How to Get That 'Doggie Smell' Out

You'll need to investigate the real source much more. Carpet alone isn't the issue, so spraying and cleaning the carpet may never get the smell out; the padding beneath absorbs smells (and if it's urine, you need new carpet, period) and even the flooring -- even concrete! -- can hold smells in some cases. You feel sure this isn't urine but if it is, it can actually permeate the concrete or wood beneath carpet and pad and is pretty much impossible to get out.

You need to pull up the carpet and investigate. You may be able to get away with replacing the padding and keeping the carpet, but maybe not.

If this is mold rather than dog smells, you need to replace it all, immediately, as it's not just a smell issue, it's a health issue.

This is why I'm a huge fan of hardwood floors instead of carpet and padding. Much easier to keep clean and sanitary. If you have hardwood under the carpets, consider getting it refinished instead of replacing carpet -- today you can get hardwood redone at reasonable prices and with products that are "low-odor" and "low-chemical" so there aren't nasty chemicals in your air.

If you rent, your landlord needs to know that there may be a mold issue. I'd have a professional mold abatement company check the house (including inside walls, they have devices to detect mold pretty non-invasively) if this isn't a dog issue.

Are you 100 percent certain that a dog used to live in this house? You mention dog smell but don't say whether that's based on just how it smells to you or on knowledge that a dog or dogs actually lived there. What smells like wet dog to you could be water that created mold, or other mold smells.

Put a large bowl of baking soda in each room. This should help absorb the odor. If you think it is dog urine then pick up some Simple Solution or Natures Miracle at the pet store and use that to clean the carpets.

The best option would be to replace the carpet. But, if you can't, go to Costco and buy the big bag of baking soda. Before you go to bed at night, or before you leave the house for the day, sprinkle it liberally over every inch of the carpet. Even feel free to walk over it, or use a broom, to get it down into the fibers. Let it sit overnight, or all day, and then vacuum it up. I'm assuming you have a good vacuum cleaner. With any luck, it will absorb and eliminate the odors.
An air purifier might be useful too.
Have you replaced the filter in your air conditioning system? If the filter has captured these odors, you may just be redistributing them. Replace it!

Maybe it is not even a smell from an animal... maybe, there is moisture accumulation somewhere in your house... and what you are smelling is mildew/mold???
Look at the basement, foundations, walls/baseboards, gutters/downspouts, ceilings, near plumbing/toilets, etc.... for water damage or water infiltration signs. Look in the interior AND exterior.
Water/moisture accumulation, leaves a stagnant smell as well...

Damp/wet wool, also smells like stinky wet dog....

Just some ideas... to investigate further.

I think I might try soaking the entrance with some Nature's Miracle. It doesn't work only on urine. I'm assuming you're talking about carpeting as you walk in, but it could be some other surface. Acting on the guess that whatever is being, um, fragrant could be below the surface, I would pour the NM on (not spray it) and hope it would get into the carpet pad or the subflooring. Can't hurt to try!

If that didn't work, I'd call a flooring expert.

All that said, when we moved into our house years ago (when my children were babies), there would be a definite odor near the front door. I would also smell it in the summertime in any of the front bedrooms, when the windows were opened. I blamed it on recalcitrant kitties (I had to apologize to them). It turned out to be the bushes planted by the front door, which had a distinct and rather unpleasant odor!

Hi!
When we moved into our home there was a "wet dog" smell, too. IT was NOT from a dog, though. The previous owners were smokers and it was from that. It would get worse when it was damp out. I smelled it much more than my husband, but when he ripped the carpet out (I just couldn't take it anymore) THEN he smelled it. We had it sitting on our back porch under an awning and when it rained the dampness in the air made it so much worse. He apologized for telling me that I was basically a lunatic and just smelling things that weren't there! LOL :)

You really may just need to replace the carpet. We only had to in the living room. I guess they didn't smoke as much in the bedroom and the spare room had wood flooring.

Good luck!

Until you can fix it, though, try running a dehumidifier. It definitely got worse in damp weather!

Setting out bowls of coffee beans (like the baking soda suggestion) can also help.

All you can do is mask the smell. If it smells WET is may be that some moisture from cleaning the carpet is still in there and you can try a dehumidifier or even just running the heat high for a few days... but the smell will always come back when your carpets get some moisture on them.

We just did our floors and ripped out the carpets. The carpets were cleaned when we moved in 3 months ago... OMG you will not believe how much dirt/sand/wet and yucky stuff soaks into the pad under the carpets. Given our carpets were OLD...there were two pads underneath! and some stuff (probably dog urine, we have been told the previous owners had huskies) had still stained the boards underneath! Carpet is just nasty! Blech! I will never consider putting carpet anywhere... we will over time go and replace ALL of it in our house.

How about using Nature's Miracle to spray the carpet?

Try doing a deep cleaning throughout the house.

Open up the back door & front windows renting a huge floor fan to air
out the house.

If you rent, call the landlord to see if there might possibly be some mold
under the carpet.

If you own the house, I would rip out the carpets & lay down wood flooring w/big area rugs (you can find them cheap at discount stores or even Home Depot).

Updated

How about using Nature's Miracle to spray the carpet?

Try doing a deep cleaning throughout the house.

Open up the back door & front windows renting a huge floor fan to air
out the house.

If you rent, call the landlord to see if there might possibly be some mold
under the carpet.

If you own the house, I would rip out the carpets & lay down wood flooring w/big area rugs (you can find them cheap at discount stores or even Home Depot).

God the only way I know to get rid of deep down smells is removing what the smell is attached to. Cleaning the carpet won't get it out. When I pulled up my carpet you would not believe how much soaked into the pad, sometimes even the sub floor. I tore out all my carpeting, scrubbed and sealed the sub floor, and then put in hardwood and the like because I never wanted to deal with that smell again.
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With the one cat yes, but most of it was dogs who came in from the rain soaked. They lay down in one spot and dry but what drips off soaks into the carpet. God knows why but wet dogs love to lay on carpet. So what you are smelling is probably 'wet dog'.