Bovine Coccidiosis

Hi Readers,

Many who know me are aware that my passion for animals stemmed from growing up on a sheep and cattle farm, which has hugely influenced my career choice. This week I thought I’d write about a disease in my favourite animal, as I’ve always been interested in pathology especially in cows.

Bovine Coccisiosis is my chosen disease for this week, a disease caused by single celled protozoa (from the genus Eimeria). Their complex lifecycle involves asexual and sexual reproduction and know for the damage they do to intestinal mucosa. There are more than a dozen species of coccidia, however only three (E.bovis, E. zuernii and E. alabamensis) are thought to be clinically significant.

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The signs of infection are dependant on factors such as age, immune status and level of challenge. The signs however include: diarrhoea (which could contain blood), tenesmus (straining to empty the bowel without success); in more chronic and subclinical forms, an appearance of a ‘poor doer’, stary coat, pasty faeces, reduced appetite and poor growth rate.

The following is a flow chart of the life cycle of this protozoa that I made to help me understand it:

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(click to enlarge)

Faecal oocyst counts are frequently recommended for confirming a diagnosis of coccidiosis. Many samples should be taken from in contact as well as affected calves and all should be examined.

(Oocyst is the encysted zygotic stage in the life cycle of some sporozoans (a protozoan of the phylum Sporozoa))

There are some treatments for Coccidiosis are available. These include decoquinate (Deccox) – in feed, diclazuril (Vecoxan) and toltrazuril (Baycox) – all anticoccidials, two given by a drench. Sulphonamide drugs can also be used and proper nursing is also important (with oral electrolyte fluid being given if diarrhoea is causing dehydration).

Again, as I have mentioned many times, PREVENTION IS BETTER THAN A CURE! So the following measures should be in place to prevent this infection reaching and affecting a herd. It has been found in 50% of dairy herds visited by XLVets and problems are also being seen in suckling beef calves. Those affected are mostly between 2-3 months old.

  • An ‘all in, all out’ policy – allowing pens to be thoroughly cleaned between loads
  • Disinfectant may help – but most coccidial oocysts are highly resistant to most disinfectants
  • Pens should be well bedded – to keep pens clean
  • Good drainage and ventilation – to keep pens dry
  • Feed should be in troughs off the floor and clean (free from faecal contamination) as well as water troughs
  • Scouring calves should be isolated – for treatment and reducing risk of transmission to other animals
  • Strategic dosing (in feed or via drench) if time of challenge and disease can be predicted (weaning time/ when weaned calves are grouped in rearing sheds)

Other top tips include:

  • Minimise stress at all times by avoiding mixing (especially when weaning)
  • Avoid overstocking
  • Early diagnosis and treatment is essential

 References:

Alan Walker XLVets Fact sheets

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