislocated knee
joint. But it is usually a kneecap that will not stay in place. This can happen
in any Toy Breed with weak ligament, tendon, or muscles, or if the groove for
the kneecap is too shallow. There are four grades of luxated patella. However,
if your puppy has any grade it could possibly need surgery, or at the very least
anti-inflammatory medications for a very long time.
Hydrocephalus
This condition most common in the tiny dogs, is a build up of cerebrospinal
fluid within the brain sometimes referred to as Water-on-the-brain. NOT
to be confused with OPEN FONTANEL. An open fontanel or molera in the Chihuahua
is entirely normal. However if the opening is extremely large, involves
one or more openings, is pulsating or bulging, or if the eyes are wide-set
and focused outwards with excessive white showing, please have your vet
examine it closely. This condition is usually visible by four months or
so. These puppies are often poor growers and unthrifty in looks. They can
be uncoordinated and also suffer from seizures.
Vaccination Reaction
It is true that some animals have a systemic reaction, including a low-grade
fever or muscle aches and pain. This reaction is more common in young and
toy breed dogs and causes them to eat less and sleep more for 24-48 hours.
Rarely, dogs will have a more severe reaction, characterized by hives,
swelling of the face, or even vomiting. This reaction is easily prevented
Please check with your Vet about giving antihistamine at the time of subsequent
vaccinations. In some rare cases dogs will have a more severe reaction
leading to death. Leptospirosis, the component most likely to produce such
strong reactions, can be left out of some vaccines. If your dog has had
a vaccine reaction in the past, don't skip future vaccinations but do warn
the veterinarian so he can take steps to prevent a recurrence.
THERE IS NO SUCH THING AS A TEA CUP CHIHUAHUA!!! DON'T BUY FROM ANYONE WHO TRIES TO CONVINCE YOU THAT THEY HAVE A TEA CUP CHIHUAHUA!!
The following "Teacup Statement" was taken from the Chihuahua Club of America...
Tea Cup Statement
The Official AKC Breed Standard describes the Chihuahua as a small dog that comes in two varieties or coat types. The difference in coat type (the Long Coat and the Smooth Coat) is the only official description used to identify a difference within this breed. Our standard does not categorize the Chihuahua by size.
For the purpose of showing and record keeping, the American Kennel club includes the Chihuahua (along with 19 other breeds) in the Toy Group. Therefore, irrespective of their weight or physical stature ALL Chihuahuas registered with the AKC are considered to be a toy breed of dog.
As with all living things, there will be size variance between individual dogs within this breed. Look within the human family - brothers and sisters will differ in height and in weight, as well as other physical attributes. They are described as humans, male or female, and there is seldom if ever a need to break the description down further. The same holds true in regard to the Chihuahua; they are Chihuahuas - Long Coat / Smooth Coat!
Unfortunately, the additional adjectives used to describe the size differences and physical appearances are many and have been misused for so long they now seem legitimate. Teacup, Pocket Size, Tiny Toy, Miniature or Standard - are just a few of the many tags and labels that have been attached to this breed over the years. The Chihuahua Club of America is concerned that these terms may be used to entice prospective buyers into thinking that puppies described in this way are of greater monetary value. They are not and the use of these terms is incorrect and misleading.
Occasionally, within a litter, there may be a puppy that is unusually small. That puppy is a small Chihuahua and any other breakdown in description is not correct. To attach any of these additional labels to a particular puppy is to misrepresent that Chihuahua as something that is rare or exceptional and causes a great deal of confusion among those new fanciers who are looking for a Chihuahua.
The Chihuahua Club of America does not endorse nor condone the use of any of these terms and would caution the perspective puppy buyer not to be misled by them.
We recognize that many Chihuahua fanciers do want the very small
puppy. While they are adorable and can be perfectly healthy, the buyer should be
cautioned as to the extra care that may be required with regard to their
general health and well-being.
THE CHIHUAHUA
A CLOSER LOOK
By Laurence Fitt-Savage
Reprinted from Chihuahua Handbook of 1996
The most individual attribute of
any breed tends to be the head; the chihuahua is no exception. As a toy/lap/pet
dog this individuality is a key function of the breed.
