Home › Animalia › Animal health › Animal diseases › Paramphistomosis
Paramphistomosis
Paramphistomosis is caused by cone-shaped, thick, bright pink to red flukes, which are called rumen flukes or rumen flukes. These flukes have two faces, and this is what confuses breeders. The adults, attached in clusters to the wall of the...
What is it?
Paramphistomosis is caused by cone-shaped, thick, bright pink to red flukes, which are called rumen flukes or rumen flukes. These flukes have two faces, and this is what confuses breeders. The adults, attached in clusters to the wall of the rumen and the network, are generally well supported: hundreds of them can be found in an animal which has never appeared ill. It is the young forms which cause the disease. After being swallowed, they cling en masse to the wall of the beginning of the intestine, dig into the mucosa and cause violent diarrhea, capable of killing animals within a few days. The parasite develops around water: ponds, ditches, irrigation canals, shallows and the edges of reservoirs, like the great liver fluke, of which it shares part of the environment. It is increasing in several regions around the Mediterranean.
Key point
The young form of Paramphistomosis can kill previously healthy lambs in a few days, and the usual douvicides do not stop it. Sudden diarrhea in a flock returning from a humid area warrants a call to the veterinarian without delay.
Commonly observed signs
These signs are neither exhaustive nor specific. Only a veterinarian can establish a diagnosis.
Related signs — each one links to its page:
In the serious form, which mainly affects young animals and batches recently placed on damp plots: abundant, liquid diarrhea, often grayish or greenish, with a fetid odor, which appears suddenly on several animals at the same time.
Intense thirst, animals staying near the water trough.
Rapid dehydration, sunken eyes, skin that remains wrinkled when pinched.
Marked depression, refusal to eat, animals lying down and never getting up again.
Soft swelling under the jaw and sometimes under the stomach, linked to the leakage of proteins through the damaged intestine.
Very rapid weight loss, in just a few days.
Deaths can occur despite treatment, when intestinal lesions are already established.
In the chronic form, due to adult rumen flukes: few or no signs, at most a drop in condition and production in the most heavily loaded animals.
When to consult without delay
This list does not replace veterinary advice. It gathers situations that justify a prompt consultation.
Causes and risk factors
Adult flukes live in the rumen and the network, and lay eggs which go into the droppings.
In stagnant or slow-moving water, the eggs hatch and the larvae enter small freshwater snails, where they multiply.
The larvae leave the snail and encyst on plants on the edges of ponds, ditches and flooded areas, where they remain infesting for a long time.
The animal swallows them while grazing or drinking. The young flukes then cling in very large numbers to the wall of the beginning of the intestine, hollow it out and make it bleed: it is this phase which causes the disease.
The survivors then move up to the rumen, settle there and become adults, where they generally no longer cause much harm.
Rainy years, periods following a flood and the drying up of ponds at the end of the season, which concentrates animals on very contaminated banks, are the times most at risk.
Wet pastures: edges of ponds and reservoirs, ditches, irrigation canals, lowlands, flood-prone areas of northern Tunisia and irrigated plots.
End of the dry season, when the ponds shrink and animals come to graze on the vegetation growing on the exposed banks: this is the most dangerous time.
Rainy years and periods following floods.
Direct drinking from natural water points rather than from the trough.
Young animals, not yet exposed, suddenly placed on a very busy plot.
Shared or successive grazing with cattle.
Animals already weakened by other digestive parasites.
Transmission
There is no direct contagion between animals and no risk for humans: everything passes through the vegetation and water of wetlands.
Cattle share the same parasite and contaminate the same plots: mixed grazing can maintain pressure even if there are few sheep.
A contaminated wet plot remains so for a long time, with the encysted forms surviving on the plants.
Direct watering in a pond or ditch is a major mode of contamination, often underestimated.
Diagnosis and care
Diagnosis is the veterinarian's responsibility, based on clinical examination and laboratory tests. Care is decided case by case.
The veterinarian relies on the context: sudden diarrhea on several animals, wet plot, season.
The analysis of droppings is misleading in the severe form: young flukes do not yet lay eggs, so the search for eggs can come back negative at the very moment when the animals die. A negative result never rules out the diagnosis.
On the other hand, a careful examination of the liquid droppings can show, with the naked eye or under a magnifying glass, very young pinkish flukes eliminated with diarrhea: this is a very telling element, to show to the veterinarian.
In chronic carriers, searching for eggs in droppings using a sedimentation technique makes it possible to assess the pressure on the herd.
The autopsy of a dead animal is decisive: bright pink conical flukes hanging in clusters on the wall of the rumen, and young forms visible on the mucosa of the beginning of the intestine, red and damaged.
