Final answer:
Milk-spot lesions on a pig's liver indicate a Taenia solium infection, also known as swine tapeworm, which pigs contract by eating contaminated vegetation. Proper cooking, meat inspection, and good hygiene are key in preventing such infections. Infections from different parasites or amoeba can also cause serious liver damage.
Step-by-step explanation:
Milk-spot lesions on the liver are an indication of a Taenia solium infection in pigs. This parasitic infection, more commonly known as swine tapeworm, occurs when pigs ingest vegetation contaminated with eggs or gravid proglottids from the parasite. Humans can also become intermediate hosts through the ingestion of undercooked pork containing cysticerci, leading to a condition known as cysticercosis. Cattle can become infected similarly through Taenia saginata. Prevention of such infections largely resides in ensuring proper cooking and meat inspection, alongside maintaining good hygiene to prevent fecal contamination of food sources.
The liver can also be affected by other infections that may cause damage, such as those by the amoeba E. histolytica, which forms abscesses, as well as viral infections like hepatitis that lead to inflammation and damage to hepatocytes. Infections by parasites such as schistosomes can result in liver and blood vessel damage, while liver flukes like Fasciola hepatica affect the bile ducts. Each of these infections can result in significant liver damage if left untreated.