Management of pain in older horses, especially brood mares and stallions, can be challenging. There are several levels of
expectations for older horses and the management style oftentimes needs to be dictated by the animal's use. Therefore the
goal of management is to use various local and systemic therapies in order to allow the horse to perform its duties with a
minimal amount of pain.
There is no better example of this than in broodmares. The effectiveness of management is often dictated by the breed. For
instance, in Thoroughbred racehorses the mares must undergo live cover and carry to term and facilitated breeding techniques
cannot be used. This places more weight and stress on the mares and consequently makes management more difficult. With these
mares aggressive oversight of their feet, fetlocks, suspensory apparatus and carpi are needed especially if they have a racing
history. However mares that can undergo facilitated breeding techniques such as Quarter Horses can be managed more effectively.
In Quarter Horse mares embryo transfer can be used. In addition, with the use of shipped semen some mares can live their lifetime
at a single farm without much transportation. Some breeding managers are uncomfortable if the mares don't periodically carry
to term; however that must be weighed against the potential negative complications of carrying on their musculoskeletal system.
Stallions can also have limitations due to musculoskeletal pain. Again, in Thoroughbreds this is significant as they must
live cover and aggressive pain control is needed. In other breeds such as Quarter Horses, in which artificial insemination
can be used the collection techniques can be modified to enhance the horses comfort. Breeding dummies can be manipulated,
such as being lowered, or the horse can sometimes be collected standing. In addition, horses that are euthanized can have
semen stored for later use.
Several types of diseases can influence the musculoskeletal system in these older horses. Systemically, things such as Cushing's
disease or metabolic syndrome can have effect on the horse's feet. Laminitis consequently is a common sequela of these diseases
and periodic systemic screening of these horses is needed. In addition, nutrition can have a large influence on these horses
especially if their carbohydrates are not adequately monitored.
Hoof disease is very common in older horses especially if they have had any lameness history. Laminitis is common in older
horses for various reasons and it is often our recommendation to do yearly radiographs to be sure that the angles remain normal
and the stresses are minimized on the feet. There are some horses that benefit from a lifetime in shoes and that oftentimes
is dictated by the horse itself as well as the condition. Navicular syndrome is also very common and in the advanced stages
can be very limiting to the horses comfort. In some instances when aggressive medical therapy and shoeing fails, a palmar
digital neurectomy is needed to maintain comfort. However care must be taken that the flexor surface of the navicular bone
is closely analyzed as those horses with neurectomies could suffer from complete rupture of the deep digital flexor tendon
requiring euthanasia or heroic efforts to fuse the distal interphalangeal joint. Many older horses are maintained of isoxsuprine
which oftentimes can maintain an improved level of comfort. Even though this is a contentious approach in some horses it does
have a significant impact.
Joint disease is common and needs to be managed based on common principles. The problem with using intraarticular corticosteroids
in older horses is that even normally accepted doses of these steroids could potentially have a negative effect on the horse
systemically especially if they suffer from Cushing's disease. Therefore it is not uncommon to evaluate the horse's metabolic
status prior to recommending intraarticular corticosteroid administration.
Diseases of the suspensory apparatus are not uncommon especially in retired racehorses. It is now recognized that degenerative
suspensory desmitis can occur and that there may be a genetic link. This is not uncommon in the hind limbs of western performance
horses such as cutters and reiners who have had a significant amount of stress in their hind limbs. It is difficult to properly
support these horses. Sometimes extended heel shoes can help however not in all cases. It does seem that if the horses are
comfortable turn out and light exercise can be beneficial to maintaining muscle tone and strength and hence compensating for
suspensory apparatus loss.
In general several things need to be kept in mind when making recommendations for orthopaedic pain in the older horse. If
the horse is comfortable enough to be turned out this is often beneficial and in some cases in chronic joint disease horses
can actually do better when turned out as apposed to being confined. Systemic treatments such as supplements isoxsuprine and
occasional anti-inflammatory medications can also be beneficial. Local application of medication can also be beneficial and
various different types of shoeing schemes can be beneficial depending on the horse. It's important to remember that the breeding
scheme and the plan can also have an influence on the horses comfort and that to must be taken into consideration.
In summary, managing the older horse can often times be difficult and the horses can often show a large variation in comfort
even in a small amount of time. It is this authors opinion that the goal is often to find a steady course of comfort and not
to overreact to short durations of increased pain. This commonly occurs and shoeing recommendations made when in fact the
original shoeing scheme may have been more appropriate.