Types of horse teeth and their characteristics. Using age-related variability of teeth to determine the age of a horse What are the pairs of incisors in horses
Stallions and geldings over four years old have forty teeth, which are divided into twelve incisors (four toes, four middle and four margins), twenty-four molars and four canines, which appear only by the age of five. The teeth are equally spaced in both jaws - upper and lower.
Mares have thirty-six teeth because they do not grow canine teeth.
The main technique for determining the age of a horse is to assess the degree of abrasion of the incisors - milk and permanent. (Milk incisors differ from permanent ones in smaller size, shape and greater whiteness.)
A foal up to two years old is sometimes called a coletooth, since by this time he had not yet lost a single tooth.
At two and a half years, milk hooks fall out, permanent ones cut through.
By the age of three, the lower permanent hooks begin to touch the upper ones and rub in. Then the cups are gradually erased.
By the age of three and a half, the middle milk incisors fall out. By the age of four, fangs begin to appear, and the milk edges barely hold or even fall out.
By the age of four and a half, the milky edges are replaced by the permanent ones, which by the age of five are aligned with the rest of the incisors and begin to wear off.
At the age of five, the horse has all teeth permanent, but their cups are unevenly worn.
At the age of six, the cups on the hooks are noticeably worn out lower jaw... In the interval from five to seven years, the cups on the middle incisors of the lower jaw were erased.
At eight years old, the cups on the edges of the lower jaw were erased, at nine - the hooks on upper jaw.
In this case, the chewing surface of the front teeth in horses from one to eight years old has the shape of irregular ovals lying along the jaw and touching each other on small sides.
By the age of ten, the middle incisors are erased, and by the age of eleven, the edges on the upper jaw.
By the age of twelve, the chewing surface of all the incisors of the lower jaw is erased (eaten) so much that it takes an irregular shape tending to rounding.
Age-related changes in horse teeth.
In horses ranging from fourteen to eighteen years old, the teeth take on the shape of almost triangles with rounded edges. By the age of twenty or more, teeth in the form of longitudinal-oval formations are extended across the front edge of the jaw. By the way, in horses eighteen and older, the teeth of both jaws protrude forward, there are large gaps between them.
Correspondence of the age of the horse and the person.
An important feature of the horse's mouth is the presence of a bare gum, which creates a gap between the incisors and molars. It is on the gum free of teeth that the metal bit is placed. By exerting metal pressure on the gums through the reins, the rider controls the horse: collects it, makes it turn in the right direction, does not allow it to be arbitrary.
"They don't look a gift horse in the mouth," says popular wisdom. In short, even if the horse was presented to you is not very good, the donor is only thanked and no complaints are made against him. And yet, from time immemorial, people have tried to look their new horse in the mouth and examine its teeth. Since it is they who are a kind of metric certificate, according to which with high degree the reliability of the specialist determines her age.
Younger than their age, when determining the age by the teeth, horses seem to have especially strong, so-called "resin" teeth, which are very resistant to abrasion.
It is very difficult to determine the age of a horse and up to five years, if it has an incorrect closing: carp or pike teeth.
Carp teeth are when the teeth of the upper jaw move over the lower ones and rub on the lower enamel with the inside.
Pike teeth have a different configuration. Here the lower jaw protrudes forward, the lower teeth rub inwardly over the upper enamel.
Determining the age of a horse by the teeth after twelve years, even experienced specialists cannot always make it accurate, and if there is no metric data, they say about such horses: over twelve years old.
Comparison of the structure of the jaw of a horse and a person
Strong teeth
Their condition is influenced by the breed of the animal, the characteristics of the food and the shape of the bite. Compared to regular horses, blood horses have a harder bone mass, therefore, strong, respectively. teeth too.
If the upper and lower teeth of the horse are positioned incorrectly, erasure will occur unevenly. When grazing, the horse chews on stones and sand along with grass, which increases tooth decay. Therefore, two horses of the same age can have very different teeth.
Horses have 12 incisors and 24 molars. Stallions, unlike mares, have 4 canines. The incisors of the horse's teeth are designed for cutting grass, and the molars are for chewing it, the canines are not involved in the eating process.
Normally, stallions have 40 teeth, and mares have 36. The teeth are located along an arched line, which is called an arcade. There is an upper arcade and a lower one, which is smaller.
