How to prevent and treat sulfonamide poisoning in ducks?

Sulfonamides are a class of drugs with a relatively broad antibacterial spectrum, capable of inhibiting most Gram-positive and Gram-negative bacteria, and they also have an anticoccidial effect, making them a commonly used drug in poultry. However, improper use can cause poisoning.

1. Causes

When using sulfonamides, an excessive dosage or a overly long treatment course may lead to poisoning. Sulfonamide drugs at a concentration exceeding 0.2% in drinking water and feed are toxic to ducks. Also, those allergic to sulfonamides, or those who accidentally take an excessive single dose, or those whose treatment course exceeds 1 week are all prone to poisoning.

2. Symptoms

Acute poisoning is mainly manifested as restlessness, head shaking, anorexia, diarrhea, convulsions, paralysis and other symptoms. Chronic poisoning is mostly seen with excessively prolonged medication. Affected ducks show: listlessness, reduced or lost appetite, thirst, ruffled feathers, diarrhea or constipation, and slow weight gain; some affected ducks have localized swelling on the face and blue-purple skin; laying ducks show a drop in egg production, and some lay thin-shelled eggs, soft-shelled eggs, or eggs with rough shells; in severe cases, anemia, jaundice, and prolonged blood clotting time occur.

3. Lesions

The pathological changes of sulfonamide poisoning are characterized by hemorrhages of varying degrees in the major organs of the body. The blood is thin and clots poorly. There are hemorrhagic spots of varying sizes under the skin and on the eyelids. The pectoral muscles show diffuse or brush-like hemorrhages, the muscles are pale or appear translucent and light yellow, scattered bright red hemorrhagic spots are present in the thigh muscles, and the pectoral muscle interstitium is edematous. There are petechiae ranging from needle-tip to bean-sized on the larynx, and the tracheal mucosa is hemorrhagic. The mucosa at the junction of the proventriculus and gizzard has old purplish-red spots or band-like hemorrhages, and there are hemorrhagic spots beneath the gizzard koilin layer. Scattered hemorrhagic spots are present on the intestinal serosa. Hemorrhage of the duodenal mucosa is relatively obvious. The ceca are filled with relatively thin, soy-sauce-colored contents, and the cecal tonsils are swollen and hemorrhagic. The cloacal mucosa shows diffuse hemorrhage. The liver is congested, purplish-red or yellowish-brown, slightly enlarged, and a small number of hemorrhagic spots or needle-head-sized necrotic foci can be seen on the surface; the center of the necrotic foci is sunken and dark red, with a gray periphery. The gallbladder is enlarged and filled with thick green bile. The spleen is mostly enlarged and congested. The kidneys are swollen and earth-yellow, with purplish-red hemorrhagic spots visible on the surface. The ureters are thickened and filled with white urates. There is hemorrhage in the endocardium, and some heart muscle has grayish-white nodules. The lungs are congested, and there is bronchial hemorrhage. The testes are grayish-yellow, enlarged, and some have hemorrhagic spots.

4. Diagnosis

The diagnosis of this disease should be based on a history of sulfonamide use, the appearance of acute or chronic poisoning symptoms, and, in combination with the pathological changes characterized by hemorrhages of varying degrees in the major organs, a diagnosis can be made.

5. Prevention and treatment

When using sulfonamides, the dosage and duration of use should be strictly controlled. Generally, medication should not exceed 1 week. Drugs added to feed should be ground fine beforehand, first added to a small amount of feed and stirred evenly, then mixed into a large amount of feed and blended uniformly. During medication, adequate drinking water should be provided to ensure the ducks can drink. Once poisoning symptoms appear in a duck flock, the drug should be stopped immediately, and the ducks should be encouraged to drink as much water as possible; severely affected birds can be given a 1% to 5% sodium bicarbonate solution to drink to prevent crystalluria and hematuria; for those with severe symptoms and difficulty breathing, vitamin C preparations can be fed as well.