my dog keeps killing mice, what should I do?

hello reddit. I have a 3 year old shih tzu that loves to chase mice and kill them. I just want to ask what I need to do next or what medicines or vaccines I should give her to prevent her from having yet another leptospirosis? for context, she already survived having a leptospirosis back when she was 1 years old and the reason why she got it is because of chasing all the mouse that we have in our house. We are poor and rn we kinda have a rat problem (that we already got rid of but came back) and I am worried about my dog yet again. please don’t judge I just want help because I want to save up money to take her to the vet to make sure I will be able to buy her her needs and shots if any is needed. should I take her to the vet immediately? thanks in advance for answering and im sorry for my bad english im from asia

EDIT/UPDATE: Hello everyone! I really appreciate all of the replies and the kindness that I have gotten from all of you! bc of this post, my dog has a new nickname now!! Just for a quick update, I took her to the clinic today and told her vet that she has been killing a lot of mice lately and was able to kill 3 just last night, hence, why we took her there. Thankfully, she got a lepto vaccine last year (I saw it on her record) though it had expired recently so I am glad that we took her to the clinic asap so she can get an update on her lepto vaccine! I will also try to buy medicines in preventing lepto and de-wormers bc some of you suggested that I get her de-wormed as well. I really appreciate all of the help! As for our mice problem, we are trying to fill our house up with traps and I am trying my hardest to not let my dog roam around the house too much in order for us to avoid having her kill yet another one of those gremlins. She is currently just leashed inside our house but only when we are busy and cannot monitor her every move. I will still monitor her if there had been any changes bc her vet didn’t really mention much about her mice killing spree and just told us to make sure she is not getting a hold of any mouse pee but still we have no idea since the last time she got a lepto is when she killed a mice and it peed on her mouth. Thanks again everyone!