Diagnosis of chicken gout caused by high calcium diet

In recent years, high calcium feed caused gout phenomenon often occur, long onset time, high mortality. Two gout diagnoses are reported below.

I. Incidence

In May 2000, a household in Jinhu Town raised 1000 chickens. After 30 days of age, it was considered that the content of calcium hydrogen phosphate was insufficient, so it increased from 1% to 3%. After feeding for 20 days, 210 chickens died successively, and the mortality rate was 21%. After changing feed, the chickens improved. After the test, the diagnosis is high calcium caused gout. In May 2001, Zhang raised 2000 chickens in Jianyang Town. At the age of 12 weeks, calcium hydrogen phosphate test contained less calcium and phosphorus, and then added pure bone powder 1% and stone powder 0.5%. After adding more than 20 days, chickens were found dead. After autopsy, gout was diagnosed and feed was changed. 400 died sporadically after delivery, with a mortality rate of 20%.

II. Clinical symptoms

Sick chickens are depressed, their combs are white, they are anaemic, their feathers are fluffy, they like to lie down, their appetite is reduced or they are wasted, they are thin, they are weak, their eyes are closed, their crops are empty, they have diarrhea, and their feces contain white urate. Most sick chickens showed swelling and thickening deformation of the soles and feet, joint swelling of 1~1.5 times, soft joints to touch, light pinching and dodging, struggling, unstable standing of mild symptoms, inability to stand, paralysis and inability to feed. Egg production of hens decreased or completely stopped production. The normal value of urate content in blood was 1.5~3.0 mg/100 ml, while that of sick chickens was 15 mg/100 ml, which increased by 5~10 times.

III. Changes in autopsy

The subcutaneous tissue, joint capsule, thoracic cavity, abdominal serosa, pericardium, internal organs (such as heart, liver, spleen, lung, kidney, mesentery, etc.) of sick chickens are covered with a layer of white lime urate. Liver is slightly enlarged and brittle, with diffuse small white particles in section; pulmonary congestion; kidney enlargement is 2~3 times, red and white alternate patterns, knife cut has sand sound, some kidney surface is covered with a layer of rough white film, one or both sides of ureter are dilated and thickened, ureter is filled with lime-like sediment obstruction urinary catheter. No obvious changes were found in the esophagus, glandular stomach and muscular stomach.

IV. Laboratory tests

Smears of heart, liver and swollen joint cyst fluid of diseased chickens were taken for microscopic examination, no pathogenic bacteria were found, many needle urate crystals were found, and no parasite eggs were found in feces examination.

V. Differential diagnosis

The chicken house is well ventilated, dry, fresh air, suitable temperature, protein content in feed does not exceed 20%, no sodium bicarbonate, sulfa drugs and moldy corn have been eaten. No infectious bronchitis, coccidiosis, pullorum bacillosis, colibacillosis, etc. occurred after investigation.

VI. Prevention

1. Discovered sick chicken immediately picked out, timely diagnosis, find out the cause of treatment.

2. Find out is high calcium caused gout, timely subtraction of more bone powder, stone powder and calcium hydrogen phosphate.

3. Drink antidotes for kidney swelling, drink 0.2% water from 8:00 to 10:00 every morning, that is, 50 kg water plus 100 g, 3 days for a course of treatment, drink enough water in the afternoon.

4. The diseased chickens were fed with green and juicy feed, and appropriate potassium permanganate and 0.5% edible alkali or 0.5% sodium bicarbonate were added to sufficient drinking water for 3 days, and then the concentration was changed to 0.25% for 3 days to promote the excretion of urate in the body. (Editor's note: If antidotes for kidney swelling have been used, sodium bicarbonate is generally not needed.)

5. Strengthen scientific feeding management and epidemic prevention hygiene, moderate exercise, sufficient sunshine in chicken houses and frequent cleaning.

6. Reasonable formula according to different age of chickens and paying attention to the ratio of calcium and phosphorus are the keys to prevent the occurrence of this disease.