It could be seen as a typo, but it is also important to spell things right in Spanish, as the absence of just one letter can mean the word is pronounced differently or even mean a different word.
Una perra can mean "a coin", but indeed too a ❤❤❤❤❤ (female dog and the dirty word). Like practically all animals there is a female word for it (like "una gata"), but is only used when you specifically know/mean the female animal
No that word does exist in Spanish, but only for the female. Male would be un perro