Fowl Cholera
Have recently received results from necropsy on 18 week pullet. Diagnosed avian cholera. Am I better off to cull the entire flock and start again?My main concerns are 1. Are all my birds now carriers if they have been exposed? (some have been symptomatic but seem to have recovered) 2. Can't find any info on weather or not the eggs will be safe to eat and my husband only likes runny egg yolks. 3. How long before I can get new chickens if I do have to cull the entire flock? I am hoping total flock replacement is not the case as I have some lovely silver, gold and blue laced Wyandotte pullets and wheaten maran pullets. Am also concerned that it will be hard to ever achieve a clean environment again if I do depopulate as there is a large wild bird presence as well as wild rabbits and some mice.
Fowl cholera presents in various degrees. Acute cholera causes rapid death. Chronic cholera can take weeks to cause death.
Typical carriers are rodents. A good systematic rodent control program will help reduce exposure.
Fowl cholera is caused by Pasteurella multocida. It is not transmitted via the eggs, so your husband can continue to consume eggs.
I would not kill the flock. Transmission is usually quite slow. Initiate a vaccination program for all inbound chickens. This is best done before they begin to lay.
Have your vet advise you regarding vaccination and vaccine choice.
These birds that you have might be worth maintaining the flock alive. Ask for antibiotic resistance to the lab and try to vaccinate (only if healthy) the birds. New birds, if introduced to the same flock, should be vaccinated twice previously, if possible, with a vaccine prepared with the same strain that was isolated.
Birds will stay carriers, so make sure biosecurity is well maintained. Rabbits, rodents, wild birds are all carriers, so separation from your birds should be kept.
Do not worry about eggs.
Yosef Huberman Yes, absolutely right! Biosecurity is very important to prevent not only cholera but other dangerous poultry diseases as well.
How did you evaluate the vaccine program life or killed in comparative with treatment program?
Regarding fowl cholera (in chickens), the best is to use dead or inactivated vaccines elaborated with the present local strain that is actually causing the outbreak in the farm. The protection is good if the vaccine is well grown and a good adjuvant is added. I recommend aluminium type adjuvants. Treatment with antibiotics may stop the mortality but usually Pasteurella multocida remains in the farm and for that reason, it is highly recommended to vaccine each new batch of pullets before laying, given at least 2 subcutaneous injections separated by 3 or 4 weeks each. If the disease persists, the best is to isolate and include new strains in the vaccine at least every 2 years because bacterial antigen variation occurs frequently. Therefore, I advise to contact a vet with access or collaboration with local laboratories.
Following the above message - In your case, an autogenous water in oil emulsion inactivated vaccine is the prevention of choice. It made from microorganisms which have been isolated directly from your farm.
Yair Saar, Yes, it could be a good choice as far as a double emulsion is used (water in oil in water), not a simple one (water in oil) because the lipopolysaccharide of Pasteurella multocida, together with the oil, could produce deleterious post-vaccinal reactions, particularly in young birds.
If you got a problem, you can use the vaccines for a few flocks or 1-2 years with continuous improving biosecurity and rodent control and monitoring pathogens by checking titer or isolation. If free from fowl cholera so no need to the vaccine.
