X-ray diagnostics of tail development anomalies in dogs and cats

The tail of dogs and cats, as an integral part of the vertebral column.
The structure of the dog's tail: bones, muscle tendons.

The tail of a dog can be considered as the final part of the vertebral column, because its anatomical structure is similar to the structure of the spine. The bone base of the tail is the vertebrae, most often there are 20-23 of them, less often fluctuations from 15 to 25. The first two or three tail vertebrae are well developed and have all the characteristic anatomical formations for a typical vertebra. The remaining tail vertebrae gradually decrease in size, their parts change in such a way that the last tail vertebrae have the appearance of small blunted cones. Such anatomical changes are due to the fact that, unlike other parts of the spine, the dog's tail does not carry a special load.

The vertebral bodies are interconnected by intervertebral discs, which are cartilage. In addition, the tail vertebrae are interconnected by ligaments (tendons) of three types. The arches of the vertebrae are connected by inter-arched yellow ligaments. The spinous processes of the vertebrae are connected with the help of inter-spinous ligaments, the transverse processes are connected by inter-transverse ligaments. The movements of the tail are carried out with the help of the tail muscles, among which there are three long muscles starting from the sacral and iliac bones and many short intercostal muscles that are located between the transverse processes of the tail vertebrae.

The length and shape of the tail of cats

In ordinary long-tailed cat breeds, the length of the tail is diverse and individual, it can vary from 20-23 cm to 40 cm from the sacrum to the tip. The number of vertebrae is also different: there are from 20 to 27, within the same breed there are common trends: Persians have shorter tails, Maine Coons and Orientals of considerable length. In the tail, the following parts are distinguished, between which there are no clear boundaries: the root of the tail, the stem, or the tail itself, and the tip of the tail.

The root of the tail consists of 4-6 vertebrae, starting from the sacrum, consisting of fused inseparable and flattened vertebral bodies, which together with the adjacent pelvic bones create a bone ring for attaching limbs. The vertebrae adjacent to the sacrum are also short, wide and flattened, but already the fifth or sixth tend to acquire a cylindrical shape, losing barely noticeable remnants of spinous and transverse processes.

The middle part of the tail, or stem, consists of 10-15 vertebrae, which have elongating cylindrical smooth bodies with noticeable intervertebral cartilage and a slight thickening to the articular surfaces, which gives them the appearance of antique thread coils. The articular gaps between them are made of a jelly-like substance that causes the mobility of the vertebrae around the long axis of the tail. This determines the sufficient mobility of the tail as a whole.

With a violation of mineral metabolism, accompanied by a lack of calcium or its increased excretion, the vertebral bodies have an insufficient mineral component, look refined, while the organic cartilaginous matrix of the articular parts grows, and the tail takes the form of beads or beads. If the cartilaginous part of the joints is compacted and the jelly-like substance - lubricant loses its qualities, when the tail moves, a sound of "tearing" or clicking appears, which can serve as a symptom of insufficiency of the chondroxide system of the body as a whole. This is sometimes revealed during an exhibition examination in cats of the Scottish Fold breed. Further "shrinkage" of the cartilaginous intervertebral parts leads to the appearance of a rigid stiff tail and a decrease in exhibition ratings.

In the final part of the tail, the vertebral bodies gradually shorten and thin out. The tail ends with the last, smallest and thinnest, rudimentary or underdeveloped, often asymmetrical or sharp, terminal vertebra. Its terminal part, devoid of a restraining intervertebral disc, acquires a free form in the form of a carnation or a slightly curved awl. It would seem that there may be claims from experts against him, an underdeveloped one. But it is the last vertebra, which in fact happens to be asymmetric, that becomes a "stumbling block" when receiving an exterior assessment from the judges.
Tail anomalies in dogs and cats

The dog's spine and its tail are one unbroken straight line, so it should be understood that it is a continuation of the dog's spine. It is logical that an anomaly of the spine cannot be a physiological norm, it is directly or indirectly related to many functions of the body - the structure of the bone marrow, nerve endings, psychomotor functions, labor activity, etc.     Of course, this does not mean that any dog with a host anomaly is a potential invalid, but it is already at risk.

Deformations of the tail are mostly the result of splices or incorrect location of the tail vertebrae.

