Coccidiosis Eimeria mitis, Lower-Intestinal (Ileum), Subclinical Infections in Laying Hens
Eimeria mitis infection In layers, this species may affect egg production and induce a moult. The lack of distinct gross lesions causes this species to be overlooked or misdiagnosed in subclinical infections. (1, 2)
Coccidiosis rarely occurs in layers and breeders during the laying cycle, because of prior exposure to coccidia and resulting immunity, if a flock is not exposed to a particular species early in life or immunity is depressed because of other diseases, outbreaks may occur after layers are moved to production houses. Outbreaks of any species in layers can reduce or eliminate egg production for several weeks. (1, 2)
Single-comb white leghorn hens infected with either B4 or C2 strain of Eimeria mitis produced watery droppings as early as day 5 PI. E. mitis infection did not affect egg weight. However, specific gravities of the eggs produced by the hens infected with E. mitis were lower than those produced by the controls. Egg production was significantly reduced temporarily, but most birds returned to production within 14 days. Many of the birds that ceased to lay went through a complete-body moult (56% of the C2-infected hens and 20% of the B4-infected hens). Hens that ceased to lay regained considerable amounts of pigment in their skin, beaks, and shanks. (1, 2)
Eimeria mitis produced watery droppings as early as day 5 PI. E. mitis infection did not affect egg weight. However, specific gravities of the eggs produced by the hens infected with E. mitis were lower than those produced by the controls. Egg production was significantly reduced temporarily, but most birds returned to production within 14 days. Many of the birds that ceased to lay went through a complete-body moult. (1, 2)
Infections with this intestinal species of coccidia is a major predisposing factor for Clostridium sp. infection. Colonization of small intestine by Eimeria sp. may lead to intestinal mucosal damage which may then, in turn, provide natural substrates (plasma proteins) required for Clostridium sp. proliferation. (1, 2)
Observed Clinical Signs Happenings
- Egg production drops gradually
- Egg production was significantly reduced temporarily, but most birds returned to production within 14 days
- Many of the birds that ceased to lay went through a complete-body moult.
- Watery droppings as early as day 5 post infection (PI). In many instances may be overlooked
- Induce a moult
- Poor feather cover or feather loss
- Specific gravity test of the eggs produced by the hens infected with E. mitis was lower than those produced by the controls
- Ungraded or second's eggs increased
- Thin-shelled and soft-shelled or porous eggs
- Egg specific gravity score lower (should be above 1.080 (1.068 thinnest shells)
Coccidiosis Eimeria mitis, Lower-Intestinal (Ileum), Subclinical Infections in Laying Hens DOES NOT show, exhibit or manifest any of the following clinical signs happenings:
- Egg production declines rapidly
- Mortality above the standard
- Visibly sick birds
- Flock behaviour activity change
- Respiratory abnormalities
- Neurological Nervous
- Lameness or unusual movements, incoordination, ataxia
- Eyes abnormalities
- Head, Comb, Wattles, Face, Nostrils, Sinuses, Mount, Beak, Earlobes, abnormalities (except eyes)
- Body Parts (Neck, wings, breast, abdomen, shanks, legs, hocks, feet, joints, vent, and skin, abnormalities), skinny body, retarded growth, weight depression
- Feed Consumption Changes
- Diet or Feed Changes (Recent Feed delivery, Recent formulation /diet, Other silo or improper storage, another feed brand)
- Internal Egg defects
- Causing Agents
- Protozoal Infection parasites. Eimera mitis. Intestinal coccidiosis
- Affected Systems/Organs
- Lower small intestine. Digestive Tract
- Ingestion of viable sporulated oocysts is the only natural method of transmission. Oocysts can be spread mechanically by many different animals, insects, contaminated equipment, wild birds and dust.
- Mainly Affects
- Egg production and Performance
- Adequate Pullet coccidial immunization program. Anticoccidial drugs. Good hygiene practices, vaccinations, coccidiostat in feed or water.
- Suggested Actions
- Can be managed with feed additives, off-the-shelf medications
- Can be managed with vaccination programs
- Diagnosis should be confirmed with rapid assays and/or a certified laboratory
- Veterinary intervention is recommended
Impact on Egg quality
Impact on Liveability
Impact on Production
Overall Economic Impact
- Y.M. Saif.2008.Disease of Poultry. 12th Edition. Page 1073
- David E. Swayne. 2013. Diseases of Poultry 13th Edition. page 1155
- Mark Pattison, Paul F. McMullin, Janet M. Bradbury. Dennis J. Alexander. 2008. Poultry Diseases. 6th Edition.
- Paul McMullin. 2004. A Pocket Guide to Poultry Health and Disease. First Edition.
- Steven Leeson, John D. Summers. 2008. Commercial Poultry Nutrition. Third Edition.
- Donald D. Bell, Williams D. Weaver. 2009. Commercial Chicken Meat and Egg Production. Fifth Edition.
- Gail Damerow 1994. The Chicken Health Handbook.
Avian Diseases 36;718-721, 1992. Effects of Eimeria mitis on Egg production of Single-Comb White Leghorn Hens