| Various organic chemicals are dangerous, especially those used to treat seed grain. |
|
Cassia
obtusifolia
seeds are frequently found in corn and soybeans. When present at ≥2%, they reduce feed intake and lower body weights, increase feed conversion in broilers, and significantly depress egg production in laying birds. Necropsy lesions are absent. |
| Seeds of many species are toxic to chickens. Concentrations >0.05% in the feed produce signs of toxicosis. At 0.2%, weight gain is reduced markedly; 0.3% causes death in 18 days. Lesions consist of ascites, swelling or cirrhosis of the liver, and hemorrhages. Resistance to the toxin increases with age. |
| Cottonseed meal contains appreciable amounts of gossypol, which produces severe cardiac edema that results in dyspnea, weakness, and anorexia. When fed to laying hens, gossypol also causes egg-yolk discoloration. |
| Lasalocid is an anticoccidial compound that has been used in hot summer months because it increases water consumption. When used at other times of the year, the level of salt in the ration is reduced to prevent excessive water elimination and wet litter problems. If the salt level is reduced too much, it will result in stunting, increased lameness, and a characteristic clinical picture in broilers manifested by the bird walking on its toes. This clinical syndrome has been
called lasolocid toxicity when, in reality, it is due to low levels of salt in the feed. |
| This ionophore coccidiostat is widely used in the broiler industry. At levels >120 ppm, it reduces feed intake and weight gain; in layers, egg production is reduced. Signs of toxicity include a characteristic paralysis in which the legs are extended backward. Mortality occurs in naive turkeys if they are switched to a feed that contains monensin. They become paralyzed with the legs extended backward; no lesions are seen at necropsy. |
| This coccidiostat is used in broilers. It should not be fed to layers, as it can cause discoloration and reduced hatchability of eggs (although the effect is reversible once the nicarbazin is withdrawn). It also may result in reduced heat tolerance in birds exposed to high temperature and humidity. |
| This has been used to treat several bacterial diseases in poultry, but is no longer approved for use in the USA. When fed at 0.022%, it causes hyperexcitability manifest by rapid movements, loud squawking, and frequent falling forward. In turkeys, which are more sensitive to nitrofurazone than are chickens, it produces cardiac dilatation, ascites, and when fed at 0.033%, death. |
| When this compound, widely used in feed to improve weight gain and feed efficiency, is improperly mixed or fed at a level 2-3 times higher than normal, it induces a high-pitched chirp and a “duck-walking” stance. Cervical paralysis is frequently seen in chickens that consume excessive amounts. Clinical signs are usually reversible in a few minutes. Chronic exposure may produce intrahepatic cholangitis. |
| Residues have been reported in the fatty tissue of chickens and turkeys in excess of the 5 ppm permitted in edible tissue, and in egg products in excess of the permitted 0.5 ppm. PCB depress egg production and hatchability, and levels of 50 ppm result in cirrhosis of the liver and ascites in broilers and a drop in egg production and hatchability in hens. (See also
halogenated cyclic hydrocarbon poisoning,
Halogenated Aromatic Poisoning: Introduction.) |
| Quaternary-ammonia-based compounds are widely used as disinfectants. (See also
antiseptics and disinfectants,
Antiseptics and Disinfectants: Introduction .) Turkeys are very sensitive; levels of 150 ppm result in substantial mortality. Clinical signs include reduced water intake, nasal and ocular discharge, facial swelling, and gasping. Necropsy lesions include caseous ulcers at the base of the tongue and commissures of the mouth. |
| Salinomycin is commonly used as an anticoccidial compound in the broiler industry. When used at 60 g/ton of feed, the compound is safe. Toxicities occur when broiler feed containing salinomycin is accidentally fed to naive breeder hens. Clinical signs in these hen flocks include paralysis with the legs extended backward and decreased feed consumption, egg production, and hatchability. Levels of salinomycin >10 g/ton in breeder-hen feed are sufficient to produce these
clinical signs. Necropsy lesions are absent in birds with this clinical picture. |
| Sulfonamides are widely used for treatment of several bacterial and protozoal infections in poultry. Sulfaquinoxaline, when fed at 0.25%, results in severe pancytopenia. Hemorrhages are common on the legs, breast muscle, and in virtually all abdominal organs. The bone marrow is pale, and the blood is slow to clot. Toxicity is frequently seen in hot weather when sulfaquinoxaline is provided in drinking water. Water consumption increases rapidly as the temperature increases,
which leads to increased drug intake. This toxicity usually is responsive to vitamin K therapy. |
| Thiram is used to treat seed corn. It is toxic to chicks at 40 ppm and to goslings at 150 ppm; it causes leg deformities and weight loss. At 10 ppm, it causes soft-shelled eggs, and at 40 ppm, egg production and hatchability are reduced. Turkey poults tolerate up to 200 ppm. |
| A crystalline halogen has been identified as the “toxic fat” factor in some feeds. In young pullets, it reduces growth, retards sexual development, and increases mortality. Hatchability is decreased. Turkeys and ducks are less susceptible than chickens. Signs of intoxication include ruffled feathers, droopiness, and dyspnea. Lesions include ascites and hydropericardium, liver necrosis, subepicardial hemorrhage, and bile duct hyperplasia. Although the amount of toxin varies in
feeds from different sources, 0.25-0.5% fed for 35-150 days produces typical lesions. |
