One of my does had triplets 3 weeks ago. She has been nursing all 3 fine but seemed a little off past 2 days or so, panting and not as social but eating fine. Today she is staying in the hot stall instead of the cool breezeway. I walked her out to a shady spot in the pasture and she grazed for a minute or so then headed back to the barn walking very stiff legged. The stiffness is new and considerable, Any thoughts? She's had all vacs and wormings necessary and still eating fine.