Easier Said than Done:Managing Coccidiosis and Necrotic Enteritis in Conventional and ABF

FlocksYuko Sato DVM, MS, Dipl. ACPVSeptember 20th, 2018 IPA Fall FestivalWest Des Moines Marriott

Veterinary Diagnostic and Production Animal Medicine

Appreciation• Dr. Mohamed El-Gazzar, ISU Poultry Extension• Kevin Stiles and Iowa Poultry Association

Content(s) from:• Proceedings from 2nd International Conference on

Necrotic Enteritis (July 11-12, 2018) in Denver, CO, USA.

• Dr. Greg Mathis, Southern Poultry Research• Dr. Steve Fitz-Coy, Merck Animal Health• Dr. Hector Cervantes, Phibro Animal Health

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IPA Fall Festival

What is coccidiosis?• Life cycle takes about 4-7 days to complete

• 7 different pathogenic types in chickens• 3 cause most disease issues:

• Eimeria tenella• Eimeria maxima• Eimeria acervulina

• Immunity to one type does not provide for others.

• Coccidiosis is different from a bacterial or viral infection since the parasite is “self-limiting” and will stop multiplying before killing the bird. 3

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Source: ThePoultrySite

1 oocyst (cocci egg) can produce…• 400,000 acervulina• 58,000 maxima• 72,000 tenella• 12,000 necatrix

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Eimeria maxima• Ballooning of intestinal walls in mid-gut area with

giant oocysts

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Eimeria acervulina• White plaques in the duodenum (upper gut) that

looks like ladders or “tiger stripes”

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Source: www.fwi.co.uk

Eimeria tenella• Hemorrhage and necrosis of the ceca with caseous

cores. Hemorrhage and discoloration is often visible from the outside of intestines.

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Y. Sato, ISU-VDL

Y. Sato, ISU-VDL

Clinical and subclinical coccidiosis• Outbreaks occur between 3 - 8weeks of age• Clinical signs include droopiness, listlessness,

huddling/chilled birds, blood or mucus in the feces, diarrhea, dehydration…

• Subclinical coccidiosis can cause decrease weight gain, increased FCR, predisposition to secondary disease (necrotic enteritis)• This can be monitored by:

1. Lesion scoring via necropsy2. Oocyst counts (OPG) via fecals

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Control by management• Vaccination• Bird density

• Lower density = lower cocci pressures• Brooder and growout management

• Prevent overcrowding and from litter eating• Sanitation

• Waterers and feeders at height level to avoid contamination

• Litter management• “New House Syndrome”• Moisture level control 12

Coccidiosis treatment• Chemicals: Robenz, Clinacox, Nicarb, Zoalene,

Amprol, Deccox, Coyden, Poultry Sulfa• Nicarb only in the winter

• Clinacox has trouble with immature E. maxima• Amprol for severe cecal coccidiosis

• Ionophores: Coban, Bio-cox, Monteban, Maxiban, Avatec, Aviax II • Leaky compared to chemicals

• Avatec better with E. acervulina• Resistance issues and drugs need to be rotated on a

regular basis (every 3-6 months)13

Mathis and McDougald, Av Dis 1980

Vaccination/natural immunity

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• Only option in organic flocks (no anticoccidials)• Ensure suitable environment for oocyst cycling to

occur (ideally 3 cycles)• Avoid anticoccidials in the feed

Example of a successful coccidiosis vaccine program (monitoring by OPG)

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How much is too much?

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Necrotic enteritis• Most commonly in 2-8 week old broilers• Caused by Clostridium perfringens type A or C

• Overgrowth of normal bacteria (dysbacteriosis)• Severe necrosis of intestinal mucosa• Bacteria produces toxin that causes toxemia and

sepsis à acute mortality • Birds are often dehydrated

• Mortality, if untreated, can be up to 50%• Early diagnosis & tx <2% mortality

• Sudden death in well-fleshed birds

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Necrosis of villous epithelium

Bacteria

Coccidia

Risk factors for necrotic enterits (NE)• Coccidiosis

• Damages intestinal integrity (leaky gut)

• Most trouble with Eimeria maxima• Removal of coccidiostats or antibiotics • Environmental and management conditions

• Poor ventilation and barn sanitation

• Stress and immunosuppression• Stocking density, other diseases (e.g. IBD)

• Nutritional stress• Cereal grains (increases viscosity/GI transit time)

• High levels of protein 20

NE – a multifactorial process

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Source: BIOMIN

Treatment• Antibiotics in feed or water

• Penicillin• Lincomycin• Aureomycin (Chlortetracycline)

• Growth-promoting antibiotics (e.g. low dose BMD)• Anticoccidials (if concurrent coccidiosis)

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Control and prevention• Vaccination or coccidiostats for cocci control• Probiotics, prebiotics, organic acid blends, other

feed additives to avoid dysbacteriosis• Litter amendments (PLT, windrows, etc)• Better gut health by revisiting vaccination programs

(e.g. IBD titers)• Proper temperature, lighting, and stocking density in

the barns

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www.immucox.com

Alternative treatments• Prebiotics

• Selective stimulation of good gut bacteria growth• Reduces pH, making unfavorable for C. perf

• Probiotics• Competitive exclusion by inoculating with good gut

bacteria• Oregano oil and organic oils

• Some good data suggestive of reduction in E. tenellalesion scores

• Can potentially mess up cycling of vaccines• Saponins (e.g. yucca extracts)

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Summary• Pick the treatment most likely to be effective for the

type of coccidiosis you want to control.• Be mindful of label directions and withdrawal

periods to avoid tissue residues.• Alternative treatments have promising data but

there is no silver bullet – synergistic effects.• Good management is required for both necrotic and

coccidiosis control and is critical for success of treatment and control.

• Focus on prevention by creating a favorable gut environment (gut health).

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Thank you!!! Any questions?

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