Review/Oorsig Volume 23, Issue 02 - Page 21

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 21