Prevention and treatment of myocarditis in calves with degeneration and necrosis of myocardial skeletal muscle

Calf metabolic disease-selenium deficiency, characterized by degeneration and necrosis of myocardium and skeletal muscle. Due to the diseased muscle of calves fade, showing boiled meat-like or fish-like, it is also known as white myopathy. The disease is caused by selenium deficiency in feed and occurs frequently in 1-3-month-old calves.

Calf

(1) etiology. Primary ⑴: the content of selenium in soil and forage grass is too low. ⑵ secondary: when the content of sulfide in the soil is too much (caused by sulfur fertilizer) or the intake of forage grass containing too much sulfate, the reaction between selenium and sulfur reduces the absorption and utilization of selenium in feed by calves, resulting in selenium deficiency. ⑶ in addition, sudden changes in the weather and other stress factors can also induce myocarditis.

Symptoms. ⑴ acute type: most calves of 10-120 days old had sudden onset, hyperheartbeat, irregular rhythm, ataxia, and died of heart failure in a short time. ⑵ subacute type: the sick cow is depressed in spirit, moves slowly, the back is hard, the hindquarters shake, and can not afford to lie down in the later stage. The buttocks were swollen, the touch was hard, the breathing was accelerated, the pulse increased more than 120 beats / min, and arrhythmia occurred and died within 6-12 hours of onset. ⑶ chronic type: growth stagnation, dyspepsia, diarrhea, emaciation, rough coat, no luster, spinal curvature, general fatigue, like lying unwilling to stand. Light calves are expected to recover if they are treated in time. Occasionally, there are diseases such as foreign body pneumonia or enteritis.

(2) the course and prognosis of the disease. The diseased calves with acute selenium deficiency have rapid onset, rapid death and high mortality; the course of disease in subacute type is 1-2 weeks, and the chronic type is longer. Except for acute type, as long as early diagnosis and reasonable treatment are given, the cure rate is high and the prognosis is good.

(3) Prevention and control. On the premise of improving the feeding management of diseased cattle with selenium deficiency (such as restricting activities, keeping warm in barns, avoiding stress factors, etc.), ⑴ should carry out causative and symptomatic therapy, such as intramuscular injection of 0.1mg / kg body weight sodium selenite solution or oral sodium selenite solution 10mg / 50kg body weight, interval of 2-3 days, re-administration, or vitamin E preparation. ⑵ for chronic cases, anti-inflammatory with antibiotics or sulfonamides, should not be combined with hormone therapy and myocardial nutrition drugs, especially concentrated sugar, vitamin C, salvia miltiorrhiza solution to buffer myocardial inflammation. ⑶ to prevent the disease, usually need to supplement selenium, often oral selenium salt, newborn calves, should be subcutaneously injected with sodium selenite solution (3-5 mg) and vitamin E (50-150mg), after an interval of 2 weeks, once again.

(4) pay attention. ⑴ in the initial stage of the disease should not use cardiotonic agents to prevent cardiac nerve excitation, accelerate heart failure, resulting in death, only when there is chronic heart failure, can use appropriate amount of sodium camphor sulfonate or sodium potassium, but avoid digitalis preparation. ⑵ should strengthen nursing care for sick calves and avoid exercise and stimulation.