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TANYA'S
COMPREHENSIVE GUIDE TO
FELINE CHRONIC RENAL FAILURE
PERSUADING YOUR CAT TO EAT
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Diet can be a very useful way of controlling CRF and helping your cat to feel better. Unfortunately, many CRF cats have very poor appetites, which may have a variety of causes such as stomach acid, dehydration and/or anaemia. Please see the Index of Symptoms and Treatments for more information on possible causes of inappetance.
Treating whichever of these potential causes is present is essential, and may even solve the problem for you. However, your cat needs to eat whilst you are sorting out the possible causes of inappetance; in fact, it is essential that a cat does not go too long without eating because of the risks of hepatic lipidosis. The American Animal Hospital Association recommends that you should contact your vet if your cat has not eaten for one or two days.
Even after treating whatever problems may be present, since cats eat to live rather than the other way round, you may find your cat has got out of the habit of eating and has to be tempted into doing so again. Therefore this section contains suggestions on helping your cat to eat. The good news is, once you have got your cat eating again, he/she may feel better for it and soon get back into the habit.
Please see the Food Composition & Nutritional Requirements page for an explanation of your cat's physiological needs and a discussion of the low protein debate, and the Which Foods to Feed page for what to do if your cat refuses to eat the prescription diet which your vet recommends, plus information on why I don't necessarily consider Fancy Feast to be a bad food for CRF cats.
How you store and serve food can make a difference to some cats. If you use tinned food, be sure to store any leftover food in glass containers in the fridge rather than in the tins themselves. The Food Standards Agency has more information about why this is a good idea. It can also be helpful to avoid washing cat bowls with any type of soap and detergent, but simply to use very hot water instead. I also use flat plates to serve food. It is thought that cats do not like their sensitive whiskers to touch the bowl while they are eating, and whilst healthy cats may not mind this so much, it is worth trying flat bowls to see if this helps, particularly if you have Persians as I do.
Where you serve food can also make a difference. If your cat is weak, don't place the food bowl miles away from his/her favourite resting place. Novelty may also help: I used to feed my cats in the kitchen but once one of them became ill and needed a lot of encouragement to eat, I had food bowls all over the place. I have found that a cat may refuse to eat a plateful of food in one room but will eat that self same plateful of food in another room.
Whilst it is hard to be precise, a cat needs approximately 30-35 calories per day per pound of body weight, or possibly more if the cat is particularly active. As an example, a 9 lb cat would need 270-315 calories a day. Therefore, as you can see, feeding a teaspoonful of food a day is not going to be enough to maintain your cat's weight, let alone increase it if your cat is too thin.
Stanley Marks discusses feline dietary and calorie needs in Diagnostic and Therapeutic Approach to the Anorectic Cat (2001), World Small Animal Veterinary Association World Congress 2001. Metabolizable energy: a way to looks at caloric density by Dr Holly Nash explains how foods vary in terms of the number of calories which are actually available to a cat after digestion. "Pet foods with higher ME numbers provide your pet's body with more concentrated calories for more energy. With a higher ME, your pet's body will receive more energy from a smaller amount of food." This can be helpful for CRF cats who tend not to have much appetite. Petdiets can help you work out how much food your cat needs each day.
This section covers foods that taste good to many cats (so they may be prepared to eat them on their own) but which also can help keep them going at times of crisis, or enable them to gain weight if they need to do so.
If you are looking to provide your cat with additional nourishment, one possible food might be eggs. Washington State University College of Veterinary Medicine has stated: "Proteins with high biologic value can be readily converted to body proteins with minimal waste production. Animal proteins have a higher biologic value than vegetable proteins. Eggs have the highest biologic value."
A human study, Organic and inorganic dietary phosphorus and its management in chronic kidney disease (2010) Noori N, Sims JJ, Kopple JD, Shah A, Colman S, Shinaberger CS, Bross R, Mehrotra R, Kovesdy CP, Kalantar-Zadeh K Iranian Journal of Kidney Disease 4(2) pp89-100, reports that "fresh (non-processed) egg white (phosphorus-protein ratio less than 2 mg/g) is a good example of desirable food, which contains a high proportion of essential amino acids with low amounts of fat, cholesterol, and phosphorus". In another human study, reported in Renal and Urology News (2008), egg white even helped lower phosphorus in patients who ate six cooked egg whites in place of a meal each day.
