I found the following on another site. The author speaks alot of common sense, or at least I think so. I sing the same tune.
[You must be registered and logged in to see this link.]KazJaps 02/13/04 10:35 AM
Loc: Australia
I totally agree with Caveny in that the easiest way to proceed would be to destroy this flock & start again. But is the immediate destroying of positive flocks the only available option for disease management? Well of course, no! Is the eradication of positive flocks, in every situation, always the most practical & effective method of disease control? Once again no!
These are questions that immediately come to mind:
With the destroying of flocks:
1: Are you able to find clean replacement stock & of the genetic quality that you seek?
2: What is the probability of reinfection to a new flock?
And if you keep positive birds:
3: How prominent are Mycoplasmas in your area & where would YOU be spreading Mycoplasmas to, especially if many other small flocks are positive? Certainly not to others that practise biosecurity.
4: Is there a possibility of disease containment (ie quarantine)?
5: If there is little possibility of disease containment then what does this imply about the likelihood of reinfection of a clean flock?
6: Are there positive birds in the flock showing resistance to disease? These resistant birds are valuable in breeding programs. Part of the problem with eradication programs is that if All surviving birds are eradicated in a flock, genetic resistance is not allowed to develop in a population.
And this leads to the next question that keeps coming to mind.
Why are some people once severely burned by diseases relying totally on other breeders to do all the hard work in establishing clean & resistant breeding stock? Why aren’t they doing this themselves? Where are you going to get clean stock from if everyone keeps killing their flocks and passing the buck on to someone else? And will the few clean flocks available provide RESISTANT breeding stock or are all the tested resistant birds being killed in the process of positive flock eradication?
Quote: "Unfortunately it WAS by culling that commercial flocks were cleared of this disease."
But you see, all commercial flocks are NOT clean of Mycoplasmas. The eradication programs worked well with commercial breeder flocks, but Mycoplasmas still occur in production birds (& Caveny mentioned previously it still occurs in breeding stock). Do all commercial operations immediately kill off production flocks when found positive to Mycoplasmas? No!!! If keeping flocks clean of Mycoplasmas is difficult for commercial operations, what are your chances of keeping your flocks clean? Now apply this to your own situation and take a realistic look at the likelihood of providing such strict biosecurity to your own flock. Remembering here, that you are literally putting all your eggs in one basket, relying totally on isolation as a defence mechanism. One slip up means destroying your flock & starting again.
Successful eradication of Mycoplasmas in breeding flocks was not achieved by the immediate killing of all breeding flocks found positive to MS & MG. Why would you do this when it is known that a high percentage of flocks are positive? You would be losing valuable breeding stock & eradicating a large percentage of the gene pool, including proven RESISTANT stock. Such eradication programs of well-established & wide spread diseases are not achieved overnight. It is my understanding that part of the eradication program entailed segregation (isolation) of breeding stock, treating breeder eggs, gradually eradicating infected parent stock & keeping the clean (isolated) offspring for the next breeding generation.
I do not see where the eradication of all small flocks found positive to Mycoplasmas will achieve anything productive, in situations where it is known the likelihood of reinfection is very high & when such a high percentage of the population is positive. Be realistic here. What are you achieving? Yes, if you know you have a high probability of successfully isolating your stock from Mycoplasmas, by all means, buy TESTED CLEAN stock & keep in strict quarantine. But if you are contemplating exhibiting any stock, well forget about relying on biosecurity alone, unless it is a one-way trip to the show, and forget about free ranging if there is the slightest possibility of contact with wild animals. The risks are just too high. There are no commercial flocks in Australia positive to virulent Newcastle Disease. So why has the government decision been made for the compulsory vaccination of all commercial flocks? What, isn’t the quarantine practises enough?
Take this into consideration. The majority of small flocks are positive to Mycoplasmas. Are all of the birds in these flocks showing signs of disease? NO!!!! It is the misconception I keep reading that if an animal is positive to a pathogen or is positive to antigens, it must be diseased. WRONG!!! I can’t remember now where I read this but I think it is that a large percentage of the human population carry the herpes virus responsible for the common cold sore. But it is only a minority of people that ever develop cold sores (disease). Now put this into a poultry perspective. Would you eradicate all individuals found positive to the virus or would you use the large percentage of individuals found resistant, in breeding programs? In a wild bird breeding program, would you prefer to have wild birds from the UK (found positive to antigens of the West Nile virus, therefore signs of resistance) or wild birds in the USA tested negative to West Nile virus antigens but found susceptible to the disease? The ideal would be breeding stock negative to pathogens & tested resistant to disease. But how many backyard breeders have the resources & money to do this sort of lab work?
In my situation, the reliance on biosecurity alone is such an unrealistic gamble on the health of my flock, that if I did this I would be totally irresponsible. It is much more sensible for me to prepare for the likelihood of exposure to common diseases in my area. I do this by selection/breeding of birds found to have resistance to low mortality diseases & vaccinating for the virulent diseases in my area.
If anyone wants to read up on genetic disease resistance “Poultry Breeding & Genetics” has a lot of information on the topic.
I do know someone personally who is in the process of eradicating Infectious Coryza from his breeding stock. He is achieving this by setting up a quarantine area for infected parent stock & artificially incubating eggs, rearing young stock in another quarantine area. He doesn’t buy birds anymore, never exhibits birds & lives on large enough acreage for a quarantine system to be successful.
Quote: "If my cat or dog became ill with a disease that would infect every other cat or dog they met then yes I would definately have them culled.I would expect everyone to do the same."
Why would you kill your cats, dogs over some disease that has such a low mortality rate? Why do you believe you would HAVE to kill your pet & why would you be letting a positive animal have contact with other animals? Ever thought of vaccines? Does your vet advocate killing all pets found positive to infectious diseases or advocate the vaccination of all animals? Wouldn’t he/she be doing everything to save the life of an infectious animal?
Why aren’t you upset that people DO NOT kill off all flocks found positive to Marek’s Disease? Why aren’t you upset that no one is doing anything about eradicating coccidia? Why people have been letting protozoa spread everywhere! I don’t know, I hope I’m not the only one out there that doesn’t immediately think about gathering a possie together & stringing someone else’s neck because OUR birds have contracted a disease. Unless someone has intentionally come in to my chook yard carrying an infectious disease with the sole intention of infecting my flock, the sole responsibility of my flock’s health is ALL MINE!