By Dr. Becker
If you live in the Pacific Northwest and your dog goes swimming, boating or fishing with you – or if you live elsewhere and are in the habit of offering raw fish to your pet – you should be aware that your dog could be at risk for salmon poisoning.
Salmon poisoning is a life-threatening condition most commonly caused by raw fish taken from coastal streams and rivers in the Pacific Northwest, from San Francisco all the way up to the coast of Alaska.
Cause of Salmon Poisoning Disease
The organism Neorickettsia helminthoeca, which embeds with Nanophyetus salmincola, a fluke present in raw fish, is what causes salmon poisoning disease.
Salmon, trout, lamprey and other fish native to the Pacific Northwest can be carriers, as well as sculpin, redside shiner, shad, sturgeon, candlefish and large-scale sucker.
When a dog eats infected raw fish, the larval flukes release the rickettsiae organisms, which then travel in the bloodstream to the liver, lungs, brain, and lymphoid tissues, causing necrosis, hemorrhage, and hyperplasia.
Symptoms and Diagnosis
Infected dogs will begin showing symptoms within 6 to 10 days after eating contaminated fish. Symptoms can include loss of appetite, depression, high fever, vomiting, diarrhea, discharge from the nose or eyes, and weight loss.
Diagnosis is accomplished either by fecal analysis to detect parasite eggs, or through a needle sample from a swollen lymph node to check for the presence of bacteria. Standard treatment involves an antibiotic and a dewormer. Many dogs respond immediately to treatment and begin improving within a few days. Once fully recovered, some dogs develop lifetime immunity to the disease.
If you know or suspect your dog has eaten raw fish and is having any of the above symptoms, you should make an appointment with your vet right away. Left untreated, salmon poisoning can be fatal within two weeks.
How to Prevent Salmon Poisoning Disease in Your Pet
When you’re near bodies of water with your dog, make sure he has no opportunity to eat raw fish.
When handling raw fish, make sure to wrap the waste carefully and dispose of it where your pet can’t get access.
Avoid feeding raw fish to your dog. Freezing fish meat can inactivate both the Neorickettsia helminthoeca and Nanophyetus salmincola organisms, depending on the freezing temperature, the time needed to freeze the fish tissue, the length of time the fish is frozen, and the fat content of the fish.
I recommend you deep-freeze salmon and all types of anadromous fish (fish that swim upstream to spawn) for at least 7 days if you plan to feed it raw, or cook it before feeding it to your pet.