You can try scrambling the eggs, some cats enjoy these. Some people choose to only feed the white, because this provides additional protein but does not contain high levels of phosphorus. According to the US Department of Agriculture's Food and Nutrition Information Center, one large egg white weighs about 33g and contains 17 calories, 3.6g protein, no fat and 5mg of phosphorus. This is a lot less phosphorus than a chicken breast, and the protein in eggs is more digestible. However, it is important to cook egg whites until they are hard, because uncooked egg white contains something called avidin, which combines with one of the B-complex vitamins (biotin) to make it unavailable, and CRF cats do need their B vitamins. Cooking the egg whites destroys the avidin. Some cats will eat cooked egg white voluntarily, but it tastes a little bland that way, so most people simply mix it into their cat's other food.
In the USA you can buy cartons of egg white in supermarkets, but be careful because some brands contain onion. However, a brand called All White consists of nothing but egg whites. Amazon sells a 100% egg white product called Just Whites.
In the UK Sainsburys sells Two Chicks Free Range Liquid Egg Whites; these are also available from Waitrose and Tesco. Fifteen free range egg whites cost around £2.89. Holland & Barrett sell Tropicana 100% egg white powder. Whichever brand of dried egg white you buy, make sure it is pasteurised.
This is a food specially formulated for convalescent cats: it has high levels of liver, is very mushy and extremely smelly. Quite frankly, the smell makes me feel ill; which is probably why all my cats adore it. Once Thomas gave up on ham, we were at our wits' end; but Hills a/d kept him going through his crisis and was a real lifesaver.
This food is a prescription food, so it is only available from vets, and should not be fed to a CRF cat long-term because it contains a lot of liver (too high in Vitamin A) and is high in phosphorus; but it is excellent for short periods of crisis and/or convalescence.
Incidentally, contrary to what many people assume, a/d actually has fewer calories than k/d.
Once opened, a can of Hill's a/d should be kept for a maximum of 36 hours.
Hill's Petfoods is the manufacturer's website. Click on prescription diet on the left, then choose a/d.
This is a nutritionally complete liquid supplement formulated for CRF cats, which is relatively high in fat and low in protein.
Not all cats like it, it is quite expensive (about US$5 a can, but often you have to buy an entire case), and it is not stocked by many vets, but it may be helpful if you are feeding your cat via a feeding tube. or if you want to get more calories into your cat. It could be useful if your cat is not eating normal cat food (e.g. if your cat is only eating baby food) because it is nutritionally complete.
It is available from Agri-Med , Entirely Pets or Vet America in the USA. Catty Vet will also ship to Canada or UK.
Clinicare RF is the manufacturer's website.
I hqve not been able to find Clinicare RF in the UK, but Liquivite is a possible alternative. It is a canned liquid food made from chicken, liver, beef and eggs, with a relatively low phosphorus content (0.75% on a dry matter analysis (DMA) basis.
It is estimated that around 80% of cats are lactose intolerant, which can cause diarrhoea and vomiting. For this reason, it's usually recommended that cats are not fed milk, but if your cat is not lactose intolerant, it is usually safe to feed milk, though it does contain protein and phosphorus.
If your cat is lactose intolerant, there are special lactose-free milks available for cats, such as Catsip, which also has added taurine.
If you are in the USA or Canada, you can try using baby foods to tempt your CRF cat to eat in the short-term. Aim to buy the simple meat-based foods rather than those containing veggies and fruit. When I tried this with Tanya, I had great difficulty finding suitable baby foods, since most of the UK baby foods seem to have large amounts of carbohydrate rather than the meat which cats usually prefer and need; but Heinz have recently introduced a food called Four Month Mum's Own in Beef Puree flavour which appears to be suitable.
Please ensure you purchase a food without any onion or garlic or onion powder (see Which Foods to Feed). In principle baby foods sold in the USA have to list every single ingredient on the jar, so if the ingredient is not listed, the food should not contain it. Gerber Stage 2 meat and Beechnut meat baby foods in the USA are safe at the time of writing, but formulations can change, so do check the labels.
Gerbers 2nd Foods contain around 90 calories a jar and although they can be relatively high in protein, they are low in phosphorus - they contain 69mg per jar, about the same as a portion of prescription food containing the same number of calories. Gerber's 2nd Food Ham with Ham Gravy is currently the lowest in phosphorus and protein, and although people worry that ham baby food will be high in sodium, it actually isn't. There is information about the levels of phosphorus, protein, sodium and fat in a number of US baby foods in the food data table.