The dog's tail can also be damaged in a fight or pinched. In such cases, you should immediately contact a veterinarian, who will give an opinion on the freshness of the injury and accurately describe (possibly by taking an X-ray at the same time) its nature. Only in this case, a dog with a deformed tail as a result of injury can be allowed to breed. A conclusion made too late, for example after an inspection at an exhibition, is not recognized. Conscientious breeders do X-rays at the age of 8 months (up to this age, tail deformities may be genetically determined).

Any deformities of the caudal vertebrae, determined visually or by palpation, as a result of examination and palpation, should be adequately evaluated by an expert.

Judging of anomalies of the tail vertebrae and other tail defects determines the breeding policy of nurseries.

All variants of anomalies appear after the birth of animals, and most often at the age of 2 to 8 months, although deformities of the last and penultimate vertebrae can occur throughout the life of the animal.

If individuals with congenital tail defects are definitely culled, then in the case of a late manifestation of the anomaly, most animals with a weak defect participate in breeding.

The main question that interests breeders is whether these anomalies are hereditary in nature, and, if so, whether they are determined by the same gene (genes) as gross congenital disorders of the tail vertebrae, leading to the appearance of visible nodes and creases.

There are different types of tail defects, but in general they can be divided into three groups:

- genetic deformity of individual vertebrae,        
- fusion \ ossification of two or more vertebrae,                          
- violation of the relative position of two vertebrae relative to the axis

There are problems in completely different places of the tail, but most often, according to statistics, at the very tip, on the last 2-3 vertebrae. And although the defective tail itself does not affect the dog's health, it entails many problems.

Any deformity of the tail is, of course, an anomaly in the structure of the vertebrae, which usually occurs at an early stage of embryogenesis (approximately in the first quarter of pregnancy). Like many skeletal anomalies, it can be either genetic (hereditarily transmitted) or not hereditary, but arising as a result of spontaneous mutation.

Of course, various viral diseases (for example, banal adenovirosis suffered by a bitch at the beginning of pregnancy), as well as some medications affect the formation of the fetus, including the formation of its spinal column.

Thus, the appearance of a deformed caudal vertebra anywhere in the tail, in the form of a wedge-shaped, segmented, fused or hypertrophied fragment, should be considered the basis for disqualification of the animal.

Since the deformity of the tail in most cases can be determined immediately after birth, many conscientious breeders, having discovered it, subject puppies with irregular tails to humane euthanasia or, after activation, distribute them to people who do not plan to participate in breeding work and exhibitions, with the mandatory conclusion of a contract on non-breeding use and desirable sterilization of the dog.
The main types of anomalies of the tail structure

Shortening of the tail- short tail is found in some dog breeds - French bulldogs, Old English Shepherd (English bobtail). Bob (Eng.) - a piece of wool, a brush, a weight for a watch: all this assumes some kind of short rounded small formation left over from tail (Eng.) - tail. This name - bobtail - began to define all breeds of cats that have tails shortened with kinks or zigzags. The tail of a bobtail can have any shape, mobility or fixity. The main thing is that it should consist of any number of vertebrae from 5 or more, some of which should be deformed, and the total length of the conglomerate should not exceed 13 cm. The whole bean should be well pubescent, giving the impression of a pomade, pompom or chrysanthemum. If hairless bobtails are bred, their bob should probably look like a ball of snakes or a pretzel. Probably, it is not worth recommending such a selection.                   

The features of beans are described in the standards. Almost straight remnants of tails with a small end hook or "burr" are required for pixie beans and Karelian bobtails.

There is a remnant of the tail, the beginning of which looks normal, and only after 6-8 ordinary vertebrae a more or less twisted bob appears. Such an effect of a disqualified bobtail is considered a disadvantage.

The complete absence of a tail, characteristic of English cats from the Isle of Man, or Manx, occurs as an undesirable mutation in various bobtail populations. Breeding of completely tailless cats is limited to only two breeds: Manx and Cymric. Cymric is a semi-long-haired variation of the former. In all other breeds, tailless animals are not allowed to breed. The reason for this lies in the genetics of manxism.

Manxism in its extreme manifestation is the complete absence of a tail or the preservation of its insignificant remainder. Such genetic damage to the entire vertebral column before its complete disappearance occurs under the influence of the M gene and due to the resorption of embryos. This lethal effect appears only in homozygotes - MM. All other breeds of cats have a recessive gene m, under the influence of which normal long tails grow.

