COCCIDIOSIS IN RUMINANTS: INTESTINAL COCCIDIA
Coccidia that affect ruminants can be divided in two groups according the life cycle type, direct (intestinal) or indirect (extraintestinal).
Within the group of intestinal coccidia, different genuses of Eimeriidae family are present, such as Eimeria, Cytoisospora and Isospora, or from Cryptosporidium genus which is inside Cryptosporidiidae family.
Many of these names are known for their involvement to other species beside ruminants, such as Eimeria which has great influence in poultry production or Cryptosporidium that affects domestic animals like dogs and cats.
In cattle, the most pathogenic coccidia are Eimeria bovis and Eimeria zuernii that mainly cause liquid diarrhoea in Young animals and they also have been related to nervous symptoms. When this problem becomes chronic there is an alternation between pasty and liquid faeces and the animal performance is reduced.
In sheep and goat, the main parasites with more effect are from Eimeria genus but of different species.
The most pathogenic species for goat are Eimeria arloingi, Eimeria nenakohlyakimovae and Eimeria crhistenseni. Instead, for sheep are Eimeria ovinoidalis and Eimeria crandallis.
Coccidiosis in small ruminants produces more mortality than in cows and it usually affects young animals between 3 and 8 weeks-old. However, the symptoms are very similar and the main lesion is catarrhal enteritis, which could become into a bloody or necrotizing enteritis depending on the case.
To prevent coccidiosis, many coccidiostats has been used in this and other animals such as: robenidine, monensin, toltrazuril, diclazuril, salynomicin and aprolium. But at the moment, none of these are inside the positive list of the European feed animal register as a product intended for ruminants.
For this reason, it’s necessary to search natural coccidiostats to use them as a preventive. In other species, like chicken, the use of these products is spread and has good results versus vaccination or chemical coccidiostats. The mechanism of action of natural coccidiostats is based on the optimization of the intestinal immune system, to break the reproduction of parasites.
Dra Núria Martín Gairal
Veterinary Veterinary of technical and registration department at Biovet S.A. Laboratories