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The pathology of the locomotor apparatus in the horse is a good part of the work that the clinical veterinarian specialist do and has become increasingly important when it comes to racing. Given that the center of gravity is displaced cranially in horses, around 65% of the weight of the animals forelegs support it and is therefore around 85% of total lameness that will affect the earlier train. Of this percentage that can be seen , 70% will be due to lameness affecting the structures contained in the hoof. It is therefore an anatomical region of great importance that requires sport medicines.
The hoof is a continuation of the epidermis of the coronet. At this point the dermis of the skin is continued with the dermis (corium) of the hoof, in this region where the hoof is located it is called the perioplic corium, coronary, laminar (or lamellar) of the frog and solar corium .
The hoof protects the internal structures and acts by dispelling the impact produced when hitting the ground during movement. The solar surface of the hoof on the legs is wider than in the later, reflecting the difference in shape of the distal surface of the third phalanx.
The exploration of the hoof should start with a simple inspection that will allow us to determine its shape, size and location relative to the axis of the limb (poise). Thus we can value any tupe of injury such as wounds, quarter cracks, foreign bodies, Palpation is important in determining the presence of increased temperature reflecting in inflammatory processes. Palpation also helps to explore the coronary border of the heel region.
The application of pressure (used for this exploration we use hoof testing forceps that allows us to locate delimit or trigger points within the hoof. The foreceps are also used to strike the top of the wall and sole to determine sensitivity.
Of all the additional screening tests the most widely used are conduction anesthetics, intraarticular anesthesia and radiology.
We begin first by using neuro blocks in small regions to diagnose the lateral branches and the medial palm digital nerve (or sole). Within moments it determines the height of the heels or pastern and finally half the height of the proximal sesamoid (abaxial). Just like intraarticular blocks in the region of the hoof anastesia is used in the interphalangeal articular joint and in specific cases we anesthetize the Podotrochlear apparatus.
Appropriate Radiographic views used depending on these cases are:
-View LM
-Palmarodistal dorsoproximal-oblique view 65 °
-Palmarodistal palmaroproximal oblique view (sky line)
-Palmaromedial Dorsolateral oblique 65 º
-Palmarolateral dorsomedial oblique 65 º
*Other tests that currently apply to the diagnosis of the condition of the hoof are ultrasound, scintigraphy, magnetic resonance imaging and arthroscopy.
CORONITIS
Inflammation of the coronary band is usually the result of a systemic disease. It occurs infrequently and usually accompanies febrile processes or laminitis boxes.
Symptoms and Diagnosis
- Normally it usually affects two or more hooves, showing initial inflammation of the coronary band with production of exudate and pain.
- During a period of 7-14 days it can produce a complete separation of the hoof wall of the coronary band.
Differential Diagnosis
- Subsolar abscesses
- Laminitis
- Pedal bone fractures
- Septic arthritis of the distal interphalangeal joint
Treatment
It reduces the use of NSAIDs phenylbutazone and
flunixin meglumine types, but with poor results in most cases. In horses that are recovered are often left with permanent changes in the growth of the hoof, making it poor to prognostic.
SUBSOLAR HEMATOMA
It is a relatively common cause of lameness in horses and occurs in all animals that are overworked on rough terrain. Direct trauma causes bleeding into the palm between sensitive and non sensitive plates of the hoof. When it affects the heels in the area between the bars and heels it is often called a "corn". Some horses are predisposed especially in the case of flat palms and low heels. It is also typical of animals with secondary pedal bone rotation to pedal osteitis.
In horses that have flat soles (palmitiesos) it is difficult to place the shoe without compressing too much of the palm, which compromises blood flow in certain areas and therefore predisposes to the formation of hematomas. In horses in which the growth of the heels is almost parallel to the ground it is often that callus formation occurs.