There are 4 types of manxness:

Cats with a complete absence of tail and tail vertebrae – "rumpy" or true manx (rampy)
Cats that have only a few fixed fused tail vertebrae – "rumpy-riser"; 1-4 tail vertebrae, usually fused together, (rampy riser)
Cats whose number of vertebrae is much larger than that of the rumpy-riser, the tail is mobile, but ugly in shape – "stumpy"; 5-14 fused in tension or bumpy vertebrae (stamps)
Cats with a shortened tail of normal mobility and shape - longie

The rumpy subspecies does not have any tail at all, while the rumpy-riser has a small growth in place of the tail, the stumpy is a certain tail trim, and the longy subspecies look like ordinary cats.

All variants of the born Manx - rampi, rampi riser and stamps - are heterozygous for the Mm gene. Long-tailed kittens born from two manx are homozygous for the normal mm gene, but under the influence of the accompanying groups of polygenes in this areal population, they have shorter tails due to shorter tail vertebral bodies.

Small anomalies and the structure of the caudal stem

S.Jansen-Nullenberg notes that up to 20 hereditary factors can play a role in tail defects, which are attributed to deviations in the structure of the skeleton. In this regard, tail defects have various forms. Not only the absence of a tail and its shortening can manifest, but also various forms of fractures, hooks and bends, too small or too large vertebrae, deviations in the shape of vertebrae, defects of intervertebral joints.

Hereditary factors that are responsible for these manifestations do not limit their impact only on the vertebrae of the tail, but also affect the development of the entire skeleton. Sometimes it concerns only the vertebral column and the skull, and sometimes the limbs, including the fingers. There are cases when deviations in the structure of the skeleton are associated with defects of various organs.

S.Jansen-Nullenberg cites the following deviations in the structure of the skeleton associated with tail defects:

Curvature of the neck, sternum, sacrum;
Splitting of vertebral arches;
Absence or splitting of the hard palate - cleft palate;
Deviations in the structure of the chest.

Combined malformations of the heart and kidneys and abnormalities in the structure of the genitals can also accompany tail defects. In kittens born viable, all these deviations may not manifest themselves at the same time, and in most cases, at first we completely do not notice the hidden anomalies and the deviations mentioned above. In these cases, they are hidden by "normal" genes, or the present deviations are so small that they remain unnoticed. If we notice a tail fracture in a cat, which in most cases is determined immediately after birth, it most likely has a hereditary basis. The type of this fracture in appearance may be indeterminate. The existing deviation in the structure of the skeleton, which does not interfere with the cat itself, will be passed on to her descendants, who will certainly have problems if such a cat participates in breeding.

