To All the Squirrels I Love Despite Their Scars

Battle pet versions (your own collected or the ones in the wild) of the pets have been reported to not work in some specific cases, so you might want to do the whole achievement with critters only.

Check the comments/replies for a list of those which do not work.

Compact coords from list of Triet:
/way Azsuna 31, 35 Albatross Chick
/way Azsuna 59, 39 Coastal Sandpiper
/way Azsuna 34, 43 Felspider
/way Azsuna 40, 59 Tenebrous Snake

/way Highmountain 57.0, 55.6 Black-Footed Fox Kit
/way Highmountain 54, 42 Echo Batling (in cave)
/way Highmountain 56, 54 Long-Eared Owl

/way Stormheim 62, 51 Golden Eaglet
/way Stormheim 55, 46 Tiny Apparition

/way Suramar 42, 58 Glitterpool Frog

/way Val'sharah 64, 74 Auburn Ringtail
/way Val'sharah 38, 62 Blighthawk
/way Val'sharah 55, 73 Gleamhoof Fawn

This DOES work with collected pets, except these ones:

/way Azsuna 34, 43 Felspider
/way Azsuna 40, 59 Tenebrous Snake
/way Suramar 42, 58 Glitterpool Frog
/way Val'sharah 38, 62 Blighthawk

They are not collectable, so you have to find and love them. Felspider has collectable version, but you need uncollectable one.

You can follow this route (get the waypoints from Bloodleh's comment) while clicking the macro below to easily just fly over each spot and love the critters without constantly spamming the chat with love messages, the macro only posts /love if you have target on something. Keep an eye on your chat when you're flying over an area where you're supposed to love a critter and make sure that you see it pop up in the chat that you have loved it, as some people have pointed out, you might want to make sure that the "Felspider" is not a battle pet and is the critter version. The macro will always target the closest target so you can just move around in the area until you see that you target a critter version.

/tar Gleamhoof F
/tar Blighthawk
/tar Auburn R
/tar Felspider
/tar Tenebrous S
/tar Albatross C
/tar Coastal S
/tar Echo B
/tar Black-Footed Fox Kit
/tar Long-Eared Owl
/tar Glitterpool F
/tar Tiny A
/tar Golden E
/stopmacro [noexists]
/love