News Excerpt:

Recently, scientists from University of California, Riverside have confirmed in a new study that a dog-killing flatworm parasite has been discovered in southern California’s Colorado river.

About the newly discovered parasite in colorado river:

• Heterobilharzia americana, commonly called the liver fluke parasite, was previously predominantly observed in southeastern United States (Texas and other Gulf Coast states). 
• It has never been documented to extend as far west as California.
• The new study shows that it is far more common than previously thought. 
• Since 2019, a total of 11 dogs across three counties in California have been diagnosed with this disease, resulting in one fatality. 

Lifecycle of Heterobilharzia americana liver fluke:

• The researchers found that two varieties of snails could transmit the parasite Galba cubensis and Galba humilis. 
• It was a surprise to find Heterobilharzia americana in these snails carrying the pathogens in the Colorado river.

• Following its transformation within a snail, the flatworm emerges with the objective of locating a mammal to infect. 

• During the transformation phase, it can only sustain itself independently for approximately 24 hours. 
• If a dog or raccoon is in the water or consuming it, they become susceptible to infection.

Spread and symptoms of the parasite:

• The parasite enters the dog through the skin when canines wade or swim in freshwater inhabited by infected snails, the intermediate host. 
• The worm gets into the veins of the intestinal lining and that’s where it develops into an adult and mates. 
• The presence of the adults in the veins isn’t the problem, It’s the eggs that get into the lungs, spleen, liver, and heart. 
• The immune system tries to deal with it, and hard clusters of immune cells called granulomas form and eventually, the organ tissues stop functioning.
• It then lays eggs that get into the lungs, spleen, liver and heart, causing canine schistosomiasis, which affects dogs’ livers and intestines.

• Other than dogs, the parasite can infect other species, including raccoons, marsh bunnies, horses, mountain lions, and opossums.
• Symptoms start gradually with a loss of appetite, and eventually include vomiting, diarrhea, profound weight loss, and signs of liver disease.

Detection and prevention of Heterobilharzia americana

• Awareness and early detection are critical in managing the spread of Heterobilharzia americana. 
• Pet owners should be vigilant for symptoms, especially if their dogs have been exposed to potentially contaminated water sources.
• A simple fecal test can confirm the presence of the parasite, allowing for timely treatment and preventing further spread. 
• Preventive measures also include avoiding contact with known infected water bodies and promoting research on snail control and parasite eradication strategies.
• It is not known to cause disease in humans, but It can cause swimmer’s itch, a red rash where it penetrates human skin, but it’s not able to cause infection.

Way forward:

• The discovery of the Heterobilharzia americana parasite in the Colorado River serves as a stark reminder of the interconnectedness of ecosystems and the unexpected ways in which diseases can spread.
• By raising awareness, conducting diligent research, and implementing preventive measures, we can protect our beloved pets from this hidden danger.
• It underscores the importance of vigilance in monitoring our natural waterways, not only for the health of our canine companions but also for the broader implications on public health and environmental safety.
• Through community education and scientific investigation, the spread of this parasite can be stopped ensuring the safety and well-being of all who rely on these vital water resources.

Additional Information:

About colorado river:

• Colorado River, major river of North America, rising in the Rocky Mountains of Colorado, U.S., and flowing generally west and south for 1,450 miles (2,330 kilometres) into the Gulf of California in northwestern Mexico. 
• Its drainage basin covers 246,000 square miles (637,000 square kilometres) and includes parts of seven states—Wyoming, Colorado, Utah, New Mexico, Nevada, Arizona, and California. 
• For 17 miles the river forms the international boundary between the U.S. state of Arizona and Mexico. 
• The river drains a vast arid and semiarid sector of the North American continent, and because of its intensive development it is often referred to as the Lifeline of the Southwest.