The most common small anomalies of the tail spine

1. The tail is in the usual non-standard position. More often, this condition of the tail has to be seen in the calm home state of the animal. At the exhibition, it is quite difficult to see a cat's tail thrown on its back with a "steering wheel", like a husky. We observed such a case, and in a state of emotional excitement, the cat's tail became ordinary. Sphinxes really like to curl the tail into a spiral and press it to the warm side or, sitting "piggy bank", wrap it around the paws and hide the tip inside. Such a tail is easily straightened, occupies a standard physiological position, in which no deformations are detected. Thus, this deformation is not anatomical, but physiological, which makes it possible for the expert not to reduce the exhibition ratings and titles.
2. "Nervous" tail. In an excited state ("exhibition stress"), the tip of the tail turns out to be rigidly tense and slightly bent. In a calm or distracted state, normal flexibility returns to the tail, it completely straightens. There are no bone nodes and other fixed deformities. The exhibition rating is not reduced.
3. The asymmetry of the last, rudimentary vertebra - both in the form of a carnation and in the form of a crooked awl does not reduce exhibition ratings. In a lion, by the way, the tip of the tail is covered with keratinized skin, turning into a tail claw, capable of causing serious damage on impact.
4. A short, bluntly ending tail without characteristic reduced terminal vertebrae causes reasonable suspicion of cosmetic correction of any defects. Now veterinary specialists have begun to practice cosmetic operations to correct tail defects, cryptorchidism, hernial holes and other anomalies. Competently carried out, they do not leave scars: many operations on cats pass without a trace. In the absence of a postoperative scar, a reduction in the score is possible only for a shortened tail. Veterinary documents confirming the absence of surgical interventions are not taken into account.
5. Tail with a "pouch". Excess skin at the end of the tail, the so-called "pouch", has nothing to do with bone deformities, however, it raises suspicions of removal of a defective vertebra without proper correction of the skin residue. At the same time, it can occur by itself. Veterinary cosmetology, perhaps, corresponds to the trend of the time, but the dishonesty of a certain part of breeders who use "doctored" animals in breeding does not allow them to adopt its successes and recommend cosmetic operations on the tail to owners of animals with small deformities of the terminal tail vertebrae, no matter what positive cosmetic effect this does not achieve.
6. Hard tail of Scottish folds. The gene for feline lop-earedness does not correspond to that of dogs at all. In cats, it not only makes the ear cartilage soft and small, but also affects bone and cartilage tissue. In the homozygous state, this gene leads to a violation of the formation of the bone system, the appearance of a loose "square" pastern, osteochondrosis and a rigid spine. Therefore, folds are bred only in a heterozygous form, using cats with erect ears - straits as partners, but only from fold breeding. It would seem that what is wrong with British cats as straits? However, the observations of breeders of this breed confirm that if excellent British straights are born from mating a fold with British cats, winning rings among purebred Britons, then folds from such mating are weak, with semi-erect ears, not only going beyond the contour of the head, but also towering over it, like a collie. At the same time, true straights do not participate in championships, but are highly valued by specialists. You can't get great folds without good straights. In this case, with the right zootechnical and genetic approach to breeding Scottish folds, the hard tail of the folds is their "weak link". If the examination reveals a tail that bends badly and clicks when bending, this serves as a basis for reducing the assessment.
7. Angular deformation of the axis of the tail stem (from the penultimate vertebra), detected both palpationally and visually, as well as a node throughout anywhere in the tail, serves as a basis for disqualification of the animal both as an exhibition exhibit and as a breeding producer. The presence of an X-ray confirming that this is not a congenital deformity, but a callus after an injury is not taken into account.
8. Habitual dislocation of one of the tail vertebrae can cause transient angular deformation of the tail. Such an anomaly occurs, although quite rare. When pulling the tail, it "falls into place" with a slight click.
9. The late appearance of the terminal deformity of the tail, which was not determined during the adolescent period of life and in the first adult year of the animal's life. The etiology and pathogenesis of this phenomenon have not been fully studied. It is impossible to exclude the intrauterine influence of damaging factors during the fetal, and not the embryonic period of development of this animal. Probably, there is a unilateral shortening and sclerosis of the ligamentous apparatus of the tail. A joint biochemical and X-ray examination of such animals should be carried out. They usually leave the rings, but actively participate in breeding based on their previous ratings and titles. Given that this pathology is of intrauterine origin, but not genetic (not hereditary), the participation of such animals in breeding is probably justified.
10. The complete absence of a bobtail tail is the basis for disqualification, as is the deformation of the tail vertebrae, leading to the appearance of a fracture or knot.

Wedge-shaped vertebra (semi-vertebra) in dogs and cats

At the same time, it has been shown that a number of tail anomalies can entail a variety of pathological changes.

Willis (1992) points to the occurrence in dogs of such breeds as the Yorkshire Terrier, bulldogs, pug, Boston Terrier of the so-called semi-vertebra, that is, a wedge-shaped vertebra. The nature of the inheritance of this anomaly has not yet been fully clarified, most likely, it has a polygenic basis.

The wedge-shaped vertebra is also described in cats. With this anomaly, the vertebrae acquire a wedge-shaped shape and often fuse together, which leads to curvatures and various thickenings of the tail, often in the form of nodes. Wedge-shaped vertebrae can occur not only in the caudal spine, but also in other departments. This, in turn, can lead to compression of the spinal cord and infringement of the roots of spinal nerves, in some cases causing paralytic phenomena and violation of the trophic innervated organs.

There are several degrees of manifestation of this anomaly:

- some shortening of the tail due to deformation of the last vertebra or several vertebrae;
- a curved movable tail, due to the deformation of one or more vertebrae in different parts of it;
- a shortened hook-shaped or knotted tail, due to deformation and fusion of individual vertebrae.