Symptomatology
-Mild limp and chronic forelimbs
-Tendency to decline in jumping to avoid pressure
-Sometimes the lameness is severe
Diagnosis
In most cases lameness is bilateral but may be more intense at one end. Hoof examination usually shows alterations of poise with the support of the shoe inside the white line. Note that in horses with depigmented hooves are often seen during the quarter cut the presence of small hematomas without lameness. The pressure test is usually positive when tested with forceps.
Differential Diagnosis
-Subsolar abscesses
-Navicular disease
-Pedal bone fractures
-Pedal osteitis
Treatment
The application of closed shoes ("mouth of jar/egg bar") in horses with "corns" tends to improve the clinical support distributed throughout the hoof. Sometimes when there is a collapse of the heels you can proceed by reconstruction of the heel with a synthetic resin. For subsolares hematoma of the palm it is useful to apply an astringent dressing "empuchada" and systemic NSAID administration for 5-7 days which is the average time for recovery, keeping the horse at rest.
SUBSOLAR ABSCESSES
Probably the major cause of acute lameness in the horse. Its due to the colonization of pathogens in different hoof structures either because of cracks in it, subsolar hematomas or penetrating wounds. Due to the anaerobic conditions that occur in the hoof it is usual to find different species of Clostridium and therefore in any of these cases it is necessary to treat prophylactic with a tetanus serum.
Symptomatology
-Acute lameness associated with exercise
-The horse is not to support its weight on the affected limb
-Heat and increased palmar digital pulse at the beginning
-After 24-48 hours it may appear swollen in the area of the pastern.
-If not treated tend to seek out the softest area of the hoof in the coronary border, where drained.
-The pressure testing forceps in some cases will allow us to locate the abscess (especially in chronic cases).
Diagnosis
The horse will improve lameness with a abaxial block. Radiographs are an indicated routine LM and DP, as in some cases allows the location of the abscess and primarily to rule out other pathologies.
Differential Diagnosis
-Pedal bone fractures
-Navicular infection of the sac or the sheath of the deep flexor
-Laminitis
-Subsolar hematoma
-Fractures of the navicular bone.
Treatment
Where drainage has occurred through the coronary border, it is sufficient to clean the wound topically. In more severe cases: Following the application of a tetanus protector you locate the area of abscess using exploration foreceps and proceed to the curettage of the same area until you find pus. The affected area should be scraped and a protective bandage placed around
the hoof, it should be changed every 48 hours for 6 days, after which we proceed by shoeing the animal. Apply also an anti-inflammatory therapy. The administration of systemic antibiotic therapy is not useful because the infection is located in some of the irrigated areas of the hoof.
QUARTERS
These cracks/wounds or wall cap are usually the result of excessive dryness and weakening of the wall and hooves that are too long. Those that occur at this level of the toes are often accompanied by separation of the wall of the sensitive film. They are usually longitudinal. When they cross they are spoken of as "frowns". These are typical causes of direct trauma to the coronary band which will leave a wound that accompanies every quarter growth. The turn may have longitudinal growth of distal to proximal (most common) or from proximal to distal (especially in cases of damage to the coronary band).
Etiology
-Injuries
-Poor hoof care
-Laminitis
-Excessive humidity followed by dry conditions (grass)
Symptoms and Diagnosis
The diagnosis is a logically simple visual inspection and in most cases are not accompanied by the lameness table. In cases involving deeper structures and hence sensitive to the wall, lameness will vary from moderate to severe if infection occurs as well. It is important to assess the shape of the hoof and poise that especially predisposes bad quarters in the area of the quarters and heels.
