Help! I have 2 older chickens that haven't been laying, not sure if due to age or hot Texas summer. They are Ameracaunas, about 4.5 years old. I also recently got 2 chicks and they have been kept separately. Last week I noticed 2 eggs had been laid. 1 smelled odd and had some yellow goop outside. 1 felt hollow. I threw both away. Today I found what looked and felt like a normal egg, but to be sure I decided to crack it into a jar and save for later in case something was off about it (didn't want anyone else in my family getting an unpleasant surprise) Thank God because when I cracked it it made a loud explosion sound and flung green goop everywhere. It was the worst thing I have ever smelled in my life. What could cause this? And what can I do about it? I'm not sure we even have a vet here that treats chickens. I had a hard time finding anyone to see my rabbit. Do I need to be concerned about it spreading? Of the 2 chickens one has been looking worse for the wear. They are both perky overall, pecking around the yard and doing their usual thing, but 1 has been sleeping with her mouth sort of hanging open and looks tired to me. Of course it has been 100 degrees every day for months.