Developmental Orthopedic Disease Risk Factors

 

There are numerous risk factors that enhance the onset of DOD. The major risk factors include nutrition, genetic predisposition, trauma, and exercise. Within this section of the website we discuss the relevance of trauma and genetic predisposition. Relevant information regarding exercise is discussed within the prevention section, while information regarding nutrition is found within its own section.

 

Trauma

Factors such as trauma and mechanical stress create a predisposition that increases the presentation of DOD symptoms [4]. An obese horse will have greater mechanical stress placed on joints and therefore a higher chance for trauma during exercise of impacting already strained joints. This same comparison can be made for foals that are over exercised  as overworked joints have an increased load, increasing the risk of trauma and stress to the joints. Although there are many factors identified to influence DOD expression, both trauma and excessive exercise among young foals are commonly observed [3]. The severity of trauma varies from case to case. For example, early life trauma in a foal can cause a higher likelihood for DOD to develop [3]. As one can imagine, the most crucial time for orthopedic disease to occur is during growing periods where joints and growth plates are undergoing changes in structure and development. Excessive exercise during these times have shown to have direct negative impacts on the foal presenting itself as orthopedic diseases. It has been found that housing larger groups of horses together in an increased herd number may cause DOD relating to excessive exercise, as was shown through radiograph confirmation [6]. 

 

Genetics

There can be greater prevalence of different forms of DOD seen among particular breeds [18]. Any horse breed can be affected by osteochondrosis and physitis [3]. One study exploring osteochondrosis found that genetic factors are “the most consistent and principal factors contributing to the development…” of osteochondrosis [27]. Additionally, breeding horses with previous DOD presence can increase the occurrence of DOD in offspring [20]. This means that horses with DOD are not good breeding prospects. Additionally, this shows that risk factors for DOD can be present at the individual level as well as the breed level. Please see below for information on DOD prevalence in different horse breeds and crosses. 

 

While genetic predisposition is an accepted risk factor for DOD, overall research is lacking. Some research has been conducted on warmbloods, standardbreds, and thoroughbreds, likely due to their economic importance due to their involvement in equine competitions. 

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Thoroughbreds [4]:

 

• Severe DOD commonly on fore fetlock 

• Severe DOD on distal part of the hock

• DOD is also commonly found on the carpus

 

Warmbloods and Standardbreds [4]:

 

• Severe DOD on the proximal part of the hock, and the femoro-patellar joint in Warmbloods and Standardbreds 

• Warmbloods primarily affected on the:

  • dorsal part of the hind fetlock

  • fore fetlock

  • femoro-patellar joint

  • carpus 

• Higher DOD incidence rate and more serious in Warmbloods

• Standardbreds are often affected on the: 

  • carpus 

  • plantar part of hind fetlock

  • proximal part of the hock 

• DOD commonly found on the carpus in Standardbreds