The idea of worms in our food is gross, to say the least. So, when I tell you that worms, or parasites, are in most wild-caught fish — that may not be news that you love to hear.
But does salmon have worms? And if so, what do worms in cooked salmon look like?
Salmon can have worms, and the worms in cooked salmon look like long, thin strands of cooked spaghetti. In some cases, they may be difficult to spot. They’re usually white or almost clear.
It’s important to remember that worms in seafood are like small insects in veggies and fruits — they’re prevalent and of no risk as long as proper food-handling techniques are followed.
We dive into some key topics throughout this article to provide you with everything you need to know about these worms and how to avoid ever encountering them, so read on!
We cover the following items in this post:
- Why Does Salmon Have Worms Sometimes?
- What Do Worms in Cooked Salmon Look Like?
- How Common Are Worms in Salmon?
- Can You Get Parasites from Cooked Salmon?
- Does Freezing Salmon Kill Parasites?
- Does Smoking Salmon Kill Parasites?
- What Happens If You Eat a Worm in Salmon?
- Final Thoughts On Worms In Cooked Salmon
Why Does Salmon Have Worms Sometimes?
According to PETA, every wild-caught fish can have worms. Yes, you read that correctly.
The most common worm, or parasite, is the nematode larvae, also known as “roundworms.” The name roundworm comes from the parasite’s round shape. Roundworms, like other types of parasites, need to find a host body to survive.
These parasites have a few common ways to infect salmon:
- If the salmon eats a fish already infected with roundworms
- A transmission from salmon to salmon, living in the same area
- If the salmon is raised in an area where roundworm growth is prevalent
What About Farmed Salmon?
It is rare to find roundworms in commercially farmed salmon.
This is due to the following reasons:
- Their diet is strictly controlled. Farmed salmon are fed salmon feed, which is an optimal food source that balances plant-based protein, fish oils, fishmeal, and animal trimmings.
- They are surrounded by other healthy salmon. Healthy salmon have a much lower chance of transmission of parasites.
So, if you’re nervous about parasites from salmon, seek out farmed salmon at your local stores!
What Do Worms in Cooked Salmon Look Like?
Chances are that the worms are going to be so small that you won’t be able to see them, particularly once the salmon has been cooked. But, if you’ve already cooked the salmon, they will look like long thin strands of spaghetti, likely with a white or lighter color overall.
Your best bet is to look at the salmon before cooking it. The worms will look like white strings or thin spaghetti, similarly to how they look when cooked. However, they will be easier to see as the meat has a stronger pinkish-orange color prior to cooking, so the difference in color makes the appearance of worms pop out more.
How Common Are Worms in Salmon?
A B.C. Centre for Disease Control research paper notes that nematodes have been found in roughly 75% of wild-caught salmon from the Pacific Ocean.
If you are consuming farmed salmon, then chances are that there are no parasites at all. The salmon farms do a great job of ensuring that their meat is nice and clean.
Should I Be Concerned?
No, you shouldn’t. Especially if you’re eating salmon in the US, where strict FDA guidelines are followed by suppliers of the fish.
This is because the worms found in salmon are commonly killed before you ever have to worry about them.
These worms are killed in the following ways, which we expand on further throughout the rest of this article:
- Cooking the salmon kills worms
- Freezing the salmon kills worms
You’re more likely to accidentally eat roundworms if you’re consuming raw or undercooked fish. However, even this is extremely rare in the US as the freezing and curing processes are so common.
As long as the salmon is frozen or cooked prior to you consuming it, you shouldn’t worry about the worms!
Can You Get Parasites from Cooked Salmon?
As long as the salmon has been cooked properly, then you shouldn’t get parasites from it. Per the FDA, cooking salmon to an internal temperate of 145° F (63° C) kills roundworms.
If you don’t have a meat thermometer for an accurate temperature read, we suggest using the flake test. This test requires cooked salmon and a fork.
You gently push down on the salmon with a fork. If the salmon splits across the fat strips, or white stripes, in a flakey manner — then it is fully cooked and ready to eat.
Does Freezing Salmon Kill Parasites?
Yes. However, the salmon will have to be frozen at the correct temperature for the right duration of time to ensure the parasites are dead.
The below overview informs the temperatures and timelines necessary to kill roundworms by freezing salmon:
- 7 days at -4 ° F (-20 ° C)
- 15 hours at -31 ° F (-35 ° C)
It’s critical that the salmon is frozen solid, through the thickest parts of the meat. So, if you’re not sure exactly how long the fish was frozen, use that as your guide.
If you don’t freeze the fish long enough, then the parasite is just going to become ‘dormant’. This means that as soon as you thaw the salmon, it is going to wake up again.
It shouldn’t really be too much of an issue if you are freezing the salmon for short periods of time, as long as the meat will be fully cooked once thawed.
Does Smoking Salmon Kill Parasites?
It depends on the smoking process that is being used.
- If the salmon is cold-smoked, then no. The temperature will not be high enough to kill the parasites, however, it will be high enough to kill bacteria that are lurking around in the fish. Be sure the fish was properly frozen and cured prior to smoking it to reduce the risk of ingesting roundworms.
- If the salmon is hot-smoked, then yes. This method should be enough to kill off any parasites in the fish as the meat is fully cooked.
Remember that you can eat cold smoked salmon raw, as it has been frozen and cured prior to cold smoking the fish. Even though the fish isn’t technically cooked, it is safe to eat!
What Happens If You Eat a Worm in Salmon?
Most of the time — nothing.
Per the CDC, these worms cause no damage or symptoms in the majority of cases. You essentially don’t realize you consumed them and your body removes them.
However, in rare cases, people can feel the effects of roundworms if consumed.
The roundworms can:
- Cause tissue damage
- Impact your eye health negatively
- Potentially affect your nerves
- Possibly create permanent problems in areas they infiltrate
If you believe you’ve consumed roundworms, please contact your healthcare provider to confirm your belief and create a plan for treatment. If confirmed, your doctor will likely recommend you take a medicine called albendazole. It helps prevent the growth of larvae as well as the multiplication of the parasite. You should then pass the roundworm through your poop.
Final Thoughts On Worms In Cooked Salmon
Worms in wild-caught salmon, or other wild-caught fish, are extremely common. However, they rarely impact consumers as they are killed during the freezing or cooking process, of which both are very common in the US.
Consuming raw or undercooked fish greatly improves your chances of ingesting roundworms. But, even then, if the fish was properly frozen at -4 ° F (-20 ° C) for at least 7 days prior to cooking, the parasites will have died. Additionally, if the fish has been properly cooked to reach an internal temperature of 145° F (63° C), the parasites will die as well.
The likelihood of ingesting roundworms is very low in the US due to strict FDA requirements on the handling of seafood. However, it is possible to get them, so be sure to freeze and cook your fish properly.
Frequently Asked Questions (FAQs)
What Is the White String in Salmon?
The white strings in salmon are likely worms known as ’roundworms.’ These are common in many different fish species, especially those that were wild-caught. These worms shouldn’t impact you as long as the fish is properly frozen or properly cooked. We discuss how to do both in this article.
Are There Always Worms in Salmon?
No, not always. Although they are more common than the average consumer knows, they are not guaranteed to be found in salmon. They are especially rare in farmed salmon.