Coccidiosis - Sheep - Poultry - Cattle - Prevention and Treatment

Coccidiosis is a parasitic disease causing an acute invasion and destruction of the intestinal tract of animals caused by coccidian protozoa (microscopic, spore-forming single celled parasites that live and reproduce within an animal cell.)

Coccidiosis spreads from animal to animal by ingestion of infected tissue or contact with infected faeces. Coccidiosis is a disease that can infect dairy and beef cattle, sheep, goats, pigs, poultry, rabbits, horses, dogs and cats. In horses, dogs and cats it is less frequently diagnosed but can result in clinical illness.


Coccidiosis Symptoms

The symptoms of coccidiosis include diarrhoea which may have traces of blood in severe cases, fever, lack of appetite, weight loss, emaciation and in extreme cases death. Fortunately, many infections of coccidiosis are not severe enough to present obvious symptoms.

Coccidiosis is most common in young animals in confined areas that have been contaminated with oocysts (the stage of the coccidian parasite that is shed in the faeces of animals infected with the parasite.) The clinical symptoms of coccidiosis are most prevalent where an animal is in an overcrowded area, poor sanitation, poor nutrition, stressed from being weaned, transported, sudden environmental changes or severe weather or change in feed.


Coccidiosis Species

If an animal has loose droppings the first thing you want to rule out is coccidiosis, which has a number of species varying in severity. Coccidiosis is a parasite that attacks the animals gut and there are six species of Eimeria(coccidiosis) which are an issue, E. tenella, E. brunetti, E. necatrix, E. maxima, E. mitis and E. acervulina.

All of these species live in and attack specific areas of the gut and the only way to treat and prevent coccidiosis is to establish which specific coccidiosis strain is causing the disease. Frequently the issue can be that there is more than one species working together to cause the disease and symptoms.


Coccidiosis Life Cycle

A better understanding of the life cycle of coccidiosis is a crucial factor in controlling the parasite. The parasites life cycle starts with an unsporulated oocyst which is like an egg with the early stage and yet to develop into coccidiosis. At this stage in its life cycle even if ingested it can’t currently cause the disease.

The coccidiosis oocyst becomes infective when it sporulates which it can do in under 24 hours in a humid temperature of around 25-30ºC

The oocyst can survive for several years as it is protected by a thick almost impermeable wall which protects it from extreme temperatures, both hot and cold and even most common disinfectants. This makes it very difficult to destroy.

When an animal ingests the sporulated oocyst the gut has chemicals in which break down the wall of the oocyst and enable the coccidiosis to become infective and is called the sporocyst. Sporocysts develop into sporozoites which are able to attack the cells of the gut walls and replicate.

The action of the sporozoites replicating in the cells of the gut cause the cell to burst and starts the next stage of coccidiosis which is called merizoites. The invasion and destruction of the gut wall continues and eventually leads to the production of more oocysts which pass through the animal in their faeces, this enables the disease to spread to other animals.

Through the life cycle of the coccidiosis a single oocyst can destroy several thousand cells in the gut so if an animal is infected by eating a large number of oocysts then this means that millions of cells in the gut can be destroyed.

However, if an animal eats a few oocysts and only a few thousand cells in the gut are destroyed, the animal may have no ill effect and build up an immunity to coccidiosis.


Coccidiosis in chickens

If a chicken has loose droppings the first thing that needs ruling out is coccidiosis. In severe cases, chickens will be in great pain and will stop eating and will hunch over with its feathers ruffled. The attack on its gut will stop the guts absorption of nutrients and will give it diarrhoea and weight loss.

If poultry have a severe case of E.tenella coccidiosis it can cause the bird to bleed into its gut which will be seen in the birds faeces. It can also develop anaemia which will be demonstrated by losing colour in its comb and wattles.

Poultry that ingest a few oocysts without developing any of the clinical symptoms although they may develop immunity, unfortunately, they can produce millions of oocysts which infect the rest of the flock. Chicks don’t develop an immunity from their mothers and are at high risk of developing coccidiosis with or without clinical symptoms but should build up an immunity.


Treatment in Poultry

There are three important components that must be adhered to successfully treat coccidiosis.

  1. Firstly the poultry need to be treated to kill the coccidiosis and stop further damage to the gut, this requires an anticoccidial medication.
  2. Use antibiotic therapy to control the bacterial disruption in the gut.
  3. Your poultry will need nurturing in a warm dry environment continuing any advised medication regime. Multivitamins and a probiotic to restore gut flora with a product such as Beryl’s Friendly Bacteria.


Anticoccidial medication

Anticoccidial medications are not suitable for use in organic poultry but can be used for conventional poultry systems. Anticoccidial medications are typically added to the chicken’s food, examples of these medications used in chicken feed are below:

  • amprolium (e.g., Amprol, Corid)
  • decoquinate (e.g., Deccox)
  • diclazuril (e.g., Clinacox)
  • halofuginone hydrobromide (e.g., Stenorol)
  • lasalocid (e.g., Avatec)
  • monensin (e.g., Coban)
  • narasin (e.g., Monteban)
  • nicarbazin (e.g., Nicarb 25%)
  • salinomycin (e.g., Bio-Cox, Sacox)
  • semduramicin (e.g., Aviax)
  • sulfadimethoxine and ormetoprim 5:3 (e.g., Rofenaid)

Alternative medications need to be sought for organic poultry, one option is the coccidiosis vaccination. There are various vaccines for different species of poultry as different strains of coccidia affect different species.

There are also two different types of coccidiosis vaccines: virulent and attenuated. The most common being virulent, which means it includes a low dose of the live parasite to stimulate immunity.

