What clinical sign is associated with enzootic calcinosis?

Enzootic calcinosis primarily affects ruminants, such as cattle and sheep, and is characterized by the accumulation of calcium in soft tissues, leading to various clinical manifestations. One of the key signs associated with this condition is shifting leg lameness. This occurs because the excess calcium can lead to osteodystrophy, which compromises the integrity of the bones and joints, causing discomfort and lameness.

Shifting leg lameness is particularly indicative of the condition as it reflects the underlying skeletal and muscular issues caused by the abnormal calcium metabolism and deposition. The lameness may be unilateral or bilateral and may affect different limbs over time, hence the term "shifting."

The other options, while they may represent other conditions or health issues, do not specifically align with the hallmark signs of enzootic calcinosis. Excessive salivation is typically associated with dental or gastrointestinal diseases, progressive weight gain is more indicative of metabolic disorders or certain dietary practices, and frequent urination is often linked to renal problems or diabetes. In contrast, the connection between enzootic calcinosis and shifting leg lameness is well-documented in veterinary literature, making it the correct choice.