Your garbage disposal smells like dead animal carcass, literally.
It's gross, but probably isn't happening for the reasons you think.
First, let's pump the breaks a little bit. It's likely not a literal dead animal stuck in your drain. I'll cover that, but it's a distant possibility. When people say "their garbage disposal smells like dead animal flesh" they might simply be referring to something that just smells really bad. Moreover, food waste that rots - especially if you're dealing with some kind of meat - can also smell like a dead animal.
Odds are that the smell you're dealing with is not an animal, but rather some kind of stubborn waste build up in or around your garbage disposal.
I'll deal with five possible causes and solutions in this article.
For some, it might be time to replace an old garbage disposal. If that's your situation, be sure to browse through our list of best garbage disposal recommendations. Otherwise, let's continue on to simple fixes for when your garbage disposal smells like dead animal flesh.
1. Just Needs a Good Cleaning
Thankfully, the most likely scenario is that your garbage disposal just needs a good cleaning, similar to the splash guard situation (next). Usually, cleaning can be accomplished by a combination of the following tactics: Warm water, soap, ice cubes, lemon slices, cleaners like ammonia or bleach, or baking soda and vinegar.
Try one or more of these tactics before assuming there's an actual dead animal in your plumbing system.
If a simple cleaning solves your problem, it was likely just a small amount of stuck and decomposing food waste.
How do I know?
It's hard to know for sure if a cleaning is all that's needed, but this is usually the first line of defense against bad smells in a garbage disposal in general.
Warm water, soap, ice cubes, lemon slices, heavy cleaners, and Drano are all options worth trying.
2. The Rubber Splash Guard
On almost every garbage disposal there's a rubber splash guard that prevents food from being flung out of the disposal back into the sink (or further). The problem with these is that owners tend to forget about the food that catches and builds up underneath the guard itself. This can be really nasty, but also simple to fix.
If you notice a build up of waste and that the smell is coming directly from the top of your disposal - and you notice zero smell coming from other sinks in the house - clean it off by hand and run it through the dish washer, then use some warm water and soap to clean the inside of the unit while the cover is off.
Make sure to unplug the garbage disposal first.
Splash Guard Scenario
How do I know?
Check underneath the splash guard. If it's caked with gunk, take a wiff to see if it matches what you're smelling in the open air.
Use a strong cleaner for the splash guard, then run it through the dishwasher. Also consider cleaning out the garbage disposal itself with at least soap and warm water.
3. A Dry P-Trap or Something Stuck There
The P-Trap is the circular pipe you see beneath most sinks in either a kitchen or a bathroom. This pipe's function is to hold water in order to prevent sewage gas from leaking up through your drain. If this pipe dries out or gets something stuck in it, you could easily start to notice a nasty smell coming out of the compromised sink.
If your splash guard is clean and only one sink smells bad, this is a strong possibility.
How do I know?
It's harder to diagnose this without taking apart plumbing. But if your splash guard is clean, there's no clog, no visible waste stuck in the disposal, and only one sink is giving off the smell, the P-Trap is a likely problem area.
You'll need to take apart the plumbing and see if the P-Trap is either dry or harboring some sort of nasty biological substance. This might be another one worth calling a plumber for if you're not cozy with the DIY process.
4. A Garbage Disposal Clog
A garbage disposal clog might mean your disposal still runs, but has something stuck in the spinner or in one of the grinding stages. I've written a fairly comprehensive article about dealing with clogged garbage disposals, so head over there if you think that's the root cause of your dead animal smell. A stuck piece of meat or bone could definitely give off a nasty odor if it has sat long enough.
How do I know?
Clogs can impact the sound of your garbage disposal and cause it to run noisier, even when water is running. You might also see the actual clog through the sink hole.
Refer to the aforementioned article on dealing with garbage disposal clogs.
5. An actual dead animal? Not likely.
I must address the distant, yet obvious possibility.
Your plumbing gas will vent through a pipe that goes to the outside of your house, usually on a roof. This vent could - potentially - serve as a grave for some unfortunate critter that gets stuck in it. This means not only would the smell of a rotting animal start going back through your plumbing, but sewage gas that would normally be escaping through the vent is now blocked by the stuck animal.
Moreover, all drains can act as a doorway into your sewage and plumbing lines, provided the object entering the "doorway" is small enough.
It's not common, but small animals like mice, birds, and (unfortunately) even snakes have been found stuck inside plumbing and sewage gas vents.
In that situation, the carcass can smell for several weeks, depending on the speed of decomposition.
If you're really thinking it's the case, find the sewer vent outside your house on the roof (if you're comfortable with that process). Shine a flashlight down and see if a bird or perhaps a squirrel has gotten stuck.
If you can smell a dead animal but can't see it, and none of the other solutions I list here work, you'll need to get a local plumber involved.
Dead Animal Scenario
How do I know?
It's the least likely scenario, so exhaust all other options here before assuming the worst.
Check the sewage gas vent and/or call a plumber
Again, if your garbage disposal smells like dead animal flesh, the odds of it being an actual critter stuck in your pipe is pretty small.
If it is, the sewage gas vent is the most likely culprit.
But if you check the vent and it's fine, go through the processes I've outlined here. One of them will probably solve your problem, thus saving you the trouble (and expense) of having to call in a plumber and start pulling out pipes.