The skull of the chihuahua is of
most unusual shape. The skull of 'basic dog' is like an elongated cube, with a
bony occipital peak and a slight bony ridge along the center line of the skull,
where the plates of the cranium knit together. The chihuahua, as a legacy of the
dwarfing of the breed, has a large rounded baby-like skull. Mammalian babies
tend to be born with disproportionately large heads (and eyes) which grow on
more slowly than the rest of the animal. In the chi this largeness of head and
eye is never completely lost. The large head of a whelp requires that the many
bones which knit together to form the skull must be capable of movement at birth
to allow the bitch to pass the head. In chis these bones do not always grow
together as the head develops and changes shape during puppyhood. A small gap
(molera) is left atop the skull where the bones fail to meet. Provided this gap
is not large, and that there are not several gaps, the presence of a molera is
of little significance. In many chihuahuas the cranial plates do knit together,
they should not however form a crest or ridge where they meet.
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In shape the skull should resemble an apple (a cooking apple is generally thought most descriptive), it should not be a perfect round (ball) shape. A round skull would lose breadth between the ears, and less room within the cranium. The eye sockets should be well protected with a bony surround. It is this protection of the eye sockets which lifts the front lobes of the skull and creates greater width at eye level. This protection also forms the basis for the required distinct stop. A round skull lacking this protection will either have small eyes, or 'frog' eyes which stick out.
Jaws and cheeks are supposed to be lean, muzzle 'moderately short, slightly pointed' and the stop 'definite'. Coarse dogs have too broad a muzzle and broad cheeks. There is not enough distinction between muzzle and skull. Snipy dogs have cheeks pinched in beneath the eyes, and narrow muzzles; their jaw muscles are of poor substance.
The muzzle itself is fairly short; the chihuahua is a member of the brachycephalic group (large heads and short muzzles). Ultra short muzzles are not desirable. They can lead to respiratory problems. Long muzzles are untypical---they spoil the balance of the head, lead to 'foxy' faces with insufficient cheek and stop, often allied to flattened, plain heads. The muzzle is slightly pointed---flattened muzzles tend to be coarse, or too short (even perhaps with a turned up nose). The flat muzzle often accompanies an undershot mouth, if too pointed it may indicate an overshot mouth.
The 'definite' stop does not mean the skull is at right angles (90 degrees) to the muzzle. Given that the muzzle is the horizontal (sloping neither up nor down), then the skull should describe an angle of approx. 100 degrees. A very short muzzle may appear to be set in the skull, describing an angle less than 90 degrees; a legacy of the flat-faced breeds introduced into chi ancestry to shorten the muzzle (Pugs, Pekes, etc.). It is potentially a source of breathing problems.
A correct scissors bite is such that, side view, the top incisors just overlap, in front of the bottom ones, but the bottom canine fits neatly in front of the top one. If the incisors meet edge to edge, this is a 'level' mouth, not scissors. "Set square to the jaws", it must be noted, means that the teeth are set at approx. 90 degrees to the gums. It does NOT mean that the incisors should be lined up neatly in a straight line like guardsmen; the dental arch (arcade) should curve gently forward from the canines.
Given that the head and muzzle are the result of dwarfing, it is not too surprising that the upper and lower mandibles are not evenly shortened; the result is an over- or under-shot bite. If overshot, the upper incisors protrude beyond the lower, in severe cases the bottom incisors may be level with the top canines. If undershot, the bottom incisors stick out beyond the top ones.
Ideally the incisors should be even in size, strong and white, with six top and bottom. In shorter muzzles this is sometimes difficult to achieve---there may be insufficient room, so the dog may have only 4 bottom incisors (acceptable in U.K. if the teeth are of even size with no large gaps); the teeth may be uneven in size, or the bottom incisors may be set in a straight line. How serious these mouth faults are is a difficult point. Unless severe, a poor bite will probably have no significant effect of the dog, but successive generations may show deteriorating mouths. Uneven teeth, or the odd gap are considered by some to be unavoidable in the best heads, although there is no reason why the best of heads should not carry a perfect mouth.
Although large, a chihuahuas eyes
should not protrude, as this would increase the risk of injury. Bulging, frog
eyes are not attractive, and are particularly prone to weeping and damage.
Weeping of the eyes is quite a common problem in chihuahuas, the most serious
cause is ingrowing lashes, but draughts, dust and the moulting of the fine short
hair around the eyes are also causes. When injured the eyeball often turns
cloudy blue, either in whole or just around the injury. This should not be
confused with the staring, light blue 'wall eyes' (common in merle collies)
which look uncanny and unattractive, and are not the light eyes permitted by the
standard. The ruby eye is associated with pale pigmentation of the nose, in
light colored chihuahuas, and reflects a most attractive color in the
dark.