The veterinarian rules out other causes of sudden diarrhea, particularly infectious ones, which require different behavior.
Treatment
You need to know this above all: most of the products commonly used against the large liver fluke or against roundworms do not act on the rumen flukes. A herd treated with the usual douvicide can therefore die of Paramphistomosis. A limited number of molecules are effective, especially on young forms attached to the intestine. The choice, form and timing are strictly up to the veterinarian, especially since some of these products do not have authorization for this indication everywhere. The severe form is an emergency: beyond antiparasitic treatment, the animals need to be brought in, rehydrated, put to rest with clean water and quality food. Supportive treatment may be necessary, if prescribed. Immediately removing the lot from the wet plot is part of the treatment: letting the animals become recontaminated every day condemns the intervention. No dose or rhythm can be improvised, and blindly treating the entire herd on a fixed date is not recommended. Waiting times for meat and milk vary depending on the product and must be requested before any slaughter or milking.
Treatment depends on the cause and the animal's condition: it must be determined by a veterinarian. No self-medication.
Prevention
Fence ponds, ditches, reservoir banks and marshy areas, particularly at the end of the dry season when the vegetation on the banks attracts animals.
Drink from the tank rather than from natural water points; repair leaks that create permanent puddles.
Drain marshy areas where technically possible.
Avoid grazing young, non-immune animals on the heaviest wet plots.
Do not mow green fodder in flood-prone areas to distribute it to animals.
Take into account the cattle present on the same plots, which maintain the cycle.
Talk to the veterinarian from the first case in the herd: the strategy is based on the plot level, not the bottle level.
Possible complications
Death within a few days in the acute form, especially in young animals, sometimes despite treatment.
Severe dehydration and collapse of general condition.
Prolonged leak of proteins from the damaged intestine, with edema and lasting weight loss.
Growth retardation which does not recover in affected lambs while they are growing.
Increased susceptibility to other parasites and herd diseases.
Recurrence each season if the wet plot is not managed.
When to see a veterinarian
Several animals from the same batch suddenly present with liquid and fetid diarrhea: call the same day.
An animal is dehydrated, depressed, refuses to get up.
Sheep lose weight very quickly after grazing on the edges of a pond or a flooded area.
A soft swelling appears under the jaw or under the stomach.
You observe small pink shapes in the liquid droppings: keep a sample and show it to the veterinarian.
Animals die despite treatment against fluke: the product used was perhaps not active on rumen fluke.
Prognosis
The acute form has a guarded prognosis: when diarrhea has set in, the intestinal mucosa is already largely damaged and some losses are inevitable even with rapid treatment.
Animals caught early, taken out of the plot and supported, generally recover well, but take time to recover.
Chronic carriers of adult rumen flukes live normally.
At the herd level, everything depends on controlling water points: without fencing or controlled watering, the disease returns.
Frequently asked questions
I treated against fluke and my lambs still die: why?
Because rumen fluke is not liver fluke. Most of the products used against the great fluke have no action on it, in particular on the young forms attached to the intestine, which are the ones that kill. You need a specific product, chosen by the veterinarian.
The scat analysis is negative, does that clear me?
No. In the severe form, young flukes do not yet lay eggs: the analysis can be negative at the very moment when the animals die. The veterinarian then relies on the context, on the examination of liquid droppings and, if an animal dies, on the autopsy.
My sheep grazed the edge of the pond which is drying up, is this risky?
It is even the most dangerous situation. At the end of the dry season, the grass grows back on the exposed banks and concentrates the infesting forms, while the animals come there willingly. Fencing these banks is the most effective measure.
Can these flukes make me sick or infect my family?
No. Rumen flukes of ruminants are not transmitted to humans, either through meat or through contact with animals. This is not the case for all flukes: the large liver fluke can infest humans through aquatic plants eaten raw.
References
FAO — Organisation des Nations unies pour l'alimentation et l'agriculture
ANSES — Agence nationale de sécurité sanitaire (France)
Content reviewed by the TunisieVet editorial team · Updated 11 August 2026
AT A GLANCE
Need a veterinarian?
Find a practitioner near you on TunisieVet, with their specialities, hours and contact details.
Find a veterinarianCategories
This information is provided for educational purposes only and is not a substitute for a veterinary consultation. If you have any concerns about your animal's health, consult a veterinarian.
Thinking of welcoming a pet? Dogs and cats are waiting for a family in Tunisia, and adoption is completely free.
Adoption listingsTo discover
Related diseases and linked Animalia content.
Rabies
Viral · Vaccine available
Toxoplasmosis
Parasitic
Coccidiosis
Parasitic
Foot-and-mouth disease
Viral · Vaccine available