PINE BLUFF — Livestock producers whose lambs and kids have dark scours (diarrhea) and do not respond to standard antibiotic treatment or deworming are most likely dealing with coccidiosis, Dr. David Fernandez, Extension livestock specialist and interim assistant dean of academic programs for the University of Arkansas at Pine Bluff School of Agriculture, Fisheries and Human Sciences, said. Producers’ best option for dealing with this parasitic disease is taking steps to prevent it from ever occurring in their flock in the first place.
“Coccidiosis is caused by parasites that are shed in feces,” he said. “Infections occur when young lambs or kids ingest fecal material usually found in their water or feed or on the udder of the ewe or doe.”
It is not uncommon for adult sheep and goats to shed coccidia oocysts throughout their lives. Adults that have been gradually exposed to coccidia early in life will develop immunity, often without showing signs of disease.
“The oocysts sporulate when weather conditions are warm and moist,” Dr. Fernandez said. “Youngsters are exposed, and the disease develops over the next week or two. Unfortunately, once you have to treat your animals for the disease, the damage has already been done.”
Protozoa attack the lining of the small intestines, damaging the cells that absorb nutrients and often causing blood from damaged capillaries to enter the digestive tract. This causes dark, tarry feces or bloody diarrhea.
New oocysts are shed, and the infection can spread. Sick lambs and kids will become chronic poor-doers and should be culled.
“Producers can help ensure they don’t lose animals to the disease by practicing due diligence in regard to the hygiene of the animals’ living conditions,” Dr. Fernandez said. “First and foremost, feeders and waterers should be kept clean. It’s best to choose designs that keep feces out of the feed and water.”
Lambing and kidding areas should be kept dry and clean. Since hot, summer sunlight kills oocysts, producers can use it to their advantage to sterilize bedding and equipment that may have become contaminated earlier in the year.
Dr. Fernandez said there are a number of drugs – coccidiostats – that can be added to the feed or water to reduce the potential for coccidiosis outbreaks. Examples of coccidiostats include Lasalocid (Bovatec®), monensin (Rumensin®) or decoquinate (Deccox®). These drugs slow the rate at which coccidia are shed into the environment, reducing the likelihood of infection allowing a change for immunity to develop.
“When using coccidiostats, producers should follow label restrictions carefully,” he said.
Deccox and Bovatec are approved for use in sheep, and Deccox and Rumensin are approved for use in goats under specific conditions. However, Deccox and Rumensin are not to be used in lactating sheep or goats.
“Rumensin can be toxic to sheep if it is not properly mixed in the feed,” Dr. Fernandez said. “All three coccidiostats, especially Rumensin, are toxic to equines – horses, donkeys and mules. Be sure to keep equines away from medicated feed or water.”
In the past, once an animal showed signs of coccidiosis, producers could treat it with Albon, Sulmet, Di-Methox or Corid (amprolium). However, none of these drugs are currently approved for use in sheep or goats, and a veterinarian can no longer prescribe them off-label, as it is a violation of federal law to use these drugs on food-producing animals.