Coccidiosis is caused by protozoan parasites of the genera Eimeria or Isospora that infect the intestinal tract. It causes damage to the intestinal mucosa and is an important disease affecting poultry and livestock production. Clinical signs include vomiting, diarrhea, weight loss, and decreased egg production. Treatment involves the use of anticoccidial drugs like ionophores, amprolium, sulphonamides, and quinolones. Proper management practices to control environmental contamination with parasite oocysts are also important to control coccidiosis on farms.

1. Anticoccidial drugs
By:MohamedKhalid Ali Newera

2. • coccidiosis introduction
• Etiology
• life cycle
• Pathogenesis
• Economic losses
• Treatment
• Control measures

3. coccidiosis introduction
characterized by:
1.Host specific
2.Tissue specific
3.Immune specific
Definition : is a usually acute invasion and destruction of
intestinal mucosa by protozoa of the
generaEimeria or Isospora.

4. Etiology
 Eimeria species (intracellular parasite)
 host-specific protozoa
 Oocyst survive for years.
 Dryness and direct sun are lethal.

5. Mode of infection
Ingestion of sporulated oocyst.

6. Mode of transmission
Mechanical transmission through persons
and equipements.

7. Life Cycle

10. Clinical signs
• Vomiting
• Immunosuppression
• anorexia
Dogs and
cats may
shed oocysts
in feces but
remain
asymptomatic
.
In poultry :
• Drop in egg
production
• Emaciation
,pale legs and
peak

11. 1.Broiler growth and weight are reduced.
2.feed conversion rate is reduced by 5-10%.
3.increase in condemnation rate at processing.
4.increase in mortality rates.
5.increase the susceptibility to other disease agents.
Economic Importance:
in poultry

12. In other animal
 Immunosuppressive effect
 Cost of treatment
 Decrease production
 Mortility

13. Anticoccidial drugs

14. Characters of Ideal anticoccidials :
1-Efficacy : Broad spectrum activity.
2-Safety : Wide margin of safety , at least three-fold difference
between registered and toxic level.
3-Cost effectiveness : least effective cost.
4-Residues : Should be metabolized, excreted, without toxic
residues.
5-Carcass and meat quality : should not affect organoleptic
criteria.

15. Causes of Coccidiostat failure :
1. Not effective against all species of Eimeria
2. More than average exposure oocysts
3. Low inclusion level of Coccidiostat
4. Faulty management ( wet litter )
5. Intercurrent disease
6. Drug resistance after prolonged uses.

16. Ionophores
Category :Streptomyces
Actions:anticoccidials
Toxic effects : directly facilitates
Ca++ transport in cells and increased
intracellular concentration of Ca++ in cardiac
and skeletal muscle cells

17. Mechanism of action:
facilitate transport of Na+ ion in cells and elevates
the intracellular concentration of Na+ ion. This
increased concentration of Na+ ion inhibits the
certain mitochondrial functions such as substrate
oxidation and ATP hydrolysis.

18. Monensin
Category :fermentation product of Streptomyces
Actions:
1. 1st antibiotic used as an anticoccidials. Due to its broad spectrum
activity, it acts on trophozoites and 1st generation schizonts. Its activity
is generally within 1st 2 days of life cycle of coccidian.
2. increases the weight gain and feed conversion and in some cases
causes suppression of necrotic enteritis

19. M.O.A: This drug has ability to form complexes with
sodium and potassium ions in the host and developing
parasite.

20. Lasalocid
Actions:increases weight gain, feed conversion and
reduces the lesion in severe coccidiosis
Category :fermentation product of Streptomyces

21. Amprolium
Category: quarternized derivative
Action : active against E. tenella, E. necatrix and
E. acervulina and to lesser extent E. maxima.
N.B. Combination of amprolium with ethopabate,
sulphaquinoxaline or even pyrimethamine extended and
strengthened the spectrum of activity.
N.B. may lead to development of drug resistance

22. M.O.A.1. thiamine antagonist and due to its close structural
similarity it blocks the thiamine receptors.
2.suppresses the sexual stages, gametogony and sporulation
of oocyst.
side effect: thiamine deficiency
Treatment of toxicity : add thiamine
Uses : it is only agent which can be used in
laying birds both for prevention and treatment
of outbreaks.

23. Nicarbazin
Action: broad spectrum activity and
effective against all Eimeria spp.
N.B. may lead to development of drug resistance
Uses: The drug is suitable for administration
to broiler flocks

24. M.O.A. can enter the cells of the coccidia and paralyze the
intracellular energy-supplying ATP which leads to the interruption
of cellular energy supply and the cease of function of sodium-
potassium ion pump which results in the abundant influx of sodium
ions and with them the influx of abundant water which causes the
intracellular imbalance of ions in the cells of the coccidia or the
rupture of the cells and the death of coccidia occurs.
Side effect :
1.reduces both egg production
2. Reduces the proportion of fertile eggs that hatch.
3.causes depigmentation of eggs, mottled egg yolk
and poor hatchability,

25. Sulphonamides
Action : broad spectrum of activity
against eimerian species and have
coccidiostatic action.
M.O.A.inhibit growth in which Sulfonamide
and PABA (necessary for growth) is similar in
nature

26. Sulphadimidine
Action :against E. tenella, E.
necatrix and other species of
coccidia.
Side effect : The problem of this drug is that it interferes
with vitamin K synthesis in the intestine and resulting into
prolongation of blood coagulation time. At higher doses it
causes loss of egg production in laying hens and hyperplasia
of the somniferous tubules of testicles of male birds.
Category: sulfonamide derivatives

27. Ethopabate
Category:monocyclic aromatics
Action : anticoccidial activity especially against
intestinal forms
M.O.A. competitor of PABA for absorption by
the parasite and interferes with folate synthesis.

28. Quinolones
M.O.A. inhibiting DNA gyrase
Action : anticoccidial activity

29. Buquinolate
Action :broad spectrum of activity against
all chicken coccidia

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