This shall be the largest ever compilation of all blue dog appearances ever
The blue dog painting from Friends.

https://en.wikipedia.org/wiki/Blue_Dog_Coalition
also, uh, how do I not see Bluey? ah there’s the fucker right in the middle
They’re in our politics too?!
Ok there is a psyop or conspiracy happening. This means something
they’re everywhere…
https://en.wikipedia.org/wiki/Sun_dog SKYPUPPERS!
I just wanted to say that I see you’ve got a blue lego dog. That is all.

Really?? Nice!!
Ok, I see the balloon one on the left side. Is there another balloon on the right side?? Otherwise, I do not see it!! And the fool is me… 😁
No Bandit Heeler?
If Vaporeon qualifies despite its appearance because it evolved from something that was based on a fox, then Suicune shouldn’t qualify despite its appearance because it’s based on a leopard.
Also, I don’t know what that Vulpix is from but they aren’t blue (switch it for an Alolan one?). I’m guessing it’s some fan-made sprite because it’s sort of similar to a couple of real ones.
What about Sonic the Werehog? I’m pretty sure they meant wolfhog.
then Suicune shouldn’t qualify despite its appearance because it’s based on a leopard.
Suicune evolved(?) from a Vaporeon, if you pay attention to certain pokemon game lore.
Three pokemon (Vaporeon, Jolteon, and Flareon) were trapped in the ‘burnt tower’ when it burned down. Ho-Oh saved them and revived them into the three ‘legendary dogs’.
I guess I’ll have to make a part 3 now
You should include Sonic just so that people comment telling you sonic isn’t a dog
Better yet, draw some dog ears on sonic
Old Mother Hubbard has a blue dog named Lamont.

Vaporeon is dog-like enough for you, but Krystal Fox isn’t?
Not sure how applicable, but some of Skyrim’s more ethereal NPCs have a ‘ghost’ effect which causes them to be transparent and monochromatically blue. ‘familiars’ and ‘wolf spirits’ appear to be blue wolves due to this.
And New Vegas’ K9000 cyberdog gun is also a blue dog, in a way.
All these blue dogs and you missed BlueKandy.
Add the AC7 dog png but hue-shifted to blue