Frilled Dragon "neck pouch" please help

Hello, I was hoping to get advice on our frilled, Mia. She has a few different symptoms; she is lethargic, has no appetite (but will drink water), she will continually vent and she has a "neck pouch". She is three years old, has a healthy history, but recently lost her companion (he went due to dehydration [our vet didn’t seem the most knowledgeable]). She had these problems before her companion passed, but they seem to be getting worse. She is losing weight and energy, and we are currently feeding her cricket paste through a syringe and supplementing with Jump Start. No one has been able to tell us what exactly the neck pouch is, it is an inflation of the loose skin around the bottom of her neck and under the frill. We have found mostly air but also liquid in it. She is able to breathe, eat and drink with the pouch just fine, and it will even deflate day to day. If anyone could help us out I would really appreciate it. Thank you for your time.

Enclosure: H 3’, W 3’, L 6’
Temperature: 75-80, 90-95 in basking spot
Substrate: Care Fresh
Misc: Sandbox, 2 UTH’s, 2 18" UVB’s

sorry to hear about the little bugger.... the only thing i can think of is either parasites... or goiter.

http://www.endocrineweb.com/goiter.html

I would aspirate the pouch and submit fluid for aerobic and anaerobic culture and cytology. That should give you a good start.