Thank goodness for Google... I'm a first timer as far as raising chicks from a day old, they are two months now but noticed one of my comets yawn.. no bigs i but thought and being a vet assistant I didn't have any experience with livestock and barnyard animals like I do with cats and dogs etc but I am trained for observing so that's what I did.. I noticed she yawned so I watched her and 30 seconds later she yawned again.. I meant to Google it and I forgot, so I saw her do it again today and yup she kept doing it so I grabbed my phone and used trusty Google n sure enough GAPEWORM comes up first on the list and by typing in chicken yawning it came right up... easily treated with apple cider vinegar it says?? I remember seeing treating water with apple cider vinegar but with medicated food I didn't need to I was told, then soon forgot.. Not good.. well they are on mash now which is not medicated and I seem to have at least one with GAPEWORM... She was panting last night in the coupe but it was hot even in northern Maine so I thought to myself it's cooling down so she'll be ok... ill Start treatment tomorrow as oi with have no cider vinegar but saw its one tsp of apple cider vinegar to one gallon of water ratio and it's that easy?? I'm hoping so...all water from now on will be treated I've had really good luck with my 12 chickens (4 different breeds) that are two months old now... my 1 year old intact male cat is still guarding them (although he kills anything and everything feathered or furred, winged or not, and he even got a rabbit cuz it was eating the chicks grain and he terminated it, to my horror) ... He helps me coupe the babies at night even tho most have gotten the hint to go into the coupe n not just find something high and get in it we have raccoons the size of med digs up here in the north woods but my cat is just like an Australian Shepherd, no joke, he heels those chickens in and everything, comes around back side while I'm sending them in.. It's quite amazing but if u are a newbie n notice ur chicken yawning? Keep watch.. it could just be a simple yawn but more than once it's probly GAPEWORM...apple cider vinegar is a must... Now I know..