Differential Diagnosis
-Subsolar abscesses
-Subsolar hematoma
Treatment
Any treatment must be accompanied by adequate rehydration of the hoof and corrective shoeing if necessary (to correct the aplomb). Hoof oil should be used on the hooves 2-3 times per week to maintain the elasticity of it. Reactive ointments applied around the coronary band (CORNUCRESCIN) are useful for growth in weak hooves and dietary supplement products based on biotin and methionine. Given that the average growth of the hooves are 1 cm per month, any quarter with a certain rest period will be solved. However, due to the pressure logic of the owners and disadvantages of keeping the horse idle/stopped there are often different techniques used for fixing them:
1 .- In mild cases when the quarter is superficial and with distoproximal growth its enough to limit the same growth with a transversal cut on the end. Together they make a reduction in the palm to the height of the quarter to avoid pressure on the horseshoe.
2 .- In case of quarters longer and/or deeper proceed fixing them with a wire and/or synthetic resin that maintains the horse stabilized during normal exercise. Do not use these resins in areas near the border because they produce coronary burn.
3 .- In cases where traumatic injury occurs at the coronary band it will always need to rest for approximately 1 month to allow the growth of the cornea.
4 .- The use of pitcher box horseshoes (egg bar horseshoes) aid in the immobilization of the wall and both the quarters and frowns.
The frowns in most cases do not require any fixing.
DISTAL PHALANX FRACTURES
These fractures are more typical in sport horses and especially in harness breeds and pleasure horses than in thoroughbreds. It mostly affects the lateral wing of the coffin bone (fracture type I) and others become intra-articular (type II).
Symptoms
The cause is always a direct trauma. Immediately after exercise the horse appears with acute lameness, then after a while begins by not putting weight on the affected hand or foot. In cases where the fracture is intraarticular, lameness will improve after 2-3 days of rest in the box, while if the fracture is not articulate the improvement will be considerably longer. Heat often appears in the hoof and increased digital arterial pulse. Pressure testing with forceps in the affected area will be positive in most cases. Occasionally there will be pain when striking the hoof.
Diagnosis
Requires neuro blockers and radiological study. Some fractures in difficult locations or small size require tests such as scintigraphy and magnetic resonance imaging.
Abaxial blocking the palmar digital nerve branches is positive, but in some cases the improvement that can be observed is 60-70%. The radiological study requires dorsopalmar view, medial lateral, dorsolateral palmaromedial oblique and dorsomedial palmarolateral oblique. In X-ray negative cases it should be repeated after 10-14 days until the analysis allows us to see the fracture line.
Differential Diagnosis
-Fractures of other phalanges
-Subsolar abscesses
-Infection of the navicular bag
-Fractures of the navicular bone
Treatment
It requires a rest period of between 6 and 12 months. In the case of non-articular fractures, after three months of rest in the box, the horse can move to a small enclosure to complete the recovery time. In any case it becomes necessary to place a closed
horseshoe with tabs on the quarter to prevent the expansion of the hoof and thus immobilizing the pedal bone as possible.
In the case of joint fractures in horses three years old and older we recommend internal fixation with a screw, which in many cases and after the rest period must be removed because it causes irritation of the sensitive film. The most common complication in cases of osteomyelitis fixation is to obtain adequate preoperative asepsis of the hoof.
FRACTURES OF THE EXTENSOR PROCCES
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Also called type IV fractures of the distal phalanx and may or may not affect the insertion of the common digital ligament extensor. It should be distinguished from the secondary ossification centers that can be seen in some horses that do not limp.
Normally they produce medium-grade lameness after exercise, which can become chronic. The digital flexing test is usually positive and thickening may appear in the dorsal portion of the coronary border. This latter phenomenon is more typical in chronic cases of fracture of the zygomatic (supraorbital) process, which leads to the disease that is presented with a mild chronic pyramidal lameness and changes in the growth pattern of the dorsal wall.
Diagnosis
Confirmatory diagnosis is made by block anesthesia of the abaxial and distal interphalangeal joint and the realization of a LM radiograph in this area to demonstrate the presence of the fracture.
