Suckling Pigs courtesy of wikipedia.orgDomesticated Pig courtesy of Pig behind fence courtesy of Wikimedia Commons

Interactions with Other Species:

Domestic pigs interact every day with other organisms –the most interesting and most prevalent being parasitism.  

Parasitism is a destructive symbiotic relationship involving two organisms where one organism is benefiting and the other is being harmed by the relationship. Some of these parasitic relationships can cause mild symptoms to severe symptoms and even death.

Atrophic rhinitis

Atrophic rhinitis (AR) is caused by the mycobacterium Pasteurella multocidia. This mycobacterium attacks the fine network of bones within the snout. AR commonly appears in young piglets, because at this time the immune system is not fully developed. The first signs of AR are sneezing and rubbing snouts. Discharge may appear out of the nose and eyes. As the infection continues pigs will commonly sneeze blood. AR can be prevented by placing the pigs in a better environment. Keeping pigs out of dust heavy environments should bring the levels of AR down.


Leptospirosis in Liver courtesy of Wikimedia CommonsLeptospirosis is a reproductive disease cause by Leptospira bacteria. Leptospira commonly causes spontaneous abortions and the birth of weak or stillborn piglets. The disease also can cause lowered milk production. This can be treated with antibiotics. Lower-immune pigs become infected when the bacteria enters through the mouth. The bacterium travels to the kidney and quickly multiplies. The bacteria is then spread to the urine and then taken up by other pigs that are in close association.  

Lice courtesy of Wikimedia CommonsLice

Lice are very common in the domesticated pig. Pigs will rub and scratch causing patches of fur to be lost. Many treatments are available. Treatments should be repeated every 12 days to ensure the termination of the lice infestation.


The disease Salmonellosis results from infection with the bacterium Salmonella, which can be spread in a variety of ways.  Pigs acquire this infection when coming in contact with infected feces. The domestic pig can also become infected if it comes into contact with infected food. The most common strain of Salmonella in pigs is Salmonella choleraesuis. This can lead to pneumonia and gut problems. The infection  Salmonella choleraesuis can easily become septic and spread to important areas of the body.  

To learn more about Salmonellosis click here.

Nematode courtesy of Wikimedia CommonsStomach Worms

There are several types of internal parasites that occur in the stomachs of domestic pigs.

These worms belong to the phylum Nematoda. The red stomach worm is most likely to be seen in pigs that are allowed to graze on an open pasture. The only sign of red stomach worm may be less weight gain than normal. This infection can also result in stomach ulcers.

The large round worm is most common however. The female round worms can lay over a million eggs per day. The eggs can be transported on the boots of farmers and are fairly resistant to disinfectants. The roundworms enter via the mouth and are transmitted from pig to pig through fecal matter.    Taenia solium is a common pig flat worm - in fact it is called the "hog flatworm". T. solium use pigs as an intermediate host and live in a variety of pig tissues, most commonly the skeletal muscle.


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