Healthy adult chickens should look like this:

         This article is from the book Raising Chickens For Dummies.
         
                    Healthy adult chickens should look like this:

• They have bright, clear eyes.                   
• They have clean nostrils, with no discharge. 
• They breathe with their beaks shut, unless they have just been chased to be caught or it's very hot. 
• The comb and wattles are plump and glossy. In roosters, large blackened areas of the comb indicates frostbite, which may cause temporary infertility. 
• They don't have any swellings or lumps on the body. Don't mistake a full crop on the neck for a lump. 
• Their legs are smooth, with shiny skin. They have four or five toes, depending on the breed. They don't have any swellings or lumps on the bottom of the feet.
• The feathers look smooth, and there are no large patches of bare skin. Look carefully through the feathers for lice.
• They are alert and active.