Diagnosis and Prevention of Mycoplasma Infection in Cattle

Cattle infected with mycoplasma exhibit various clinical symptoms, requiring timely diagnosis and early treatment. What are the different symptoms caused by mycoplasma infection?

1.Mycoplasma Pneumonia in Cattle

This respiratory disease in cattle is characterized by necrotizing pneumonia caused by mycoplasma, similar to contagious bovine pleuropneumonia, with a morbidity rate of 50-100%. It manifests in two forms: acute and chronic.

Chronic Form: In chronic cases, symptoms are usually absent. Calves appear healthy and eat normally, with mild mucous or purulent discharge from the eyes and nasal cavities. Some calves may have normal or slightly elevated temperatures (38.5–39.5°C); respiratory rates may vary from normal to 100 breaths per minute, and pulse rates remain normal. Occasionally, calves exhibit severe dry cough, usually sporadically. Auscultation of the chest may reveal wheezing and asthma-like rales. Postmortem examinations can show pericardial effusion with clear yellow fluid; mild lung involvement might include localized red consolidation in the apical, cardiac, and diaphragmatic lobes, sometimes with purulent foci. Severe cases may exhibit extensive caseous or purulent necrotic lesions in the lungs.

Acute Form: Initially, only a few cattle show symptoms, but within 24-48 hours, the number of affected cattle increases. The group shows reduced feed intake and coughing, while affected cattle appear depressed with drooping heads. Symptoms include anorexia, high fever (40-42°C), lethargy, sweating, mucopurulent eye and nasal discharge, rapid breathing (over 40 breaths per minute), dyspnea, and labored breathing. Auscultation of the chest reveals high-pitched wheezing and stridor. The lungs exhibit consolidation, and lung sounds are often not discernible. Clinically, persistent fever, short, harsh coughs, and severe coughing at dawn and night, along with dyspnea, weakened or absent localized alveolar sounds, enhanced localized alveolar sounds, crepitations, and dullness upon percussion in certain areas, are characteristic.

Prevention is crucial, focusing on avoiding the introduction of infected or carrier cattle. During cattle procurement, it is essential to understand the local epidemiological situation and reinforce quarantine measures. Newly introduced cattle should be isolated for at least a month, and only after confirming they are disease-free can they be mixed with the herd. Improving herd management and enhancing resistance through better nutrition and a clean, sanitary, and dry environment is also key. "Early diagnosis, early isolation, and early treatment" are fundamental principles for controlling this disease.

Drug susceptibility tests have shown that mycoplasma in cattle is sensitive to tetracyclines (tetracycline, doxycycline, oxytetracycline, florfenicol), quinolones (enrofloxacin, ciprofloxacin, ofloxacin), and macrolides (tylosin, tilmicosin, erythromycin). However, many cattle farms have developed resistance to these drugs. Clinical trials indicate that combining these medicines with some traditional Chinese medicine significantly enhances therapeutic efficacy.

1. Mycoplasma Arthritis

Commonly occurring at around 15 days of age, it involves swelling and significant pain in one or several joints of the forelimbs or hindlimbs. Other symptoms include reduced milk intake or complete anorexia, depression, firm joint swelling, difficulty in joint flexion and extension, severe joint deformation, and a hopping gait. Cattle with concurrent mycoplasma pneumonia can die within 5-7 days, with a mortality rate exceeding 50%. Calves that survive often suffer from severe joint deformities, rendering them valueless for further rearing.

2. Mycoplasma Mastitis

Mycoplasma mastitis is a contagious disease characterized by a sharp decline in milk production. Affected cows appear healthy otherwise but suffer from severe mastitis or milk with watery or serous deposits of sandy or flake-like sediment.

Mycoplasma is a common issue in cattle farms, particularly in newly purchased cattle. Effective control measures include proper facility design, ventilation, hygiene, nutrition, stress management, early disease detection and treatment, and biosecurity. Good control measures result in healthier herds, better daily weight gain, and improved reproductive performance during the production phase.

3. Recommendations for Prevention and Treatment of Mycoplasma Pneumonia

Prevention Recommendations:

• Enhance the herd's immunity.
• Maintain a clean and sanitary rearing environment.
• Minimize stress.

Purchased Cattle:

Administer 30% oxytetracycline injection（Oxytong 30 L.A.） at a dose of 0.05 ml/kg body weight upon arrival, with a repeat injection after two days.

Provide electrolytes, multi-vitamins ((Elec-Vamino), Astragalus membranaceu & Ligustrum lucidum Ait granules(A traditional Chinese medicine); and Isatis tinctoria Linnaeus granules（A traditional Chinese medicine）in drinking water.

Treatment Recommendations:

Combine intramuscular injections with oral medications.

Intramuscular Injection:

Administer Kanamycin Sulfate injection and Tylosin Tartrate injection (Tylotong). On the other side , administer Flunixin Meglumine(Flunitong) and Ceftiofur Sodium.

Oral Administration:

Administer Qingfei granules(A traditional Chinese medicine for clearing lungs)+ Isatis tinctoria Linnaeus granules（A traditional Chinese medicine+ sarafloxacin hydrochloride + and Astragalus membranaceu & Ligustrum lucidum Ait granules(A traditional Chinese medicine). Dosage based on cattle weight.