Coccidiosis is found in almost all goats, present in their small intestine. Older goats are often not affected, unless under stress. Baby goat kids are at particular risk, and left untreated, an outbreak can wipe out much of your young herd.
There are a number of factors, stress being the greatest. Any type of change for your goats can cause stress and trigger an outbreak. Some examples of stress causes could be:
Coccidia has a 21-day life cycle. It lives and produces oocycsts (coccidia eggs) in the cells of the small intestine. Adult goats often have a level of immunity, more so than the young goats. Oocysts (eggs) are expelled via feces into the environment, where after 2-3 days, they are able to infect another host. This is why it is imperative to add to/change the bedding, and upon completion of kidding, to sanitize the area, to prevent build-up. Coccidia is very resistant to disinfectants, and thrives in warm, moist environments. Hot sunshine will help kill it, as will a dry environment.
Loss of appetite, dehydration, emaciation, weakness, anorexia, death. Depending on the severity of the case, diarrhea may be short-lived or very severe, dark and bloody, even to the point of death. Diarrhea can be with or without mucous.
Prevent by eliminating stress factors such as those listed above, providing dry bedding, clean water, and clean feed, sanitizing, and feeding coccidiostats (Monensin/Rumensin, Decoquinate/Decox, lasalocid / Bovatec). Coccidiostats can be administered through the feed, or through their water supply. If you are planning to treat your baby goats before weaning as a preventative measure, it is necessary begin the treatment 21 days before weaning, in order for the coccidiostat to be effective at the time of weaning. In severe cases of repeated outbreaks, it may be necessary to inject all kids with a sulfa drug. Talk to your vet if this is your situation, as this method of prevention is expensive and labour-intensive. If you keep your baby goats with the does after birthing (this is not recommended because of the high likelihood of passing diseases from doe to kid, see "baby goat" for more info), consider treating the doe 21 days before she kids, to lower the amount of oocysts in her feces, thereby lowering the risk of contaminating her kid. After kidding is done, be sure to clean out and sanitize your barn before the next kidding begins.
If you have an outbreak in your herd, it can quickly become serious, causing much loss. Isolate and treat those who are infected, clean out your pens and sanitize. Sulfa drugs are usually effective, such as sulfamethazine, sulfadimethoxine (Albon), sulfaguanidine, tetracycline, amprolium (Corid R). These drugs (called coccidiostats) are not necessarily labelled for use on goats, and most if not all will require prescription (or a vet-script) from a vet for extra label use. These drugs will not kill coccidia, but will slow down the growth and help reduce the number of oocysts that are being excreted. Once you have gotten coccidiosis, it may be a good idea to continue to add coccidiostats such as those listed above (Monensin/Rumensin, Decoquinate/Decox, Lasalocid / Bovatec) until kidding is finished, and you have a chance to properly clean out and sanitize your barn.
Mike Metzger, Michigan State University Extension
Merck Manual: Veterinary Manual
Ontario Goat: Success from the Start!