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Chihuahuas ears are set on the side of the head rather than the top, and are carried erect, flaring out at an angle, often wrongly described as being at 'ten to two'. Particularly alert, or dozy, chis will naturally use their ears, pricking them higher, or laying them flat to the skull, but in repose should revert to the 45 degree angle. The ears are large, with rounded ends to the pointed tips, not to be confused with the rounded ends of the 'bat ears' of such as the French Bulldog. Because they are so large, chihuahuas ears sometimes take a while to become fully erect. The ears of teething pups are often soft at the tips, bending forward or back. Truly soft ears, those which fail to stand up, flop down beside the head and are both a serious fault in the show ring and are more likely victim of problems such as canker. Small, kitten ears set high on the head produce an alien, foxy, pommy expression and are sometimes difficult to weed out of breeding lines.
The neck is 'slightly arched,
medium length' for strength, as it both carries the weight of the head and is
part of the fore-quarters assembly. If the neck is long and whippy the whole dog
will probably be built along racy, whippet-like lines with long spindly legs.
Extension of the vertebrae of the neck generally accompanies a pro rata
extension of the rest of the spinal column, giving long, weak backs, slab sides
and long, ratty tails. This so called 'deer-type' is no longer as common in
chihuahuas. More common is the chi with a stuffy neck---too short a neck leaves
too little room for the muscles, and is associated with heavy, overbuilt
forequarters. The head, in such a chi, often looks as if it has been stuck
straight on to the body, especially in longcoats where the ruff hides the true
lines of the neck. When felt the neck, measured from base of skull to the
shoulder should be approx. one-third of the length of the back.
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The arch of the neck is required for strength, to be effective it must carry the head forward, and not up (star-gazing). If the arch of the neck is inverted the dog's movement suffers, being less smooth and rhythmic, choppy and without reach and drive.
It should be noted in passing that a chihuahua should have no loose folds or flaps of skin on the neck. The chi should offer clean bodylines to the eye.
The forequarters of the dog may not always receive as much attention as the hindquarters, but they are equally important. The hindquarters provide the drive, the forequarters propel on the turn, absorb the impact of each stride or jump, ensure travel in a straight line, assist in maintaining the stability of the center of gravity and carry weight. Faults in the forequarters assembly can therefore have serious consequences. Note that the foreleg does not end at the elbow, although its structure is harder to see than that of the hindquarters.
The shoulder, as the foundation upon which the forequarters are based, should be correctly laid, the most efficient arrangement is generally accepted to be 45 degree from the horizontal (side view). An upright shoulder (an angle significantly greater than 45 degrees) tends to shorten the shoulder blade, thereby also shortening the muscles anchored to it, reducing their efficiency. There is also a loss of reach, as the foreleg cannot straighten beyond the angle of the shoulder, and this reduces drive and is the root of a number of serious gaiting faults.
If the hindquarters are better angulated than the front and provide more drive than the front can accommodate, problems occur. Unless a corrective remedy is found the dog 'Pounds'---the front legs hit the ground before the hind legs have completed their forward push, the resultant excessive strain may cause the dog to 'break down' in front, especially at the pasterns. Excessive rising and falling at the withers often betray this condition. To avoid pounding the dog may flick up its front pads just prior to impact. This reduces the shock of impact, the dog lands on the heel pads, which act as buffers. 'Padding", as this fault is known, often looks most smart to the casual observer, but it is only the dog's natural compensation for its structural deficiencies, and a trap for the unwary!
Overreaching is another problem
caused by an imbalance of drive, the hind feet interfering with the front. To
avoid tripping on its own feet the dog may then have to 'Crab', swinging the
hindquarters out to one side so it appears to walk sideways. When walking
directly toward you the hind legs of the 'crabbing' dog are visible beside the
forelegs (a), those of the correctly moving dog are masked (b).
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An alternative method of avoiding contact is to throw the front legs high in the air, the 'Hackney' gait. This is specifically described in the standard as a fault, in part because, for just a few specific toy breeds this is, for differing reasons, the required gait.
