Is there any bl where one of them have a pet ?

Yes there is. Check "Desire me if you can", red haired guy have a cat.

https://www.mangago.me/read-manga/give_me_a_hug_mr_frog/
https://www.mangago.me/read-manga/umeya_kun_no_haru/
https://www.mangago.me/read-manga/motekei_ouji_no_renai_command/
https://www.mangago.me/read-manga/shiba_kun_to_shepherd_san/
https://www.mangago.me/read-manga/fukujuu_to_amagami/
https://www.mangago.me/read-manga/aimai_na_wolf/

An actual pet? Or like a human 'pet'? Because that's also a thing

a human pet

Oh. Ignore all my recs but the second to last one then lol

HAHAHAHAHA

https://www.mangago.me/read-manga/shitsukekata_nijuumaru/

The Tosa's Master, but it's kinda hardcore pet keeping if you're into that.

Souteigai no Sweet Marriage
https://www.mangago.me/read-manga/souteigai_no_sweet_marriage/

Chigireru Kubiwa

lolll it’s ok!! i’ll still read it

thank you everyone, a random request but i love a good emotional support animal

OMG i mean an actual pet, im sorry I worked all day im confusing myself, so the list you gave is PERFECT