Tooth arrangement The dental cavity is filled with mucous tissue with blood vessels and nerves. All the necessary nutrients get into dentin from the blood vessels of the pulp. The root of the tooth is called its hidden part, which is located in the gum of the horse, and the visible corolla. A canal passes through the dental cavity from the root to the corolla.
As the tooth wears off, the enamel begins to push inward and resembles the shape of the bottom of a bottle. Therefore, by sawing off a part of the erased tooth surface, you can see whiter enamel and gray bone substance. The maximum cup depth is achieved only on the upper incisors.
At the bottom of the depression there is cement; after the calyx is rubbed off, it is surrounded by an inner enamel layer and forms a trace of the calyx. The horse's teeth are covered with enamel on the outside, and at the root with cement, which captures the entire crown and calyx.
Erasing teeth In the process of erasing, five layers of the tooth surface can be distinguished:
- internal cement;
- outdoor cement;
- enamel layer adjacent to the inner cement layer;
- enamel layer adjacent to the outer cement layer;
- dentin inside.
Incisors
Of the 6 upper and 6 lower incisors of horses, hooks, edges and middle teeth are distinguished. Two toes are located in the center on both sides of them are the middle ones, and along the edges there are edges.
Distinguish between milk and permanent incisors. Unlike milk teeth, permanent teeth are larger and yellow in color.
In a young horse, the incisors form a semicircle, gradually taking a flat shape in an adult animal and straightening with old age. The position of the upper and lower teeth to each other also changes with age. In a young animal, the jaws resemble ticks, but with age, the incisors protrude forward and are located at an acute angle to each other.
Fangs
Canines in horses grow only in stallions, two at the top and two at the bottom. In mares, in rare cases, they can grow, but they will be poorly developed.
It is impossible to determine the age of a horse by the canines. Ideally, they erupt at 4-5 years old, but this can happen at 2 years old or 8 years old.
Only the erupted canines are pointed, on the side facing the tongue, their surface is rough, and the outside is smooth. At first, the canines are located next to the incisors and facing them, with age they move away and turn away from the front teeth. Internal roughness is gradually smoothed out. The upper canine teeth can wear down to the gums, while the lower canines become longer and dull.
An old horse can be distinguished by the presence of tartar on its tusks.
The horse has 6 upper and 6 lower molars. A toothless gum section separates them from the incisors and canines.
The first three upper and lower molars change, the rest are permanent. The first and second deciduous molars change at 2-3.5 years, and the third at 3.5-4 years.
Horse teeth by year In front of the first molars, called small molars, "tops" grow. These denticles should fall out with the first primary molars, but they may persist until adulthood.
The snaffle bit, which is in the horse's mouth and lies in its toothless part, can abut against the tops and cause pain to the animal.
On the upper jaw, the molars of a horse have cups, on the lower one they are not.
Horse changing and teething
Most often, foals are born toothless. The first baby teeth appear during the first week - these are the hooks. Then the middle teeth grow, and by 9 months - the edges.
The change of deciduous teeth to permanent ones should occur at the age of 5 years. At 1 year old the horse has temporary incisors, then at 2-3 years old the central incisors are replaced by permanent ones. By the age of 4, the middle permanent incisors erupt, and after them the edges. The extreme incisors are the last to change.
Milk fangs in stallions erupt at six months and change at the age of 5 years.
The timing of teething and changing teeth depends on the type of food, the breed of the horse and the personality of the animal.
A horse's teeth, especially with age, require constant care. Bad teeth make it difficult for a horse to chew food properly. Pain to an animal can be caused by:
- teeth growing in the wrong position;
- fragments of knocked out teeth in the gums;
- worn out teeth;
- sore gums or teeth.
Dental problems in a horse can be identified by anxiety of the animal, refusal to eat, irritation. But often the horse gets used to the pain and does not show anxiety. Therefore, it is important to regularly examine the animal's mouth.
A specialist can easily identify dental problems based on the following signs:
- the animal has difficulty chewing food, salivation increases;
- present bad smell from the mouth and nostrils;
- there are undigested food particles in the manure;
- the horse does not listen to the commands of the rider, is nervous;
- swelling of the nose and discharge from it.
The nutrition of horses kept in a stable is different from that of pasture. Uneven erasure of teeth occurs. Sharp ends must be sawed off, otherwise the horse may bite or cut the lip.
In young animals it is necessary to remove in time the “tops” on which the bit can press.
A veterinarian will provide a quality examination and care of the horse's teeth. He uses a special mouth dilator in his work, and restless animals are given a sedative.