Shoulders are also required to
be 'lean, sloping into slightly broadening support'. This refers to the view
from the front of the dog. The shoulders lay along the ribs; too much muscle on
the shoulder pushes the tops of the shoulder blades apart. These 'loaded
shoulders' are heavy, rather than lean, and result in a lack of balance. The
shoulder point is tied in closer to the ribcage and the elbow is forced out of
line, which is an ugly fault. A dog with loaded shoulders may also appear
overbuilt at the front, tailing off to weaker hindquarters.
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Balance is determined in two
situations; on the move (kinetic balance) and standing still (static balance).
Static balance is achieved if the dogs structure allows standing on all fours
with the minimum of effort. For this to be possible the base of the support (the
heel pad) must be vertically beneath the center of gravity of the shoulder,
although the support is not a solid vertical 'pole'.
"Forelegs set well under" means that the
humerus must be long enough to set the legs under the shoulder, the best
arrangement being the humerus set at 90 degrees to the shoulder blade, and of
the same length. The ultra straight 'terrier front' is the result of a
shortening of the humerus with a resultant shorter, more upright shoulder. This
may look extremely smart, but it is most definitely incorrect in a chihuahua.
The foot is set too far forward, rather than being well under. The leg appears
to be a continuation of the neck, with no brisket visible in front of
it.
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The straightness throws the foot forward of the center of gravity and straightens the pasterns until they tend to knuckle over. This is not the straight front the standard refers to. A short humerus would bring the elbow above the brisket line. To give freedom of movement the elbow is lower. This of course, is freedom of movement front to back, 'looseness' refers to side to side movement and is not wanted.
To get the heel pad beneath the
center of the shoulder requires a slight bend at the pastern joint. If the
pasterns are too upright weight will be thrown forward on to the toes, risking
damage to the foot. The standards 'straight forelegs' refers to the legs as
seen from the front. if completely straight (side view) from elbow to heel the
leg muscles are constantly at work equalizing the pull forwards and back, so
that the leg tends to quiver. If the muscles are weak the pastern will knuckle
over. If the pastern bends forward too much there is constant strain on the
muscles of foot and leg, and displace certain small bones in the
foot.
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Viewed from the front the foreleg should be straight from point of shoulder to the pad. However to be in complete balance the foot may incline inwards slightly from the vertical, to ensure that the foot is vertically beneath the center of gravity of the shoulder blade.
Once on the move, kinetic balance requires maximum work for minimum effort, to increase stamina and reduce fatigue. Viewed from the side the radius and ulna should be parallel with a line drawn from foot to center of the shoulder, when the foot is in contact with the ground.
From the front the foreleg should still be straight, but it must be noted that the faster a dog moves, the greater the tendency to place the feet near the center line beneath the body. This is not a fault, it helps prevent body roll, which would be unduly tiring. However, the speed a chihuahua is normally gaited at in the ring should not require anything approaching single-tracking. The opposite of single-tracking, 'paddling' can also be a problem. Tied in elbows are restricted in their movement, as a result the legs are thrown wide of the body, which rocks from side to side because the feet fall so wide apart.
Other gaiting faults combine
various features of a front that is not straight, the leg bending at elbow,
pastern or even just the foot. Movement is most efficient when the leg, from
point of shoulder to foot, is a straight column of bones. Loose elbows which
'flap in the wind' wide of the body throw the leg inwards. Weak
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pastern joints throw the pastern out,
or turn the feet both in and out. 'Weaving' is the result of the elbow problem,
'winging' that of the pasterns.
Each forelimb is an entirely separate structure, only anchored to
the main frame of the dogs skeletal structure by muscle and ligaments. Therefore
weak musculature will compound the problems of poor bone structure, or it may
force sound structure into unnatural situations. Faults of both bone and muscle
must therefore both be considered important. Equally problems evidenced in
puppyhood may resolve as the adult dogs develop and harden the necessary muscle,
roadwork is often the prescribed remedy for loose elbows in a young
dog.
Age is not always
a benefit however. Continued muscle development on upright shoulders often
results in the fully mature dog, at 2 or 3 years old, becoming overbuilt in
front, characteristically 'stuffy' in neck.
The hindquarters, from the croup to the feet, are more involved in the provision of drive than in the maintenance of stability. Thus the dictates of stable balance are modified to cope with the not entirely compatible requirements for providing drive. The hip joint is therefore a more straightforward ball and socket joint, with the hip securely anchored to the spine, creating fewer mechanical constraints to the delivery of push. It should also be noted that the hock is a joint, not to be confused with the hind pastern.
