Liver Flukes in Cats: Signs, Causes, and Therapy

Liver flukes are a sort of worm-like parasite that may trigger liver and bile duct infections in lots of animals, together with cats. On this article, you’ll find out about the most typical sorts of flukes that may have an effect on cats, the areas the place they happen most frequently, and the way they’re recognized and handled.

What’s a Liver Fluke?

What a liver fluke appears to be like like underneath a microscope. D. Kucharski Okay. Kucharska / Shutterstock.com

Not like how we usually consider the phrase “fluke”, a fluke within the parasite world will not be a stunning stroke of luck. Simply the alternative, flukes are a sort of flatworm parasite that may trigger infections. Most frequently that is in both the intestines or the liver and bile ducts. Flukes are additionally referred to as trematodes.

Liver flukes are people who particularly migrate to the liver and bile ducts of affected animals, the place they stay, inflicting progressive irritation and injury over time.

There are a number of several types of liver flukes that happen in cats all through the world however solely a pair are seen in the USA. On this article, we are going to point out all of them however focus totally on the one in every of chief significance within the US, Platynosomum fastosum, the reason for “lizard poisoning” in cats.

Forms of Liver Flukes that Have an effect on Cats

1. Platynosomum Fastosum

This liver fluke is the one in every of chief significance within the US. As a result of ingesting contaminated lizards is one route that cats can purchase an infection, the sickness it causes is also called “lizard poisoning”.

fastosum happens primarily in Florida, different heat, matter areas of the southeast US, and Hawaii. You might also see it known as P. concinnum. They’re primarily the identical liver fluke. One other referred to as P. illiciens that happens in Thailand is taken into account the identical parasite, however is a variation occurring extra in Southeast Asia.

2. Opisthorchis Felinus

Opisthorchis felinus is a liver fluke discovered primarily in Italy, Japanese Europe, Russia, and elements of Asia. In these areas, it may be a important explanation for bile duct irritation and an infection (cholangitis) in cats who catch and ingest uncooked fish. The identical route of an infection may happen in folks, inflicting the situation opisthorchiasis.

3. Clonorchis Sinensis

Clonorchis sinensis, often known as the oriental liver fluke that infects folks, has additionally been discovered within the bile and pancreatic ducts of canine and cats throughout elements of Asia.

4. Metorchis Orientalis/Conjunctus

Metorchis orientalis/conjunctus are very small liver flukes which were discovered within the bile ducts and gallbladder of carnivores, together with canine and cats. They’ve been present in North America, however should not thought-about important within the US. In addition they happen in Europe, Russia, and China.

Eurytrema Procyonis

Eurytrema procyonis is a liver fluke that primarily impacts raccoons and foxes within the Japanese US. It has been discovered generally within the pancreatic duct, bile duct, and gallbladder of home cats.

Causes of Liver Flukes in Cats

Cats who hunt small anole lizards like this one, a standard discovering in Florida and related areas, are at greater threat for liver fluke associated illness. Chris Mercer / Shutterstock.com

Cats get contaminated by liver flukes by means of ingesting a smaller animal that has the infective stage (referred to as metacercariae) in its physique. These smaller animals are referred to as intermediate hosts. Flukes require 1-2 intermediate hosts as a part of their life cycle.

Snails are widespread first intermediate hosts. They ingest fluke eggs handed in stool by contaminated mammals. The snails are then eaten. Cats might get contaminated at this stage, however snails aren’t tremendous appetizing for them. A second intermediate host extra typically ingests the snails and that second intermediate host is then eaten by the affected cat.

Second intermediate hosts can embody fish, amphibians, and reptiles. Fish are the principle intermediate host for Opisthorchis felinus. For Platynosomum fastosum, cats purchase the parasite by means of searching and consuming frogs and lizards.

Signs of Liver Flukes in Cats

When cats eat a lizard or frog performing as an intermediate host, the infective stage is a sort of cyst referred to as metacercariae. After ingestion, these cysts will “hatch”, permitting the child flukes to emerge. For liver flukes (versus intestinal flukes) the juveniles will discover their option to the bile duct (which opens into the small gut) and migrate by means of these ducts to the gall bladder.

