The Vinland Saga does mention that at least one bull and one cow was brought to Leifsbuthir (L'Anse aux Meadows). The bull is said to have terrified the skraelings when it burst out of its pen during a trade visit.

But there are two basic reasons there was, so far as we can tell now, no lasting impact.

First, the nature of the trips to what is now Newfoundland was not to live long term. Most scholars (Birgitta Wallace for sure, though this is just from what I've heard her say at lectures) would agree that the goal was to find resources and return to Greenland. So, what was brought there was generally brought back, if it wasn't consumed along the way. The point was to collect more stuff, not leave anything behind.

Second, the trips involved relatively few people and, accordingly, very few animals. Even if some animals were accidentally introduced, there would not have been a viable population for them to survive long term.