Static balance is achieved when,
viewed from the rear, the hind feet are equally spaced either side of the center
of gravity (an imaginary vertical line drawn through the center of the pelvis,
usually the root of the tail). For perfect balance the leg should form a
straight, vertical column of bones from pad to hip joint. A modified balance is
achieved by spreading the hind legs apart and back slightly,
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usually to display alertness or
aggression, or to lower the croup and straighten the topline. Free-standing
chihuahuas should not show more than a minor amount of stretch, and never stand
artificially stretched like a gundog.
Balance, modified or not, will be lost if
the hind legs are not straight, i.e. if the hocks are turned in or out. Turned
out hocks are the less common, they turn the feet in, 'Pigeon-toed'. Turned-in
hocks, 'Cowhocks', are a well-known and more prevalent fault. Lack of room
forces the stifle out, which in turn forces in the hocks and splays out the
feet. In cows this allows room for the udder but in dogs it is a fault as it
seriously weakens drive. Drive is provided at an angle to the desired line of
movement.
When the dog moves away these
faults and more may be revealed. Hocks "well apart" refers to the fault of
moving close (brushing hocks). This fault has to be distinguished from
single-tracking, which is the natural tendency of most breeds as their speed
increases. The reason and extent of this tendency are the same, front and back.
When a dog is 'moving close' behind, the hind pasterns brush past each other and
may even touch. The stifles usually break the hip-foot line as well. Drive is
lost as a result. The condition is often attributable to weak rearing
muscles.
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The differing requirements for
hindquarters mean that the pelvis thought most efficient at 30 degrees to the
horizontal (not the 45 degrees of the shoulder). If the pelvis (& thus
croup) is steeper, forward reach is gained, but push and follow through are
restricted. If the pelvis is flat, forward reach is reduced, but the length of
muscle from pelvis to hock shows an apparent increase. This however is not so as
the femur, which tends to lie at 90 degrees to the pelvis, is nearer the
vertical, straightening the stifle joint and decreasing that joints ability to
operate as a pulley for the rearing muscles and ligaments. A shallow croup
gives hind movement that is stilted, in Spitz breed style, whilst a steep croup
shows up as slack hind movement and a "Goose-rump".
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Angulation of the hindquarters (good turn of stifle) is required for extra speed. Increasing the turn of stifle proportionately increases the length of both the thigh and second thigh, thereby also lengthening the rearing muscles. These muscles, particularly of the second thigh, provide the drive. Weak hind muscles lead to poor hind action, hence 'Muscular' in the standard.
The natural result of lengthening
the second thigh, by developing a good turn of stifle, is that the hind pastern
shortens, giving hocks that are 'well let down'-i.e. close to the ground. A
shorter hind pastern gives greater endurance. Ideally the hind pastern should
incline slightly forward---foot slightly behind the hock, but a vertical hock is
the norm in the showing. The hind pastern should not incline backwards, foot in
front of the hock, since these 'sickle hocks' imply that the achilles tendon is
unable to fully extend the leg. In more severe cases the dog may look as though
it bounces up and down on its hind feet. Rather than being directly under the
pelvis, the hind foot should stand so that the hind pastern is beneath the point
of buttock.
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The stifle joint is most unusual in construction. The patella runs between grooves on the end of the femur, to prevent overstraightening and act as a pulley for the rear muscles. If the muscles and ligaments are slack the patella may jump the groove. In a dwarfed breed like the chihuahua it is more likely that the groove may not develop in proportion to the joint, shallow grooves therefore tend to be more common. This fragile joint is particularly susceptible to external damage. Enthusiastic pulling and tweaking of the hind leg can have serious results. The judge may find this patella luxation (slipping stifle) evidenced by hopping, locking the leg straight when standing, or by feeling (& sometimes hearing) the patella move when gently handled. The problem is another that age tends to amplify, and the unnatural wear on the joint may lead to arthritis.
Hip dysplasia also regularly leads to arthritis, and is not confined to big dogs, it is known in chihuahuas. HD can be debilitating in its severest form. HD occurs where the ball joint of the femur does not fit snugly in the socket of the pelvis. The result is uneven wear on both surfaces, and strain on the muscles. Subclinical HD (showing no external symptoms) is tested for by X-Rays in the most susceptible breeds, which tend to be the larger and heavier ones. Like all other structural faults HD must usually be assumed to be hereditary and breeding programs planned accordingly to discard, rather than store up problems for future generations.
