There is no test as such for excess stomach acid or other toxins, but these are some of the symptoms you might see (though some of these may also be due to other causes, as mentioned under each category):

Loss of Appetite

Nausea can be hard to detect, though it is often manifested in a lack of appetite. The cat may also lie scrunched up, looking uncomfortable.

High phosphorus levels, dehydration or anaemia may also cause nausea.

CKD cats often vomit. Vomiting may be seen alone or in conjunction with the other symptoms in this section. Many cats with excess stomach acid or uraemia vomit regularly without treatment.

There is a difference between vomiting and regurgitation. Vomiting is usually accompanied by a lot of abdominal movement, whereas regurgitation happens suddenly and with less warning. Vomiting means the cat is emptying the stomach, whereas regurgitation is where food has not yet reached the stomach but is being ejected from the eosophagus more or less intact, often because of eating too fast or hairballs. Regurgitation is often sausage-shaped. The American Association of Feline Practitioners explains the difference and links to a number of sites, including one with a video of a cat vomiting.

Cats who vomit immediately after eating may have a gastric motility problem - ranitidine may help with this.

Occasionally vomiting is caused by constipation, particularly if your cat vomits before, during or immediately after using the litter tray. 

If you are giving your cat sub-Q fluids and s/he regularly vomits after fluids, this may because of the type of fluid used.

Coco's page has practical advice from a CKD parent.

Vet Info has information on vomiting.

Diagnosis and management of acute and chronic vomiting in dogs and cats (2007) is a paper by Dr TR Tams.

Diagnosis of disorders causing vomiting in cats is a paper by Dr TR Tams which is more specific to cats.

Managing vomiting in cats: what's new for an old problem (2008) Zoran DL Presentation to the 2008 Nestlé Purina Veterinary Symposium has an overview of vomiting in cats.

Vomiting does not just include food - the classic symptom for a CKD cat is to vomit clear or white foam.

1. Firstly, try these simple natural treatments - for some cats, especially those in early stage CKD, these are the only treatments they need:

2. If these treatments don't seem to be helping after a couple of days, move onto the histamine H2 antagonists (acid blockers), which are a group of medications commonly used to control excess stomach acid. These help the vast majority of cats. You can use these in conjunction with the natural treatments.

3. If your cat is still struggling, consider anti-nausea medications. These medications are usually very effective for nausea and vomiting, and may be the best choice for cats with additional issues, such as gastric mobility, or cats with concurrent pancreatitis or IBD. They can usually be used in conjunction with the medications outlined above:

• Ondansetron (Zofran)

• Metoclopramide (Reglan)

• Maropitant (Cerenia)

How I treat uremic crises in dogs and cats with chronic kidney disease (2009) is a presentation by Dr D Polzin to the 34th World Small Animal Veterinary Association World Congress which discusses various treatments.

Natural Treatments                                                                                                                          Back to Page Index

Raising your Cat's Bowls

If you wish to pursue natural methods of controlling stomach acid and the accompanying vomiting, nausea and loss of appetite, a herbal remedy called slippery elm bark (SEB) is often very effective. It soothes the digestive tract, so it can also help with both constipation and diarrhoea. The Holistic Treatments page has more detailed information on SEB.

Use of Acid Blockers (Histamine H2 Antagonists)                                                       Back to Page Index

Another popular over the counter histamine H2 antagonist is ranitidine (trade name is Zantac 75), which works in a similar way to famotidine. Some people prefer to use ranitidine, especially if their cat has experienced increased vomiting with famotidine, as happens with a small number of cats (usually those with creatinine over 5 USA, 450 international).

According to Feline constipation, obstipation, and megacolon: prevention, diagnosis, and treatment Washabau R a Presentation to the World Small Animal Veterinary Association World Congress 2001, ranitidine may also help some cats with constipation.

Ranitidine Dosages

One reason why people may decide not to use ranitidine is that it usually has to be given twice a day, whereas famotidine is usually only given once every other day, or occasionally once a day.

• The usual dose is 0.25 to 1.00 mg per pound (0.5 - 2.00 mg per kg) every 8-12 hours, though most people find twice a day is fine.

