Coccidiosis in Poultry

COCCIDIOSIS is one of the most flock-devastating protozoan parasitic diseases that can effect backyard chickens. ‘Cocci’ management should forever be at the forefront of any good health and nutrition program for your flock.

If you’ve ever survived a round of Cocci in your own flock, you know what I mean about devastating. If you’re new to the Fancy with a cute little backyard flock, your days are numbered for heartbreak. It will come from nowhere in the form of a once healthy nice little bird suddenly looking as though they’ve ruffled their feathers. They may already be sulking in a corner. Then comes the bloody diarrhea or the oozing of clear fluid from the mouth when you pick them up. By this time, it’s too late – most of the damage is already done, and it’s only taken about 96 hours to get there. Cocci outbreaks are particularly disappointing because they usually strike our youngsters. Adult birds have some resistance to it, but only to the particular strain they’ve already been exposed to. If you bring in a brand new strain from another farm on your shoes, and conditions are right for their multiplication (damp litter or soil, spring-like temperatures), the adults will fall victim too. (This is a good reason to practice ‘biosecurity’, which is a subject for another day.)

Chickens are not the only birds affected by Coccidiosis. Turkeys, geese, and ducks, among others, are affected as well. Cocci are a naturally occurring protozoan parasite found in almost every soil sample. There are about nine different strains within the Eimeria genus that do harm to chickens. Some of these strains are questionable, but most are verifiable. I happen to know that my soil samples contain Eimeria of the Necatrix stain. There was poultry kept on my farm before I owned it, and that virtually guarantees the Cocci eggs (oocysts), are on site.

The nature of a chicken or duck’s eating habits – poking and dibbling amongst the litter (and manure), makes them vulnerable to cocci infection. The cocci oocysts are shed by previously infected birds through their droppings into the litter or on the ground. Then another bird comes along and ingests the oocysts, which are then crushed by the gizzard and the sporozoites are released. To over-simplify – from there, they live, replicate, and destroy different parts of the digestive tract, depending on the strain. The entire process from ingestion to the shedding of oocysts in the droppings is between 4 and 6 days.

The damage is irreversible. It is only when a bird is infected with a relatively small quantity of oocysts, that the bird then has an opportunity to fight off the infection and build immunity to future infection. Keeping litter fairly clean helps to keep the oocyst population down, and gives your birds a better chance of surviving their infection.

Keeping the litter of your youngsters very clean until adulthood is one way of reducing cocci outbreaks, but there are better ways. One better way is to feed your youngsters medicated feed from hatch to adulthood. To date, this is the most effective way. The type of medicated feed you want to use is one that contains Amprolium. Some starters also include Bacitracin, which is OK, but that prevents most forms of enteritis – which sometimes occurs as a result of a mild case of Coccidiosis.

There is also a fairly new Cocci vaccine on the market. It is available through at least one of the suppliers who advertise in the Poultry Press. I would call around though, more than one may carry it.

For those waterfowl breeders out there, I have good news. Previously thought to be harmful to ducks, the latest veterinary science claims that neither Amprolium nor Bacitracin are toxic to ducks. As part of a study, I have had my waterfowl on medicated feed for over a year now, and everyone is thriving.

I don’t think this article would be complete unless I cautioned you against using some of the previously recommended medications for Cocci, that have now been designated as toxic to chickens and waterfowl at dosages required to be effective. The primary ones are the family of Sulfonamides. Among these drugs, sulfaquionoxaline (‘SQ’), is one of the most toxic. There’s also a sulfamethazine-based product sold at a well-known farm supply store under the product name ‘Sulmet’. I personally would never use this product on my birds.

In conclusion, remember your easy options for never having to weep over the death of your next ‘Best of Show’ from something as simple to control as Coccidiosis. Start and maintain your youngsters on medicated feed for the first year, keep that litter clean and dry to keep the population of oocysts in check, or, consider the Cocci vaccine. And, if all else fails, there’s always the very expensive Amprolium in liquid form until the powder’s back.