Catch pet hair before it reaches the pipe: brush the animal first, bathe it with a fine drain catcher in place, and bin the hair. Never flush cat litter or feces, since sewage treatment may not kill Toxoplasma. Keep fats and grease out of the kitchen drain, and clean strainers weekly.
Catch fur before it reaches the drain
The best fix for pet hair is a fine-mesh drain catcher, set in place before the animal gets wet. A wet coat can release a lot of hair in one bath. Brush the animal first, ideally outdoors, since brushing pulls out much of the loose coat. Then bathe with the catcher in place, and lift it out to empty into the trash as it fills, not after. A quick rinse under the tap keeps it working. Hair goes in the bin every time, never down the drain.
A catcher that fills mid-bath is doing its job. Empty it and continue. If the animal is large or the coat is thick, expect to empty it several times. Some owners prefer a washable mesh cover over the whole drain, laid flat, because it covers the openings in a wide strainer. Either works if it is emptied. If the fur is matted or being clipped, do the clipping before the bath, over a towel or outdoors, so clippings do not reach the water at all.
A drain that is fitted with a plain rubber stopper, or a drain with no catcher, is the setup that most often ends in a clog after a dog bath. If you have no catcher, put a piece of fine mesh over the drain and remove it before pulling the stopper. Do not rinse fur down the drain to get rid of it. Rinse it into the bin.
Why pet hair and soap scum are a bad pair
Fur alone passes through many pipes, but it clumps with soap scum. USGS explains that in hard water, soap reacts with calcium to form soap scum, and Phoenix water is hard. Pet shampoo, conditioner and body oils add to the film, and the fur binds to it at the trap under the tub. A tub used for dog baths can build a plug faster than a family shower does.
You can see it coming. If the tub takes longer to empty after each bath, or the water pools around the stopper, the film is already catching fur. Clear the drain before it sets. Pull the stopper or cover, take out the visible fur by hand, and work a barbed plastic drain tool down the drain to lift out what sits in the trap. For the stopper types and tools, see why a bathtub won't drain. For the same problem in the shower stall, see why a shower keeps clogging.
Wet fur also brings dirt, oils and outdoor mud. If the dog is muddy, rinse the worst of it outdoors first. Sand and grit settle in the trap and add weight to the plug.
Cat litter and pet waste never go down the toilet
Do not flush cat litter or cat feces. Litter is made to clump when it gets wet, which is the opposite of what a drain needs, and it can settle in the trap and the line behind it. A toilet is also the fixture where a clog is most disruptive, since a toilet that keeps clogging backs up into the bathroom. There is a second reason that has nothing to do with your pipes. The Companion Animal Parasite Council says "Sewage treatment may not kill Toxoplasma in cat feces." It advises you to "Put cat feces in plastic bags for disposal in a sanitary landfill."
Scoop the box into a tied bag and put it in the trash. The CDC says "Change litter boxes daily." The CDC explains why: the parasite does not become infectious until 1 to 5 days after a cat sheds it, so cleaning the box every day removes the feces before they are infectious. The same CDC page advises that people with weakened immune systems and pregnant women avoid cleaning litter boxes if possible, and that hands get washed after cleaning one. Put the scooped waste in a lidded trash can or a bag you tie shut, rather than in a bathroom wastebasket.
The reasoning applies to "flushable" litter too. A label on the bag does not change what CAPC says about sewage treatment. Trash is the safe answer.
For dog waste, use the trash, and do not flush a bag, because plastic does not break down in a sewer line.
The kitchen and laundry drains matter too
Pet food and pet dishes cause clogs of their own. Grease is the classic kitchen clog, and the City of Phoenix says "The biggest problem is coagulated grease and cooking oil." If you cook meat for your pet or pour off fat, cool it in the pan and scrape it into the trash. Rinse pet bowls into a bin first, so the sink strainer catches only a little. Wet food, rice and kibble paste settle in the trap the same way human leftovers do. The kitchen sink page covers that pattern in more depth.
If you wash pet bedding, check the washer's lint trap and drain hose, since loose fur collects there. A washer that drains slowly can have a fur mat in the standpipe. Shake blankets and beds outdoors before they go in the machine, and wash pet bedding on its own so fur does not migrate to the family's clothes and then to the lint screen. Washing machine drain overflow explains what a clog in that line looks like. What not to put down the drain lists the rest.
Outdoors in Phoenix, roots matter. The city says the second biggest problem in its sewer lines is roots from trees and invasive shrubs such as oleanders. A line with roots is already narrow, so it has less room for fur, litter and grease.
Routine that keeps pipes clear, and when a plumber is needed
A short routine is enough. Empty the catchers after every bath. Pull the tub stopper monthly and wipe the hair ring. Brush the animal before baths. Empty the litter box daily. When one drain is used for pet baths, it earns extra attention. Time how long an inch of standing water takes to drain now and then, since a slower time is the first sign the film is catching fur. Keep a small bin and a pair of gloves near the tub so emptying the catcher is a five-second habit, not a chore that gets skipped. If the household sheds a lot, how often you should get drains cleaned helps you set a schedule.
Call a licensed plumber if the hair mat is beyond reach, if more than one drain is slow, or if water backs up into a tub or shower when you run another fixture. Those can indicate a shared or deeper drainage problem; the symptom pattern alone does not prove a hand tool cannot reach it, and a camera can show what is in there. Call one too if litter or a bag has gone down the toilet and the toilet will not clear with a plunger. Do not keep flushing, because that pushes the blockage further into the line. HQ Plumbing & Air offers 24/7 emergency service, gives upfront pricing and free estimates, and is licensed and insured.