• You therefore would give a 10lb (4.5kg) cat 2.5 - 10 mg twice a day.

• The standard size pill is 75mg, so for a 10 lb (4.5kg) cat who is getting the higher dose, it is usually easiest simply to give an eighth of a tablet twice a day (i.e. 9.375 mg, or a little under 10 mg).

• Some people give up to twice this amount, but as with famotidine, I suggest starting low and increasing the dose if necessary since ranitidine is also excreted by the kidneys. Be guided by your vet.

Ranitidine tastes quite bitter and can make cats foam at the mouth, so you may find it easier to give it in a gelatine capsule (gelcap). Many people prefer to give the second dose of the day at bedtime because this seems to help cats who vomit at night or first thing in the morning. It usually takes effect pretty quickly, within a couple of days.

The main problem with ranitidine is dividing the tablets up into cat-sized dosages. If you find it hard to cut the pill into eight, you could try dissolving it in water and giving an eighth of the resulting mixture via syringe.

Ranitidine Oral Suspension

There is also a liquid (syrup) form of ranitidine, but this is peppermint flavoured, so not many cats would like it, plus you need a prescription for it. However, I understand you can obtain it in a beef flavoured compounded suspension from Thriving Pets. If you enter the word "tanya" (without the ") in the promotional code box, you will receive a 10% discount on orders over US$55. Shipping is free for orders over US$55 after the discount.

Ranitidine Injectible

There is also an injectible form of ranitidine, which is prescription only, obtainable from most US pharmacies (they may need to order it for you). This comes in a 25mg/ml strength, usually in a 6ml vial. You can either inject this directly into your cat, or  if your cat is on sub-Qs, by adding it to the injection port of your IV line. A possible dose is 0.3ml twice a day, but ask your vet. Injectible ranitidine usually needs to be refrigerated but it is safe to take it out about 30 minutes before using it so it can warm up a little before use.

Ranitidine Side Effects and Interactions

Plumb's Veterinary Drug Handbook recommends separating ranitidine from phosphorus binders. 

It is also advisable to separate ranitidine from ACE inhibitors such as Fortekor.

Pet Place has more information about Zantac (no need to register to read the article, just click on Close at the bottom of the pop-up).

Cimetidine (Tagamet)

You may be offered another drug in this family called cimetidine. Cimetidine has many more drug interactions than either famotidine or ranitidine, including with amlodipine (a calcium channel blocker used to treat heart disease or high blood pressure), and diazepam (Valium), which is sometimes used as an appetite stimulant. It also has the most marked rebound effect (a temporary increase in stomach acid) if it is stopped. I would therefore suggest using famotidine or ranitidine instead. 

The effects of cimetidine on renal function in patients with renal failure (1980) Larsson R, Bodemar G, Kagedal B, Walan A Acta medica Scandinavica 208 (1-2) pp27-31 explains that cimetidine may cause an increase in creatinine levels. If your cat's creatinine levels rise while using cimetidine, you may find they improve once you stop the medication.

If the natural treatments above don't work, and your cat does not respond too well to acid blockers such as famotidine, or perhaps shows some improvement but still vomits fairly frequently,  you may need to consider trying one of these other medications. These medications treat nausea and/or vomiting but they all work in different ways, so discuss with your vet whether one of them might be suitable for your cat.

Treating feline pancreatitis (2009) Robertson J DX Consult 2(1) offers a brief overview of these three treatments.

Pharmacologic control of vomiting (2009) Tams TR discusses the use of these medications and others in cats.

Ondansetron (Zofran)

This drug is commonly used to control vomiting in cats with pancreatitis or cancer. I first heard of somebody using ondansetron for a CKD cat in 2002, but it has not been used routinely in CKD cats until recently, mainly because it was extemely expensive. Since the generic version recently became available in the USA, however, it is slowly becoming quite popular for use in CKD cats, not least because it is very effective. Its trade names include Zofran in the USA, Setronon in Europe and Emeset in the UK.

Ondansetron works in a different way to metoclopramide below (it selectively inhibits serotonin 5HT3 receptors), so it does not lower the seizure threshold as metoclopramide does. 

Pet Place discusses ondansetron and mentions that the usual dose for cats is 0.11mg per pound bodyweight every 8-12 hours. (No need to register to read the article, just click on Close at the bottom of the pop-up).

Merck Veterinary Manual has some brief information about ondansetron.

Some people use another drug in this family, dolasetron (Anzemet), which only needs to be given once a day, but dolasetron seems to be more commonly used at this time for cats with pancreatitis. Pharmacologic control of vomiting (2009) Tams TR has some information about dolasetron. 

Ondansetron Dosages

Ondansetron comes in 4mg pills, and the usual dose is 1 mg each day, so one pill contains four doses. The pills are tiny, so can be hard to cut into quarters.

You can be charged as much as US$6 for a single pill, so you need to shop around, because it is possible to buy the generic pills much more cheaply. Thriving Pets sells ondansetron for US$1 per pill, or 80 cents each if you buy thirty. A prescription is required. If you enter the word "tanya" (without the ") in the promotional code box, you will receive a 10% discount on orders over US$55. Shipping is free for orders over US$55 after the discount.

Metoclopramide is a prescription only medication which works by regulating stomach contractions. This means it can help with nausea caused by a lack of motility in the stomach. Since metoclopramide can cross the blood/brain barrier, it also acts on the brain to control feelings of nausea.

Pet Place has some information about gastric motility problems in cats (you don't need to register to read the article, just click on Close at the bottom of the pop-up window).

Metoclopramide Dosages

Metoclopramide comes in 10 and 5mg tablets or a liquid. Injectable metaclopramide is also available as 5mg/ml in 2 ml or 10 ml vials. It must be given 20-30 minutes before eating.

A typical dose would be 0.1 to 0.2 mg per pound (0.2 to 0.5 mg per kg) every six to eight hours, so a 10lb (4.5kg) cat would get 1 mg to 2 mg at a time, but be guided by your vet.

Metoclopramide Side Effects and Interactions

Metoclopramide may have various side effects, including constipation, hyperactivity and agitation or drowsiness; very occasionally, twitching may be seen.

Metoclopramide also lowers the seizure threshold, so should not be given to cats prone to seizures. Drugs mentions that it may increase the risk of bronchospasm in asthmatics, and intravenous metoclopramide may worsen hypertension (high blood pressure).

On 26 February 2009, the US Food and Drug Administration warned against the "chronic use of these products [metoclopramide-containing drugs] to treat gastrointestinal disorders." This is because products containing metoclopramide have been linked to a condition called tardive dyskinesia, i.e. involuntary and repetitive movements of the body, which may continue even after the treatment is stopped. One such movement mentioned by the FDA is lipsmacking (although it should be noted that lipsmacking in CKD cats is normally caused by stomach acid or nausea, anaemia or dehydration). The FDA therefore recommends that products containing metoclopramide should not be used for longer than three months. Obviously this warning applies to humans, but I would discuss the warning with  your vet if you want to use metoclopramide for longer than three months.

I used to recommend giving metoclopramide at least two hours apart from famotidine (Pepcid AC) or ranitidine (Zantac 75) because, according to Plumb's Veterinary Drug Handbook, the metoclopramide could bind with these other medications and reduce their effectiveness. However, the most recent edition of Plumb's does not mention this interaction, so it appears that you do not need to separate metoclopramide from these other medications after all.

Veterinary Partner has more information on metoclopramide.

Pet Place also has some information (no need to register to read the article, just click on Close at the bottom of the pop-up).

Drs Foster and Smith have some information about possible side effects. They also mention that metoclopramide is similar to PABA, the sunscreen component, so people who are allergic to PABA should not touch metoclopramide.

Maropitant (Cerenia)

Maropitant is a new treatment from Pfizer. It is approved for the treatment of vomiting and nausea in dogs but is sometimes used off label in cats (in some parts of Europe it is approved for travel sickness in cats). Treatment for visceral pain with the new NNK-1 receptor antagonist maropitant in cats (2011) Boscan P, Monnet E, Twedt D & Nyiom S found that maropitant may also be an effective painkiller.