Video: Cool teeth
Many have heard the saying “They don’t look a gift horse in the mouth”, but not everyone knows what it means. Let's see what teeth mean in the life of a horse and its owner. How many teeth should a horse have in accordance with the norm? After all, it is by the teeth that you can determine the age and health of a horse, and, based on these data, determine its price.
Looking at the teeth can tell if the horse is having digestive problems. Diseases and abnormalities in the development of the teeth affect the process of chewing food by the horse, which affects its entire health. The horse's teeth serve it not only for chewing food, but also for defense or possible attack.
It is interesting! Stallions have approximately 40 teeth (12 incisors, 24 molars and 4 canines), and mares have 36 teeth (due to the absence of canines).
Features of horse teeth:
- among all herbivores, horses have the most complex teeth;
- the teeth of these equids grow in the alveoli, forming arcs or arcades;
- the body of the tooth itself consists of an invisible part - a root, and a visible part - a corolla (a root with a corolla connects the canal with vessels and nerves);
- in some equids, the dental coating has extraordinary strength - such teeth are taller than ordinary ones and look darker;
- bad habits of the horse also affect the jaw - biting or pampering with the tongue;
- between the incisors and the main teeth, horses normally have a space without teeth;
- as the tooth wears away, the heavy-duty enamel becomes concave like the bottom of a bottle.
It is interesting! Blood steeds have a bone mass that is harder than normal horses, so they have a stronger skeleton and jaw.
During abrasion, dental layers are determined:
- internal and external cement;
- inner and outer enamel;
- dentin (located inside the tooth and makes up 80% of the tooth mass);
- pulp (connecting material, nerve endings, vessels)
- dental cup (surface);
- enamel folds.
It is interesting!The average horse makes 70-80 chewing movements per minute, secreting up to 50 liters of saliva.
The order of changing teeth and their types
Milk teeth in equids appear at the age of 1-2 weeks (sometimes the foals are already born with toothed teeth), and are replaced by molars at the age of 2 to 5 years.
Baby teeth:
- bright snow-white color,
- have a wide scapular crown,
- noticeable neck,
- small size,
- almost no cement,
- uniform surface, very small grooves.
In a horse, teeth are in the stage of growth throughout their life, and as they grow back, they wear off, like in all herbivores. Therefore, the age of horses is determined by the teeth. In order for animals with teeth to be all right, they need to be fed as close as possible to how a horse eats in the wild. She should have plenty of hard fodder: hay and straw. And horses should chew these roughages as long as possible throughout the day. The horse usually eats when he is awake, and he spends only 4 hours a day on sleep. If only compound feed is given, then the horse's calorie needs are, of course, satisfied, but the teeth do not receive the load that they should receive in their natural environment.
Important! Permanent teeth are yellow, larger and rectangular, while milk teeth are bluish-white, wedge-shaped with a pronounced "neck".
Table 1. When different types of teeth change
| Teeth type | When change |
|---|---|
| Incisors - Front | The first to grow. At 2.5 years old, dairy products are replaced with permanent ones. The two teeth in the center are called toes. They capture and cut the feed. They are also used for attack and defense. If the animal is young, its jaws are like ticks, with age they move back. There are 12 incisors in total, 6 each above and below. |
| Premolars - medium | Premolars erupt second, then change. The middle teeth are replaced at 3.5 years of age. They are mainly used for grinding food. Total premolars 6. |
| Edges (molars) - extreme teeth | Appear last. At 6-9 months. At 4.5 years, the top and bottom triplets are replaced by permanent ones. Molars grow indigenous at once. Their function is to grind food. There are 12 of them in total. |
| Fangs | Found exclusively in horses, shown at the age of 5 years, 2 each on the upper and lower jaw. They first appear in the vicinity of the incisors and reach for them, but then gradually turn in the other direction. In exceptional episodes, they appear in mares, but they are poorly developed and quickly fall out. |
Video - How to saw a horse's teeth
Anomalies and defects
The most frequent violation in the formation of the teeth of equids is considered to be pathological and inhomogeneous abrasion.
It is interesting!Anomalies are known when both the milk tooth and the main tooth are present at the same time.
