Coccidiosis in Calves and Lambs: Signs and Control

Coccidiosis is a common parasitic disease that can affect young calves and lambs, causing scour, poor growth and loss of condition. In more severe cases, coccidiosis can lead to significant illness and death.

For farmers and livestock keepers, recognising the signs early and having a suitable control plan can help reduce the impact of coccidiosis on animal health and performance.

What Is Coccidiosis?

Coccidiosis is caused by microscopic, single-celled parasites known as coccidia.

The parasites are spread through faecal contamination. Young animals ingest infective coccidial oocysts from contaminated bedding, feed, water, housing or pasture. The parasites then multiply within the intestinal tract.

As infection pressure builds, damage to the gut can lead to diarrhoea, reduced feed intake and poor growth.

Coccidial oocysts can build up rapidly in contaminated environments, particularly where young animals are kept at high stocking densities or hygiene and drainage are difficult to maintain.

Signs of Coccidiosis in Calves

Coccidiosis in cattle is most commonly associated with young calves.

Signs can vary depending on the level of infection but may include:

• Diarrhoea or persistent scour
• Blood or mucus in the faeces
• Straining when passing faeces
• Reduced appetite
• Poor growth or weight loss
• Dullness and lack of energy
• Dehydration
• Loss of body condition

In severe cases, calves may become seriously ill.

Coccidiosis can also affect performance without dramatic clinical signs. Damage to the intestinal tract and prolonged recovery can contribute to reduced growth and lower weaning weights.

Signs of Coccidiosis in Lambs

Coccidiosis is particularly important in young lambs and is commonly associated with groups where infection pressure has been allowed to build.

Signs may include:

• Dark or watery scour
• Blood or mucus in the faeces
• Straining
• Reduced appetite
• Poor growth rates
• Loss of condition
• Dull or tucked-up appearance
• Dehydration

Severely affected lambs may require additional supportive care.

It is important to remember that not every scouring lamb has coccidiosis. Nematodirosis, salmonellosis, nutritional problems and other causes of diarrhoea can produce similar signs and may sometimes occur alongside coccidiosis.

What Increases the Risk of Coccidiosis?

Coccidiosis problems are often linked to a build-up of environmental contamination.

Common risk factors include:

• High stocking densities
• Dirty or wet bedding
• Poor drainage
• Contaminated feed and water areas
• Mixing animals of different ages
• Repeated use of the same pens or grazing areas
• Overgrazing
• Stress
• Poor nutrition
• Continually adding younger animals to an existing group

Once large numbers of oocysts are being shed in faeces, infection pressure can increase quickly.

Good management is therefore an important part of any coccidiosis control programme.

How Can Coccidiosis Be Controlled?

Good Hygiene

Regular cleaning of pens, feeders and water areas can help reduce environmental contamination.

Remove dirty bedding and organic material thoroughly before using an appropriate disinfectant. Not all disinfectants are effective against coccidial oocysts, so always check the product's approved claims and directions for use.

Keep Bedding Clean and Dry

Wet, heavily contaminated bedding can increase infection pressure.

Provide adequate clean bedding and ensure housing has suitable drainage and ventilation.

Reduce Faecal Contamination of Feed and Water

Where practical, raise feed and water troughs to reduce contamination with faeces.

Clean troughs regularly and consider moving feeding points where contamination is building up.

Avoid Overcrowding

High stocking densities can increase environmental contamination and the number of infective oocysts young animals are exposed to.

Reducing overcrowding and managing animals in suitable groups can help lower infection pressure.

Avoid Mixing Age Groups

Older animals may be shedding coccidial oocysts into an environment shared with younger, more susceptible animals.

Keeping calves or lambs in similar age groups can form an important part of a control programme.

Treatment and Prevention of Coccidiosis

A range of anticoccidial treatments may be available for calves and lambs.

The correct product and timing of treatment are important. Depending on the species and circumstances, products containing active ingredients such as diclazuril or toltrazuril may be used as part of a coccidiosis treatment or prevention programme. NADIS also identifies decoquinate as an in-feed preventative option in certain situations.

However, treatment should not be used as a substitute for good hygiene and management.

Where coccidiosis is suspected, speak to your vet or suitably qualified animal medicines advisor. Correct diagnosis is important because several diseases can cause scour and poor growth in young livestock.

Always use animal medicines according to the product label and professional advice.

Don't Ignore Scour and Poor Growth

Persistent scour, reduced appetite and poor growth in calves or lambs should not simply be accepted as part of rearing youngstock.

Identifying the cause early can help reduce losses and protect the performance of the wider group.

If several animals are affected, animals are severely dehydrated or symptoms are worsening, seek veterinary advice promptly.

Coccidiosis Control Products and Livestock Supplies

At Skipton Dairy Services and Alwyn Pickles & Co, we supply a wide range of animal health products, livestock medicines and youngstock supplies for cattle and sheep farmers.

Our team can help with product availability and provide advice within the scope of our animal medicines qualifications.

Animal Health Information: This guide provides general information only and is not a substitute for veterinary or SQP advice. Always follow product labels and seek professional advice when selecting or administering animal medicines.