DOD: What we need to know and what we need to learn

The term "DOD" describes a variety of orthopedic disorders in growing horses. Contracted tendons, wobbles, phystis, osteochondritis, osteochondrosis dissecans (OCD) and angular limb deformities are all considered Development Orthopedic Disease.

Genetics, nutrition, hormonal imbalances, disease and basic management practices may all contribute to DOD.

Here's an update on what we know and what you can do to avoid problems with DOD:

Unfortunately, some of the best sires in the world have been implicated as major contributors to an increase in this form of DOD.

Nutrition

Although nutrition's link to DOD is very complicated, the good news is that nutrition holds the greatest promise for reducing the severity, if not the incidence, of DOD.

Feeding excessive amounts of grain to young horses causes an unnatural fluctuation in levels of hormones such as insulin, growth hormone and thyroid hormones. The result is the development of the over-conditioned horse with orthopedic disorders.

Mineral imbalances may also influence the incidence and severity of DOD.

Horsemen have recognized the need for proper calcium and phosphorus intake for decades; however, improper calcium and phosphorous levels continue to be a common finding on farms with high levels of DOD. Unpredictable calcium levels in forage sources rather than ignorance or improper fortification of grain mixes are probably at fault. This is also true of copper, zinc and selenium levels.

If the incidence of DOD is greater than average in your stable, consider having a complete analysis of all pastures, forage and water sources.

Equine Diseases

Growing horses that have been exposed to equine diseases such as pneumonia or strangles founder fescue forage graze grazing hay cribbing tack saddles stalls barns bridle stifle stringhalt shivers boarding fences hackamore snaffle">es are at increased risk of DOD.

The horse's body sometimes defends itself from such diseases by sequestering the pathogens in bone tissue, where they adversely affect bone development. Growing horses that have had such diseases should be watched closely and perhaps maintained at a lighter body weight than normal to reduce severity and incidence of DOD.

Management

Lack of free exercise, sudden changes in nutrition levels, and exposure to stress can contribute to DOD in young horses.

Free exercise increases bone strength. Thus it's best not to confine growing horses to stalls for more than 10 hours a day.

Abrupt changes in energy, protein or mineral intake level of growing horses can sometimes trigger abnormal growth rates and orthopedic disorders. Likewise, increased stress, such as poor weaning programs, can adversely affect growth weights and increase the weakling's susceptibility to DOD.

Growing horses should be managed to promote consistent and steady growth rates. Pushing horses to grow as rapidly as possible to prepare them for sales and shows only increases the chance of orthopedic disorders.