Salmon Poisoning in Dogs

Dogs who ingest anadromous fish that inhabit the coastal streams and rivers of the Pacific Northwest (prevailing coast from Northern California up to and recently including Vancouver Island, Canada) risk contracting the salmon poisoning disease. The fish can contain a parasite called nanophyetus salmincola, which are in turn infected with the microorganism neorickettsia helminthoeca, thereby passing the microorganism onto your dog.

If identified in a timely manner, salmon poisoning is treatable. The symptoms are similar to those of a gastrointestinal illness. If your dog has roamed from your sight and exhibits these symptoms because he may have eaten something you are unaware of, or if your pet has ingested raw or undercooked fish, immediate veterinary care is crucial. Typical symptoms are listed below:

• Vomiting
• Diarrhea
• Fever, which will reach limits around 104 Fahrenheit
• Loss of appetite, which may result in weight loss
• Swollen lymph nodes
• Weakness
• Depression
• Discharge from the eyes or nose
• Dehydration

If your dog has ingested salmon, trout, largescale sucker, shad, sturgeon, redside shiner, sculpin, candlefish or lamprey that carry the microorganism neorickettsia helminthoeca, he will begin to show the symptoms of salmon poisoning disease within 6 to 10 days. 90% of dogs who consume the affected fish will die if the disease is untreated.

The parasitic flukes nanophyetus salmincola have three different hosts: the snail, the fish and the canine. If your dog eats a parasitic fluke that carries the neorickettsia helminthoeca, the fluke will release the microorganism in the dog’s intestinal tract. The microorganisms then spread to:

• Liver
• Lungs
• Lymphoid tissues
• Brain

This then causes:

• Necrosis (death of cells in organs or tissue)
• Hemorrhage
• Hyperplasia (abnormal increase in volume of organs or tissue because of the increase of new cells)

Bringing your dog to the veterinarian at the first signs of illness is always the recommended route. Canines suffering from salmon poisoning disease can be treated successfully if the infection is diagnosed soon enough. If you aren't sure of what Rover was able to digest because he left your line of sight, or if you know for a fact that your pet has consumed raw fish, relay this important information to your veterinarian upon arrival at the clinic.

A fecal sample can detect the presence of parasitic eggs. Fluid taken from a needle inserted into a swollen lymph node can show the presence of the rickettsial organism. A positive result in either one of these tests, along with accompanying symptoms, can lead your veterinarian to confirm a positive diagnosis.

Treatment of salmon poisoning is fairly straightforward, but the length of the regimen will depend on how sick your dog is when he arrives at the hospital. If your dog is experiencing severe vomiting and diarrhea, he may need to be hospitalized in order to get the dehydration and illness under control.

The veterinarian will begin treatment with the administration of intravenous fluids if necessary. Antibiotics, to kill the microorganism responsible for the illness and a dewormer, which will kill the parasite will be given. Anti-diarrheal medication and drugs to combat the nausea may be dispensed as well.

The recovery from salmon poisoning can be relatively quick. Dogs who have been infected with the rickettsial organism can show signs of recovery within two days of treatment. Of course, if you feel that your pet is not recovering well, communicate with your veterinarian for further evaluation. Monitoring your dog’s health is always a responsible part of pet ownership.

Though your dog may now have immunity from this microorganism infection, refrain from allowing your pet to eat raw or uncooked fish as there is always the risk of infection from an alternate strain.

Prevention of re-occurrence is possible. Be vigilant in keeping your dog on the leash when near rivers or beaches, or areas where garbage may be easily accessible. Be sure to cook fish thoroughly, or freeze for two weeks minimum before allowing your pet to eat any.