If they didn't have any symptoms I doubt it was white muscle disease:
All breeds of sheep and goats are suceptible to WMD, and the condition may develop under extensive or intensive management systems. WMD is most commonly found in newborns or fast growing animals. Kids are believed to be more susceptible than lambs, possibly because they have a higher requirement for selenium. The disease can affect both the skeletal and cardiac muscles.
When the skeletal muscles are affected, symptoms vary from mild stiffness to obvious pain upon walking, to an inability to stand. Lambs/kids may tremble in pain when held in a standing position. A stiff gait and hunched appearance are common. Affected lambs/kids may remain bright and have normal appetites, but eventually they become too weak to nurse. When the problem occurs in newborns, they are born weak and unable to rise. Sudden exercise may trigger the condition in older lambs and kids.
When the disease affects the heart, the animal shows signs similar to pneumonia, including difficult breathing, a frothy nasal discharge (may be blood stained), and fever. The heart and respiratory rates are elevated and often irregular. Skeletal and cardiac muscle disease may occur concurrently.
All breeds of sheep and goats are suceptible to WMD, and the condition may develop under extensive or intensive management systems. WMD is most commonly found in newborns or fast growing animals. Kids are believed to be more susceptible than lambs, possibly because they have a higher requirement for selenium. The disease can affect both the skeletal and cardiac muscles.
When the skeletal muscles are affected, symptoms vary from mild stiffness to obvious pain upon walking, to an inability to stand. Lambs/kids may tremble in pain when held in a standing position. A stiff gait and hunched appearance are common. Affected lambs/kids may remain bright and have normal appetites, but eventually they become too weak to nurse. When the problem occurs in newborns, they are born weak and unable to rise. Sudden exercise may trigger the condition in older lambs and kids.
When the disease affects the heart, the animal shows signs similar to pneumonia, including difficult breathing, a frothy nasal discharge (may be blood stained), and fever. The heart and respiratory rates are elevated and often irregular. Skeletal and cardiac muscle disease may occur concurrently.