There are 4 types of genetic anomalies that cause a change in the shape of the tail: crease, fracture, bending and nodulation.

A hall is a form of deformation of the tail, when the next vertebra rises above the previous one (such a deformation is like a step up the "ladder" leading to the tip of the tail). These deformed vertebrae of different sizes have rounded edges.

Kink- this form is the opposite of the previous one. In this case, the vertebrae are arranged as if by "steps of a ladder" leading down to the base of the tail.

Bending is a form of deformation of the tail, when one or more reduced vertebrae seem to have jumped out of the line visually connecting the base of the tail and its tip and passing through the middle of the bodies of the tail vertebrae. The bodies of the popped vertebrae may have the shape of a wedge.

Nodulation. In this form, there is a fusion of two or more altered vertebrae. Externally, it looks like a boa constrictor that swallowed a rabbit.

There is another important point that experts should pay attention to. A differential diagnosis should be made between anomalies in the development of the tail and its traumatic damage. Tail injuries most often occur in puppies extracted from the mother's womb with the use of incorrect delivery techniques. In this case, the X-ray image shows a sharp exit of a group of vertebrae without pathological changes beyond the line, which is visually drawn through the middle of the vertebral bodies.

Tail length

A hall is a form of deformation of the tail, when the next vertebra rises above the previous one (such a deformation is like a step up the "ladder" leading to the tip of the tail). These deformed vertebrae of different sizes have rounded edges. In general, tail deformity is a genetic deformity of individual vertebrae, expressed in the fusion / ossification of two or more vertebrae, or in violation of the relative position of two vertebrae relative to the axis (at an angle from 160 to 175 degrees).

Tail loss is caused by a triple dominant gene mutation, as a result of which the development of protein molecules in the embryo is disrupted and leads to a violation of the bone and cartilage formation of the spine. The cause of tail creases was discovered by geneticists in 1937. The general idea about the causes of the anomaly - tail crease is caused by a triple mutation of genes that lead to crease only if all three occur simultaneously. At the same time, these mutations can also occur separately (one or two) - most often in the same litter where the puppy was born in a crease, or in dogs of close kinship.

A double dominant mutation of genes (two of the three listed above) leads to a violation of the formation of musculoskeletal tissues in embryos and puppies. That is, teeth, joints, various deformities, dysplasia, pathologies of bone development, muscle atrophy, overbites, underbites, etc..

A single dominant gene mutation (one of the three listed above) is lethal and leads to the death of embryos on the 8-10 day of pregnancy, as well as to a decrease in the vitality of newborn puppies and their death

That is, it turns out that the tail area is the VISIBLE presence of semi-lethal recessive genes, which can signal threatening problems to offspring if you tie a bitch and a male with semi-lethal genes. After all, in this case, puppies may be born that will carry not a recessive - semi-lethal gene, but children already with lethal genes. And this, accordingly, is incompatible with life.

Tail crease is a marriage in almost all breeds (except bulldogs, etc.). It often happens that the cause of crease is not only deformed vertebrae immediately at birth, but also uneven tension of the ligaments of the tail, which disfigure the vertebrae after birth.

In practice, the only correct way to check for a tail crease is an X-ray examination of the tail.

There are different types of creases, but in general they can be divided into three groups:

- genetic deformity of individual vertebrae,
- fusion \ ossification of two or more vertebrae,
- disturbed relative position of two vertebrae relative to the axis (at an angle from 160 to 175 degrees).

There are creases in completely different places of the tail, but most often, according to statistics, at the very tip, on the last 2-3 vertebrae.

In practice (as it turns out), very often unwanted creases are eliminated by amputation of a couple of the last vertebrae of the tail. The tail just gets a little shorter, but there are no traces left from the crease.

The topic of tail crease is very relevant for dogs with shortened limbs: dachshund, Pekingese. In one of the magazines "Friend" it was written that chondrodystrophy (or as it is also called – achondroplasia - shortening of limbs), coupled with a tail crease, in most cases lead to discopathy. There is a lot of information in this regard on dachshunds.

The kink is this form, the opposite of the previous one. In this case, the vertebrae are arranged as if by "steps of a ladder" leading down to the base of the tail.