Differential Diagnosis
-Soft tissue swelling
-Osteoarthritis of the distal interphalangeal joint
Treatment
Fractures that result in small fragments can be treated arthroscopically to remove them and value the possible presence of degenerative changes in the dorsal aspect of the joint. Large fragments in most cases require surgical fixation. In both cases as a secondary result it usually develops osteoarthritis, so the prognosis is poor.
PASTERN DERMATITIS
Commonly called "thrush", is a seborrheic dermatitis that affects the palmar portion of the pastern and fetlock and sometimes the third distal of the cane. It's considered a trigger to the same continuous presence of moisture and shod horses are predisposed to this condition. After development it is often complicated by the appearance of organisms such as Dermatophilus, Staphylococcus spp and fungi.
Symptoms and diagnosis
- It is observed in the initial stages a moderate dermatitis with inflammation of the palmar region of the pastern.
- After some time there is secretion and formation of exudate and infection that can lead to moderate lameness. Exudates dry out and produce the formations of scabs and excoriations.
- Differential diagnosis must be explored by palpation and with an allergic dermatitis treatment.
Treatment
It is important to keep the infected area dry and clipped. By local cleaning of the affected area and applying an antibiotic ointment and an anti-inflammatory is usually a sufficient solution to the disease, although in more complicated cases it may require a systemic administration of an antibiotic therapy.
NAVICULAR SYNDROME
INTRODUCTION
Navicular disease is one of the most common causes of chronic and intermittent lameness of the forelimbs of the horse. Since 1752 it was described as such by Jeremiah Bridges, many researchers have tried to uncover the intricate etiopathogenic mechanism that causes it. The results to date, although not definitive, offers signs of hope for a full understanding of the short to medium term disease.
Anatomy
The distal sesamoid or navicular bone is a bone that changes the direction of the deep digital flexor tendon (FDP) passing for insertion into the distal phalanx or coffin bone. Presents a proximal border and distal with holes for the passage of nutrients in the small vessels, as in either the medial border or lateral. The articular surface has two depressions for articulation with the distal articular surface of the middle phalanx or coronet. The flexor surface is characterized by the presence of a bursa that connects to the same borders with the borders of the opposite surface of the FDP. It produces synovial fluid, which reduces the friction between these two structures.
The distal border is characterized by the development of synovial invaginations to form synovial conformations. Bone density is uniform, radiation gives the appearance of increased density in this area due to the increase in thickness to the sagittal border.
Etiology
Because the term disease implies a specific cause, the term of navicular syndrome best describes the complex etiological and pathogenetic mechanisms producing clinical signs associated with the navicular bone.
This term should be reserved to the bilateral and chronic lameness of the forelimbs, for which, it follows a specific diagnostic criterion, however, and once clarified at this point, the disease of the navicular will be more talked about due to its more widespread use.
Some predisposing factors for this disease include inadequate conformation and faulty shoeing practices, which can create abnormal forces in the region of the hoof. In the case of too low heels (underrun-heels) or too long toes or either a mixture of both, excessive pressure of the FDP on the surface of the navicular flexora can occur. For some authors, these conformations could be by themselves the cause of the disease; It is also common to find this process in the case of too small hooves in relation to body mass.
The excessive bruising of the hoof on hard, irregular surfaces also appears to predispose: However, highlighting that the navicular bone is very well protected from it by these ligaments (proximal, distal and laterally), and palmarly supported by the FDP. On the other hand the disease also occurs in young horses who have been subjected to minimum stress.
The theory that was most widely accepted was that this disease is due in large part to poor circulation. The experimental occlusion of the navicular arteries and its branches results in arteriographic images and histologically compatible with navicular disease.
The blood contribution of the navicular bone of a healthy adult horse has a specific pattern characterized by the presence of 4-8 distal arteries by supplying the central portions and the distal of the bone, and 9-14 proximal arterials covering the same proximal portion; for its part, the lateral and medial portions receiving their own blood contribution.
