Salmon poisoning is an illness dogs get from eating raw or undercooked salmon, steelhead and trout. The fish is not the problem: it carries a parasite, and that parasite carries the organism that makes dogs ill. Signs usually appear five to seven days later, sometimes much later, long enough that most owners have forgotten the fish.
Why this is a Delta conversation every autumn
Ladner sits where the Fraser meets the sea, and the fall runs bring fish, boats and anglers back in numbers. Along the dyke trails, the sloughs and the riverbank, that means fish in places dogs can reach: a spent salmon washed up at the waterline, a pile of scraps left behind after someone cleaned a catch, a head or a set of guts in the long grass, a cooler that got tipped over on the back of a truck.
It also means fresh fish coming into houses. A family that has been out on the water often brings home more than it can eat, and a trimmed-off piece handed to the dog seems like a kindness.
This is not a rare curiosity. Salmon poisoning happens along the Pacific coast because the whole chain sits here: a freshwater snail, a fluke that uses it, the salmon that pick up the fluke, and the dogs that eat the salmon.
How it actually works
A tiny flatworm called a fluke lives in the flesh of Pacific salmonids. Inside that fluke is a bacterial organism. When a dog eats raw fish, the fluke attaches in the gut and releases the organism, which spreads through the lymph nodes and the rest of the body.
Three details matter for owners:
- Only dogs and their wild relatives become ill. Foxes and coyotes are affected too. Cats and people do not develop it, so a cat that steals raw fish has different things to worry about.
- The delay is the dangerous part. Most dogs seem completely normal for five to seven days before anything shows, and in some cases it takes several weeks.
- It does not take a whole fish. A scavenged mouthful on a walk is enough.
The signs, in the order they usually appear
It tends to start with a high fever and a dog who simply is not themselves. Then:
- Low energy, hiding, or a dog who does not get up for the walk
- Refusing food, sometimes suddenly and completely
- Vomiting, often repeatedly
- Diarrhea, which may become dark or bloody
- Rapid weight loss over a couple of days
- Swollen glands under the jaw and in front of the shoulders
- Discharge from the eyes or nose
- Obvious dehydration and weakness
Left alone, this illness is often fatal. Caught early, the outlook is far better. The difference between those two sentences is usually how quickly the fish gets mentioned.
Tell us about the fish, even if it was a week ago
This is the single most useful thing you can do. A dog with a fever, vomiting and no appetite could have any number of things going on. A dog with a fever, vomiting and no appetite who was down by the river last Sunday is a much shorter conversation, because it tells us exactly what to look for and lets us confirm it quickly.
Please volunteer it even when it feels irrelevant, and even when you are not certain anything was swallowed. Sniffing around a pile of scraps counts. If your dog is unwell, our urgent care service would far rather hear about a maybe than miss it.
Confirming it is often straightforward once we are looking, because fluke eggs can be found in a stool sample. That is a job for our diagnostics service, and a dog who is already unwell is worth starting on straight away.
Keeping it from happening
- No raw salmon, steelhead or trout. Not as a snack, not as a trimming, not the skin. Cook it through and it is safe.
- Be careful about raw diets that include Pacific fish. Commercial deep freezing at a low enough temperature for long enough makes fish safe, but a home freezer is not the same thing. If you feed raw, book nutrition counselling with us to go over where the fish comes from and how it has been handled.
- Smoked is not automatically cooked. Cold smoking does not reach a temperature that deals with the parasite.
- Leash up near the water in the fall. The riverbank, the slough edges and the areas around boat launches are exactly where scraps and carcasses end up.
- Teach a reliable leave. On a dyke trail with a strong smell in the grass, it is worth more than any other command.
- Clean up your own catch properly. Bag the waste rather than leaving it, both for your dog and for the next one along the path.
- Watch the garden too. Gulls and eagles drop fish in odd places, and a dog will happily find one under a hedge.
What about cats, and what about people?
Cats do not get salmon poisoning. Raw fish still is not a good idea for them, for the usual reasons, but a cat who ate a scrap from the counter is not at risk of this particular illness.
People are not at risk from it either. You cannot catch salmon poisoning from your dog, and handling fish does not put you in danger of it. Normal hygiene after handling raw fish and after cleaning up a sick dog is sensible regardless.
The other side of the fall river
Autumn puts dogs in contact with more than fish. The same walks that pass the fishing spots also pass standing water, ditches and sloughs, which is where our guide to leptospirosis and standing water in Ladner and Delta comes in. The habits overlap nicely: carry your own water, keep to the path where you can, and know what your dog just put in their mouth.
Frequently asked questions
My dog ate raw salmon yesterday and seems completely fine. Should I worry?
Phone us and tell us now rather than waiting. Looking fine on day one is expected, because signs usually take five to seven days. Knowing the date it happened means that if a fever turns up next week, nobody has to work backward from nothing.
Does cooking really make salmon safe for dogs?
Yes. Cooking it through destroys the parasite that carries the organism. Plain cooked fish with no bones, no oil and no seasoning is fine as an occasional food for most dogs.
How long after eating fish would my dog get sick?
Most often five to seven days. It can be considerably longer, occasionally up to about a month, which is why this illness gets missed. Anything unusual in the weeks after a trip to the river is worth mentioning when you call.
Is a dead fish on the beach as risky as a fresh one?
Assume yes. A spent or decaying fish carries the same parasite, and it brings its own problems on top, including the kind of bacteria that cause severe stomach upset. Dogs are very drawn to them, so this is the one to watch for on autumn walks.
Can my dog get it twice?
Dogs can develop some immunity after recovering, but it is not reliable enough to relax about. Keep the same habits afterward.
What should I do if my dog has a fever and was near the river last week?
Call us and come in the same day. Bring the date of the outing and anything you know about what was eaten. A dog who is losing weight quickly, vomiting or refusing food should not be watched at home overnight.
Speak to the team at 48th Avenue Animal Hospital
If your dog has eaten raw fish, or is unwell in the weeks after a trip to the river, phone us and say so.
Published by the team at 48th Avenue Animal Hospital.
This article is for general educational purposes only and is not a substitute for an in-person veterinary examination or advice about your individual pet. If you have an urgent concern about your pet, contact 48th Avenue Animal Hospital or your nearest emergency veterinary hospital right away.
48th Avenue Animal Hospital
5020 48 Ave, Delta, BC V4K 3V3
Phone: (604) 946-7779
Hours: Monday to Friday 8:00 AM to 8:00 PM; Saturday and Sunday 9:00 AM to 5:00 PM