At a first glance this image seems a bit chaotic, but let’s read what we can from it.
Apparently, a mad dog (as implied by it’s blue head) is causing all the trouble. Man on the right got bitten and the doctor is examining him. We might think that this is a representation of medical practice, but the hen at the top tells a different story. If it’s hungry and has a good appetite the recovery is inevitable, so, not to our surprise, superstition has a much bigger role in this particular situation. 
Image is from a 12th century Herbarium.

At a first glance this image seems a bit chaotic, but let’s read what we can from it.

Apparently, a mad dog (as implied by it’s blue head) is causing all the trouble. Man on the right got bitten and the doctor is examining him. We might think that this is a representation of medical practice, but the hen at the top tells a different story. If it’s hungry and has a good appetite the recovery is inevitable, so, not to our surprise, superstition has a much bigger role in this particular situation. 

Image is from a 12th century Herbarium.