i had paratyphoid last year and baytril and parastop in my opinion doesnt cure them .. they might look the part after getting treated but will always be carriers therefore the youngters will have it and so on .. some pigeons show the symptoms swollen joints and twisting kneck but some only show it in times of stress e.g racing.. mines were coming back late and sitting like hedgehogs on the roof .. got my droppings tested and found it was para .. i culled all last years youngsters and i done my stock and old racers for paratyphoid this year and they looked down for a few days but they were ok after a few days .. if they dont come round after 10 to 14 days they could well be carriers .. the jag is very harsh on them i dont think i would vaccinate again unless i had an outbreak of it .. if the birds have been given cider vinegar this also can give them a bad reaction when injected .. !!