Table 2. Possible problems with teeth
| View | Description | What to do |
|---|---|---|
| Sharp teeth | Sharp edges appear on the top of the tooth, wounding the gums and cheeks of the animal, which causes inflammation and ulcers. The feed also slips off sharp teeth, which prevents its natural chewing. | The sharp edge is cut or chipped off with special tongs. |
| Ladder teeth | In connection with congenital malformations the bones of the skull may cause differences in the density of the teeth, uneven growth in different directions. This makes the chewing surfaces of the teeth uneven, and the chewing process itself is defective. To the extreme degree of abrasion, the tooth is missing to the base, causing painful sensations to the animal. | It is corrected by removing the most protruding teeth. |
| Sawtooth teeth | Outwardly, they are similar to ladder-like ones, but differ in that the grooves are replaced by elevations, each protruding tooth in the upper jaw in a pair comes across a shortened tooth in the lower, and vice versa. This occurs due to the heterogeneous density of the tooth enamel. This abnormality makes it difficult for the horse to chew food and causes digestive problems. | The protruding teeth are cut off by a veterinarian. |
| Scissor teeth | The upper and lower jaws touch only the sides, which does not crush the food, but crumples it. This pathology can be natural, or caused by long-term chewing on one side in the presence of inflammation on the other side. Such an anomaly is unilateral or bilateral. As a result, the cheeks and lips of the horse are injured, the food gets stuck between the teeth. | Sawed with a rasp and shortened with special dental scissors. |
| Progeny (pike teeth) | Shortening of the upper jaw is a natural pathology. The incisors of the lower part move forward and do not contact the upper incisors. This leads to trauma to the lips and mucous membranes. The food is not chewed enough, the teeth are abnormally erased. | The veterinarian cuts off the sharp edges, making it slightly easier for the horse to eat. |
| Prognathia (carp teeth) | The opposite progeny is a natural pathology of the shortened lower jaw. The problems are the same. | The protruding edges are cut. |
| Smooth teeth | Uniform tooth surface without protrusions. This happens in horses in years. The food slips and shreds a little. | Corrected with a special diet made from chopped feed. |
| Extra (arrived, tops) | They can appear at any age before the first permanent teeth. They give the horse discomfort, sometimes even pain. do not have a pair on the opposite jaw. Usually they fall out by themselves along with milk teeth, because they have no alveoli, and they are not tightly connected to the jaw. If a snaffle bit is used, it can push against the extra teeth, causing pain in the horse. | If they do not fall out on their own, they are removed by a veterinarian. |
| Missing teeth | This pathology often does not interfere with the horse's nutrition. | |
| Divergence | The teeth diverge, and a space is created between them, sparse teeth. This pathology is natural, or appears due to a delay in the growth of molars, after the loss of milk teeth. Gaps between teeth make chewing difficult. | Corrected by the timely removal of milk teeth. |
| Convergence | Abnormal approach of the roots of the main teeth. Causes discomfort to the horse when chewing food. | |
| Retention | If the tooth is located instead of the jaw row in the body of the jawbone, this makes it difficult for the horse to chew food. | The tooth is removed. |
| Caries | The hard substance of the teeth falls apart as a result of infection with pathogenic microflora, traumatic injuries, deficiency of vitamins and minerals. | The veterinarian removes a neglected tooth, if not, treats it with a special solution. |
| Pulpitis | The soft tissues of the jaw become inflamed as a result of advanced caries or broken teeth. | Not healthy teeth to be pulled out. |
| Dental calculus | Appears over the years in many living organisms. In advanced situations, the mouth smells foul, the gums are painful. | Chipped off with special tongs. |
| Tumors of dental tissues, foreign bodies | Corrected by deletion. | |
| Cracks and fractures | Are caused by damage. | Removed by a specialist under local anesthesia. The oral cavity is treated antibacterial agents... Cracks are processed with a rasp. |
Video - Removing a canine from a horse
Establishing age from a horse's teeth
IN modern world we focus more on documents when buying a horse, and earlier age a horse literally up to a year, as well as its health was determined exclusively by the teeth.
Throughout its life, the horse's teeth are gradually erased when the feed is rubbed, normally this happens evenly. At birth, foals have depressions on the surface of the incisor called “cups”.
