Lameness

 

Exams

Laminitis

Navicular

Degenerative Joint Disease

 

Laminitis

Prevention And Treatment

Every day veterinarians across the country see hundreds of cases of laminitis, a painful
disease which affects the horse’s feet. What’s especially alarming is that
some cases are preventable. In fact, it may be that we are killing our horses
with kindness.

Consider that a common cause of laminitis is overfeeding — a management factor that
is normally within our control.

By learning more about laminitis, its causes, signs and treatments, you may be able
to minimize the risks of laminitis in your horse, or control the long-term
damage if it does occur.

LAMINITIS DEFINED

Laminitis results from the disruption (constant, intermittent, or short-term) of blood
flow to the sensitive and insensitive laminae. These laminae structures
within the foot secure the coffin bone (the wedge-shaped bone within the
foot) to the hoof wall. Inflammation often permanently weakens the laminae
and interferes with the wall/bone bond. In severe cases, the bone and the
hoof wall can separate. In these situations, the coffin bone may rotate
within the foot, be displaced downward (“sink”) and eventually
penetrate the sole. Laminitis can affect one or all feet, but it is most
often seen in the front feet concurrently.

The terms “laminitis” and “founder” are used interchangeably.
However, founder usually refers to a chronic (long-term) condition associated
with rotation of the coffin bone. Whereas, acute lamini­tis refers to
symptoms associated with a sudden initial attack, including pain and inflammation
of the laminae.

CAUSES

While the exact mechanisms by which the feet are damaged remain a mystery, certain
precipitat­ing events can produce laminitis. Although laminitis occurs
in the feet, the underlying cause is often a disturbance elsewhere in the
horse’s body. The causes vary and may include the following:

  • Digestive upsets due to grain overload or abrupt changes in diet
  • Sudden access to excessive amounts of lush forage before the horse’s system has had time
    to adapt; this type of laminitis is known as “grass founder”
  • Toxins released within the horse’s system
  • High fever or illness; any illness that causes high fever or serious metabolic disturbances
    has the potential to cause laminitis, e.g., Potomac Horse Fever
  • Severe colic
  • Retained placenta in the mare after foaling
  • Stressed or overheated horse
  • Excessive concussion to the feet, often referred to as “road founder”
  • Excessive weight bearing on one leg due to injury of another leg or any other alteration
    of the normal gait
  • Various primary foot diseases
  • Bedding that contains black walnut shavings
  • Prolonged use or high doses of corticosteroids

RISK FACTORS

  • Factors that seem to increase a horse’s susceptibility to laminitis or increase the severity
    of the condition when it does occur include the following:
  • Heavy breeds, such as draft horses
  • Overweight or horses prone to be “easy keepers” with thick cresty necks and fat pads over the tail head.
  • High nutritional plane
  • Ponies
  • Unrestricted grain binges, such as when a horse breaks into the feed room (If this happens,
    do not wait until symptoms develop to call your veterinarian.
    Call immediately so corrective action can be taken before tissue
    damage progresses    .)
  • Horses who have had previous episodes of laminitis

SIGNS

Signs of acute laminitis include the following:

  • Lameness, especially when a horse is turning in circles
  • Heat in the feet
  • Increased digital pulse in the feet
  • Pain in the toe region when pressure is applied with hoof testers
  • Reluctant or hesitant gait (“walking on eggshells”)
  • A “sawhorse stance,” with the front feet stretched out in front to alleviate
    pressure on the toes and the hind feet “camped out” or positioned
    further back than normal to bear more weight.

Signs of chronic laminitis may include the following:

  • Rings in hoof wall that become wider as they are followed from toe to heel
  • Bruised soles or “stone bruises”
  • Widened white line, commonly called “seedy toe,” with occurrence of seromas (blood
    pockets) and/or abscesses
  • Dropped soles or flat feet
  • Dished hooves, which are the result of unequal rates of hoof growth (The heels grow
    at a faster rate than the rest of the hoof, resulting in an “Aladdin-slipper”
    appearance.)

TREATMENT

The sooner treatment begins, the better the chance for recovery. Treatment will depend
on specific circumstances but may include the following:

  • Diagnosing and treating the primary problem (Laminitis is often due to a systemic or
    general problem elsewhere in the horse’s body.)
  • Dietary restrictions
  • Treating with mineral oil, via a nasogastric tube, to purge the horse’s digestive tract, especially
    if the horse has overeaten
  • Administering fluids if the horse is ill or dehydrated
  • Administering other drugs, such as antibiotics to fight infection; anti-endotoxins to reduce
    bacterial toxicity; anticoagulants and vasodilators to reduce blood
    pressure while improving blood flow to the feet (Corticosteroids are
    contraindicated in laminitis, as they can actually cause laminitis or
    exacerbate existing cases.)
  • Stabling the horse on soft ground, such as in sand or shavings (not black walnut), and
    encouraging the horse to lie down to reduce pressure on the weakened
    laminae
  • Opening and draining any abscesses which may develop
  • Cooperation between your veterinarian and the farrier (Techniques that may be helpful include
    corrective trimming, frog supports, and therapeutic shoes or pads.)

LONG-TERM OUTLOOK

Many horses that develop laminitis, make uneventful recoveries and go on to lead long,
useful lives. Unfortunately, others suffer such severe, irreparable damage
that they are, for humane reasons, euthanized.

Your equine practitioner can provide you with information about your horse’s
condition based on radiographs (x-rays) and the animal’s response to treatment.
Radiographs will show how much rotation of the coffin bone has occurred.
This will help you make a decision in the best interest of the horse and
help the farrier with the therapeutic shoeing.

MANAGEMENT

Importantly, once a horse has had laminitis, it may be likely to recur. In fact, a number
of cases become chronic because the coffin bone has rotated within the foot
and because the laminae never regain their original strength. There may
also be interference with normal blood flow to the feet, as well as metabolic
changes within the horse. Extra care is recommended for any horse that has
had laminitis, including:

  • A modified diet that provides adequate nutrition based on high-quality forage and without
    excess energy, especially from grain
  • Routine hoof care, including regular trimming and, in some cases therapeutic shoeing (Additional
    radiographs may be needed to monitor progress.)
  • A good health-maintenance schedule, including parasite control and vaccinations to reduce the
    horse’s susceptibility to illness or disease
  • Possibly a nutritional supplement formulated to promote hoof health

SUMMARY

The best way to deal with laminitis is preventing the causes under your control.
Keep all grain stored securely out of the reach of horses. Introduce your
horse to lush pasture gradually. Be aware that when a horse is ill, under
stress or overweight, it is especially at risk. Consult your equine practitioner
to formulate a good dietary plan. Provide good, routine health and hoof
care. If you suspect laminitis, consider it a medical emergency: Notify
your veterinarian immediately.