Getting parasites from eating canned Tuna?

On the 22nd. of August, it was my cat's first birthday. For is cake, I have him wet food, with some canned tuna on top and some temptation cat treats. He has eaten tuna in the past, so I didn't think he was get an issue. Yesterday, when I was cleaning his litter box, he had diarrhea. I was wondering if he could have gotten parasites from the tuna.

Is it possible or could be something else?

I really doubt that it was any sort of parasite or pathogen from the tuna.  Since it was a tuna meant for human consumption, it has gone through a very rigorous canning process.  That said, you can have ONE can out of thousands where something slipped through,  Drat,  I'm eating a tuna sandwich right now...

I'm thinking that the combination of all of it might have been a bit rich for the tummy,  Keep a watch, and if it continues, hie thee to a vet!

No parasites can survive the canning process . It requires very high temperatures that would kill any parasite. Most likely it was just too much for his tummy to handle. If he gets worse or doesn't improve soon, call the vet for advice.

@SebNari96

It could be something else he ingested that does not agree with his tummy. It could also be that he's off tuna for some time and suddenly the change of diet or it can be even from the cat treat.
How many times was it? If it's only once, then it's an isolated case unless it's like few times s day for days. Then you have to bring him in for the vet to check.

Sebastian gets tuna not as a meal, but a tasting treat. When we make tuna salad or something, we give him a bit of tuna. It's less than a tablespoon or tablespoon. He gets tuna, two or three times a month. It's normal for him.

The week of his bday, he did get tuna twice that week before I was going to eat tuna and crackers. He got a bit of tuna then. He knows when we are dealing with tuna. I've given Sebastian tuna before at least twice a week in the past, but he was fine. All I can think of is, he ate something he wasn't suppose to. I am giving him till the end of this week to see if he gets regular again. Also, we can't take him to the vet till the end of this week.

Make sure he gets plenty of water between now and then, even if you have to syringe it into him.  Cats can dehydrate so quickly!

Ok, I actually have some, so I'll make sure he gets it.