Table 3. How to determine the age of a horse by teeth
| Horse age | Sign |
|---|---|
| 1 year | Hooking grooves disappear |
| 1.5 | Washed on the teeth in the middle |
| 2 | Disappear at the edges |
| 5 | Milk teeth are replaced by molars |
| 6 | The cups of the lower hooks are erased |
| 7 | Cups in the middle at the bottom disappear |
| 8 | No cups on the bottom edges |
| 9 | The cups of the upper hooks are erased. "Jams" of the upper edges are formed |
| 10 | The cups of the middle teeth from above disappear |
| 11 | No cups on top edges |
| From 12 to 16-18 years old | The surface of the tooth changes the shape of an oval to a round one. "Jams" disappear. Sometimes after 15 years "secondary seizures" may appear |
| 18-24 | The chewing surface will become triangular |
| From 24 | Washed back into oval |
Also, the age of the horse is given by "root stars". At 7-9 years old, on the teeth from below, they look like narrow stripes of yellow-brown color, at 10-14 years old they look like oval-shaped stripes, and at 15 they will become round.
If you do not set yourself the task of finding out the age of the horse with the correctness up to a year, and you just need to find out whether a young horse or an old one, you can slightly raise the horse's upper lip and see the angle at which the incisors meet from above and below - the sharper it is, the older the horse is.
Wearing a horse's teeth depends largely on the conditions of keeping in the stable or pasture, on the differences in feed and general care.
Horse Diseases
If you notice that:
- the food you left for the horse is not touched;
- she willingly grabs food, but chews slowly and painfully;
- she drops food while chewing;
- she is losing weight;
- throws his head back;
- produces a lot of saliva;
- she somehow strangely holds her head;
- does not obey the usual commands;
- tries to chew food with only one side;
- she has an unpleasant odor from her mouth;
- swelling of the nose;
- undigested feed is visible in the manure.
In all these cases, you need to urgently show the horse to the veterinarian, who will examine it with a special mouth expander oral cavity animal and carry out the necessary procedures using a sedative or anesthetic for difficult cases.
What a specialist is obliged to inspect:
- External jaw integrity.
- The chewing part of the teeth.
- Labial surface.
- The upper part of the tongue.
- The shape of the teeth, cups.
- Presence of tartar.
What a horse might be concerned about:
- inflammation of the gums;
- inflammation of the tooth surface;
- fragments of injured teeth in the gums;
- abnormally growing jaws with sharp edges;
- badly worn teeth.
As with humans, caries is considered the most common dental disease in horses. At first, a small dark speck forms, and then grows into a large hole, the tooth breaks. Therefore, it is necessary to identify and treat the incipient caries with special preparations in time, and if it is started, remove the tooth under the supervision of a specialist.
Important! Most often, caries is located on the upper molars, on the lower ones - less often. Almost never occurs on the incisors.
Horse teeth brushing - step by step instructions
Step 1
The horse's mouth is opened with the hands or a special instrument called a yawner. Secure with a special lock.
Step 2
The veterinarian's assistant fixes the horse's head and moves his tongue to the side.
Teeth cleaning
Prevention of horse dental diseases
For a horse to have healthy teeth, simple rules must be followed:
- Regular veterinary examination (2 times a year).
- Timely filing of the sharp edge of the teeth and restoration of symmetry and balance (this procedure is completely painless for the horse).
- Treatment of teeth with a special solution for the prevention of caries.
- Timely removal of milk teeth that did not fall out on time.
- Removal of wolf teeth.
The ancient Greeks knew how to determine the age of a horse by teeth. So, Aristotle (384-322) in his book "History of Animals" (vol. VI, ch. 22) indicates that a horse at 2 1/2 years old changes its front incisors (two at the top and two at the bottom), a year after this - the middle incisors and a year later - the extreme. Aristotle quite correctly notes that it is possible to accurately determine the age of a horse only during the period of replacement of milk teeth with permanent ones.
In horses, we distinguish between incisors and molars. There is a free space between the incisors and molars in the form of the so-called toothless edge. The horse has 12 incisors: 6 on the upper and 6 on the lower jaw and 24 molars - 6 on each side of the upper and lower jaw. Stallions also have 4 canines, one on each side of the upper and lower jaw. In total, stallions, therefore, have 40 teeth, and mares have 36.
The age of a horse is determined by the incisors and partly by the canines. The molars also change with age, but they are rarely used for age determination due to the difficulty of examination.
The six incisors of the upper and lower jaw are subdivided into hooks, middle and margins.
To determine age, five periods of changes in the dental system are used:
1) eruption of milk incisors;
2) erasure of milk incisors;
3) eruption of permanent incisors;
4) erasure of the cup of permanent incisors;
5) change in the shape of the rubbing surface of the permanent incisors. Milk teeth are smaller than permanent ones (about half), whiter, they have a "neck", which makes them look like a spatula.
