Sea Grant Extension Veterinarian Helps Control Virus in Koi Ponds


CORVALLIS, Ore. – Call him the koi doctor. An ichthyologist a la koi. The koi keeper’s confidant.

His patients are living works of art – brilliantly painted Picassos that swim in elaborate ponds and fetch up to $70,000 apiece. When disease strikes, the fallout can be disastrous, costing koi keepers in Oregon and around the world hundreds of thousands of dollars.

One half of a two-man SWAT team called in to render medical support for ornamental fish, Oregon State University’s Tim Miller-Morgan is a Sea Grant Extension veterinarian for aquatic pets, based at OSU’s Hatfield Marine Science Center in Newport, Ore.

His specialty is koi, brightly colored varieties of the common carp (Cyprinus carpio) originally developed in the mountainous Niigata region of Japan in the 1800s. Rice farmers who were raising carp for food noticed interesting color variations on certain fish and began breeding them for the unusual patterns.

Miller-Morgan’s success as a fish doctor is the result of a gamble taken by the OSU Extension Service and Oregon Sea Grant. They hired him six years ago to work alongside OSU professor Jerry Heidel, director and pathologist at the OSU Veterinary Diagnostic Laboratory, and launch an ornamental pet fish health program in the state.

It was a gamble that’s paid off, putting OSU – and Miller-Morgan and Heidel – at the epicenter of ornamental fish health and disease prevention practices.

“Oregon Sea Grant took a chance to develop this program in a state where ornamental fish are not thought of much,” Miller-Morgan said. “The fact this has blossomed into a international program shows there was a real need. It’s been amazing.”

Through the program, Miller-Morgan has taught seminars in 25 states within the U.S., as well as in Indonesia, Israel and Japan – and next month he’s off to India.

The ornamental fish industry worldwide is estimated at $15 billion. In the Pacific Northwest, water gardening and koi keeping are major hobbies, particularly in the metro areas. One Portland couple, for instance, installed an elaborate koi pond then built their house around it.

What’s unique about the OSU program is that Miller-Morgan and Heidel are serving ornamental fish hobbyists, as well as the small business owners that sell fish to hobbyists.

“Nobody’s doing this,” he said. “Other extension programs primarily serve the fish farmers. We also serve the small dealers, helping them implement good health management practices, which keeps disease from spreading to hobbyist aquariums and ponds.”

Miller-Morgan spends about half his time working with koi keepers, retailers and importers, mainly trying to prevent the spread of a hard-to-detect koi herpes virus that can be fatal for the fish and devastating for hobbyists.

“When I was hired, I never imagined that koi would be such a big part of the job,” he said. “But this virus can kill off 90 percent of the population in a pond in about 14 days. And if any fish survive, they’re carriers for life, so you can’t ever show them again.”

Because many koi are so valuable, Miller-Morgan’s work has taken on a critical urgency. No vaccine is available yet in the U.S. to prevent the virus, which first appeared 10 years ago and has evolved into seven different strains.

The virus attacks the fish’s gills, destroying cells, and also affects the skin, kidneys and gastrointestinal tract, damaging the fish so severely that other disease agents move in.

That was part of the reason it took years to positively identify the virus. The secondary diseases mask the virus, and detecting it requires advanced diagnostic techniques. The virus was first identified in the United States by a fish veterinarian working in the Midwest.

Miller-Morgan said this shows the value of veterinarians being involved in the ornamental fish industry. Now that the virus can be identified, he and Heidel and their program are taking steps to prevent its spread.

“We’ve spent a lot of time in the past few years educating people about the importance of quarantine on disease,” Miller-Morgan said. “Fish are often moved through the system so quickly the disease doesn’t develop until the fish are in the hobbyist’s pond.”

Although the United States has no quarantine requirements in place, Miller-Morgan and Heidel are developing a certification process for U.S. dealers who adhere to practices that reduce the risk of introducing the virus. Through a series of seminars and presentations, they hope koi dealers will eventually become certified – a change hobbyists will welcome.

What draws people to koi keeping? Miller-Morgan’s not sure. But for some, it appears to be akin to collecting art. “It’s like they’re buying a Picasso…a piece that will live 30 to 40 years and grow up to 36 inches long,” he said.

Most local hobbyists are not into the reproduction, breeding or developing lines. Fish farmers do that.

“Local hobbyists simply enjoy the fish as pets,” Miller-Morgan said. “You can almost think of koi as Labradors that live in water. They will eat out of your hand, and they eventually recognize the person who feeds them.”

Even amid the economic downturn, these hobbyists are very committed to keeping up their ponds, he said. Which means Miller-Morgan will continue making the rounds as the koi doctor, dispensing medical advice and helping ensure the ornamental fish industry stays healthy.

Visit Tim Miller-Morgan’s blog, “Words from a Wet Vet” at: http://seagrant.oregonstate.edu/blogs/wetvet