Problems in Rearing

Coccidiosis

Where poultry or gamebirds are kept there will also be coccidia- this is a fact of life. All birds will therefore be exposed to this organism at some point in the early rearing period. Coccidia have a complicated life cycle but it is the replication of the coccidia in the wall of the gut which leads to damage of the gut wall. This damage can lead to the poor absorption of nutrients which can lead to weight loss. Birds can also feel lethargic as a result and then fail to feed in which case they deteriorate further become dehydrated and then dye.

There are three species of coccidia that can affect pheasants- Eimeria colchici, Eimeria phasiani and Eimeria duodenalis. Eimeria colchici is considered the most pathogenic. Pheasants appear to be less susceptible to severe clinical coccidiosis compared with partidges. Red legged partridges can be challenged with Eimeria legionensis which is highly pathogenic and can result in very high morbidity and mortality.

As with the other causes of enteritis in gamebirds the first signs may be hunched lethargic birds with mortality, watery yellow droppings and then mortality. With coccidiosis morality can be very quick.

It is paramount to get a diagnosis as soon as possible. Post mortem examinations of ill live birds is recommended. Post mortem examinations usually reveal birds in poor body condition, failing to feed with scant intestinal contents. The caeca (last part of the gut) often contains watery yellow fluid, milky white fluid or hard caecal cores.

In order to confirm the diagnosis scrapings are taking form the gut wall lining at various levels of thie intestine and examined microscopic for evidence of coccidial oosyts (eggs). This help to confirm the diagnosis.

Treatments are limited but toltrazuril and amprolium can be used with success where the disease is diagnosed early enough.

Hexamita (Spironucleus)

Hexamita is a parasite that is commonly found in the intestine. It's life cycle is not fully understood but it is often observed in cases of enteritis. Birds are often affected from 3 weeks of age where birds can suddenly become lethargic with yellow diarrhoea. Rapid weight loss results coupled with poor feed intake resulting in high mortality. The birds breast bone becomes very prominent as a result of the rapid weight loss.

Post mortem examination is critical to ensure that birds can be diagnosed and treated correctly. Gross pathology in these birds can be summarises as follows- poor body condition, scant feed throughout the gut, thin walled intestine often dilated with watery contents and dilated caecae (last part of the gut) with a large amount of water yellow fluid. Confirmation requires taking intestinal scrapings and microscopic examination. It is then possible to visualise the Hexamita organisms darting around in the intestinal contents. For this reason it is always recommended to submit live birds for examination. If the birds have been dead for sometime then the Hexamita may also die within the birds. Once dead they cannot be identified using microscopic examination of wet smears.

Control of hexamita is reliant on management practices. It is essential to maintain high standards of cleansing and disinfection to prevent the spread of hexamita between groups of birds and between seasons. It is postulated that most birds carry a low level of Hexamita at all times and it is not until birds become stressed that they are then able to multiply within the birds. Birds should have continuous access to a high quality of feed of the appropriate physical form. Any changes in ration should take place gradually. Birds should have access to clean fresh water at all times and the litter quality should be maintained to the highest standards. Temperature regulation is critical and birds should not be chilled at any time. If birds are being allowed access to the night shelters and run then this should be a gradual process and take into consideration the weather conditions. Fresh ground should be used each season where possible and birds should not be reared on multiage facilities where ever possible.

The prognosis for Hexamita is dependent on how soon the problem was detected, whether the birds are still feeding and drinking, whether management changes are made to keep birds warm and improve feed and water intake, whether optimal facilities are available to medicate birds via the drinking water.

Treatment for hexamita is limited since the loss of Emtryl (dimetridazole). However tetracyclines have been shown to be of benefit in some cases. Often this may be helping to address secondary bacterial overgrowth within the gut. The use of electroytes and glucose can also be beneficial by supplying the birds with some nutrients particularly at a time when feed intake may be low and the absorption from the gut low due to the damage present.

Trichomoniasis

Trichomonas is a very similar organism to hexamita. Often birds have a very similar clinical presentation to hexamita too. The birds often stop feeding, lose weight rapidly and develop yellow watery droppings. Post mortem examination can reveal an enteritis with a thin walled intestine and watery contents. The caecae is often dilated with watery yellow contents. Changes in management as recommended with Hexamita can help to prevent the condition and reduce mortality in exisiting cases. Treatment with multivitamins, electrolytes and glucose can help to reduce losses. The use of tetracylines can help to reduce bacterial overgrowth within the gut.

There are many other problems which will not be discussed in detail here. To learn about problems in breeders click below: