I've never had to do this but after a thorough cleaning I've heard painting the slab with Kilz or a similar high quality primer will cover pet odors. also vinegar is cheap and is a natural deodorant.  

Walls & Ceilings & Woodwork & Cabinetry & Every Surface - all will need a good white vinegar/water wash.  

Look for burn marks on floor coverings, window sills, fireplace mantle and bathroom vanity.To reduce the smoke smell, wipe down the entire apartment with a vinegar wash and set pans of white vinegar around the place.

I had to cut out the bottom 2 to 4 feet of drywall on one to finally get rid of the smell and treat the cement floors like crazy with white vinegar.

So before the vinegar sometimes the honey approach goes further. 

We also make sure the laundry room is swept weekly, the drums for both the washer and dryer are wiped down with vinegar monthly, and the dryer vent  to the outside is cleaned periodically. 

I purchased an o-zone generator from MaxBlaster; that combined with a strong vinegar scrub on the walls and floors did the trick.

Disclaimer: I'm a 23 year old filled with piss and vinegar! 

(pillows and stuffed animals can be put directly in the dryer on high heat). we took all the furniture apart that we could, and covered the entire room with diatomaceous earth(including taking dresser drawers out and getting every nook and cranny- being thorough is key), pulling all small items, picture frames, legos, toys, candlesticks, anything on the walls, in the closets, storage items- everything we didn't cover in de, in the center of the room and/or soaked in tubs of vinegar. we wrapped the legs of all furniture that couldn't be taken apart with saran wrap, and placed them in shallow bowls of vaseline(makeshift trap). when the bedding and fabric items came out of the dryer, we bagged them in garbage bags, and secured the bags with packing tape, making sure there were no cracks or tears, then put them in the center of the room. 4. we did that to each bedroom, the living room, dining room, and bathroom. in the kitchen, we puffed de behind the switch plates with the foam inserts, and under appliances that generate heat(heat=bedbug food). 5. we let it sit like that for two weeks, and when we were done, we cleaned thoroughly. we bought a good handheld steamer for everything that could be steamed. we cleaned one room at a time, starting with a vacuum, and wiping the de of hard surfaces. we left de in the nooks and crannies(by the way- they CAN live behind wallpaper, and even the tags sewn onto mattresses), and made sure that everything we put back from the center of the room was steamed, vacuumed, or wiped off thoroughly. we replaced every mattress and bought good covers for each of them, as a preventative measure. also as preventative measures, we left the de under appliances, we left the foam inserts behind the switch plates, and for a few weeks after, we left the vaseline traps in place.

To remove wallpaper he always used vinegar and hot water.