Good conformation does not begin and end with the structure of the limbs, nor does soundness relate only to movement. The spinal column, from neck to tail, has an important role to fulfill. The vertebrae are more than just protection for the spinal cord. They anchor the limb muscles which allow movement, they are the foundation of the dogs skeleton. Differing stresses along the length of the spine mean that this strength must be combined with a degree of flexibility. The spine is not just a hollow tube. The thoracic vertebrae and the neck anchor the muscles of the forelimbs, the former also support the ribcage; the vertebrae of loin and croup anchor muscles of the hindquarters and tail. The bony protrusions at the top of each vertebrae do not all face the same way, those anchoring the forelimb are angled to the rear, for the hindquarters they angle forward, and between are some with less pronounced, more upright ridges. Where these ridged vertebrae meet the neck, at the withers, there should be a slight dip, just before the withers.
The spine is naturally curved--there should be a slight rise at the withers and also over the loin, although the latter is often disguised under muscle, fat and coat, even in Smooths. The spine should not curve from side to side (viewed from above), nor should there be any pronounced dip or rise in the topline. Weakness of the spine results in faults such as a 'Sway back' - a pronounced sag in the spine between withers and pelvis, or a 'Roach or Camel back'--a pronounced rise behind the withers. A level back should not be billiard table flat, but it should not slope, height at withers should be the same as at the croup.
Length of body is now specified clearly in the standard and the definition of 'back' (not entirely agreed upon in canine circles) need no longer worry anyone wishing to understand the Chihuahua standard. It should be noted in passing however, that there is no resorting to the standard to justify personal preferences for long bitches and short, 'cobby' dogs, the chihuahua standard is totally unisex in all its requirements (except the obvious of course!).
The ribcage is an important
structure, determining the room available for heart and lungs. There are 13
pairs of ribs, pivoting where they join the spine, and connected to the sternum
by cartilage. The first 9 pairs connect by cartilage directly to the sternum,,
the next 3 pairs are connected by cartilage to the cartilage of the rib in
front, whilst the final pair are 'floating ribs' with no connection to the
cartilage of the other ribs. These joints (bone/cartilage or
cartilage/cartilage) allow the ribcage to expand outward with each breath,
increasing lung capacity. The heart rests between the lungs on the sternum
between the 3rd and 8th ribs. The ribs are set against the ribs and against the
diaphragm--the muscle which runs diagonally from the loin vertebrae, down the
rib walls, to the 7th rib and the sternum, separating thorax from abdomen. The
action of the diaphragm creates a vacuum behind the lungs, greatly assisting
breathing.
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The standard recognizes the need for plenty of heart room by requiring 'well spring ribs, deep brisket'. The ribs should spring out in their initial curve away from the spine, but then flatten and lengthen slightly to deepen the chest, the length of rib and depth of chest best increases heart and lung room. If slab-sided, with little or no spring of rib from the spine and flat sides to the ribcage room is restricted. Rounded, "Barrel ribs" offer an illusion of room, but adequate depth of brisket could only be obtained with a disproportionately large ribcage. As well as depth and width, the ribcage should also be sufficiently long, so the brisket line should not cut up before the 7th or 8th rib. If the brisket line rises immediately behind the elbows, at the 3rd or 4th rib, the heart is pressed upwards, reducing lung room. Depth of brisket should be measured through the tip of the sternum, not merely between the forelegs.
The tail completes the body's
structure, the tail bones are a direct continuation of the spinal column,
becoming progressively smaller and tapering to the rear. Control is by three
quite powerful muscles, two above and one below. The set of the tail should be
fairly high, to allow the tail to be carried up and over the back.
A low set tail is likely to accompany
a 'goose-rump', with steep croup and movement problems. If the tail is set too
high, laying flat across the back like a Pom's, the pelvis is likely to be laid
too flat, with a resultant short, stilted hind action. A twist or kink in the
tail is a fault that may be more serious than it appears, since unnatural twists
in the tail vertebrae may be symptomatic of further weaknesses along the spinal
column. The curly 'pig' tail, and the long tail twisted to one side, the results
of muscular imbalance may also signal further weaknesses in muscular
development. The typical Chihuahua tail is the result of a slight flattening of
the vertebrae combined with strong muscles, modifications which slightly reduce
tail length. A long, round bony, 'whippy' or 'rats' tail is a deviation from
type.
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