Best instrument to remove dog urine smell from mat when it's over a year outmoded? I moved into this flat/apartment almost a year ago and the lady...

I moved into this flat/apartment almost a year ago and the lady back me let her dogs wizz anywhere they pleased on the mat during her stay here. Whenever the weather warms up, close to now since it's summer, I can still smell the urine. I've gotten down on my hand and knees and scrubbed, I've put baking soda on it and permit it stand and nothing works. Removing the hearth rug isn't really an option right very soon for me, so any other suggestions would be appreciated!
Answers:    You have to, at the deeply least, elevate the carpet to see how defectively it has soaked within.

cleaning ther carpet is of no use if the nouns is soaked and there is puddling on the floor.

My cat did that and we found a pee spot so doomed to failure, it ate the varnish right fromt he floor.

I had to scrub it and cook the stench out
buy a new runner. who wants to see dog pee on their carpet?