Poisoning

By Edward T. Mallinson.

Poisoning is not a particularly common cause of poultry or pet bird illness. In the experience of most, some other disorder or problem more likely is the source of the trouble.

So when you are suspicious of poisoning, be cautious about accusations. Look first for other possibilities and contact your nearest veterinarian, cooperative extension service agent, or State diagnostic laboratory for assistance.

Feed often is falsely incriminated. Nevertheless, to be on the safe side always secure and save a 10- to 25-pound quantity of the feed or any other toxic material you suspect for laboratory analysis. Skimpy samples can be misleading and often useless to your testing laboratory.

Botulism and mycotoxicosis are two of the most common intoxications in backyard flocks. They are not man-made toxins. Instead, both are naturally occurring, essentially "organic" poisons.

Botulinum toxin develops as a natural, exceedingly toxic substance when any type of plant or animal material decays. Mycotoxins are the byproduct of the natural growth of molds on grain or other feed ingredients. This growth can occur in the field, after harvest, during storage, and right up to the time of feeding.

Botulism.

This poisoning is more likely found in chickens, captive game birds (such as pheasants, quail), waterfowl, and raptors (owls, hawks, falcons and kestrels). Vultures appear to be the only resistant birds. Pheasants seem extremely susceptible. Affected stock, regardless of type, develop severe drowsiness, weakness, and progressive loss of control of the legs, wings, and neck. Death soon follows the onset of total paralysis and deep coma.

Because of the extraordinary potency of botulinum toxin, many types of birds penned pheasants particularly need only to consume small amounts of a decaying carcass, such as pieces of tissue or maggots from a single dead mouse or a small dead bird, to develop severe poisoning. Muddy alkaline shallow ponds or lakes, rich in decaying vegetation, can contribute to extensive waterfowl deaths from botulism.

Need to Patrol Pens

As a consequence you should always patrol your indoor and outdoor bird pens on a daily basis to pick up and remove dead birds or other animals. During summer months, outdoor game fowl pens should receive even more frequent inspection. Waterfowl should be fenced and fed away from lakes and ponds when low water levels cannot be corrected.

A variety of treatments are possible to reduce botulism losses. Your local veterinarian often can be of assistance. Fertilizers containing ammonium sulfate have been used to acidify the ground where botulism has been a problem in the hope that soil acidification will reduce the probability of toxin buildup.

Occasional paralysis of the neck, wings or legs of a few scattered growing chickens is not uncommon. The condition is not botulism and affected chickens almost always recover overnight. This condition, known as pseudo-or false-botulism, is generally believed to be a less typical form of Marek's disease.

Mycotoxicosis (aflatoxicosis).

In contrast to aspergillosis and other fungal diseases caused by mold spores actually invading the body tissues of poultry or birds, mycotoxicosis is the result of eating feed contaminated with the Poisonous byproducts of fungus growth on feed ingredients. In some instances, losses specially of the young may be very high.

In turkey poults or ducklings, incoordination and convulsions may occur. In the more common, less well-defined situation, the presence of low levels of mycotoxins may induce growth depression and unthriftiness.

All species of birds may be susceptible in varying degrees. Chronic liver and kidney damage is sometimes encountered. Some mycotoxins produce sores in the mouth, others skin inflammation.

Treatment of mycotoxicosis is based primarily on removal of the offending feed, and brief supplementation of the ration with antibiotics, vitamins, and some additional dietary fat and protein.

Use Fresh Feed.

Your best prevention hinges mainly on the use of freshly manufactured feed that is fed out promptly so as to reduce the time available for further toxin development during storage.

Commercially produced feeds and grains used for home-produced feed should be free of visible mold growth and kept cool and dry. Do not allow insides of storage bins to sweat.

Mold inhibitors often are added to commercially produced feeds to retard or prevent fungal growth. Pelleted or crumbled rations are considered advantagous because less surface area is available for mold growth. Furthermore, many ingredients are protected from air-exposure damage.

Edward T. Mallinson is Associate Professor, Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland campus, College Park.