I consider it acceptable to call out from work whenever you feel you need the time off, assuming you have the time accrued. Period.
If you tried to bully me over that I'd report you to HR so fast it would make your head swim. No really, and if that didn't get anywhere I'd start going further up the food chain until something was done. You may not respect other people's emotions or their personal attachments but what gives you the right to push them around over it? I had a dog for 13 years man, he was my friend. I was devastated when my family lost him, and if some jackass tried to make fun of me over it they'd have discovered very quickly that I do not, under any circumstances, countenance a bully.
“Fairy tales are more than true; not because they tell us that dragons exist, but because they tell us that dragons can be beaten.”
― G.K. Chesterton
I'm not just a white knight. I'm a freaking Paladin.