Thursday, September 9, 2010

Basic Coccidiosis Facts

Over on BYC, i answer questions about Coccidiosis often.  And i have found that there are a lot of common misconceptions about how this disease - and the protozoa that cause it - work.  Today, i put together a semi-formal fact sheet about coccidiosis in chickens and published it on my BYC member page.  I thought i would share it here too.  I hope it can be a helpful resource for someone.  Please let me know if there is information missing that you think i should add.  And feel free to tell me if you think i'm way off base - just be prepared to back your argument.  ;)           ~Beth

Basic Information About Coccidiosis in Chickens

About Coccidiosis:
  • Coccidiosis is not a germ-spread disease, like other things.  It is a condition in which the protozoal parasites or oocysts, which naturally live in the chicken's intestines become too numerous for the chicken to handle and make the chicken sick.  Thankfully, once your chicken has endured and recovered from coccidiosis, caused by a particular strain of this protozoa, it develops a resistance or immunity to that strain and will not get sick from it again.

  • The "oocysts" that cause coccidiosis live in the soil and reproduce in the intestinal tract of your chickens.  Chickens develop their own intestinal populations of protozoa by picking up oocysts from the soil and from the feces of other chickens.  

  • There are at least 7 strains of coccidia that affect chickens.  Your soil may have one or several.

Coccidiosis is a species-specific disease.  


This means that your dogs can't "catch" coccidiosis from your chickens or vice-versa.  Sure, dogs (and pretty much all birds and mammals) can get coccidiosis, but each strain of coccidiosis affects only one species of animal.

How does medicated feed work?  


Most medicated chick starter available to back yard chicken folks contains the ingredient Amprolium. Amprolium is a thiamin blocker.  It works by blocking the absorption of the vitamin B1, which interrupts the development of the growing protozoa in the intestines of the chicken.  Medicated feed can work if and only if your chicks are simultaneously exposed to coccidia protozoa.  By this method, your chicks may be able to develop their resistance/immunity to coccidiosis, gradually without experiencing infestation.  If you are using medicated feed and simultaneously, meticulously, removing each and every dropping from your brooder and keeping your chicks away from your soil, you are preventing them from building resistance to a deadly disease.

Does medicated feed prevent coccidiosis?  


Maybe.  If you don't simultaneously expose your chicks to soil and/or adult droppings, medicated feed cannot do its job.  And even if you do, it may or may not work.  

Are there natural ways to prevent coccidiosis?  


Absolutely.  For the back yard flock, natural prevention of coccidiosis is entirely possible.  If you have ever seen a hen raise a brood of chicks, you may notice that she begins teaching her chicks to scratch in the soil for food immediately.  As soon as those babies are dry, give or take a couple of days, exposure begins.  
Subsequently, hen-raised chicks rarely get coccidiosis.  So, method one:  let your broody hen raise her own chicks.  But, since most of us don't start out with a broody hen and her chicks, we need ways to mimic her methods:


1.  If possible, allow your chicks access to the soil as soon as you get them.  The sooner they hit the ground, the sooner they start learning to be chickens.


2.  For many of us, #1 is difficult because of work schedules or weather or whatever.  Another way to mimic this is to actually shovel small amounts of soil from the chicken run and place it in the brooder with the chicks.  They will scratch through it and expose themselves to the oocysts in your soil.  This should be done regularly so as to mimic daily exposure to the soil.


3.  Once your chicks' feathers grow out, move them to the outdoors/coop situation as soon as possible.  The sooner they are experiencing a full-fledged chicken life, the sooner they can solidify their resistance to coccidiosis.

What if they get coccidiosis anyway?


Medicate.  I have not had an outbreak of coccidiosis for over a year, and i make every effort to raise my chickens without medication or drugs of any kind, but i still keep a container of Corid (liquid Amprolium 9.6%) on hand just in case.  If i see symptoms, i medicate, no questions asked.  I medicate the entire flock (of that age group), even if only one shows symptoms.  This is done by mixing 2 teaspoons per gallon in the drinking water.  Isolate the affected flock so that the only water they drink is medicated.  Remix and change the water every day for 5-7 days.  Most often, symptoms will disappear by about day 3 of medication.


How do i know if my chicks have coccidiosis?


1.  Fluffiness.  Fluffiness?  Yes.  Often, just one or two chicks in your flock will be the first to tell you that you have a problem.  One of the two most common first obvious indicators of coccidiosis is one chick, all fluffed up, sleepily huddling in a corner or near a heat lamp.  It sounds arbitrary, but when you see it, you'll remember it.


2.  Bloody feces.  Not to be confused with natural intestinal shedding, which sometimes looks like a small amount of blood mixed with the feces, coccidiosis will often cause truly bloody feces, sometimes containing more blood than feces.


3.  Time line.  If you're not sure whether you're dealing with coccidiosis, you can often verify by reviewing your time line.  This is because an outbreak of coccidiosis in chicks generally occurs 2-4 weeks after the chicks first begin being exposed to the soil/adult droppings.

Can adult chickens get coccidiosis too?


Yes.  They can.  There are exceptions to the rule, but on the rare occasion that an adult chicken comes down with coccidiosis, it is usually because it has been introduced to a new strain of oocysts in the soil.  This can happen if a chicken is moved to a new location or if adult chickens from another location are introduced, exposing the "native" chicken to new strains of protozoa.  Adult chickens with a coccidial infestation generally take it much harder than a chick and may take longer to recover.  

After the Medication


Amprolium works by limiting the absorption of vitamin B1.  This and the enormous strain placed on the chicken's body due to the infestation, warrant extra vitamins and other nutrients after the medication is gone and the chicks have recovered from the coccidiosis.  Scrambled eggs and vitamin supplements (often found at the local feed store) will help your chicks to become healthy and vibrant again.

The Opinion Portion


After hours upon hours of reading, discussions with other chicken keepers, and experiments and experiences with my own chickens, it has come to be my opinion that back yard chicken keepers make a huge mistake when they buy into the idea that you can prevent coccidiosis by keeping an immaculate coop/brooder.  Any chicken kept in any natural or sort-of natural situation, in which it is exposed to the soil, must develop resistance to the oocysts that cause coccidiosis.  It can do this gradually, by picking up a little at a time from an early age, or it can get really sick all at once at a later age, and have to be medicated, or possibly die.  As a resident of hot and humid East Texas (a fantastic breeding ground for coccidia oocysts), i have had great success in preventing outbreaks of coccidiosis by simply exposing my chicks to soil and adult feces as early as possible and consistently.  
I also do not use medicated feed of any kind.  Medicated feeds were created for large population chicken "factories" where it is impossible to give chickens fresh pasture or keep them from being exposed to an overwhelming number of oocysts, from the sheer population of chickens in a relatively small area.  If i were doing that (which i do not plan), then i would use medicated feed.  I do not believe it is necessary for the back yard chicken keeper, especially when medications such as Corid so often do such a good job of nipping coccidiosis in the bud when it does show its head.

*The information presented here is based on personal experience and observation, discussions with other back yard chicken keepers who are smarter than me, and numerous on-line sources, which confirm the scientific fact portions of this page.  If you are interested in reading more of the scientific mumbo jumbo (a.k.a. facts) about coccidiosis in chickens, this is a very helpful link.  I don't agree with all of the application portion, but facts are facts.  And the presentation is very helpful and easy to understand.

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