Coccidiosis: A silent killer of Poultry birds

The disease ‘Coccidiosis‘ is caused by parasitic Protozoa. Most coccidia in poultry belong to the genus Eimeria.

By Abdul Samad

Coccidiosis

The disease ‘Coccidiosis‘ is caused by parasitic Protozoa. Most coccidia in poultry belong to the genus Eimeria. It is common worldwide, but is especially prevalent in warm, humid climates or after periods of rain. More common in younger or growing birds, there are many strains and birds can be affected by different strains at the same time, or in succession. Coccidia causes disease in chickens, turkeys, geese and ducks where they develop in the intestinal tissues.Being so common it is a disease that you will more than likely experience during your chicken-keeping adventures (especially if you have young chooks) but rest assured it is easily treated

Symptoms

Birds that have coccidiosis often display a characteristic posture (as shown below in the image, although this is a very severe case and therefore quite pronounced in posture). They hunch up, fluff up and can drop their wings. They may also have:

  • diarrhea
  • soft mucoid faeces
  • bloody droppings
  • pink intestinal tissue in droppings
  • hunched posture with ruffled feathers
  • droopiness
  • loss of appetite or even interest in water
  • slow growth
  • weakness/lethargy
  • anaemia – look for pale comb and skin

Transmission and Incubation Period

There are two main types of Coccidiosis – Intestinal Coccidiosis and Cecal Coccidiosis. In the intestinal version the intestinal tract is affected by the Eimeria, and in the Cecal version, the cecum is affected. Coccidia have two main phases in their life cycle; one phase occurs outside the host and involves the development of the infective stages (oocysts), and the major phase which occurs within the host and involves massive multiplication and sexual reproduction. Birds ingest a number of oocysts and become infected. The severity of the infection depends on the numbers that they are host to. At a low dose the immune systems responds to the challenge and deals with the infection. When birds ingest too many they can develop visible symptoms and if the disease is unchecked it can kill them. The disease is spread by droppings of infected birds (including wild birds). It can be spread by chickens coming into contact with contaminated equipment, feed containers, feet of humans and wild birds etc as well as being contained in the soil.

Incubation Period

Caecal Coccidiosis: 5 – 6 days
Intestinal Coccidiosis: 5 days

Diagnosis

If your chicken is sick and miserable, not active/eating/drinking, has blood in their poo and exhibits other symptoms as listed above it is often safe to assume they have coccidiosis. Chickens can be officially diagnosed by a veteranian who is familiar with poultry diseases or an avian specialist vet (if you are willing to  pay for a consultation) by investigating flock history, conducting a postmortem and examining the findings, and/or a faecal test to check for the presence of oocysts in faecal specimen.

Treatment

Treat urgently with a medication for Coccidiosis according to directions – even though this is a common disease it can be fatal (this depends on the damage done to the chicken by the oocyts). Try to raise chicks on clean dry litter and avoid crowded or damp conditions. Make sure drinkers are not spilling water into the litter. Make sure water and feed is uncontaminated by droppings. Use medicated chick starter or grower. Ensure that chicks are warmly housed out of draughts. In severe cases raising chicks on a wire grill can reduce ingestion of the oocysts and help recovery. In severe cases, reducing the protein level in the feed can also be of assistance. Monitor droppings during and after treatment. Often morning droppings can show blood, even if the day is normal. Putting newspaper under perches or on brooder floors can make the droppings easier to see. Follow treatment with a vitamin supplement (especially A and K) is recommended and chickens affected by coccidiosis can take a few weeks to fully recover from their infection. Survivors of one strain may become infected with a different strain and require further treatment. Survivors of severe infections may never be productive.

Medications

Anticoccidial drugs fall into two categories – coccidiostats and coccidiocides. Medications are either coccidicidal (cidal), which means they kill the parasite, or coccidiostatic (static), which do not kill the parasites, but arrest their development. Coccidiostats are given in the feed to prevent severe outbreaks of the disease – and being an additive is often referred to as a ‘vaccine’ but definately isn’t as there are significant differences between this and poultry vaccines. The coccidiostat doesn’t actively kill the coccidia, it simply interrupts the breeding cycle and they can’t multiply into large numbers. The coccidiostat can be included in starter and grower crumbles and can be seen on the label. Old or poorly mixed feed may not be reliable as a preventive.

(Source; Aussie Chook supplies)

Author: Abdul Samad

Affiliation Address: Department of Poultry Sciences, MNS University of Agriculture Multan.