Our current
batch of chicks is
the first set we’ve ever ordered from a hatchery, so I wasn’t prepared
for all of the options.  Specifically, the hatchery asked if I
wanted to spend a couple of bucks to get my chicks vaccinated against
coccidiosis.  I said yes, but now that I’ve done the research I
probably won’t vaccinate my next batch.



Coccidiosis is a disease
caused by a protozoa parasite that lives in the chicken’s gut. 
The protozoa are present in most environments where chickens are
raised, but they often cause no problems.  However, pack your
chickens into an enclosed space, add in damp litter, and your birds
will begin to eat enough of their own poop so that the protozoa will
multiply inside them to an unhealthy level.  If your flock is
malnourished, the chickens will not only sicken but may even die.

Chickens are most likely
to contract coccidiosis between four and sixteen weeks of age. 
Initially, your sick birds will just seem a little off, hunkering down
rather than feeding.  After a few days, you’ll see blood in their
droppings.  Eventually, the chickens will either die, recover
completely, or go through recurring cycles of illness.



The best way to prevent
coccidiosis in your flock is to maintain healthy conditions.  If
your chickens are out on pasture from an early age and have an automatic chicken waterer to keep their litter dry,
chances are they won’t get sick.  If you must raise your chickens
in improper conditions, the best way to keep them healthy is to give
them medicated feed.  The coccidiosis vaccine has dubious efficacy
and has only been introduced recently as a way of letting organic
growers protect their chickens against the disease in crowded
conditions.  (Most organic certification processes will allow
vaccinated birds to count as organic, but not those given medicated
feed.)



If you do choose to
vaccinate your birds, you shouldn’t give the chicks medicated
feed.  The vaccination requires several cycles of infection, which
the medicated feed will prevent.  Your chicks won’t be harmed, but
you will have wasted your money since the vaccine will be nullified.