Some causes of ischemia of the navicular bone are partial or total occlusion of the digital arteries, the blood obstruction associated with atherosclerosis, or thrombosis of the arteries of the navicular and resulting in venous congestion.
PATHOGENESIS
There are many proposed theories to explain the pathogenesis of the disease, to facilitate their understanding it is therefore preferable by discussing them in relation to injuries associated with it:
Proximal border: they can produce enthesophytes along the insertion of the suspensor ligaments of the navicular and osteophytes less frequently along the proximal border. These lesions should be torn at the distal interfalangiana joint or have conformation defects that would lead to an excessive rotation movement of the navicular bone on its major axis. After receiving a response from the initial inflammatory it is believed that both the enthesophytes and the osteophytes do not produce an alteration of the function, although it may predispose to the development of intermittent lameness to a mild limp.
Distal border: is characterized by the presence of nutrient holes and fossae. The fossae are conducted by introversion of the synovial membrane in the nutrient hole (foramen), in such a way that produces a widening of the channel containing the artery. The increased size of a hole with the consequent formation of a massive fossa, gives place to a classic radiation image of the disease, ex: in the form of a "lollipop". These fossae vary considerably in size, shape and depth of penetration into the bone and the 1st of the same origin are found in the synovitis of the distal interphalangeal joint. They can be found in the absence of typical symptoms of this disease so its diagnostic significance is doubtful.
Flexor surface: occasionally shows changes consistent with loss of the structure of the Fibrocartilage. Certain erosions diffuses itself, which are less exposed to the subcondral bone, may be secondary to bursitis/synovitis caused by inflammation of the FDP in its path by the navicular bone. Frequently appears also are; adhesions between the navicular and the FDP, as well as osteitis and ossification of ligaments of the navicular with odd ligament suspensores. This theory, which is believed that this disease would begin in the tendon had great acceptance in the past and still today there are authors who are investigating it accordingly.
The bone structure: is common to find areas of less opacity to "cysts" mode. Its etiology is unknown at the moment and they are only considered within the navicular disease when they are associated with the sagittal border of the bone.
Symptoms and diagnosis
Horses generally display a history of lameness of the forelimbs, progressive, chronic, uni or bilateral and insidious onset. This disease is usually bilateral, but the lameness may show as unilateral.
Observing the animal at pace or trot, shows that it tends to rest on the area of the toes. However in cases where there is a secondary damage of the FDP, the animal tends to rest on the heels, which is typical of laminitis with rotation of the distal phalanx; in the event that this happens with the navicular disease one should suspect that the tendon is severely damaged.
When the animal is trotting in circles there is an intensification of the limp, which in this spectacular case compels it to make sharp turns.
Hoof exploration forceps should be used systematically to assess pain in the area of projection of the navicular. For this test use one of the branches of the forcep in the groove of the frog and the other in the quarter contrary, applying pressure; subsequently repeating the test from the opposite groove and ultimately performing pressure covering both heels. Sometimes what happens is that the animal begins to show pain when pressure is applied with the clamps over the area of the toes, which is due to that, as mentioned above, animals with navicular disease tend to rest their weight on their toes, thus suffering greater wear.
Another complementary test involves forcing the animal to tread on an object with the frog during approximately a minute, then observing the response to trot: in some cases there is an increase of the lameness.
The anesthetic blocking of the palmar digital, lateral and medial nerves at the middle level of the pastern and more selectively at the heels has always had a positive result, unless the disease is associated with a pathogen in the interphalangeal distal joint, or either the technique has been improperly performed. It is important to use a minimal amount of anesthetics (1-2 cc), in order to avoid the dorsal branches of the nerve.
Once these tests have been carried out a radiological examination proceeds, which must include the following projections of the region of the hoof:
- Dorsoproximal - Palmarodistal oblique( 60ª)
- Palmaroproximal - Palmarodistal oblique( 45º)
- Dorsolateral - Palmaromedial oblique
- Dorsomedial - Palmaro Lateral oblique
- Lateromedial
It is important priorto proceeding to the cleaning and curetting of the frog, covering the sulci and the central lagoon with a moldeable material (ex:plasticine); in order to avoid possible artifacts in the film.
