Next time you think it would be a good idea to take your dog fishing, think again.

In late May, we ventured with friends to a back-country cabin on the South Fork of Battle Creek east of Red Bluff for some trout fishing. With us were our two Labrador Retrievers, Tess (about one year old) and Lodi (about six years old). Both came from Lab Rescue.

Labradors are “water dogs,” and these two dogs of ours were so into the river and into fishing as to be counterproductive to the stealth required to seek the elusive trout. The breed, they say, originated in Newfoundland where fishermen used the dogs to retrieve fish that fell off hooks and to help haul in swimming lines or fishing nets. You would think Labradors would have no problem with fish.

We caught and ate lots of trout, and the dogs also ate a few fish guts that they retrieved from the brush.

About a week after the trip, Tess became terribly sick with an undiagnosed illness. She stopped eating and drinking and grew weak, along with constant vomiting. Dr. Prutton of Abbey Pet Hospital prescribed antibiotics, and we force fed her water to stave off dehydration. On the day before Dr. Prutton had told us the next step was to put her on an IV, she rallied, and quickly recovered.

A couple of weeks ago, we went back to Battle Creek. The fishing was phenomenal, and the dogs, once again, got their share.

Last week, Lodi starting coming down with the same symptoms Tess had shown two months ago. Only this time, he nearly died. On Saturday morning, Dr. Prutton hospitalized Lodi, hooking him to in IV to keep him hydrated and alive. He didn’t know if Lodi would make it or not.

Later Saturday, it occurred to me that both dogs had taken sick about a week after the fishing trip. I mentioned this to Dr. Prutton, and he immediately said “Salmon Poisoning!”

It turns out that Salmon Poisoning Disease is a potentially fatal condition seen in dogs that eat certain types of raw fish. Salmon (salmonid fish) and other anadromous fish, including trout, can be infected with a parasite called Nanophyetus salmincola. Overall, the parasite is relatively harmless. The danger occurs when the parasite itself is infected with a rickettsial organism called Neorickettsia helminthoeca. It’s this microorganism that causes salmon poisoning. 

Salmon poisoning occurs most commonly west of the Cascade mountain range, including northern California. Canids (dogs) are the only species susceptible to salmon poisoning. That’s why cats, raccoons and bears eat raw fish regularly with out consequence.”

Generally, clinical signs appear within six days of a dog eating an infected fish. Common symptoms of salmon poisoning include vomiting, lack of appetite, fever, diarrhea, weakness and swollen lymph nodes 

If untreated, death usually occurs within fourteen days of eating the infected fish. Ninety percent of dogs showing symptoms die if they are not treated. Thankfully, salmon poisoning is treatable if it’s caught in time. A key to its diagnosis is telling your veterinarian that your dog ate raw fish.

Given the severity of the condition, treatment is relatively simple. Your veterinarian will prescribe an antibiotic and a “wormer”. The antibiotic kills the rickettsial organisms that cause the illness, and the wormer kills the parasite. If the dog is dehydrated, intravenous fluids are given. Once treatment has been started, most dogs show dramatic improvement within two days.

Lodi is still weak, but he is back home and drinking lots of water on his own. Dr. Prutton thinks he will recover.

Next time you are fishing or purchase raw salmon and you hear the familiar begging whine of your dog, ignore it. They may not understand it, but not sharing the fish is the best thing for them. This will save them from suffering salmon poisoning, and save you from a veterinary bill.