Attenuated vaccines don’t contain the live parasite, this makes them have a lower productive and pathogenic potential, this is a major advantage of attenuated vaccines.


Coccidiosis in cattle

Young calves are susceptible to coccidiosis which is caused by protozoan parasites called Eimeria spp. The first sign of the infection is diarrhoea. The most common and pathogenic species of coccidiosis are E.zuernii, E.bovis and E. alabamensis. Infection caused by these prevents absorption of nutrients in the gut which causes lack of appetite, diarrhoea and even dysentery.

The most common time for outbreaks is 3-4 weeks after recently weaned calves are mixed. Overstocked dairy calves in contaminated housing is a high risk. A major risk of the disease comes from contaminated watercourses so this is particularly an issue for spring-born beef calves in the summer.

Surface water is always a potential threat as it can be a breeding ground for coccidiosis, salmonellosis, leptospirosis and paratuberculosis. Where possible any areas of surface water should be fenced of.


Clinical symptoms of coccidiosis in cattle

In severe cases of coccidiosis, cattle will demonstrate a sudden and profuse onset of foul-smelling diarrhoea which will contain both blood and mucus, the cattle will also have staining of the tail and perineum. Cattle may not have an elevated temperature but can look emaciated and have no appetite.


Coccidiosis treatment in cattle

All calves need to be moved from pastures infected with coccidiosis. For both treatment and prevention of the disease, Toltrazuril and diclazuril can be used. Your vet should be consulted on the best treatment for your herd and whether oral fluid therapy is required.


Coccidiosis in sheep

Lambs typically at 1-6 months old are susceptible to E crandillis and E ovinoidalis pathogens, there is also E ovina which seems to be less pathogenic. Lambs are frequently infected by older sheep which have often built up an immunity.


Symptoms of coccidiosis in sheep

The symptoms of coccidiosis are diarrhoea which can contain mucus or blood, lack of appetite, dehydration, fever, weight loss, anaemia, wool breaking and sudden death. The ileum, cecum and upper colon often are affected most, there can also be mucosal haemorrhaging. Flystrike and secondary bacterial enteric infections may accompany coccidiosis in lambs

Lambs from 1 – 6 months old that are in intensive grazing areas or in lambing pens. The clinical symptoms of coccidiosis are most prevalent where an animal is in an overcrowded area, stressed from being weaned, transported, sudden environmental changes or severe weather or change in feed and contamination with oocyst’s from ewes and other lambs.

Coccidiosis prevention

As coccidiosis will always be rife under these management systems coccidiosis is predictable. So proactive prevention is the best course of action. Coccidiostats should be administered prophylactically for 28 consecutive days beginning a few days after lambs are introduced into the environment.

A concentrated ration containing monensin at 15 g/tonne can be fed to ewes from 4 wk before lambing until weaning, and to lambs from 4–20 wk of age. The toxic level of monensin for lambs is 4 mg/kg. Lasalocid (15–70 mg/head/day, depending on body wt) may be effective. A combination of monensin and lasalocid at 22 and 100 mg/kg of diet, respectively, is an effective prophylactic against naturally occurring coccidiosis in early-weaned lambs under feedlot conditions.


Coccidiosis Treatment in sheep

Once coccidiosis is diagnosed treatment of affected sheep is not effective but if caught early the symptom severity can be reduced. A one-off treatment of toltrazuril (20 mg/kg) significantly reduces the oocyst output in naturally infected lambs for up to 3 weeks. Diclazuril (1 mg/kg) is an effective oral anticoccidial in lambs and is administered once at 6 – 8 wk of age (most common) or twice (at 3 – 4 wks of age and again 3 wks later). Sulfaquinoxaline in drinking water at 0.015% concentration for 3–5 days may be used to treat affected lambs. In groups of lambs at pasture, frequent rotation of pastures for parasite control also helps control coccidial infection.

Lambs that have been exposed early in life from infection from the ewe or contaminated housing usually build a natural immunity to coccidiosis.



Farming News

Orf virus in sheep

Nematodirus warning as weather warms

Lambing losses causes lamb value increase

Ruminants feed conversion and water treatment

Water Supply – There’s something in the water

Smart Farming overview

Cut farm inputs by improving water efficiency

Sustainable agriculture

Farming Solutions

Agrismart offers a comprehensive range of products chosen specifically to resolve modern day farming issues at a lower cost than currently available. All our farming solutions are designed to offer smarter farm management solutions, allowing farmers to address core farming issues and take back some control in an industry that’s so reliant on the unpredictability of nature, disease and weather.

Farming Solutions

Other Farming Solutions


Monitoring temperature in cattle is an effective way of preventing illness as early warning allows treatment before illness appears.

Cattle Bolus


Agrismart currently have Livestock ID, equipment ID and security tags in production! Sheep registrationsheep taggingcattle registrationcattle tagging



Dairy & Beef Sires. We offer semen that will match your specific breeding requirements and that suit your individual farming systems – helping you to plan for profitability.

Cattle Genetics

Water ManagementAgrismart provides water systems aimed at providing a quick ROI and then cut or eliminate water costs ongoing.

Our water solution is over 75% self-sustainable and offers a mains alternative incorporating rainwater harvestinglow energy pumps, water treatment, water storage and water system installation. Providing your agricultural business with a complete water solution.

Water Management

Water TreatmentDo you have high water bills?

Fill in our water survey to find out if you can save money.

Farm and Equestrian Water Use Survey

Water Treatment

Water treatment increases yields and reduces the spread of disease & mortality. Bacterial that causes infection builds up in water tanks, pipework, and water troughs, leading to poor quality water,  disease and effects production.

If you are worried about your water quality and would like a water test or to discuss water treatment fill in the form below or send an email to

Water Treatment

Write a comment