Enzootic pneumonia

A contagious chronic pneumonia of pigs, characterized by a very high contagiousness within and between herds, but a very low fatality rate, caused by Mycoplasma hyopneumoniae.

Clinical Symptoms

The incubation period is one to two weeks, and characteristic symptoms such as dry cough and sneezing appear around 2 to 6 weeks of age.

As the symptoms become more severe, diaphragmatic breathing is observed.

Coughing increases during morning feeding, after a sudden awakening from sleep, and after intense exercise.

The symptoms are mild and the pig is stunted or atrophied. The mortality rate is very low.

In good housing conditions, pigs with cough may recover gradually and be clinically cured.

If there is no mixed infection, the disease is mild with only poor growth.

Mixed infections with other diseases can cause severe respiratory symptoms and death.

Pigs that recover from the disease can easily become carriers.

Diagnosis

Clinically, it is diagnosed by respiratory symptoms such as coughing and sneezing, but individual diagnosis is difficult.

In herds, it is diagnosed epidemiologically, i.e., by a decrease in the weight gain of piglets in the entire herd and an increase in the number of piglets coughing.

Dead pigs have a liver-shaped part of their lungs, which sinks when floated in water.

Bacteriologic, serologic, complement binding, and agglutination tests are used in the laboratory.

Prevention and treatment

Prevention

The most effective method of prevention is to purchase candidate pigs that are not infected with bubonic plague from a breeder.

If an outbreak occurs on the farm in weaner pigs (40 to 60 days old), vaccinate the piglets (7 to 21 days old) against bubonic plague.

If the outbreak occurs in early grower pigs (70 to 90 days old), vaccinate the piglets (30 to 50 days old) against bubonic plague.

Treatment

Unlike other bacteria, the mycoplasma bacteria that cause bubonic plague do not have a cell wall, so penicillin or tetracycline, which are commonly used in pig farms, are not effective.

On farms with severe outbreaks, rinsomycin at 3 to 4 kilograms (300 to 400 parts per million) per ton of feed for three weeks is an effective treatment.