A tail fracture is, of course, an anomaly in the structure of the vertebrae, which usually occurs at an early stage of embryogenesis (approximately in the first quarter of pregnancy). Like many skeletal abnormalities, it can be genetic (hereditarily transmitted), or not hereditary, resulting from spontaneous mutation.

Tail fractures usually have a polygenic (and both + and - polygenes have a great influence on the formation of the trait), autosomal recessive type of inheritance, although some authors indicate a possible incomplete dominant inheritance of this trait.

Of course, various viral diseases (for example, banal adenovirosis suffered by a bitch at the beginning of pregnancy), as well as some medications affect the formation of the fetus, including the formation of its spinal column. Naturally, there may be the appearance of its curvature and changes in the shape of the vertebrae, so to speak, under the influence of teratogens.

Although it is unlikely that under the influence of teratogens, only fractures of the tail stem will occur. Such mutations are usually multiple - in addition to fractures, other skeletal pathologies are observed - cleft lip, palate defects, chest defects, shortening of the spine, vertebral structure defects, splitting of vertebrae, etc.

Now about the physical nature of the break and bend.

A fracture is a sign of a defect in the process of bone formation, it is a violation of the ideal shape of a vertebra, a lack of a piece of bone tissue of some tail vertebra. It's definitely genetics, and it's definitely an autosomal monogen. The tail fracture occurs because the geometry is broken. Well, as a dozen rectangular bricks stacked in a pile retain the shape of a straight vertical column, and if one is somewhere in the middle with a bevel, the geometry of the entire column will be broken.

Tail fractures can have different shapes, from invisible to the eye, to obvious deformations of the tail. Until recently, the problem of the birth of puppies with various tail distortions was underestimated by breeders, because it was believed that the tail "breaks" in the womb. Many breeders still believe that the deformation of the tail occurs as a result of birth or postpartum trauma (for example, "the mother could have unsuccessfully stepped on or pressed the puppy's tail to the wall of the enclosure").

In fact, any tail defect is a consequence of the formation of an incorrect intervertebral space or insufficient development of the vertebrae. It has already been proven that tail deformity is, as a rule, a hereditary defect and dogs with it should not be allowed to breed.

In practice, the only correct way to check for a tail fracture (crease) is an X-ray examination.

S.Jansen-Nullenberg clarifies that tail fractures exist in various forms.

Here are the most common

A noticeable tail fracture immediately after birth, also called Hackenschwanz - tail "hoe";
Often determined later, not visible, but only palpable to the touch fracture of the tail in the form of a small knot, usually at the base or tip of the tail.

The first form of the fracture is inherited recessively, that is, two animals carrying the tail fracture gene (outwardly it is imperceptible) must connect with each other so that the fracture manifests in their kitten. Probably, this form is inherited polygenically. Decisive for inheritance will be how many of the corresponding polygenes are carried by the mated animals themselves and how much they pass on to their offspring.

R. Robinson noted that each polygenetic complex includes plus- and minus-polygens, and this should not be missed. Every conscientious breeding will aim to accumulate one or another type of polygenes in order to approach the ideal in this way. If defects are detected, the corresponding polygenes should be reduced by selection.

Scientific experiments on this subject have not yet been conducted, but it is known from the observations of veterinarians and breeders that if an animal carrying a tail fracture, in which it does not manifest itself externally, mates with a non-carrier animal, that is, a genetically healthy animal, then the descendants will be outwardly normal (healthy). But there is a 50% chance that a recessive gene or certain polygenes of tail abnormalities will be passed on to offspring in the genotype. These kittens then, depending on who they will be paired with, can bring healthy or less healthy offspring in relation to the vertebral column or tail. This means that the defective gene is transmitted through many generations until the mated animal "collides" with an animal that has the same genetic defect in its genotype (in our case, a tail fracture), and only then the fracture will manifest itself externally again. It is incredible that an animal carrying a tail fracture will pass on to all its descendants the gene for this defect, or, if we proceed from polygenic inheritance, all these genes; just like these genes, a cat that is a carrier of a diluent gene (also recessive) will not pass it on to all its children. If there is any doubt, it is possible to make test pairings.

The second form of tail fractures can be either recessive or polygenic. There is no evidence of this from scientific experiments, we are talking only about a thesis based on observations. Presumably, a tangible "nodule" of a cat is formed when each of the animals mated with each other has transferred a certain amount of these polygenes to a kitten.

