Salmonellosis

1. Etiology:

Salmonella are a genus of Gram-negative bacteria that contains more than 2,000 serovars, sometimes referred to as species or serotypes. These organisms are very common in animal populations and feces, residing in the intestinal tracts and feces of both warm- and cold-blooded animals. Salmonella are able to survive for months in cool organic substrates in either aerobic or anaerobic environments. Since some Salmonella survive within animal cells (phagocytes), intestinal tracts, or feces for extended periods of time, the organism is unlikely to be eradicated. Fortunately, Salmonella are quite sensitive to disinfection with most common disinfectants, but only after thorough cleaning and removal of organic debris.

2. Symptom:

The incubation period lasts 3-4 days. The disease progresses in the following forms:

1. Acute septicemia:

The most common form of the disease is in piglets; death rate sometimes reaches 100% without timely intervention. Red or purple clusters appear on their ears, snouts, faces and backs. In some cases, neurological symptoms are witnessed. The infected usually have high fever, body temperature can be as high as 40.5^oC – 41.5^oC and die within 24 – 48 hours.

2. Acute entercolitis:

Those that survive acute septicemia usually contracted with acute entercolitis. The ears, tail, nose, feet, and abdomen usually become light red to dark purple. Pigs that survive three or four days develop yellow diarrhea containing flakes of fibrin or, less frequently, blood. Animals that recover usually have decreased weight gain and stunting.

3. Chronic entercolitis:

The infected are usually sick, emaciated. Constipation and diarrhea are the most common symptoms. High fever is rarely seen but this is not the case with malnutrition, which is the main cause for the death of the infected.

3. Prevention:

Basic biosecurity:

Prevention of clinical disease relies heavily on good management and husbandry practices. All-in/all-out management systems by age and building with thorough sanitation between groups is most desirable. Pigs of different ages or sources should not be commingled. Thorough cleaning and disinfection are important before adding new pigs to empty pens or buildings.

Vaccination:

Several killed vaccines for choleraesuis are also available commercially. Experimental evidence indicates that either killed or endotoxin-based products increase the number of Salmonella organisms required to cause illness, but vaccinated animals do not become completely resistant to either infection or disease.
Vaccinate in accordance to manufacturers’ instruction.
Zoning the outbreak, try to limit the amount of transporting and travelling across the outbreak zone.
Strict control and hygiene to limit the spread of the disease

Preventive measures:

Periodically sterilize and disinfect.
Use one of the following medicines periodically to prevent diseases for the herd every 20 days, each period should last for 4-5 days.