Chicken Coccidiosis

Chicken vet Treatment of Coccidiosis in Chickens

Chicken veterinarians see coccidiosis often. It is caused by  a protozoa.  The chicken coccidia infects various sites in the intestine and damages  the intestinal lining. With a heavy infection birds loose weight, have diarrhoea, sometimes have red blood in the droppings and even death. Poultry Vets have found that  coccidia are generally host-specific, and the different species parasitize specific parts of the intestine. Coccidia  is always a potential problem.

Chicken Coccidiosis is a very common protozoal disease of poultry and is caused by different species of coccidia, mostly in the Eimeria genera. Coccidiosis in chickens can be present even in a healthy flock but may cause no disease or mild disease. Gradual exposure or recovery from an infection can allow a chicken to become immune to the coccidia in its environment. However, they can still develop chicken coccidiosis if their resistance is reduced by another disease, poor immune system or exposed to a new species of coccidia. Outbreaks can occur when birds are stressed, overcrowding, change in rations or weather, transportation and poor sanitation.

Infection is usually from inadvertently eating the poo!.  The birds droppings contaminate the food or may come into contact with table scraps or in with the drinking  water . A chicken gets infected by eating a sporulated oocyst (egg). Infected birds shed oocysts in their faeces that contaminate the environment. Oocysts can survive up to 18 months under ideal conditions in soil with the right moisture and temperature.

The chicken vets have found that birds with good hygiene will have low levels of cocci in their system and build up an  immunity to them – which is ideal.  By feeding all food including table scraps  “of the floor”, this disease can be controlled in a backyard poultry.


Chicken Coccidiosis
Chicken Coccidiosis from the Melbourne Chicken Vet.
Chicken Vet Coccidia
Chicken Vet – Coccidia oocyst

Clinical Signs

  • Slow growth in young birds
  • Damage to intestinal lining
  • Change in droppings (diarrhoea, blood)
  • Weight loss
  • Pallor and anemia
  • Death can occur quickly as internal damage is done before you notice any symptoms

Outbreaks can be mild to severe, so you may not notice that your chickens are ill. Chickens with coccidia can become more susceptible to other parasites, diseases, bacterial infections.


A faecal test can be done by your chicken vet to identify oocysts under microscopy. Post Mortem can be performed as well. The chicken vets diagnose coccidia parasite microscopically by doing a faecal flotation on a dropping sample.  Poultry vets  recommend this Laboratory test  as a routine and only using cocci medication if necessary.


Provide dry litter and clean out faecal material regularly. Food and water dishes should be kept off the ground to minimise contamination.

  • Treatments are firstly good hygiene and less exposure to the parasite
  • If the birds are laying hens  Cocci–Amprolium is a product sold at Bird-Vet Melbourne that has no with holding for laying birds – i.e. the eggs can still be eaten.
  • A more effective drug is Toltazural or Bayrtril.  This is used at a dose  rate of 3 ml to 1 liter of water for 2  days changing the water daily.  It can NOT be used in egg layers as there will be a withholding period, (The eggs need to be discarded!)
  • The chicken vet recommends ongoing treatments with Cocci-amprol or an Amprolium based product. This  will both treat and help maintain the ongoing immunity the flock needs and still enable YOU to eat every precious miraculous egg.

Your chicken vet can provide anticoccidials (e.g. amprolium, toltrazuril, sulphonamides) to treat or control coccidiosis. They are treated for 2-3 days consecutively. Treatment can repeated after 5 days to treat oocysts in the pre-patent period. Antibiotics and vitamin supplementation may be given depending on severity of the disease and type of drugs used.

Chicken Veterinary – Coccidiosis
Health checks at the Chicken vet
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