Saturday, 18 January 2014

VSR-511 Class 5


Laminitis(Founder)

Inflammation of laminae of the foot.It is peripheral vascular disease shown as decreased capillary perfusion, ischemic necrosis of laminae and pain.

It is Complex systemic metabolic disease affected by cardiovascular,renal,endocrinal,blood coagulation and acid-base status which  results in acute degeneration of laminae. Mostly fore limb affected

  • Three phases of laminitis
    • Developmental phase - initiation with trigger factor that lead to change in foot
    • Acute phase - onset of clinical signs
    • Chronic phase - 48 hrs of continuous pain
  • Etiology
    • Carbohydrate overload (grain founder)
    • Lush grass over load (grass founder)
    • Obesity
    • Endometritis (post parturient laminitis)
    • Severe systemic infection-altered vasoactive process and coagulopathy with decreased perfusion and ischemic necrosis.
    • Colic
    • Stress/exhaustion-with concussion (Road founder)
    • Drinking large amount of cold water
    • Toxins ingestion
    • Hormone imbalance and corticosteroid therapy.
    • Over exercise on hard ground
  • Clinical signs
    • Lateral recumbancy for long period
    • Increased respiratory rate with muscle tremors, sweating
    • Arched back condition
    • Laminitic gait
    • Hot to touch around coronary band
    • Digital pulsation
    • Pain response to digital pressure
    • Dropped sole
    • Laminitic ring around wall
  • Diagnosis
    • Clinical signs and history
    • Radiography
  • Treatment

o Medical treatment with NSAIDS – phenylbutazone, acetylsalicyclate, flunixin meglumine

o Complete box rest

o Use of frog support to reduce pressure on laminar band

o Removal of shoe

o Balanced diet

o Corrective trimming and shoeing

o Realignment of distal phalanx in pedal rotation.

Sand crack

  • Fissure in the wall of the hoof, parallel to the horn tubules, commencing at the coronet and extending a variable distance down the wall, usually to its plantar aspect. It may occur at any part of the wall and even in the bar, but its commonest situations are the toes of the hind foot and the inner quarter of the fore foot.
  • Types

o Superficial or deep, complete or incomplete, simple or complicated, straight, recent or old

  • Etiology
    • Thinness of the hoof wall
    • Excessive rasping of the wall
    • Injury to the coronet
    • Violent extension of the corono-pedal joint
  • Clinical signs
    • Fissure in the hoof wall
    • Oozing of blood, serum or pus
    • Swelling of coronet
    • Necrosis of lamina
    • Lameness depending on the severity
    • Spasmodic lifting of the limb
  • Diagnosis
    • Clinical signs
    • Radiography
    • Ultrasonography
  • Treatment

o Corrective shoeing

o Application of hoof bandage or clasps or horseshoe nail

o Metal plate screwing, wiring or lacing the hoof wall in shoe lace pattern overlaid with fibreglass or acrylic patches

o Thinning/stripping the horn wall and removal of necrotic tissues, pus and application of antiseptic foot baths, hoof repair material

o Blistering the coronet region to stimulate the growth of new horn

  • Prognosis for soundness
    • Good – for superficial cases
    • Guarded in long standing cases due to deformity of coronary band

Seedy toe

· It describes a condition in which dermal and epidermal layers are separated in the toe region of the foot. Newly formed horn follows the line of separation and perpetuates the defect. After sometime the separation is visible in the white line in the toe region and the dermal structures are exposed to ascending infection.

  • Etiology
    • Focal haemorrhage
    • Seroma formation
    • Failure of damaged laminae to produce keratin
  • Clinical signs
    • Brown crumbly horn like matter along the white line
    • Lameness in severe cases
    • Percussion of dorsal hoof wall produces characteristic hollow sound
  • Diagnosis

o    Careful exploration of the undermined wall with a blunt radio opaque allows radiological documentation of the extent of separation.

o    Gas shadow in the soft tissues dorsal to the 3rd phalanx on lateromedial radiographs of the foot.