In the future, the age of the horse is determined mainly by the erasure of the cup and the change in the rubbing surface of the teeth.
When determining the age in the fourth period, the main attention should be paid to the calyx - a funnel-shaped depression inside the enamel layer. The depth of the cup of the lower incisors is 6 mm, and the depth of the upper ones is 12 mm. Each year, the tooth wears off by about 2 mm. At the same time, the hooks begin to wear off a year earlier than average, and the edges - a year later than average.
A foal is usually born without teeth. Milk hooks are cut during the first two weeks of his life, with the upper ones sometimes cutting before the lower ones. The middle incisors erupt at about one month of age, and the milky edges at 6-7 months. The calyx on the milk hooks of the lower jaw wears out at the age of about 10-12 months, on the middle ones - about 12-14 months and on the outskirts - in the period from 15 to 24 months of the foal's life.
At 2 1/2 years, the foal loses its milk hooks and erupts permanent ones. By the age of three, these teeth have grown and their anterior and posterior edges are aligned. At three and a half years, the milk middle incisors fall out and the permanent ones cut through, which grow and level out by the age of four. At four and a half years, the milk edges fall out and the permanent ones cut through, which grow by the age of five.
The teething time of deciduous and permanent teeth may vary slightly depending on the breed of the horse, its individual characteristics and growing conditions. In horses of late maturing breeds and underdeveloped ones, teething is somewhat delayed.
On the incisors of the lower jaw, the calyx is erased in three years; it means that on the hooks it is erased by the age of six years of the horse's life, on the middle - by seven years and on the edges - by eight years. On the upper incisors, the calyx is twice as deep, that is, 12 mm. Therefore, on the toes of the upper jaw, the cup is erased by the age of 9, on the middle - by ten, and on the edges - by eleven. When determining the age of a horse during this period, the lower incisors are first examined and if the cups are already worn out on all the teeth, then the upper incisors are examined.
It should be borne in mind that the degree of tooth wear and, accordingly, the disappearance of the cup depends on the nature of the food and the strength of the teeth, which in turn depends on the individual characteristics of the horse. Deviations from the above diagram of the timing of the disappearance of the cup on the teeth also depend on fluctuations in the depth of the cup, which does not always exactly correspond to 6 mm on the lower jaw and 12 mm on the upper jaw. On the edges, the calyx is deeper than on the toes and middle ones, so the erasure of the cup on the edges may be delayed. Deviations in the depth of the calyx and the timing of its wear on the upper jaw are especially frequent. On the upper jaw, quite often the depth of the calyx exceeds 12 mm, hence, in order to avoid mistakes, it is necessary to be guided not only by one sign of erasure of the calyx, but to take into account everything that can indicate the age of the horse.
As they are erased, the incisors change the shape of the rubbing surface. If you saw the incisor tooth of a 6-year-old horse under a rubbing surface, then the cutting plane will be oval, with a cut below it - more rounded, with a cut even lower - triangular and even lower - elongated in the longitudinal direction (approaching the reverse oval shape). Roughly the same is observed with natural abrasion of the incisors.
Prof. P.N.Kuleshov and A.S. Krasnikov give the following table of changes in the shape of the rubbing surface of the incisors of the lower jaw with the age of the horse:
After the incisor cup has worn off, a "cup trace" remains, slightly rising above the rubbing surface of the tooth. As the tooth wears off, the trace of the oval cup becomes rounded, decreases in size and approaches the posterior edge of the tooth more and more. Observations show that the calyx mark disappears on the incisors of the lower jaw: on the toes - at 13 years old, on the middle ones - at 14 years old, and on the edges - at 15 years old.
As the tooth is erased, a dentin-filled root canal is shown. The dentin filling the root canal is less hard than the underlying dentin of the tooth. Absorbing dyes, the surface of the root canal first takes on a yellow, and then brown and black color, forming a colored stain on the rubbing tooth surface.
This spot is called the "root asterisk". The root asterisk can be seen on a horse from 8-9 years old. At this age, it is a yellow strip elongated along the front edge of the tooth (in front of the calyx mark). Gradually, as the horse ages, the root sprocket becomes darker, shorter in width and moves to the center of the rubbing surface of the tooth.
Here is the change in the shape of the root asterisk according to P.N.Kuleshov and A.S. Krasnikov:
7-10 years old - striped;
10-12 years old - made short and wide;
13-14 years old - takes an oval shape;
15-16 years old - it is made round and is located almost in the middle of the rubbing surface.
