Calf Coccidiosis
General about coccidia- Structure- Life cycle- Environmental factors for survival
Eimeria in cattle- Prevalence- Clinical coccidiosis- Sub-clinical coccidiosis
Surveillance and control
What is Coccidiosis?
Enteric disease caused by the protozoan parasites Eimeria spp
2. Bovine Coccidiosis
General about coccidia
- Structure
- Life cycle
- Environmental factors for survival
Eimeria in cattle
- Prevalence
- Clinical coccidiosis
- Sub-clinical coccidiosis
Surveillance and control
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7. Contributory factors in the development of coccidiosis
Parasite
• Number
• Type
• Dispersion
Host
• Susceptibility / age
• Stress factors (diet
change, weaning,
shipping, crowding,
etc.)
• Immune status
• Exposure
Environment
• Conditions for sporulation (temperature, oxygen, humidity)
• Management systems (loose bedding, pasture, etc.)
• Hygiene
• Feed hygiene, drinking hygiene
• Climate
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8. Importance of environment for sporulation
Sporulation time: 2 – 3 days – or more
Sporulation depends on:
Temperature
Optimum 20 - 25°C (13 - 32°C)
Oxygen
Anaerobic conditions – no sporulation (but 10% of normal
O₂ - pressure is enough)
Humidity
Must be > 60% r.h.
Decaying conditions
Delay sporulation
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9. Importance of environment for survival (2)
Oocyst survival is NOT possible
Temperatures > 40°C
Direct sunlight – 4 – 8 hours
Humidity < 25% r.h.
Decaying (rotting) conditions
Cresol-based disinfectants
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10. Prevalence of Eimeria in cattle
Prevalence relatively high:
- 2-100% of calves per herd – varying according to
management (dairy or beef)
- Most frequent in calves 3 weeks to 6 – 12 months
of age
- Few case reports for cows (calving pen)
- Shedding of oocysts at low levels common at all ages
Transmission pathway: faecal-oral route
- Horizontal (calf-calf via licking, etc.; permanent pastures)
- Cow-calf (calving pen)
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11. Eimeria in cattle
Intestinal protozoan parasite
20 species worldwide
Variable pathogenicity
Variable reproductive
potential – e.g. E. bovis
1 oocyst 24 million oocysts
Non-sporulated Eimeria oocysts
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14. Pathogenicity of Eimeria depends on
Species and size of infecting dose(s)
Number and localisation of host cells destroyed
- i.e. Number of merozoite generations
- Number of merozoites per generation
- Location of parasite (in tissue / in cell)
Degree and time of re-infection
Degree of acquired / natural immunity of host
- Incl. stress factors on host
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15. Clinical coccidiosis
Multifactorial disease
Usually a herd problem (5-15% affected)
Primarily E. bovis or E. zuernii
< 50,000 oocysts sufficient to cause clinical disease
Damaged intestinal surface (2nd merogony and gamogany)
• Anorexia (up to 1 month post infection), diarrhoea
(haemorrhagic), dehydration, weight loss or even death.
Mortality up to 7-20%.
• Severe case: chronic performance setback (low feed conversion
efficiency; prolonged heifer development period, etc.)
