{"id":97197,"date":"2025-02-04T06:03:49","date_gmt":"2025-02-04T06:03:49","guid":{"rendered":"https:\/\/cats.com\/?p=97197"},"modified":"2025-02-04T06:03:49","modified_gmt":"2025-02-04T06:03:49","slug":"liver-flukes-in-cats","status":"publish","type":"post","link":"https:\/\/cats.com\/liver-flukes-in-cats","title":{"rendered":"Liver Flukes in Cats: Symptoms, Causes, and Treatment"},"content":{"rendered":"
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Nils Jacobi \/ Shutterstock.com<\/p><\/div>\n

Liver flukes are a type of worm-like parasite that can cause liver and bile duct infections in many animals, including cats. In this article, you\u2019ll learn about the most common types of flukes that can affect cats, the regions where they occur most often, and how they\u2019re diagnosed and treated.<\/p>\n

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What\u2019s a Liver Fluke?<\/h2>\n
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What a liver fluke looks like under a microscope. D. Kucharski K. Kucharska \/ Shutterstock.com<\/p><\/div>\n

Unlike how we normally think of the word \u201cfluke\u201d, a fluke in the parasite world is not a surprising stroke of luck. Just the opposite, flukes are a type of flatworm parasite that can cause infections. Most often this is in either the intestines or the liver and bile ducts. Flukes are also called trematodes.<\/p>\n

Liver flukes are those that specifically migrate to the liver and bile ducts of affected animals, where they live, causing progressive inflammation and damage over time.<\/p>\n

There are several different types of liver flukes<\/a> that occur in cats throughout the world but only a couple are seen in the United States. In this article, we will mention all of them but focus primarily on the one of chief importance in the US, Platynosomum fastosum<\/em>, the cause of \u201clizard poisoning\u201d in cats.<\/p>\n

Types of Liver Flukes that Affect Cats<\/h2>\n

1. Platynosomum Fastosum<\/h3>\n

This liver fluke is the one of chief importance in the US. Because ingesting infected lizards is one route that cats can acquire infection, the illness it causes is also known as \u201clizard poisoning\u201d.<\/p>\n

fastosum<\/a> occurs primarily in Florida, other warm, topic areas of the southeast US, and Hawaii. You may also see it referred to as P. concinnum. They are essentially the same liver fluke. Another called P. illiciens<\/a> that occurs in Thailand<\/a> is considered the same parasite, but is a variation occurring more in Southeast Asia.<\/p>\n

2. Opisthorchis Felinus<\/h3>\n

Opisthorchis felinus<\/a> is a liver fluke found primarily in Italy, Eastern Europe, Russia, and parts of Asia. In these regions, it can be a significant cause of bile duct inflammation and infection<\/a> (cholangitis) in cats who catch and ingest raw fish. The same route of infection can also occur in people, causing the condition opisthorchiasis<\/a>.<\/p>\n

3. Clonorchis Sinensis<\/h3>\n

Clonorchis sinensis, known as the oriental liver fluke that infects people, has also been found in the bile and pancreatic ducts of dogs and cats across parts of Asia.<\/p>\n

4. Metorchis Orientalis\/Conjunctus<\/h3>\n

Metorchis orientalis\/conjunctus are very small liver flukes that have been found in the bile ducts and gallbladder of carnivores, including dogs and cats. They have been found in North America, but are not considered significant in the US. They also occur in Europe, Russia, and China.<\/p>\n

Eurytrema Procyonis<\/h3>\n

Eurytrema procyonis is a liver fluke that mainly affects raccoons and foxes in the Eastern US. It has been found sometimes in the pancreatic duct, bile duct, and gallbladder of domestic cats.<\/p>\n

Causes of Liver Flukes in Cats<\/h2>\n
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Cats who hunt small anole lizards like this one, a common finding in Florida and similar regions, are at higher risk for liver fluke related disease. Chris Mercer \/ Shutterstock.com<\/p><\/div>\n

Cats get infected by liver flukes through ingesting a smaller animal that has the infective stage (called metacercariae) in its body. These smaller animals are called intermediate hosts. Flukes require 1-2 intermediate hosts as part of their life cycle.<\/p>\n

Snails are common first intermediate hosts. They ingest fluke eggs passed in stool by infected mammals. The snails are then eaten. Cats could get infected at this stage, but snails aren\u2019t super appetizing for them. A second intermediate host more often ingests the snails and that second intermediate host is then eaten by the affected cat.<\/p>\n

Second intermediate hosts can include fish, amphibians, and reptiles. Fish are the main intermediate host for Opisthorchis felinus<\/a>. For Platynosomum fastosum, cats acquire the parasite through hunting and eating frogs and lizards.<\/p>\n

Symptoms of Liver Flukes in Cats<\/h2>\n

When cats eat a lizard or frog acting as an intermediate host, the infective stage is a type of cyst called metacercariae. After ingestion, these cysts will \u201chatch\u201d, allowing the baby flukes to emerge. For liver flukes (as opposed to intestinal flukes) the juveniles will find their way to the bile duct (which opens into the small intestine) and migrate through those ducts to the gall bladder.<\/p>\n

In cats, liver flukes may also migrate up the pancreatic duct, owing to the pancreatic duct and bile duct sharing a common opening into the small intestine.<\/p>\n

Liver flukes may make their way to the gallbladder. They also migrate from the main larger common bile duct to any of numerous branches of bile ducts spread throughout the liver.<\/p>\n

It takes about 8-12 weeks<\/a> for the younger flukes to develop into mature adults.<\/p>\n

The flukes\u2019 location contributes to signs of disease seen. Many cats may have no apparent symptoms of illness at first. But over time, the presence of the flukes cause blockages in the bile ducts (and sometimes pancreatic ducts), causing obstruction of bile flow, tissue damage and inflammation. These changes can also lead to secondary bacterial infection as well.<\/p>\n

Signs may occur as early as 7 days after infection but may take up to 4 months.<\/p>\n

While cats in earlier stages of infection or with a light burden of flukes may show no signs of illness or mild intermittent signs of illness:<\/p>\n