Nausea and vomiting, managed properly

How do I stop my cat with kidney disease from vomiting?

If she's been picking at her food for a week and you're starting to feel like you're failing at this, read this page before you buy another flavor of anything.

Nausea is the most treatable thing about kidney disease, and it's the thing that most changes how your cat feels day to day. It's also, in my experience, the most commonly under-treated part of the whole illness.

Fix the nausea and the appetite usually comes back on its own.

The two kinds of drug, and why the difference matters

There are two shelves here and people reach for the wrong one constantly. Knowing which is which lets you ask your vet a specific question, and specific questions get better answers.

Most kidney cats who aren't eating need something from the first two groups. Some need all three. Starting with the third one is the common wrong turn.

Silent nausea, which is probably what you're actually seeing

Here's the part that surprises people. Most nauseated kidney cats never vomit.

What you see instead:

• she licks her lips, or swallows over and over, when there's no food involved
• she walks up to the bowl, sniffs it, and walks away
• she drools a little, or her chin is damp
• she grinds her teeth or makes small chewing motions
• she sits hunched over the water bowl without drinking
• she eats two bites and leaves the rest, every time
• she disappears somewhere quiet right after you feed her

That's nausea. It's the everyday version of it, and it's a lot more common than the dramatic version. If your vet asks whether she's vomiting and you say no, the conversation can stop right there, so it's worth describing what she is doing instead.

What the medications do, in the order I reach for them

Maropitant, sold as Cerenia. This is usually first. It blocks the nausea and vomiting signal in the brain, it's given once a day, and it comes as a small tablet or an injection your vet can give in the clinic. It's the workhorse.

Worth knowing: the label describes short courses, and vets use it daily for months in kidney cats anyway. That's a deliberate judgment, not an error, and it's better you hear it here than notice the mismatch on the box and worry.

Ondansetron, the generic of Zofran. Works on a different receptor, so it isn't a substitute for maropitant, it's something to add when maropitant alone isn't holding her. Usually given two or three times a day. It's inexpensive as a generic.

An acid reducer. Omeprazole is the stronger of the two common options and famotidine is the more familiar one. Ask your vet which and at what dose, rather than buying the human version and guessing, because the dose in a cat with reduced kidney function isn't the dose on the human box.

One practical thing that makes all of this work better: give the antiemetic thirty to sixty minutes before you offer food, not with it. She needs to already be feeling better when the bowl appears. Otherwise the food is what she remembers feeling sick around.

The two things that pretend to be kidney nausea

Before you accept that this is just the kidneys, rule out two problems that look identical from the outside and need completely different treatment.

Constipation

This is the one that gets missed, and kidney cats are set up for it. She's running slightly dehydrated all the time, her body pulls water back out of the stool, and what's left is dry and hard to pass.

A constipated cat is nauseated, off her food, and flat. Often she's in and out of the litter box straining, which almost everybody reads as a urinary problem. You may find small dry hard pieces outside the box, or nothing in the box at all for two days.

It's fixable. More water into her, usually through wet food or subcutaneous fluids, plus a stool softener like lactulose or a dose of polyethylene glycol, the powder sold as MiraLAX. Your vet sets the dose. Untreated, it feeds straight back into the nausea and the not eating, and the two problems hold each other up.

A painful mouth

The other impostor. Cats get resorptive lesions, which are painful holes in the tooth at the gum line, and advanced kidney cats also get ulcers in the mouth from the uremia itself.

A cat with a painful mouth looks exactly like a nauseated cat until you watch her closely. The tell is that she's clearly interested. She comes to the bowl, she wants it, then she flinches away, or chews on one side, or drops food, or takes a mouthful and shakes her head. She'll usually prefer soft food and refuse anything hard. Her breath is often bad in a way that isn't just old-cat breath.

No antiemetic in the world fixes a sore tooth. If that's the pattern you're seeing, say so out loud at the next visit and ask for her mouth to be looked at specifically, because knowing it's her mouth changes what she gets, even when the answer isn't surgery.

Treating it rather than operating on it means pain control, and cats respond to that better than most owners expect:

• Buprenorphine, a liquid opioid given into the cheek pouch rather than swallowed. It's the workhorse for mouth pain in cats and it's a reasonable thing to ask about by name.
• Gabapentin, at a reduced dose. Her kidneys clear it, so a standard dose in a kidney cat leaves her sedated and wobbly. That's a dosing problem, not a reason to avoid the drug.
• An antibiotic, if the gum is infected rather than only sore.
• Soft food, warmed. Nothing hard, nothing she has to work at.
• If the sores are uremic ulcers rather than tooth disease, treating the uremia does most of the work: fluids, phosphorus control, and an acid reducer.

One hard rule. Never an anti-inflammatory meant for a person, and never a leftover meloxicam from another animal in the house. NSAIDs can take a kidney cat's function down fast.

Two honest limits. An awake exam can find a resorptive lesion, an ulcer or an infected gum, but it can't take dental x-rays, so nobody can give you the complete picture without anesthesia. I'd rather have an incomplete picture and a comfortable cat. And if your own vet does recommend a dental, that isn't a disagreement you need to referee. Ask what stage she is, what they expect the procedure to change for her, and how they'll protect her blood pressure while she's under.

There are other possibilities too, and this is why a cat who suddenly gets worse deserves a workup rather than a bigger dose. An overactive thyroid, pancreatitis, a urinary tract infection sitting silently in a kidney, and in an older cat, other things entirely. Kidney disease doesn't protect a cat from also having something else.

What you can do tonight, without a prescription

Stop offering whatever she was eating when she felt worst. Cats build food aversions fast and they hold them for a long time. If she threw up on the chicken pate, chicken pate is burned. Put it away and don't try to be clever about it.

Don't syringe-feed a nauseated cat. It feels like doing something and it teaches her that food and being held still and feeling sick all arrive together, which is a hole you'll spend weeks climbing out of. Same reason I'd rather you didn't chase her around the house with the bowl.

Offer small amounts, warmed slightly. A few seconds so it's about body temperature, not hot. Smell is most of appetite in a cat, and warm food smells like something.

Then write down the pattern, because this is what actually changes her treatment: what time of day, how long after eating, how many times, and what it looked like. Your vet can do a great deal with that and very little with "she's been sick a few times this week."

The thing I'd want you to take away

A kidney cat who won't eat is usually not being stubborn and usually not at the end. She's most likely nauseated, and nausea is a solvable problem.

If she's been off her food for more than a day or two and nobody has offered you an antiemetic yet, that's a reasonable thing to ask for by name. There's more on getting her eating again on the appetite page, and it's worth reading in that order, nausea first, appetite second.