  • Treatment

o    Regular cleaning of the defect and shoeing with wide webbed, flat shoes.

o    In more severe cases the separated hoof must be removed from the solar margin of the toe to a level where normal inter laminar band is present. The exposed laminae are medicated under a dressing.

Fractures of 3rd phalanx(pedal bone,ospedis,coffin bone)

  • Etiology: Acute trauma due to kick
  • Not common
  • By exercise on hard surface
  • More fore feet, left foot by counter clockwise racing by twisting action.
  • By penetrating foreign body through sole.
  • Improper shoeing.
  • Nutrient deficiencies.
  • Infections.
  • Classification: Based on the anatomic location of the fracture

o Type I - Non articular fractures of palmar or plantar process of the bone

o Type II - oblique articular fracture from distal interphalangeal joint to solar margin of the bone

o Type III - mid sagittal articular fracture that divide the distal phalanx in two equal parts

o Type IV - fracture of the extensor process

o Type V - comminuted fracture or secondary to foreign body penetration

o Type VI - Non articular fracture of the solar and parietal cortices

o Type VII - Non articular fractures of palmar or plantar process of the bone.

  • Clinical signs: Acute supporting limb  lameness.
      • Sudden lameness after work.
      • Increased digital pulse and Inc heat in foot.
      • Inc pain in entire sole, point of pain known by hoof tester.
      • Arthrocentesis of coffin joint-bloody fluid within articular fracture.
  • Diagnosis
    • Radiography
    • Local analgesia
    • History and testing with hoof testers before radiograph.
  • Treatment: For fracture of

o Chronic type I – Palmar digital neurectomy to relieve the lameness

o Types I to V – Non surgical management by applying bar shoe with quarter clips for 6-10 months

o Type VI - Rest and application of shoe with pad

o Type VII - Complete rest for 3 to 4 months

o If fractures are by punctured wound, it will result in bone abscess and demineralization.Treat for Abscess and correct shoeing.

o Sagittal and oblique fracture

§ Should be treated before fibrous union with internal fixation using 4.5 or 5.5 mm cortical or shaft screws (ASIF cortical bone screws-association for the study of internal fixation)

§ Pressure bandage application with antiseptic soaked guaze dressing

§ Acrylics are used for binding.

             Prognosis: Good if sufficient rest is given.

PEDAL OSTEITIS

  • Pedal osteitis is an inflammatory condition of the foot that results in demineralization of the distal phalanx.
  • Two recognized classifications are
    • non septic and
    • septic


  • Etiology

o Primarily it is associated with severe or chronic sole bruising, concussion

o Secondary is most common, caused by persistent corns, laminitis, puncture wounds, bruised wound sole, conformational faults.

o Septic Pedal osteitis develops from introduction of environmental microbes either into the soft tissues of the foot or distal phalanx.

o It causes includes chronic severe laminitis, sub solar abscess, solar margin fracture, deep hoof wall cracks, avulsion of hoof injuries, penetrating wounds of the foot.

  • Clinical signs

o Non septic PO commonly affects forelimb and the condition can be either unilateral or bilateral. Severity of the lameness depends upon on the cause and degree of injury.

o Hoof tester examination often reveals a focal or a diffuse region of increased sensitivity when pressure is applied to the sole and to the hoof wall.

o Septic PO commonly affects the forelimb; lameness grades ranging from 2-4.5 are common. On palpation, increase in temperature and prominent digital pulses can often be felt in the affected foot.

  • Diagnosis

o Radiographic assessment of distal phalanx for nonseptic PO includes atleast 3 views: 65º dorsopalmar, medial and lateral oblique projections.

o Radiographic signs include demineralization, widening of the nutrient foramina at the solar margin, irregular bone formation along the solar margins of dorsal surface of distal phalanx. Lateral border usually more roughened than medial.

o Radiographic signs of septic PO are loss of trabacular detail with indistinct margins fading into the surrounding bone, osteolysis at the margins of the distal phalanx.