Some radiological images compatible with the navicular disease are:
Projection dorsopalmar:
-central area of osteoporosis or areas of osteoporosis in the proximal or
distal border.
-New bone formation/growth.
-Changes in the trabecular bone pattern.
-Irregular distal border by the presence of septic synovials.
-Exostosis (ringbone) of the proximal border
Projection Lateromedial:
-Osteosclerosis in the medullary cavity.
-Diffuse separation between the core and the cortical.
-Soft tissue calcification.
-Fragments on the distal border.
-Exostosis (ringbone) of the proximal border.
Medical Treatment
In the past, the diagnosis of navicular disease meant the withdrawal of the animal from the sporting life. Currently, new knowledge about the disease in many cases allow full recovery for the highest demands.
Treatment should always begin with a careful examination of the hoof and correction of its balance. This can reduce the pain and slow the progression of the disease.
Corrective Shoeing
It involves giving the animal a more appropriate balance. This is accomplished on occasions, eliminating the excess off of the toes or heels. The latter must always be symmetrical and the same height both lateral and medially. The result must be as such; that a line drawn on the dorsal surface of the hoof should be parallel to the other on the palmar surface of the heels. In case of reducing impossible toes or heels, a horseshoe should be applied to facilitate the growth of the hoof in the most adequate form. The most widely used is a horseshoe shaped as an "egg" ("egg bar shoe"). It must be prepared in such a way that if the shoe is viewed laterally, the heels should reach coincident with an imaginary line drawn perpendicular to the bulbs of the heel. In the case of breaks/splits in the heels the shoe should enable the expansion of the heels at each step, which is achieved with a horseshoe where the inner rim is thicker than the external. Likewise the shoe should be thicker in the area of the heels, in order to eliminate the pressure exerted by the FDP on the navicular. It is also important to round off the shoe in the area of the toes in order to facilitate the progress of the hoof in walking; sometimes using "pads" of silicon arranged between the shoe and the hoof whose function is used to soften the contusion.
In any case it should be noted that any corrective shoeing should be gradual,
and therefore it is also possible that the animal does not show improvement until three or four months has passed after starting treatment.
Non-steroidal anti-inflammatory
Among these, the most used are phenylbutazone. It is useful during the acute phase of the disease and when always corrective shoeing has been carried out. A good pattern of treatment is the administration of 4.4 mg/Kg/PO/day of phenylbutazone until the decrease of clinical signs, passing then to 2.2 mg/Kg/PO until total remission thereof. Avoid prolonged treatments with phenylbutazone due to their toxic effects on the gastrointestinal mucosa and renal function.
Vasodilator therapy
The most widely used product is now isoxuprine, a cerebral and peripheral vasodilator. Although its mechanism of action is still unknown, the isoxsuprine is effective in the treatment of the disease. Some treated animals present a complete remission of symptoms even a year after the suppression of the drug. Two common patterns of treatments are as follows:
1.) - 0.6 mg/Kg PO/12 (h) during the first three weeks.
-0.6 mg/Kg/PO/24 (h) for two weeks.
-0.6 mg/Kg/PO on alternate days for one week.
2.)- 1.2 mg/Kg/P0/12 (h) during the first three weeks.
-1.2 mg/Kg/P0/24 (h) for two weeks.
-1.2 mg/Kg/PO on alternate days for one week
Anticoagulant therapy
Used in the past on the basis of the belief that ischemia was the cause of the disease, in an attempt to reduce thrombosis. Sodium warfarin has been the most widely used anticoagulant. Today this type of therapy is deprecated because of its weak scientific basis by the serious side effects that it can produce.
