Dirty bums need prompt attention

Small ruminants come up with a variety of reasons to have diarrhea. A change in feed, weather, stress or disease can result in a miserable animal with a messy hind end.

One cause of diarrhea in young lambs and kids is coccidiosis, but by the time diarrhea is evident, the animal is likely already experiencing disease. Dr. Heather Glennon, small ruminant Extension specialist in North Carolina, recently provided tips on managing coccidiosis in lambs and kids.

“Coccidiosis can affect cattle, sheep, goats, chickens, cats and dogs,” Glennon said. “The nice thing is that it’s host specific, even between sheep and goats. Sheep and goats share a lot of diseases if they’re kept together, but they have different coccidia.”

Coccidia are microscopic, single-cell protozoa. Ten different species can affect sheep and goats, and not all cause disease outbreaks. All animals carry a small population of coccidia. Young animals are most at risk for disease outbreak and when they have it, they suffer from severe diarrhea and dehydration.

“Oocytes can be passed in a normal pellet,” Glennon said. “It takes a couple days of warm, wet weather for the oocyte to sporulate (or hatch). At that point, they become infective to the animal. If the animal grazes in an area where feces are present or eats from a contaminated feeder, they ingest the sporulated oocytes. This cycle might be only two to seven days long, depending on the weather.”

Coccidia have a two-part lifecycle. They begin as free-living outside the animal, and once ingested, the parasitic phase begins. Warm, wet days speed up the process.

Ingestion can occur when animals lick a body part with manure on it or eat from a contaminated feed pan. Once oocytes enter the body, they enter the cells that line the small intestines. Here, they reproduce and invade the epithelial cells lining the intestines.

“The coccidia destroy the lining of the small intestine where nutrients and fluids are absorbed,” Glennon said. “When there’s damage to small intestine, if it’s long enough and severe enough, animals never do well because their small intestines can’t absorb nutrients. The quicker it’s treated and the shorter the period the animal has diarrhea from a coccidia outbreak, the faster they return to normal. In some cases, the small intestines heal.”

At about one month of age, animals lose the immunity they received from colostrum. Animals don’t generally build their own immune systems until six to eight months of age and are most likely to suffer from coccidiosis between one and five months old.

Most coccidia outbreaks occur during stress periods, usually around weaning. Changes in diet, location, weather and cohorts can be stressful. Animals that have been transported and handled by multiple people or given vaccinations or dewormers are more susceptible to a coccidiosis outbreak. They have likely already ingested oocytes, which are now waiting in the gut for the right conditions.

In some cases, diarrhea isn’t evident. Animals may appear normal, but their small intestines are damaged. This reduces feed intake and feed conversion, resulting in poor growth. Because these animals often remain untreated, they’re more economically costly than those with diarrhea.

Clinical signs of coccidiosis include mild diarrhea that may become progressively worse if untreated. This leads to potentially deadly dehydration.

“They might have a rough hair coat or open fleece,” Glennon said. “They become weak and anemic. These signs are similar to those with other gastrointestinal parasites but there may also be blood, which signals coccidia.”

If an animal has scours, the best way to determine whether it’s due to coccidiosis is through a fecal egg count. A count over 5,000 oocytes per gram of feces is too high.

“You may not see many oocytes because animals can become sick before they start shedding oocytes,” Glennon said. “It takes a big stressor event for them to shed. Not all coccidia species will cause disease. Even if you see a few in the fecal, they may not be the ones causing the diarrhea.”

Coccidia don’t usually affect animals under 21 days of age. Animals in this age group with diarrhea should be checked for other parasite infections like Haemonchus (barber pole worm), Trichostrongylus (roundworms) or tapeworm. Check records for a diet change or whether animals were moved to a new pasture.

Because coccidia are protozoans, typical dewormers are not effective. Several coccidiostats are available, but some are not labeled for sheep and goats. It’s essential to work with a veterinarian for guidance on extra label use.

There are drug treatments (such as amprolium) for coccidiosis, but not all are approved for sheep or goats so consult your vet to determine which product to use. Sick animals probably aren’t drinking as they should, so it’s best to individually drench sick animals to ensure they receive the correct dose. Some treatments have a bitter taste, so it’s helpful to flavor the mix so animals don’t fight oral syringing. If medicated water is provided instead of a drench, it should be the only water source.

Amprolium can seriously deplete lambs’ or kids’ thiamine (vitamin B1) levels, so many producers administer B1 injections during treatment for coccidiosis. Hydrate animals, provide electrolytes and support with a bismuth stomach coating product (like Pepto-Bismol) to aid in recovery.

“If the farm or animals have a history of coccidia outbreaks, consider feeding a ration that has a coccidiostat, or ionophore, in it,” Glennon said. “A coccidiostat (Bovatec®, Rumensin®) doesn’t kill coccidia but will slow shedding in the feces.” Minimizing stress is also critical in preventing coccidiosis.

Feeding a coccidiostat during gestation can help slow oocyte shedding and coccidia outbreaks. It’s also helpful to add a coccidiostat to creep feed three weeks prior to weaning to help young lambs or kids through weaning stress. There’s some evidence that resistance can occur if a coccidiostat product is fed year-round.

There are no peer-reviewed studies on organic products for coccidiosis, but Glennon said the summer perennial Sericea lespedeza (common name: Chinese bushclover) fed as pellets or on pasture keeps parasite counts down.

“Long-term feeding of Sericea lespedeza has been shown to possibly bind minerals and slow growth,” Glennon said. “There is also research on oregano oil – it will decrease the number of coccidia oocytes in feces but only by about 50%.”

Reducing fecal-oral transmission is an important aspect in preventing coccidiosis.

“Keep pens dry and clean and elevate feeders,” Glennon said. “Clean water buckets that have even a few fecal pellets in them. Make sure youngstock have a clean, dry area for feeding. Provide good nutrition for good immunity, which includes vitamins and minerals, and make sure all newborns have adequate colostrum from healthy moms.”

by Sally Colby