In cats, liver flukes may migrate up the pancreatic duct, owing to the pancreatic duct and bile duct sharing a standard opening into the small gut.

Liver flukes could make their option to the gallbladder. In addition they migrate from the principle bigger widespread bile duct to any of quite a few branches of bile ducts unfold all through the liver.

It takes about 8-12 weeks for the youthful flukes to turn into mature adults.

The flukes’ location contributes to indicators of illness seen. Many cats could haven’t any obvious signs of sickness at first. However over time, the presence of the flukes trigger blockages within the bile ducts (and generally pancreatic ducts), inflicting obstruction of bile circulate, tissue injury and irritation. These adjustments may result in secondary bacterial an infection as nicely.

Indicators could happen as early as 7 days after an infection however could take as much as 4 months.

Whereas cats in earlier phases of an infection or with a light-weight burden of flukes could present no indicators of sickness or delicate intermittent indicators of sickness:

• Gentle weight reduction or lack of ability to realize weight
• Fluctuations in urge for food
• Intermittent diarrhea
• Poor haircoat
• Intermittent lethargy
• Intermittent low grade fever

Issues Occurring in Cats with Liver Flukes

Jaundice, or a yellow look to the pores and skin, gums, and whites of the eyes, is an indication of liver and bile duct illness, which liver flukes may cause. Todorean-Gabriel / Shutterstock.com

The diploma of illness relies on what number of liver flukes are current and the way lengthy a cat has been contaminated. Extra extreme infections in cats result in indicators of liver and gallbladder/bile duct illness, which is known as hepatobiliary illness or cholangiohepatitis. By 4-6 months after an infection, flukes have triggered important tissue adjustments within the liver and bile ducts, resulting in extra noticeable indicators of sickness.

In cats the place these indicators are attributable to Platynosomum, these indicators of sickness are collectively referred to as “lizard poisoning”:

• Lack of urge for food (anorexia)
• Lethargy
• Vomiting
• Diarrhea
• Jaundice (yellow tinge to gums, whites of eyes, and pores and skin)
• Stomach distension

Cats that develop indicators of sickness to this extent will die from the illness if it goes untreated.

It is very important do not forget that these indicators of sickness should not unique to lizard poisoning however will be seen with any explanation for liver and/or gallbladder illness in cats.

Prognosis of Liver Flukes in Cats

Particular fecal testing strategies are wanted to see liver fluke eggs in a stool pattern. Peerachart / Shutterstock.com

Diagnosing liver flukes will be very difficult. Figuring out the area and chance of publicity for a cat is vital. However there are diagnostics used to additional slim down the opportunity of liver flukes being concerned in a cat’s sickness.

1. Fecal Testing

Cats with excessive parasite masses are prone to have eggs discovered of their feces, however it should nonetheless take at the least 12 weeks for eggs to start out displaying up in stool samples after an infection.

Flukes require particular strategies of fecal detection with the next methods:

These strategies should not routinely utilized in veterinary observe for a majority of parasites that may be recognized with fecal exams (as a result of these strategies don’t work nicely for figuring out way more widespread parasites). Thus flukes will be simply missed utilizing routine fecal examination methods, particularly for cats with very gentle burdens of flukes.

Parasites like flukes shed eggs intermittently, which may result in false adverse check outcomes if the parasite merely isn’t producing eggs on the time of the fecal examination. A number of fecal exams utilizing the precise methods could also be wanted.

In instances the place flukes are inflicting bile duct obstruction (which may happen with extreme illness), egg shedding could not happen in any respect.

PCR (DNA) testing is changing into extra widespread to check for fecal parasites. To my data there is no such thing as a such testing obtainable for cat liver flukes. Liver flukes will be recognized by means of PCR testing. Nevertheless, as a result of liver flukes should not intestinal parasites residing within the digestive tract, PCR testing on stool will not be correct.

2. Blood Testing

There isn’t a particular blood check for liver flukes in cats. We are able to see different blood work adjustments that happen due to the illness the flukes are inflicting in affected cats.