Local therapy
Some products administered directly into the Podotrochlear bag are corticosteroids and/or orgotein. The difficulty of the technique and the fact that the results obtained are usually temporary making its use ill-advised.
Surgical Treatment
It should be reserved for those cases that have not responded to medical treatment. There are three surgical procedures to deal with the disease:
1. Palmer digital neurectomy:
The neurectomy of the palmar digital lateral and medial nerves, as well as of their collateral branches is the most efficient technique for cases of navicular disease and do not respond to medical treatment. It is only useful when the anesthetic block of these nerves at the height of the middle part of the pastern is clearly positive. This procedure achieves the desensitization of the third caudal of the hoof which includes the navicular bone. The operation can be performed with the animal in season using only a local anesthetic, or with the animal under general anesthesia, recommending this latter method. You can use the treatment for nerve transection with "capping" epineural hooding or without it, decreasing in the first case the possibility of nerve regeneration and therefore formation of a neuroma. Decreasing in the first case the possibility of nerve regeneration and therefore the consequent formation of a neuroma. Neurectomy is contraindicated in tendinitis FDP because it may break with the normal movement of the hoof. Complications that may arise after the neurectomy primarily include the formation of neuromas, rupture of the FDP and the loss of blood supply of the hoof by fibrosis of the area. The two latter cases recommends euthanasia, while the formation of neuromas requires a new neurectomy above the affected place.
Despite the complications resulting from the operation, some horses remain free of limp for five years thereafter.
2. Desmotomy of the navicular suspensory ligaments:
thus is an emerging technique, and results need to be compared. In one study, 13 of 16 horses treated, returned to its normal activity three months after surgery.
3. Palmar digital cryotherapy:
It is a chemical neurectomy model who pursues the temporary elimination of sensitivity of the third caudal of the hoof. Desensitization with this technique can be 2 to 5 months, and like the neurectomy may lead to the formation of neuromas.
INFECTION OF THE NAVICULAR BURSA
Due to penetrating wounds in the palm or the frog, reaching the navicular bag which is located below the deep flexor tendon. This type of injury results in a limp support and the prognosis is very unfavourable. Because of its proximity it may also cause infection of the distal interfalangiana joint and the deep flexor tendon sheath.
Symptomatology and diagnosis
-unilateral and acute lameness, with support only of the toes.
- increasing heat and digital pulse.
- pain when pressure is applied in the area of projection of the frog.
The diagnosis is made by palmar digital anesthesia which is more positive at the level of the abaxial and for radiological study, which should include LM and the navicular bone skyline views. Sometimes it is not possible to assess infection-compatible radiological changes but a synovial fluid aspirate can be performed of the navicular bag by radioscopy. Samples should also be taken of the tendon sheath and distal interphalangeal joint.
Differential Diagnosis
- subsolar abscesses
- fracture of the ADA
- septic tenosynovitis
- fracture of the navicular bone
Treatment
Is aimed at cleaning up the affected tissues. The technique used today is the Arthroscopic approach of the navicular bag to check if other structures have been damaged. Antibiotic therapy should be maintained for at least 4 weeks and the success of this treatment depends largely on the speed with which the diagnosis is made. In most cases a certain degree of chronic lameness remains.
LAMINITIS
Metabolic changes of a different nature are involved in the emergence of the disease and will be explained in the corresponding class. Note that only the hoof at the changes result in rotation or collapse of the distal phalanx and a table of acute and bilateral pain, resulting in a veterinary emergency.
FRACTURE OF THE NAVICULAR BONE
Hard to diagnose in many cases, fortunately its incidence is relatively low. Causes an acute lameness that can affect any limb. It is often to find diagnostic errors by confusing the radiolucent lines of the grooves of the frog that are projected through the navicular bone in different radiological shots.