It only needs to be given once a day and does appear to be quite effective for some cats, usually taking effect within an hour. It works by blocking the stimulation of the part of the brain that instigates vomiting. I presume this means that the cat may still feel nausea (and therefore may not want to eat), but will not vomit.

Maropitant is available in either injectible or pill form. Both the injectible and the pill form are intended to prevent vomiting, but the injectible form is also designed to treat acute vomiting. The injectible form seems to sting some cats, and the oral form seems to taste horrible.

Drs Foster & Smith sells four 16mg tablets for US$7.99.

Maropitant Dosages

A commonly used dose appears to be 1mg per kg (2.2lbs) of body weight for the injectible form; Plumbs Veterinary Drug Handbook mentions that the dose for the pill form may be twice as high at 2mg per kg (2.2 lbs) of body weight. The pills should not be given in Pill Pockets or mixed with food as this may stop them being properly absorbed in the cat's body.

The manufacturers recommend that maropitant should only be given short term to dogs, for a maximum of five days at a time. Some people have used it in their cats for a few days, taken a break, then used it again. Plumb's Veterinary Drug Handbook mentions that the medication should be stopped for at least 48 hours in these circumstances. In one study on cats, Safety, pharmacokinetics and use of the novel NK-1 receptor antagonist maropitant (Cerenia) for the prevention of emesis and motion sickness in cats (2008) Hickman MA, Cox SR, Mahabir S, Miskell C, Lin J, Bunger A, McCall RB Journal of Veterinary Pharmacology and Therapeutics 31(3) pp220-9, it was used for fifteen days without a break with no apparent problems. I know that after reading about this study, some people have given their cats maropitant for longer than five days and not seen any adverse effects. Be guided by your vet on the best approach for your cat.  

Maropitant Side Effects and Interactions

Possible side effects include vomiting, lethargy, diarrhoea, twitching and drooling.  Maropitant should not be used if there is any gastro-intestinal obstruction, and should be used with caution if liver or heart problems are present.

The European Medicines Agency says on page 9 under Clause 4.8 that "Cerenia should not be used concomitantly with Ca-channel antagonists as maropitant has affinity to Ca-channels." This means that maropitant should not be used with calcium channel blockers such as amlodipine (Norvasc or Istin, commonly used to treat high blood pressure in CKD cats). The University of Zürich Institute for Veterinary Pharmacology and Toxicology also mentions this (in German), and also warns that urgent medical attention should be sought if maropitant gets in the eyes.

Pfizer product information sheet (tablets) mentions that maropitant should only be given for five days.

Pfizer product information sheet (injectible) also mentions this.

Veterinary Partner has some information about the use of maropitant in dogs, which explains more about its mechanism. It states that maropitant may interact with phenobarbital, used to control epilepsy, and NSAIDs.

Drs Foster and Smith have an information sheet about the use of maropitant in dogs.

The cat will be given a complimentary physical exam and chemistry panel at the beginning of the study. The study involves giving cats either maropitant or a placebo daily for two weeks. After two weeks, the cat will receive a second complimentary physical exam and complimentary blood tests (blood chemistry panel). During the study, the owner will be asked to fill out a daily diary of the cat’s behavior and other details. Owners receive complimentary veterinary visits and chemistry tests; a $100 stipend is offered to the participating veterinarian per cat enrolled to cover these costs.

Cautions                                                                                                                                                 Back to Page Index

The following are not recommended for CKD cats.

• Pepto-Bismol

• Antacids (Tums/Mylanta etc.)

Pepto-Bismol

Please do not use Pepto-Bismol. It contains a type of salicylate, similar to what is found in aspirin, and cats are not able to metabolise this easily, so it may be fatal even in small doses.

Some vets recommend the use of antacids, such as Tums or Mylanta. Some products in this family do actually work well in CKD cats as phosphorus binders, but they are not usually strong enough to help control stomach acid, plus using products containing magnesium is not usually recommended for CKD cats, who tend to have high levels of magnesium generally. 

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This page last updated: 27 October 2011

Links on this page last checked: 29 October 2011