YOU SAID:

Im getting a dog in December

INTO JAPANESE

私は12月に犬を取得します

BACK INTO ENGLISH

I'll get the dog in December

INTO JAPANESE

私は12月に犬を飼います

BACK INTO ENGLISH

I have a dog in December.

INTO JAPANESE

私は12月に犬を飼っています。

BACK INTO ENGLISH

I have a dog in December.