Watch our new VIDEO about Coccidiosis!
Economic losses are mainly caused by medication costs and decreased animal production due to higher feed conversion, growth depression and increased mortality. Worldwide, total costs from coccidiosis in the poultry industry are estimated to be $3 billion on an annual basis. The high costs in poultry production urge the need to effectively control and prevent coccidiosis.
VIDEO: Coccidiosis in broilers and layer pullets
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More about the disease:
Coccidiosis is caused by a protozoan parasite of the genus Eimeria. Seven species of Eimeria are described to cause the disease in chickens. Each species of the parasite has a preference for a specific site in the gastrointestinal tract. In image 1, the site of infection is displayed for the five most important species.
Coccidian parasites invade intestinal cells to replicate, thereby causing damage to the gut wall integrity. Severe cases of the infection lead to intestinal lesions, diarrhoea and death, while subclinical infection compromises animal performance. Older birds are usually less susceptible than younger birds because of earlier exposure to infection. However, there is no cross-immunity between different Eimeria species, so it is possible that one flock experiences several outbreaks of coccidiosis.
Infected chickens may shed oocysts in the faeces for several days or weeks. Depending on the right temperature and humidity, the oocysts sporulate and become infective. These oocysts can be spread by wild birds, rodents, insects, dust and contaminated equipment and boots. Subsequently, susceptible chickens become infected by ingestion of oocysts from contaminated litter. A problem is that the oocysts may survive for long periods in the environment, because they are extremely resistant to outside influences and disinfectants. Thus, once a poultry house is infected it is hard to remove the infection from the house.
Clinical signs and diagnosis
As explained in the video, clinical signs op coccidiosis are:
Reduced growth rate
Reduced feed and water intake
When birds have diarrhoea, it is important to do a post-mortem or faeces investigation to find the cause of the diarrhoea. If the diarrhoea is caused by coccidiosis, it is important to start the right treatment straight away. At the same time, it is also important to take management measures, like removing wet litter. If you have diarrhoea in your chickens, you can start off with the following guideline for treatment:
1. Take some live chickens to the vet for post-mortem. Taking dead chickens makes no sense, especially not with gut problems, because the gut structure changes within half an hour after the chicken dies. Another option is to bring some feacal samples to the vet to do a feaces investigation with the flotation method. Read more about the flotation method and performing faeces investigation in our Formulary (from page 33) which can be found in the Kepro Academy.
2. If it is confirmed that it is coccidiosis (in broilers usually at more than 18 days old, never in chicks less than a week old), take management measures like described above.
3. Start treatment, using chemical drugs, use Kepcox 2,5% Oral, Amprolium 50% Oralor CoxB3 wsp as stated in the rotation program (read more about rotating below).
4. Administrate the use of drugs in a medicine logbook.
Prevention of coccidiosis
Control and prevention of coccidiosis is based on the use of anticoccidial drugs and/or vaccines in combination with strict hygienic measures.
Taking hygienic measures against the spread of coccidiosis mainly consists of removing wet litter and ensuring a suitable stocking density in the house.
In layer pullets, vaccines are important to fight coccidiosis and can be used as part of a rotation program. See image 2 for an example of a rotation program. Preferably, these vaccines consist of live, non-resistant Eimeria species, because that will lead to repopulation with sensitive parasites and restoration of efficacy of anticoccidial drugs.
Prevention in broilers is mostly based on adding ionophores to the feed. Anticoccidial products for in-feed use may be divided into two classes: ionophores and chemical products. (Below the subheader ‘treatment of coccidiosis’ more information on chemical products will be given.) Ionophores disrupt the osmotic balance within the coccidian causing them to die. Examples of ionophores are salinomycin, monensin, lasalocid and narasin. Ionophores should be used in a rotation program because it may induce resistance. See image 2 for an example of a rotation program.
In the rotation program below, a combination of ionophores, chemical medicines and vaccines is displayed. It is important to switch the use of the different products in the months that are stated in image 2.
When you do not want to use ionophores or chemical products, prevention by using Keprogan is a good alternative.
Keprogan prevents and decreases the adverse effects of coccidiosis and the excretion of oocysts in poultry. Image 3 below, shows the effect of Keprogan in preventing coccidiosis, compared to the effect of salinomycine (ionophore). Keprogan shows good results without the harmful residues and possible resistance of coccidiostatics. So, Keprogan is a good additive in prevention of coccidiosis. Read more about Keprogan in this previous newsletter.
Treatment of coccidiosis
Prevention of coccidiosis is very important. When an outbreak does occur, due to difficult circumstances or a high infection pressure, it is also important to treat birds. Coccidiosis can be treated with anticoccidial drugs in the drinking water.
Layer pullets and broilers
In both layer pullets and broilers, a rotation program with chemical anticoccidial products, can be used. Chemical products are produced by chemical synthesis and have a specific mode of action against the metabolism of the parasite. Anticoccidial products may induce resistance, because the sensitive parasites are removed from the population and the resistant ones remain and are allowed to flourish. That is the reason why using a rotation program is important. Goal of a rotation program is to change the anticoccidial drugs before resistance can develop and infection pressure increases.
An example of a rotation program is shown in image 4. This program is only suitable for treatment of coccidiosis. Be sure to firstly diagnose if coccidiosis is the case (like described under the subheader ‘clinical signs and diagnosis’) and to always take...
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