Fasciola hepatica in Dogs: Can Your Pet Get Liver Flukes?

Introduction

Although Fasciola hepatica is well-known as one of the parasites that commonly affects ruminants, its presence in canine hosts is a new threat in places where animals and domesticated pets live together. Referred to as the "Common Liver Fluke," this parasitic worm causes considerable harm to the canine liver when dogs accidentally consume cysts of encysted metacercariae in contaminated water and aquatic plants.

Microscopic view of liver fluke in canine

​Pathogenesis in Dogs

​This parasite's life cycle includes an intermediate host which can be any species of the snail family, Lymnaea species. When dogs accidentally eat the host plant or drink water, they ingest metacercariae. From there, the parasite migrates to the bile duct via the intestines, the peritoneal cavity, and finally the liver capsule.

​Clinical Signs

​The symptoms for dogs could start mild but could also develop into chronic liver infections as follows:

​Lethargy and Loss of Appetite: 

The dog becomes weak and stops eating normally.

​Abdominal Discomfort: 

Abdominal sensitivity around the area of the liver.

​Occasional Digestive Disturbance: 

The dog suffers from vomiting and diarrhea.

​Jaundice: 

Yellow-colored gums and whites of the eyes from bile duct blockage.

​Ascites: 

Accumulation of fluid in the abdomen when chronic infection occurs.

Diagnosis and Difficulties

The diagnosis of F. hepatica in dogs may be difficult due to the unusual nature of infection among canines:

Fecal Flotation: 

The traditional floatation tests may overlook the heavy eggs of liver flukes. Sedimentation technique is recommended.

Liver Enzyme Tests: 

High concentrations of ALT and ALP may be found in the dog’s blood workup.

Ultrasonography: 

Can help detect thickening of bile ducts or adult worms in dogs’ livers.

Treatment and Prevention

The treatment of liver fluke infection in canines requires certain drugs that are specifically effective in treating parasites:

Triclabendazole: 

Recommended first-line medication against different forms of the parasite.

Praziquantel: 

Occasionally recommended for different cases, though its effectiveness is questioned.

Control Measures: 

Protect your pets from infected water and do not feed your dog aquatic vegetation.