My bantams keep going lame and then become completly paralysed with a week to 10 days.
Thet free range in the garden and I give grain and scaps...they breed well but keep getting this awful disease.
Even when paralysed they are still happy and eating.
No ticks and no loose droppings.

Please help

Will Graves' book Raising Poultry Successfully reports that Marek's disease causes paralysis. You should have your hatchery vaccinate for Marek's every time you buy from them.

The Merck Veterinary Manual says "a transient paralysis syndrome has been associated with Marek's disease; chickens become ataxic for periods of several days and then recover." Other selections: "Once infected, chickens continue to be carriers for long periods and act as sources of infectious virus." . . . "Every flock, except for those maintained under strict pathogen-free conditions, may be presumed to be infected."

Sometimes animals will react to toxins in strange ways, but I have no way here of knowing if this could be a problem also.

As I am not a veterinarian, I cannot say for sure this is your problem. The odds are your local vet doesn't know much about chickens unless you live in a broiler or layer production area, but you should consult one for advice. Marek's vaccine is available for use on the farm if you hatch your own or buy nearby. Some of the hatchery catalogs list it. One of the problems of buying from another breeder rather than from a hatchery is that the local person may pass along things like this inadvertently.

Hope this helps! Good luck.

Many breeders have successfully bred for resistance to Marek's. For the production flock, vaccination is the number one choice, but for the breeder, selection for resistance is probably the best bet. Nobody would intentionally breed susceptible stocks, but the person buying production chicks has no say in the matter. I have seen cases of this transcient paralysis, and I attributed it to Marek's, and possibly to calcium deficiency. It always seemed to happen to pullets in the first few weeks of production. I have seen paralysis in birds that were raised entirely on scratch feeds as well.