Epiphysitis may result from imbalance in the calcium:phosphorus ratio. It is seen in young, rapidly growing kids (more often in males than in females) and in young does in late pregnancy or in the early stages of their first lactation. These does are young (eg, 12 mo), extremely heavy milkers, or carrying twins or triplets. Epiphysitis is sometimes compounded by rickets (see Rickets in Animals).
Epiphysitis starts with lateral or medial bowing of one or both radii. Later changes may consist of lateral deviation of the digits on the fore- or hindfeet; lameness and reluctance to walk; an arched back; and soft swelling and pain in the carpal, metacarpophalangeal, tarsal, and metatarsophalangeal joints. Diagnosis of epiphysitis can be confirmed with radiography.
Conditions that have been implicated in its cause include an excess of dietary calcium with a calcium:phosphorus ratio of >1.4:1 (generally >1.8:1), excess protein intake, excess dietary iron, indoor housing of kids, or lack of vitamin D caused by prolonged overcast weather and low vitamin D levels in the feed. Carotene has an antivitamin D effect. Vitamin D has poor stability in prepared feed, especially when mixed with minerals. Alfalfa is high in calcium (1.4% calcium to 0.2% phosphorus) and protein. Owners frequently feed kids milk for prolonged periods because of a lack of commercial outlets for milk.
Once the probable cause(s) is identified, the diet should be corrected and the appropriate supplement given—usually injectable vitamin D and/or phosphorus or oral balanced calcium/phosphorus supplements.
Predisposing factors also must be corrected. The diet of growing kids should be changed to slow growth rate. The mating of young does <7 mo of age should be discouraged, and buck kids should be separated from doe kids by 3 mo of age to avoid unplanned matings. The diet for young does in milk with limb deformities should be corrected to allow for normal bone growth. Proper nutritional management stops limb deformities from worsening, and such deformities self-correct over time in most does.