Volume 23 • Issue 02 • 2019
Sub-clinical coccidiosis: the silent
profit eater
Dr. Chantelle Erwee, Zoetis South Africa (Pty) Ltd,
Technical Manager: Ruminants
We are all familiar with the devastating economic
effects a clinical coccidiosis outbreak can cause in
a herd. We’re also quite familiar with the clinical
signs and pathogenesis of coccidiosis. But how
familiar are we with the consequences of a sub-
clinical coccidiosis infection? How often do we
consider that the silent inappetence of such
an infection can lead to hundreds, or rather,
thousands of profits lost due to poor weight
gain?1 Are we aware of the fact that such an
infection can upset the animal’s homeostasis to
such an extent, that it might lead to the animal
never reaching its full production potential? 2
Coccidia oocysts are extremely hardy and
coupled with that, very ubiquitous. 1,2 Because of
these characteristics of the parasite, coccidiosis
(caused by Eimeria spp.) in cattle is usually
highly prevalent. 2 As far as the sheep industry
is concerned, there is a general move towards
intensive farming, coupled with higher animal
density and production, inevitably leading to
higher infection pressure. 1 Coccidiosis can lead
to significantly negative economic consequences
in these production systems. 1,2
It is important to know that most Eimeria spp.
could probably cause sub-clinical coccidiosis. 2
The parasite not only causes destruction of the
epithelial cells of the animal’s intestines, but also
disrupts the balance of the digestive microflora,
leading to a harmful rise in the percentage of
Gram negative bacteria. 1 Severe damage is
inflicted on the intestinal tissue and the animal’s
overall homeostasis is affected, even if no clinical
signs are evident. 2 It almost goes without saying,
that this has adverse effects on the animal’s
production potential and is also a welfare
concern. 2
The fact that clinical coccidiosis is potentially
a disease of serious economic importance is
mentioned earlier in this article. It is believed
that sub-clinical coccidiosis can lead to even
higher economic losses than clinical coccidiosis.2
Reasons for this may be that sub-clinical
coccidiosis can adversely affect the animal’s
intestinal physiology and feed conversion,
leading to impaired growth, however it is often
not noticed (even though it is surprisingly more
prevalent). 2
Adequate prevention involves ensuring hygienic
conditions, reducing stressors as much as possible
and where needed, the use of anticoccidial drugs. 1
Decoquinate is a non-antibiotic anticoccidial
developed specifically to aid in treatment and
prevention of coccidiosis in calves and lambs. 3
It can also be used as an aid in the prevention of
toxoplasmosis in sheep. 3
References:
Chartier C, Paraud C. Coccidiosis due to Eimeria in
sheep and goats, a review. Small Ruminant Research.
2012 Mar 31;103(1):84-92.
Daugschies A, Najdrowski M. Eimeriosis in cattle:
current understanding. Journal of Veterinary
Medicine, Series B. 2005 Dec 1;52(10):417-27.
Deccox® 6 % South African Package Insert.
Dr Chantelle Erwee is a Technical Manager in the
Ruminants section at Zoetis. For more information,
please contact Dr Erwee at chantelle.erwee@zoetis.
com or 060 960 2074.
Ref No.: RU/CE/04/19/03
The main sign of sub-clinical coccidiosis is
poor weight gain. For this reason, sub-clinical
coccidiosis is often hard to diagnose and may
only become evident once comparisons are made
with control groups. Research has shown that
using anticoccidials, especially around periods
such as weaning, can have an important effect on
the growth of small ruminants. 1
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