The root sprocket becomes round when the calyx mark disappears. It lasts until the end of the horse's life.
The root asterisk should not be confused with the calyx trace. The footprint of the cup always rises above the rubbing surface of the tooth and is located closer to the posterior edge of the tooth.
In a young horse, the incisors of the upper and lower jaw join together to form a semicircle. Gradually, as the horse ages, the dental arcades close more and more obliquely. In older horses, there is also incomplete closure of the upper and lower incisors.
Canine teeth in stallions erupt at 4 1/2 years and they grow by 5 years. Fangs on the lower jaw appear 2-3 months earlier than on the upper.
When determining the age of horses using this table, the following possible violations in the stated patterns must be taken into account.
1. In pregnant mares, teeth change may be delayed by about 6-12 months.
2. Dry and warm climates can speed up tooth change.
3. Coarse food can accelerate the erasure of teeth, which is often observed in horses with herd keeping (grazing on coarse-stemmed vegetation).
4. An individual feature in the structure of dentin can change the patterns of tooth abrasion, delaying or accelerating it (resinous teeth, rapidly wearing away teeth) *.
* (To determine the age of the teeth in cases where there is a rapid or delayed erasure of teeth, you can use the following indicative data: a) normal permanent teeth have a length from the gums: hooks - 18 mm; medium - 15 mm and edges - 13 mm; b) according to the signs on the teeth, age is determined and, if the teeth are resinous, then the difference in millimeters between the actual length and the normal one is added to the age determined by the teeth; if the teeth wear out quickly, then the difference between the normal length of the tooth and the actual length is subtracted from the age determined by the teeth. This will be approximately the number of years of the given horse.)
Horse health and performance directly depend on feeding, and not only on the quality of feed and a balanced diet, but also on proper work digestive system, including the condition of the teeth. This means that you should pay attention to the teeth of a horse not only in order to determine its age.
Poor dental health can be so distressing to a horse that it can lead to loss of appetite, malfunction and stomach problems. To avoid serious problems, more attention should be paid to signs indicating certain dental pathologies.
In what cases should the cause be found in the teeth? Various dental anomalies and diseases are primarily reflected in the chewing process. A sick animal will willingly grab the offered food, but chews it slowly, lateral movements of the jaws are hesitant and often uneven. The latter sign can indicate on which side of one of the jaws to look for the affected area.
In the literature, interesting observations have been recorded of how horses suffering from dental diseases eat one or another food. So, when horses offer hay, she at first greedily begins to grab it and chew it. But since chewing is difficult, the horse cannot swallow the grasped tuft, and it falls out of the mouth. The first unsuccessful attempt does not stop the animal, and the horse again takes the hay, tries to chew it and drops it back. This can be repeated several times until the horse gets tired and loses interest in the feed. If horses offer oats, they dig for a long time in the trough, and then begin to swallow oats in large portions, not chewing enough.
If in the morning a horse leaves food that has not been eaten in the trough (at a constant rate), if you notice a violation of chewing movements, bad breath, or during work the horse does not normally hold his head to the side, behaves restlessly, tries to get rid of the bit - all this should become reason for examining the oral cavity and dental health. Often, when viewed in the oral cavity, food debris is noticeable, under the influence of microflora acquiring a greenish color and an unpleasant odor, the cheek pocket on one side can be filled with poorly chewed food mass. In this case, it is necessary to clean the oral cavity from feed residues and only then carry out a detailed inspection.
How many teeth does a horse have?
In horses, incisors and molars are distinguished: incisors - 12 (6 - on the upper and 6 - on the lower jaw), 24 molars (6 each - on the lower and upper jaw, watch the side). In addition, stallions have 4 canines; mares have no canines. As a result, stallions should normally have 46 teeth, and mares should have 36 teeth.
Anomalies in the development of teeth
Most often, horses have abnormal erasure of teeth, in which they take several forms: sharp, ladder-like, sawtooth and scissor-like (in some sources, there are many more forms of abnormal tooth erasure).
Uneven erasure of the chewing surface of the molars of the upper and lower jaw is due, among others, to congenital anatomical features. In this case, we get sharp teethwhen on the outer surface upper teeth and sharp edges are formed on the inner surface of the lower teeth. The sharp edges of the upper teeth injure the gums, the sharp edges of the lower teeth injure the tongue, palate, and cheek mucosa. When examining a horse with such a pathology, wounds and even ulcers can be found on the mucous membrane of the cheeks, tongue, gums, if the horse has been left unattended for a long time. At the same time, the horse experiences additional difficulties when chewing, since the food easily slides off the too inclined surface of the tooth. With the formation of sharp teeth of a horse, cutting down sharp edges will help, which is better to entrust to a specialist.