R.Robinson noted that shortening of the tail is rare. But the tail is often broken or when feeling, you can feel a knot. If the manifestation of this defect is insignificant, it means the following:

1) The reduction of the defect may be irregular and a more accurate definition of damage is difficult or practically impossible;
2) The removal of the defect is prevented by a simple means of selecting the appropriate animals (elimination).

R. Robinson further wrote that the main factor in the spread of the anomaly is the lack of selection. The composition of the breeding stock is small, and the demand for kittens is great (that is, the breeder has a small number of cats or breeds a rare breed, for example, Norwegian forest cats). Therefore, there is a great temptation to include every animal in breeding, including one that should not normally be used for breeding. Thus, defective animals can pass on their vices further, even if there is a good breeding cat. The practice of selling defective kittens to people who promise not to breed with these animals is not a good solution for the future. There are enough examples when a beautiful and frequently used animal with a pedigree becomes known as a carrier of a recessive anomaly and spreads it to the entire breed.

The bend of the tail

Bending is a form of deformation of the tail, when one or more reduced vertebrae seem to have jumped out of the line visually connecting the base of the tail and its tip and passing through the middle of the bodies of the tail vertebrae. The bodies of the popped vertebrae may have the shape of a wedge.

Nodulation of the tail

Nodulation. In this form, there is a fusion of two or more altered vertebrae. Externally, it looks like a boa constrictor that swallowed a rabbit. Often, such a deformity of the vertebrae does not catch the eye, and can only be detected by palpation of the tail.

X-ray diagnostics of tail injuries in dogs and cats

Traumatic damage to the tail of a dog is quite common, especially in the practice of urban amateur dog breeding.

Clinical signs depend on the nature of the injury. When biting the tail, there is bleeding, the dog licks this place hard.

The help consists in treating the wound with a 3% solution of hydrogen peroxide or tincture of iodine with the imposition of a tight bandage that prevents bleeding. Subsequent veterinary examination by a specialist is mandatory, since various inflammatory processes are possible, and only a doctor can warn them.

When the tail is squeezed by the door, the dog squeals, fearfully tucks its tail, trembles with pain, begins to lick the sore spot. The injury site swells quickly. Assistance consists in examining the injured part of the tail. If, with a slight feeling of the tail (the damage is closed), the movement of the fragments of the tail vertebrae is not felt, then you should not worry too much - it will heal. If there are abrasions, they should be lubricated with iodine tincture and give the dog painkillers: analgin, ketophen. After 2-3 days, the pain will disappear, the dog will start wagging his tail.

In case of a tail fracture, urgent veterinary care is needed. But before taking the dog to the veterinarian, she should be given an anesthetic, put a light splint on the broken tail and fix it with a bandage, and only then deliver the dog to a veterinary institution.

A fracture of the tail vertebrae is associated with damage to spinal nerves and blood vessels, with a violation of blood supply and innervation of tissues, trophic ulcers are formed, which are easily infected and difficult to treat. A damaged tail can become a source of chronic infection. Meanwhile, an animal without a tail does not experience any moral or physical suffering. The most common cause of tail separation is an auto injury, when a dog or cat runs away from a car approaching it, but the wheel still runs over its tail.

Clinical cases

Clinical case No. 1

A Maine Coon cat at the age of 1.5 years. X-rays of the tail in a straight and lateral projection revealed a fracture and bending of the tail due to the abnormal development of the last caudal vertebra.

Clinical case No. 2.

Cat. From the anamnesis - "The cat walks sideways somehow, carefully and the tail somehow does not work."

The radiologist's conclusion: "The nature of the general changes is nodulation (local asymmetric thickening of the tail); the cause is spondylodiscitis (narrowing of the intervertebral space, unevenness and fringe of adjacent vertebral surfaces, primarily due to marginal destruction and bone growths); the cause of spondylodiscitis is most likely a history of trauma (mismatch of the long axes of the vertebrae, which indicates subluxation of the distal vertebra); possible outcomes are the formation of bone block; long-existing aseptic inflammation; up to the loss of the tail at this level."

According to the puncture of the formation - aseptic purulent inflammation.

Literature

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