Coccidiosis: threat to poultry farmers

Alok Kumar Singh1#, Snigdha Shrivastava2, B. Dasmabai3 , Deepali Tiwari4 and Pradeep Kumar5

Coccidiosis is most common problem face by commercial poultry grower as the size of flock increases problem becomes more prevalent. Coccidiosis is parasitic disease caused by single celled coccidia belonging to genus Eimeria that multiplies in intestine and causes tissue damage leads to decrease feed intake, poor absorption of nutrients and it may lead to ultimate death due to secondary bacterial infection also severe loss in poultry meat and egg production.

Life Cycle

  • Understanding lifecycle of coccidia is Essential to control its transmission to other birds; lifecycle generally includes infection, multiplication, sexual reproduction, transmission stages.
  • Coccidiosis is caused by parasite Coccidia of genus Eimeria. Its lifecycle takes 4-7 days to complete.
  • Lifecycle starts with ingestion of active “oocyst”. Oocyst is non sporulated type covered by thick walled layers. It get convert to sporulated oocyst when suitable moisture, temperature required is provided for growth.
  • Coccidia are very prolific parasite. A single sporulated oocyst contains four sporocyst. Each sporocyst has two sporozoites. So in digestive tract one oocyst releases eight sporozoites which move to cell lining of intestine.
  • Several generations of asexual multiplication takes place followed by sexual stage in which male and female organisms unite to form new oocyst protected by thick wall. This oocyst than shed in faeces which can transmit parasite to other birds in farm.
  • Coccidial infection differs from bacterial, viral infection because coccidiosis is self-limiting disease as its multiplication stops before death of bird.
  • Coccidiosis is disease of young birds between 3 and 8 weeks of age. Coccidia are species- specific. There are nine different species of Eimeria that can infect chickens. Immunity to one type does not provide immunity to other types.

Transmission in Environment

  • Most common method of transmission is by ingestion of oocyst present in droppings of infected bird.
  •  Infected birds shed oocyst for several days or week .Oocyst generally sporulate within 2 days and become infective under proper condition also it can survive many week and as long as 600 days. Usually optimum temperature for sporulation is 26-280C and 20% moisture in litter for sporulation is required.
  • Also Due to habit of pecking on litter or ground by chicken leads them to pick infection.
  • Oocyst can also spread by insects, dust, wild birds and humans (from shoes and equipment).

Symptoms and diagnosis

  • Most common signs includes droopiness, listlessness, loss of appetite, loss of yellow colour in shank, comb, wattles, huddling of chicks, blood or mucous in faeces and diarrhoea, dehydration or even death.
  • Other symptoms include poor feed digestion, poor weight gain and poor feed efficiency.
  • Generally PM finding includes thickening of intestine which gives sausage appearance. Light colour spots and haemorrhage can be seen inside gut.
  • Confirmatory diagnosis includes lab diagnosis.

Management for Control

  • Management is important to prevent infection. It generally focuses on reducing number of coccidia exposure to birds until immunity develops.
  • Early detection is essential to prevent infection to other healthy birds. It is done by close observation of initial symptoms of coccidiosis like reduce feed intake.
  • Production system is important management decision generally large scale production uses anticoccidial medication. While low density production allows low level of exposure to parasite which leads to development of immunity.
  • Good brooding practice can reduce need for medication. Brooding can be 2 stage production in which chicks are brooded in separate area before moving into grown out facility or 1 stage production in which brooding and grown out in same facility.
  • Generally one bird requires one square foot of floor space per chicks and 4 feeders per 100 chicks.
  • Disinfection is not effective against coccidia so sanitation focuses on good hygiene and removing infected droppings.
  •  Sanitation includes cleaning waterer and feeders frequently and place at height that birds cannot defecate. Keep older birds away from chicks since older birds are carrier also keep adding fresh litter to cover parasite.
  • Litter management include removal of wet or crusted litter to prevent sporulation. Moisture can be removed by propane radiant brooder that dries litter , proper ventilation to remove humidity , avoid water leak also feed containing excessive salt , protein can result in wet litter .
  • However in large poultry house decomposition of litter and manure by action of mould and bacteria lead to release of ammonia which ultimately destroys oocyst.
  • Outdoor access enables birds to pick up oocyst to develop immunity. In warm, humid environment coccidiosis is great problem while in cold, dry oocyst died. Controlling Coccidiosis on pasture is difficult in case of broiler than layer.
  • Keeping birds in floorless pen that is moved daily eliminate coccidiosis by breaking life cycle of oocyst as cannot reinfect birds.

Treatment for Coccidiosis

  • Keeping birds in good health decreases outbreak of coccidiosis. Small scale producer provides Raw milk , yogurt apple cider vinegar , probiotics etc provide good bacteria which reduces impact of coccidiosis
  • In large house routine use of drugs and vaccine is practiced some common drugs includes: – sulfa drugs given intermittently (three days on and 3 day off) at the rate of (10-20%) of diet. However in long term it causes rickets. Sulfonamides are used to treat coccidiosis.
  • Amprolium is effective anticoccidial drug and requires no withdrawal time and meat residue .It treats both intestinal and caecal coccidia.
  • Quinolones are coccidiostats which arrest coccidia in early development. This drug is used for prevention.
  • Other commonly used anticoccidial includes ionophores is not synthetic drugs but produced by fermentation which alter cell membrane and rupture parasite.
  • Preventive drugs are effective only in first part of parasitic life cycle therefore must be used early and in drug rotation manner to reduce resistance. Usually drug are withdrawn a week before slaughter in case of broiler and in layer before laying egg.
  • Vaccine is general adapted method for prevention of coccidiosis in large scale production like coccivac, immucox, advent etc. however these vaccines can cause some lesion as not attenuated or weaken in some way.


  • Common method of vaccine application includes spray cabinet used in day old chicks, feed spray, drinking water etc.
  • Vaccine should not be frozen it is not effective for batteries or cage system and vaccine booster is generally not given. Drugs and vaccine are not used together due to opposite action.
  • Both small and large scale poultry producer are interested in sustainable management of this parasitic disease hence proper understanding of its lifecycle, transmission, treatment, prevention is essential to prevent loss in poultry industry.

Alok Kumar Singh1#, Snigdha Shrivastava2, B. Dasmabai3 , Deepali Tiwari4 and Pradeep Kumar5

1Department of Veterinary Parasitology, College of Veterinary Science & A.H., Rewa

2Ph.D. Scholar, Department of Veterinary Medicine, COVSc & A.H., Rewa

3Department of Veterinary Parasitology, College of Veterinary Science, Rajendranagar

4B.V.Sc & A.H., Student, College of Veterinary Science & A.H., Rewa

5Department of Veterinary Parasitology, DUVASU, Mathura

#corresponding author- email:

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