Due to the different density of the teeth or the force of impact along the length of the arcade, a stair-like or sawtooth erasure of teeth is formed, when the chewing surfaces form a number of steps, and individual teeth can stand obliquely and incorrectly, at an angle to each other. In extreme cases of pathology, the middle teeth of the lower jaw can be worn down to the level of the alveoli, so that the horse experiences severe pain and unable to eat roughage.
Excessive oblique abrasion of the chewing surfaces of the upper and lower jaws leads to the fact that the teeth begin to touch not with the chewing surfaces, but with the lateral surfaces. Most often this occurs due to the congenital asymmetry of the bones of the skull, in particular the narrow lower jaw. In the literature there is such a description of the extreme degree of this pathology: “the chewing surfaces of the teeth on the right side on both jaws are so strongly beveled that the dental arcades are parallel to each other and intersect like scissors. As a result, the chewing surfaces of the upper and lower teeth could no longer touch each other, but the teeth continued to grow, and the lower jaws, with the sharp edges of their teeth, began to touch the upper palate and injure it. " In such cases, the horse can be helped by chipping the most protruding teeth, which again is best left to a specialist.
Among the anomalies of the teeth recorded in horses, there are many curious cases. These include congenital malformation of the jaws, in fact, the curvature of the bones of the skull. It is interesting that with such a deformity, horses are able to live long and safely. An observation of an Arab stallion was recorded, which was born with a similar deformity, lived safely for 26 years, produced 19 foals, of which only one inherited the deformity from his father.
It is not uncommon for horses to have over-completeness of teeth (in other words, extra teeth). Recall that stallions normally have 40 teeth, mares - 36. abnormal development there may be more teeth. A case was recorded when a stallion had a double number of incisors - 12 at the top and at the bottom.
In the literature, the opposite phenomenon was also recorded: lack of teeth, and this meant congenital cases of missing teeth, which, apparently, are genetically inherited traits. As an example, a horse is cited, which completely lacked the incisors on the upper jaw. At the same time, she was alive and well, only ate food like a cow.
There are many examples of finding various tumors of hard tissues of teeth, sometimes reaching impressive sizes. This is how tumors weighing 700 grams and even 1 kilogram are described.
Finally, there are known cases of extractions foreign bodies from the teeth or the space between the teeth. The most common foreign bodies are nails or pieces of wood.
Disorder of changing teeth
The change of deciduous teeth to molars in horses is often delayed at the age of 2 to 5 years. There are known cases of delayed change of teeth up to 15 years of age. The milk tooth can be abnormally rotated, tilted to one side or the other, but at the same time be in its place. In this case, the tooth becomes mobile when chewing and causes pain to the horse; food residues get between the tooth and the gum, which stale and can cause inflammation.
Often horses have both a milk and a molar of the same name at the same time. In such cases, the erupting molar can change its normal position in relation to the gum. There are many examples of such phenomena in the literature. So in a four-year-old foal, a permanent incisor on the lower jaw was described, which grew horizontally forward and permanently injured the lower lip. Or, as an example, a three-year-old mare in which one of the incisors of the lower jaw grew 4 mm behind the dental ridge and severely injured the tongue, so that the horse could hardly eat. In all cases of delay in the change of milk teeth, the latter must be removed under the supervision of a specialist.
Diseases of the teeth
Of the diseases of the teeth of horses, caries (the trivial name "caries") takes the first place. By analogy with "human" caries, at first a small gray or brown speck, soon blackening, appears, in place of which the hard tooth tissue decays and a minor defect appears. Having barely begun, the pathological process progresses rapidly, destroying the tooth tissue. Subsequently, a deep cavity is formed, colored black or brown, filled with food residues.
According to some reports, caries is more likely to affect the upper molars, less often the lower and, extremely rarely, the incisors. With large volumes of carious cavities, the tooth may split, and a dental fistula may also form.
With caries, a horse has difficulty chewing, profuse salivation, and bad breath.
When assisting an animal, depending on the severity of the lesion, the diseased tooth is either removed or the carious cavity is treated with appropriate drugs as prescribed by the doctor.