  • Treatment
    • Non septic PO

§ Rest, administration of NSAIDs, the avoidance of exercise on hard surfaces, application of protective shoes should be useful.

§ A handmade, wide web, egg bar shoe whose solar surface is deeply concave is more useful. In horses in which the sole is thin and soft can be medicated topically with equal parts of phenol, formalin and iodine to toughen them.

      • Palmar digital neurectomy recommended.
    • Septic PO

§ Debridement of the tract, removal of infected bone. Infected bone appears grayer and is softer than the normal soft bone of the normal distal phalanx.

§ Tract is packed with gauze soaked in dilute povidone iodine and protective bandage is applied. Plastic or rubber boot can be applied to protect the bandage.

§ A shoe with a removable metal plate can be applied.

·  Prognosis

o Nonseptic PO: good if condition is primary and acute unfavourable, if chronic

o Septic PO: good if infection is controlled.


Ulceration of sole

·  Commonly noticed in grazing cattle and may occur in any digit but are more common in lateral claws of hind limb and medial claws of forelimb. The seat of lesion is at the corium that overlies the flexor process of the third phalanx

  • Etiology
    • Over trimming of toes
    • As secondary to interdigital dermatitis
  • Clinical signs

o Slight haemorrhage, necrosis of the corium and surrounding tissues

  • Treatment

o Corrective trimming and lowering the heel horn of the affected claw

o Application of hoof block to healthy claw to avoid weight bearing on the affected limb

o If adequate heel depth of healthy toe is available “heelless method of trimming”-removal of all wall and sole from the posterior half of the digit to a depth with preservation of thin layer of sole and application of hoof block on the healthy toe for a period of four weeks.


Canker (Necrotic pododermatitis)

·  Chronic hypertrophic moist eczematous dermatitis involving the frog, sole and wall of the foot.

  • Common in the heavy draft horses especially in the hind feet
  • Etiology
    • Unhygienic stable
    • Poor foot care
    • Prolonged exposure to moisture
    • Hereditary
  • Clinical signs

o Peeling of horns as soaked in oil

o Ergot formation - finger like hypertrophic growth with foul smelling condition covered with Friable crust over the frog

o Progressive lameness

o Cheesy foul smelling exudates from the frog

  • Clinical signs

o Inflammation, hypertrophy, necrosis, dyskeratosis at the frog region

  • Treatment

o Removal of the infected horns under general anaesthesia and application of triple sulph powder (Zinc sulphate, Copper sulphate and Ferrous sulphate)

o Debridement and dressing with noncaustic antiseptic sugar and iodine preparation

o Daily dressing with dry sterile water proof pressure bandage

o Coverage of sole with metal or leather

  • Prognosis for soundness
    • Good – in early cases
    • Unfavourable in long standing cases


Corn

  • Contusion of the sensitive corium and sole at angle between the wall and the bar
  • Types
    • Moist , dry, suppurating or festered and complicated corns.
  • Etiology
    • Defective conformation of the foot
    • Improper shoeing for long period
    • Excessive weight bearing on the heel
    • Secondary to side bone formation
  • Clinical signs
    • Pointing of the limb
    • Bilateral forelimb lameness with shortened stride
    • Bruised condition at the angle between the wall and the bar
  • Diagnosis
    • Shoeing history
    • Clinical signs
    • Radiography
  • Treatment

o Removal of improper shoes

o Rest

o Foot bath and antiseptic dressing

o Debridement of a thin layer of sole horn over the corn

o Corrective shoeing with full and long fitted heels or wide webbed egg-bar shoe

  • Prognosis for soundness
    • Good at early stages
    • Guarded – in collapsed heel or pedal osteitis condition

 

 

Thrush

·  It is a degenerative condition of the central and collateral sulci of the frog, characterized by disintegrating horn and the presence of grey to black material in the affected areas.