Symptoms and diagnosis:
The most common form is acute and unilateral lameness of the forelimbs. Cases of chronic unilateral lameness in those cases that have not been diagnosed in time can occur. The pressure test with forceps in the area of the frog tends to be positive. How to highlight these fractures is through x-rays to include the DP view and the sky line. Today and for those cases that the fracture line can not be demonstrated, a resonance test must be carried out. To obtain quality radiographs a radiopaque substance should be placed into the grooves of the frog in order to avoid misinterpretation (plasticine is often used).
Differential diagnosis
- pedal bone fracture
- infection of the navicular bag
- subsolar abscess
- navicular disease
Treatment
Requires a minimum of three months box rest with egg-bar horseshoes and tabs in the quarters, raising the heels some to reduce pressure on the deep flexor tendon of the navicular bone.
The prognosis is unfavorable because it tends to produce a fibrous union of the borders of the fracture that is often painful. In competition horses palmar digital neurectomy can be used in an attempt to prolong the sporting life of the animal.
PEDAL OSTEITIS
Is the result of a process of bone Lysis and proliferation of the bone on the solar border of the pedal. It is usually bilateral and is related to work on hard surfaces and related to the chronic subsolar wear down. Horsemen concerns in many occasions is the reduction in training capacity. What occurs is a noticeable subclinical limp in many cases only on hard ground and forcing the horse to work in circles. Often bilateral, although one limb is usually most affected. Palmar digital anesthesia at the level of the abaxial is positive and the radiological study reveals the presence of areas of wear on the solar border of the pedal bone indicating bone Lysis and new bone formation in the periosteum. These changes become more evident in the DP view.
The treatment involves more or less prolonged rest times and the introduction of egg-bar horseshoes with different shock absorber materials (silicone) in the palm of the hoof or affected hooves. An anti-inflammatory therapy should be administered for a minimum of ten to fourteen days.
CLUB FOOT
It's a closed conformation of the hoof of the animal with a relative axis to the surface of 60 degrees or higher. It relates initially to a flexural deformity of the deep digital flexor tendon, but it may also be involved with the superficial flexor and even the suspensory ligament. On occasions it is secondary to inadequate shoeing or pathologies that limit chronic formation to the support of the hoof and thus its possibility of expansion. Characterized in chronic cases 'by excessively elongated and contracted heels with the dorsal wall of the concave hoof'.
In acute cases the treatment through the administration of NSAIDs in order to allow the normal support of the hoof and the use of corrective shoeing. Chronic cases may require the desmotomy of the accessory ligament of the deep digital flexor tendon combined with corrective shoeing.
CALCIFICATION OF THE PEDAL CARTILAGES OF PROLONGATION
In itself it is a physiological process in many cases that is not accompanied by a limp unless the calicified area secondary to trauma fracture occurs. Often is due to over reach. The lameness is unilateral and acute, responds to anesthesia of the palmar digital branch which innervates the affected side and the evidence of the fracture requires the realization of a dorsopalmer view of the pedal. It should not be confused with the presence of secondary ossification centers of the cartilage.
Treatment consists of a period of rest for 3-6 months, being a favourable prognosis.
FROG INFECTION
Pathology that occurs as a result of the grooves of the frog being infected are by exposure to conditions of high humidity to the hooves for long periods of time. When the table of putrefaction reaches into deep areas of the frog,there is a picture of acute lameness. The pathognomonic signs of the disturbance is a smelly and blackish discharge throughout the grooves of the frog.
Treatment is to clean the affected structures of the frog and apply different disinfectants. Antibiotic therapy is reserved for cases involving deep structures and therefore accompanied by a table of lameness. It may also be necessary to administer NSAIDs.
KERATOMA
Is the presence of a keratinized mass in the wall of the hoof or palm and usually secondary to a pattern of chronic infection (subsolar abscess unresolved). These bodies when they are located in the hoof wall cause pressure necrosis of the underlying layers of the hoof and therefore chronic lameness.
Treatment is surgical resection of the keratinized body through an open window in the wall of the affected hoof. |
