Wall to wall carpet, generally speaking, is not an optimum choice for pets. Animal fur, oils and dander (among other body fluids ) can get trapped within the carpet, creating a petri dish of odors and bacteria. If you must have carpet choose a the best quality you can afford consisting of nylon or olefin non-looped fibers. The synthetic fibers will provide the best wear and stain resistance. Non looped fibers are optimum because they are less like to get snagged on the pet's nails or collar's resulting in permanent damage to the carpet. Pay to have the stain resistant treatment! Know that accidents will happen. Here's a great video on how to clean pet stains.
Carpet tiles are an excellent alternative. What was once a commercial use is now in increasing in residential use. They come in great color and patterns, offering you an unique design option. They very easy to install, even for a novice DIY'er . If one (or more) get soiled simply remove, clean and/or replace. Floor tiles typically have a thick rubber backing which is an added layer of protection against moisture penetration AND helps minimize noise. These can be found on-line and at most big box stores.
Hard surface flooring such as stone or ceramic tile provide a great look. Choose a surface that is non porous and grout will need to be sealed periodically. If you are lucky enough to have in-floor radiant heat your animals will love this (and so will your toes!). In floor heat can help reduce the cycling of your furnace off/on which will lower your bills AND who doesn't want that? For more information on radiant heating, click here.
Hardwood-nothing exudes visual warmth more than wood floors . Be advised that softer woods are more inclined to show scratches than hard wood. Wood floor hardness rating are ranked on a Janka scale found here. When choosing hardwood make sure the wood is sealed. A high quality top coat does wonders for extending the life of your floor. Another advantage to hardwood is the floor can be refinished. Disadvantages are cost, installation (not typically a DIY project UNLESS you are experienced) and not compatible for high moisture areas. Hardwood floors are a great re-sale feature!
Laminate is affordable, DIY install and easy to maintain. When determining what types of laminate look for HPL (High Pressure Laminate), those with a high AC (Abrasion Coating) rating and those with a higher core rating. The thicker the core the stronger and more resilient the laminate. This is measured in mm (millimeters). Look for laminate with tight seams to avoid moisture penetration. Unlike hardwood, in the event of damage it cannot be refinished as this product is an image laminated between a backer core and topcoat. Another drawback is laminate can be slippery depending on finish and your pets nails will make a clicking noise.
Vinyl (also known as resilient) flooring comes in an array of colors, textures, patterns, forms and there is a product for every budget! You have traditional tiles in a variety of sizes, planks and sheets. Tiles can be installed as peel-n-stick (novice DIY), and troweled adhesive. Some tiles now have vinyl grout for an even more realistic look! Vinyl sheets can be installed as glued contact (100% adhesive underneath), perimeter glue (just the edges) or floating. Finishes are no-wax (requires frequent cleaning to maintain shine), urethane and enhanced urethane (most durable, less maintenance). Vinyl is great with pets due to easy clean, moisture resistant and reduces noise.
Cork flooring is also rising in popularity. Because is it is a renewable and sustainable product this appeals to to the "green factor'. This can be installed in tile, sheet or plank form. Cork flooring offers comfort under foot, reduces noise and acts as a thermal insulator. Combined with ease of maintenance and scratch resistance, this is a good pet friendly option.
Concrete can be painted, stained, and polished. Apply a topcoat and it is impervious to just about anything. Easy to clean and maintain. Definitely not a DIY install for the inexperienced. Great with radiant heat option. And this is a good alternative for allergy sufferers.
I realize this is a lot of information and hopefully this helps your zero in on the floor best suited to you, your lifestyle and your pet!