  • Etiology
    • Unhygienic ,moist stabling with poor foot care.
    • Fusobacterium necrophorum is mostly involved.
  • Clinical signs
    • Black discharge in the sulci of the frog with very offensive odour.
    • Only when sensitive structures are involved lameness occurs.
    • Mainly hind limbs affected.
  • Treatment
    • Debridement of affected and separated horn .
    • Daily topical astringent medication under dressing. Sterile bandaging after each debridement and continue treatment under plate shoe.

MONDAY MORNING SICKNESS (Equine Rhabdomylosis)

·  Monday Morning Sickness (or disease) is an old slang term used for a condition properly known as Azoturia. It is also referred to as Exertional Myopathy. It is a potentially fatal condition that makes it very difficult and painful for the horse to move and can cause failure of the kidneys. Azoturia is most commonly found in horses that are heavily exercised on a regular basis, and then not worked for one or two days but still fed the same amount of food. This results in glycogen (a carbohydrate) building up in the muscles. When the horse returns to work, this glycogen breaks down quickly and produces an overload of lactic acid. The lactic acid damages skeletal muscles, releasing muscle enzymes and myoglobin, which can lead to acute kidney failure.

·  Tying-up is a milder form of the condition that is usually seen in race and performance horses after a hard workout. While cooling down, the muscles stiffen and tremor. The muscles of the hindquarters are particularly tense, hard and painful. The pain causes anxiety and sometimes sweating.

·  The horse, is subject to muscle problems due to abnormal metabolism of energy. The byproducts of abnormal metabolism cause inflammation of muscle cells, which leads to painful spasms of the large muscles of the back and hindquarters. The clinical result is a horse that can’t move due to these painful muscle spasms.





Causes

·  The most common cause of Monday morning sickness or Azoturia is from a carbohydrate overload combined with time off. This used to be very common with draught horses who would have Sunday off and then have an episode of Azoturia on the Monday, hence the term Monday Morning Sickness.

·  The glycogen in the hard feed builds up in the muscles and produces an excess of lactic acid to be produced when the horse resumes work, the lactic acid in turn damages the muscle tissue and subsequent blood flow to the muscles. As the Lactic Acid cannot be dispersed quickly enough it causes an episode of Azoturia to occur.

Symptoms

·  These can vary depending on the severity of the attack.

o Horse will show a reluctance to move.

o Horse will refuse to move, hence the term tying-up.

o The muscles will tighten up and go hard and often be quite hot.

o The urine will be dark brown in colour due to the muscle pigment myoglobin going into the blood stream and subsequently being urinated.

o The horse may show signs of repeatedly trying to urinate with no affect.

o The horse may sweat up.

o The horse will be distressed.

Treatment

·  The use of pain killers and anti inflammatory drugs are used initially to make the horse more comfortable Fluids are often administered to help flush out the toxins.

·  The horse should then have box rest followed by gentle exercise and a new feeding program that is appropriate for the level of work. If you are riding when the horse develops symptoms then dismount immediately and place rugs over the horse to keep the horse warm.

·  Put them directly into a warm stable with plenty of bedding and water and do not want to ride them as this will only further damage muscles and cause more pain.

Prevention

·  Carefully warm up your horse and use an exercise blanket on cold days.

·  Ensure that if the horse has a rest day that the hard feed is reduced.

·  On rest days ensure that the horse is turned out as this will allow them to gently exercise.

·  Feed according to the work being done and if the horse is prone to Rhabdomyolysis reduce the carbohydrate in the feed, the use of soya oil for energy can be a useful addition in the diet.

·  The use of some supplements may be of value, for example the addition of Selenium and vitamin E are known to be good at reducing free radicals and the correct balance of electrolytes is essential to provide a natural balance.

Cording up

·  Myopathy that occurs after active muscular exertion. Horses affected are usually on high grain ration and tested for one or two days.
Painful condition of iliopsoas muscle that occurs within minutes after exertion of race.

·  Signs

o Stiffness after racing

o Back is rigid

o Palpation of iliopsoas muscle- painful.

o Muscles hard to touch.

o Involvement of gluteal and quadriceps

o Mild myoglobinuria

·  Diagnosis

o Clinical signs and history.