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16. Coccidiosis in calves – clinical signs
Pasture coccidiosis
E. alabamensis most common
- Watery diarrhoea with a bad smell
4 – 7 days after turning out on pasture
- Low or no feed intake
- Depressed
- Loss of weight up to 15%
- Few fatal cases
- Duration of 2 – 5 days
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17. Clinical Signs
Depression
Anorexia (up to 1 month post infection)
Low or no feed intake
Loss of weight up to 15%
Diarrhoea (+/- haemorrhagic)
Dehydration
Some mortalities (7-20%)
Chronic performance setback due to:
- low feed conversion efficiency
- prolonged heifer development period
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18. OPG and weight gain in calves infected with E. zuernii
(Stockdale et al. 1981)
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19. Sub-clinical Coccidiosis
Most infections (95%) are sub-clinical
Any Eimeria species can be involved
Damaged absorptive surface of intestine
Weakened immune system
Clinical Signs:
Inappetence
Inferior feed efficiency
Slower weight gain
Longer heifer development periods
Increased susceptibility to 2* infections
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Normal ileal mucosa
Superficial epithelial injury,
E. zuernii
Secondary bacterial
infection after coccidiosis
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23. Immunity
Good (non-sterile) immunity to re-infection
with same species after primary infection:
- Depends on level of primary infection
(>50,000 oocysts; Daugschies et al. 1998)
Protective immunity:
- Mainly of cellular type
- Species specific
- Boosted by continuous exposure
- Can break under high infection pressure
Transfer of colostral antibodies:(IgG1 (and IgG2, IgM)) and CD4+
cells to calves
Vaccination -Immunisation
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24. Eimeria summary
Very host specific
Direct transmission
Many species – primarily in herbivores and
birds
Most species - non-pathogenic
Disease mostly in young animals
Intestinal coccidia are very common
Pathogenic intestinal coccidia cause diarrhoea
The development cycle and its duration depends
on the coccidia species
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25. Diagnosis: On-farm surveillance
Look for signs of:
Faeces matted around tail
Dull rough hair coat – unthrifty animals
Pot-bellied in calves
Blood in faeces and/or watery diarrhoea
Weight loss, dehydration, pneumonia
Uneven sized calves
Then ensure examination of faecal samples for diagnosis (OPG
level; species ID)
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26. Diagnosis: Sampling
Faeces for oocysts examinations (direct from rectum).
Time of sampling:
2-3 weeks after turnout onto pasture (prepatent period) or
relocation / calving onto contaminated paddocks.
Multiple sampling may be necessary.
Sugar or salt flotation method
Keep samples cool, must not dry out
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27. Economic Impact
Poor health equals economic loss!
US $700 million annually (Fitzgerald, 1980)
Surviving calves weigh 22-27 kg less than uninfected
animals even one year post infection
Chronic performance setback
- low feed conversion efficiency
- prolonged development period
Reproductive and milk yield performance at an adult age
is negatively affected (Maddox-Hyttel et. al, 2003)
Treatment costs
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28. Prevention
Hygiene
Cleaning / disinfecting
Control passive vectors (rodents and insects)
Over crowding
Stress factors
Objective: lower infection pressure to break the
chain of infection
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29. Treatment
Treatment should be initiated before clinical
coccidiosis is evident (metaphylactic treatment)
Prevention is better than cure!
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30. Control of coccidiosis: time of treatment
Course of infection and treatment options
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31. Baycox 5%
Product Information:
Active: Toltrazuril
Composition: Every ml contains 50 mg Toltrazuril
Molecular structure: C₁₈H₁₄F₃N₃O₄S
Chemical structure:
32. Directions for use
Piglets:
Each piglet must be treated orally at day 3-5 with a single 20 mg
dose Toltrazuril / kg body weight, corresponding to 0.4 ml oral
suspension per kg body mass.
Calves:
Each calf must be treated orally with a single dose of 15 mg
Toltrazuril / kg body weight, corresponding to 3 ml oral
suspension per 10 kg body weight.
Lambs:
Each animal must be treated orally with a single dose of 20 mg
Toltrazuril / kg body weight, corresponding to 4 ml oral
suspension per 10 kg body weight.
33. General:
Piglets, calves and lambs: To gain maximum benefit,
the animals are to be treated before the expected onset
of clinical signs, ie During the period prepatent. This is
best achieved in situations where the onset pattern of
clinical signs in young or recently included animals are
well known and predictable.
Use only as directed. Shake well before use. Product
must be used within three months after the withdrawal
of the first dose. Thereafter the remaining product is to
be destroyed.
Directions for use
34. STOP THE DOMINO EFFECT!
By the time clinical signs become evident, substantial damage to the
small intestine has already taken place.
Treat BEFORE symptoms appear.
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