I'm very sorry to hear about your decision. I've seen you posting on here and know you're compassionate.
First off, before you cull, I'd call an extension agent or your state agricultural college and talk to them about getting a necropsy on two of them. that way if you decide to keep chickens, you'll know whether or not it was something environmental. Even if you think you won't keep them again, you might change your mind as it's not always this hard - and in fact is rarely this hard.
There are some contacts here at the end of this post for you to that end.
As for dispatching, the kindest way to do it is by cervical dislocation. If you have to do this before taking birds in, here's a good guide to it with a diagram:
http://www.inspection.gc.ca/english/anima/heasan/disemala/avflu/plan/plan-appje.shtml
I'm so very sorry. My heart really breaks for you. /hugs
Here are the contact links and numbers:
http://www.hcfair.net/Livestock/Poultry
20PLAN.pdf
The contact listed is your state NPIP rep.
Your UF contact:
Gary D. Butcher, DVM, PhD
Professor, Extension - Avian Diseases
Large Animal Clinical Sciences
PO Box 100136
2015 SW 16 Ave
Gainesville, FL 32608-0125
(352) 392-2212 ext. 5695
Fax: (352) 392-3029
email:
[email protected]
And here are extension offices in the different counties:
http://solutionsforyourlife.ufl.edu/map/
If that doesn't work, here's a list of certified avian vets for Florida:
Florida
Deerfield Beach, FL - Daryl Nick Backos (Backos Bird Clinic) - 954-427-0777
Jacksonville, FL - Rhoda Stevenson (Exotic Bird Hosp Inc) - 904-268-0204
Jupiter, FL - April Romagnano (Animal Health Clinic) - 561-799-7717
Lake Worth, FL - Greg John Harrison (The Bird Hosp PA) - 561-964-2121
Loxahatchee, FL - Susan L. Clubb (Rain Forest Clinic for Birds) - 561-795-4878
Lutz, FL - Suzanne Victoria Topor (Livingston Animal & Avian Hosp) - 813-979-1955
Monticello, FL - Kitty Remington
Myakka City, FL - Michael Bonda - 941-359-3800
Orange Park, FL - Michelle Curtis Velasco (Fleming Island Pet & Bird Clinic) - 904-264-7387
Palm Harbor, FL - Joel D. Murphy (An/Bird Med Ctr of Palm Harbor) - 727-784-0558
Port Richey, FL - Susan Sattler-Augustin - 727-863-2435
Tampa, FL - Teresa L. Lightfoot (FL Vet Specialists) - 813-933-8944 -
http://www.exoticseminars.com
Wesley Chapel, FL - Margaret Anne Wissman - 813-973-3044 -
http://www.exoticpetvet.net