·  Treatment

o Walking horse for 30-40 minutes.

o Calcium gluconate intravenous injection.

o Tranquilizers.

o Alkalization of blood with sodium carbonate.

MYOSITIS OF PSOAS

·  Inflammation of muscle is known as myositis, especially a voluntary muscle

·  This type of muscle disease (myopathy) represents a group of different diseases which all share the feature of inflammatory cells within the muscle.

·  Myositis is the early stage of muscular infection.

·  A psoas abscess is defined as a purulent infectious collection within the psoas muscle

  • Myositis can affect
    • One muscle
    • Groups of muscles

Etiology

·  Infection, autoimmune conditions, genetic disorders medication adverse events, electrolyte disturbances, and diseases of the endocrine system.

·  Some idiopathic cases of polymyositis are suspected to be related to infectious agents, especially viruses such as the paramyxoviruses or enteroviruses .

Signs

  • Pain
  • Tenderness
  • Swelling
  • Weakness

Diagnosis

·  Laboratory evaluation reveals leukocytosis with a left shift and an elevated erythrocyte sedimentation rate.

·  In cases of secondary psoas abscesses, pyuria and positive urine cultures may be found when the genitourinary tract is the originating site of infection. The diagnosis is established by radiological imaging. A psoas abscess may be detected on ultrasound evaluation, but this test is not as sensitive as CT or MRI scans.

Treatment

·  Surgical drainage and intravenous antibiotics are recommended.

·  Drainage may involve either CT-guided percutaneous drainage or an open surgical procedure.

ILIAC THROMBOSIS - INTRODUCTION

·  This is the thrombosis in the iliac arteries - the vessels into which the abdominal aorta breaks up beneath the lumbar spine, and whose branches are distributed to the hind-quarters and extremities.





Causes

·  The causes of thrombosis are chiefly injuries such as wounds, severe contusion, and stretching , diminish its vitality may determine the coagulation of blood within it. It is also a consequence of degenerative changes in the structure of the vessel, and of arrest of the circulation from aneurism or any other cause which induces the blood to stagnate.

·          For the most part thrombosis of the iliac vessels is the result of sprain inflicted by violent backward stretching of the hind legs, would result when a horse falls short in jumping and slips down, or when his legs fly back from under him, or " spread-eagle", while drawing a heavy load over a slippery surface, or out of deep heavy ground.

·  In all these positions there would be sudden and severe stretching of the vessels and injury to their coats.

·  Thrombosis from stagnation of blood

·  Thrombosis from alteration of the wall

·  There are cases in which coagulation occurs by transfusion of  blood from lower animals.

Symptoms

·   Slight stiffness of one or both hind-limbs, more especially on rising from the recumbent posture, slight swelling of the limbs are the initial sign.

·  When the animal is made to move, the blood disappears from the veins, and returns but slowly.

·  In the more advanced stages of the disease exertion brings on a rolling gait behind, and, if continued, results in paralysis of the posterior part of the body. At this time the animal breaks out into a profuse perspiration, the breathing is hurried, the muscles quiver, and the pulse is much accelerated. In some cases the affected animal strikes the belly, looks round to the flank, and shows signs of acute pain, as if the subject of colic.

·  After a short period of rest the symptoms subside, and the horse resumes his normal condition, and will most likely continue in apparent good health until the exertion is again repeated.

Diagnosis

·  Although the symptoms described are very indicative of iliac thrombosis, the diagnosis may be rendered still more complete by a careful manipulation of the affected vessels.

·  The iliac arteries are to be found striking off right and left beneath the lumbar spine, and quite within reach of the hand when pushed well forward into the rectum.

·  In carrying out this examination the hand and arm must be well anointed with oil or vaseline, and after entering the bowel the arm is turned so that the palm is presented upward; the fingers are then directed to that part of the spine where the loin joins on to the quarters, immediately beneath which the great iliac vessels - two on either side - will be felt branching off right and left from the posterior aorta.

Treatment

·  Treatment in these cases is of no avail.

 

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