Mycotoxins

Mycotoxins are toxic compounds produced by a variety of fungi/moulds. Birds can pick up these toxins through infected feed or bedding. There are several different mycotoxins, causing different symptoms. Mycotoxicosis is the umbrella term, and refers to all of those diseases caused by the effects of toxins produced by moulds. Disease is often subclinical and may be difficult to diagnose. Problems occur worldwide, but especially in climates with high temperature and humidity and where grain is harvested with high water content.

CLINICAL SIGNS

Clinical signs vary depending on the variety of mycotoxin, the dose ingested and the period of exposure. Diarrhoea can occur with accompanying weight loss and some birds can show general ill thrift and perhaps a reduced flying ability. Some mycotoxins are caustic and cause lesions in the mouth of the birds resulting in feed refusal.

POST MORTEM FINDINGS

Post mortem findings vary in accordance with the type of mycotoxin involved.

DIAGNOSIS

In severe cases, a presumptive diagnosis may be based on the history, signs and lesions. However diagnosis can be very difficult.

TREATMENT AND CONTROL

The most effective treatment is the removal of the source of toxins. Addition of antifungal feed preservatives is also helpful. Increasing protein level in the feed until mortality reduces may also be beneficial. Feed samples can be tested for mycotoxins but this is costly and false negative results are possible. Vitamins may help recovery. Some products are available that bind the mycotoxins (and/or absorb them) to limit their impact.

The most effective preventative method is to never give mouldy feed to birds, and to make sure it is stored in a cool dry place.