ALT: It is a liver cell leakage enzyme that will increase with liver irritation when the cells are underneath stress. This could happen with any form of hepatic (liver) illness. One other much less particular worth referred to as AST can also be typically elevated with ALT.

ALP: Is a much less particular worth on blood work however will be seen with hepatobiliary illness. This normally solely begins to raise with extra extreme bile duct illness.

Complete Bilirubin (TBili): With out getting technical, whole bilirubin is a price that can improve with extreme gallbladder or bile duct illness, particularly blockage or obstruction. Even a gentle improve in whole bilirubin is taken into account extremely irregular and regarding in cats.

Eosinophils: Eosinophils are a sort of white blood cell that can see will increase with parasitic illnesses. One examine taking a look at liver flukes in cats discovered that eosinophil counts have been elevated in all cats with fluke an infection however peak ranges took 4-5 months, making this a much less delicate indicator for early illness.

3. Imaging

X-ray will not be useful for diagnosing liver fluke an infection. However ultrasound will be very useful, particularly for cats with extra superior illness the place adjustments within the liver and bile ducts could also be seen.

Ultrasound is a routine diagnostic imaging check used to judge cats with hepatobiliary illness. Within the case of liver fluke an infection, adjustments like bile duct and gallbladder enlargement could also be seen. Whereas difficult to seek out, the presence of a excessive burden of flukes may very well be seen to a level inside distended bile ducts. Regional lymph nodes may be enlarged and detectable solely by means of ultrasound.

As a result of fecal testing could also be much less dependable, sampling of bile (which may very well be accomplished by means of ultrasound) has been instructed as a potential option to diagnose flukes.

Remedies for Liver Flukes in Cats

As a result of testing for liver flukes will be very difficult, treating cats perceived to be in danger could also be the very best plan of action in some instances.

For Platynosomum liver fluke infections, praziquantel has demonstrated the very best success. It isn’t authorised for this use, however a 3-5 day course repeated after 12 weeks has been instructed.

For different sorts of fluke infections, fenbendazole has additionally been described as a therapy possibility.

For very heavy liver fluke infections inflicting bile duct obstruction, surgical procedure could also be required.

Any cat that may be very unwell from hepatobiliary illness typically requires further supportive care together with:

• Intravenous or subcutaneous fluids
• Dietary assist (even feeding tubes for cats that aren’t consuming)
• Antibiotics
• Steroids
• Urge for food stimulants
• Treatment for vomiting and/or diarrhea.

Cat Care Ideas

• Liver flukes in cats should not a standard explanation for hepatobiliary illness in cats besides in areas the place these parasites are discovered (southeast US and tropic areas)
• When you have a rescue cat that develops indicators of hepatobiliary illness inside only some weeks or months, all the time test if they might have originated from the next threat area.
• Non-specific indicators of sickness can happen generally in cats. But when these indicators happen on and off again and again (even when your cat seems regular in between) it’s a good suggestion to get a veterinary examination.
• Any time a cat stops consuming for greater than 24 hours, it’s best to all the time contemplate this an pressing want for a veterinary examination
• Any indicators of jaundice (yellow tinge to pores and skin, gums, and whites of eyes) are related to extreme liver or bile duct illness and must be thought-about an emergency.

Prevention of Liver Flukes in Cats

Cats who hunt lizards, frogs, and fish are at greater threat of liver fluke an infection. Kristi Blokhin / Shutterstock.com

Cats can solely purchase liver flukes by means of ingestion of the intermediate host (lizards or frogs for Platynosomum and fish for Opisthorchis). Due to this fact, cats who’re searching a lot of these animals are at highest threat.

Retaining cats in these extra tropic areas indoors can nearly get rid of the chance.

In instances the place the chance is excessive however searching can’t be eradicated from a cat’s routine, screening fecal samples with the suitable methods may very well be thought-about each 12-16 weeks.

If the chance is excessive sufficient, empirical therapy with a praziquantel product each 12 weeks could also be a consideration.

For those who stay in a area the place liver flukes could current the next threat of sickness, be sure that to debate choices along with your native veterinarian.