Do not feed baby foods exclusively long-term, because like other human foods they lack taurine, an amino acid which cats need to obtain from their food: a lack of taurine in a cat's diet can cause serious heart and eye problems. If you feed them exclusively for longer than a few days, add 500mg of taurine to it, which is not perfect which will reduce the risks somewhat. However, it is OK to feed a little baby food each day without taurine e.g. when giving pills, as long as it is in addition to a more balanced (usually a commercial) cat food.
Kat Karma has some data on US baby foods (scroll to the bottom of the page).
This is certainly not the best food for a CRF cat, but if your cat is recovering from a crisis or being extremely pernickety, you may have to resort to offering tasty human foods to tempt your cat back into eating.
Chicken or lightly cooked fish are possibilities. Thomas would only eat ham for two weeks when his anaemia was at its worst; even though the levels of sodium in the ham were very unhealthy, eating ham was better than not eating anything at all. Many commercially sold chickens have a lot of salt too.
Do not feed these sorts of foods long-term, because they lack the nutrients which a cat needs, particularly taurine, an amino acid which cats cannot manufacture themselves, and a lack of which can cause heart and eye problems; but in order to kick-start eating, they can be ideal. Please do not feed your cat anything containing onion or garlic and be careful about feeding tuna (see Which Foods to Feed).
Nutri-Cal You may also be offered a high calorie supplement called Nutri-Cal, which comes in a tube. Many vets stock it, and although it is relatively high in carbohydrates and has some additives, which mean it is not the best choice for a cat, it does help tempt some cats to eat, so it might be of help during a crisis.
Nutri-Cal appears to contain a relatively high amount of Vitamin A, so do check with your vet before using this, because too much Vitamin A is not good for CRF cats.
Nutri-Cal is the manufacturer's website. Vet UK sell NutriCal in the UK.
Until your cat is stable, you may have to resign yourself to having a "kitty smorgasbord" available for a while. This means you have a selection of foods for your cat to choose from, which you rotate to suit your cat's current preferences. When Harpsie (non-CRF but he had a severe kidney infection) was sick and off his food, we ended up with eighteen different foods on offer. We had to build a shelf just to hold them all!
We found he might eat one of the foods one day, then refuse it the next. Sometimes we would offer him five or six foods before we found one he would eat. Then a week or so later, a food he had previously turned down might be back in favour.
We also found that he might refuse a food in the kitchen but be prepared to eat the same plateful of food in the lounge. Or he might eat the food if we moved it back into the middle of the plate. The plate mattered too: he seemed not to like plastic plates but preferred china (well, he was an English gentleman...)
In our experience, cats who are off their food tend to prefer pâté-type foods to more lumpy foods; often with lumpy foods cats merely lick off the gravy.
If you can persuade your cat to eat of his/her own accord, it is usually much less stressful for both of you; but you may also need to use some of the following tips.
Many CRF cats no longer routinely ask for food, or not frequently enough to maintain their weight, so they need your help. Try to offer your cat small amounts of fresh food at regular intervals, if necessary taking the food direct to your cat (we used to have a rule that cats eat in the kitchen but that soon went out the window once we were faced with a sick cat). Just offer a spoonful at a time. If your cat eats it, offer a little more.
If you also have the time to offer food frequently, you can find that although your cat only eats a little each time, over the course of a day it can add up to a reasonable food intake. You may also find that this reduces the build up of stomach acid in your cat.
If you are out at work all day, you could try using a timed automated feeder which opens two separate compartments at times of your choosing so that your cat can have access to fresh canned food. These are also useful at night.
Pet Planet sells an automatic feeder in the UK for £28.90. Pets Direct sells an automatic feeder in the UK from £34.99, click on Cats, Feeding Accessories. Drs Foster and Smith in the USA sell one for US$44.99. Mighty Pets sells an eight day automatic feeder for US$71.99.
Many cats, including mine, do not like food fresh from the refrigerator - it seems to be too cold for them. Try taking the food out of the fridge half an hour before feeding it. Alternatively, you can try actually warming your cat's food. The sense of smell (and sometimes of taste) in human renal patients is impaired, and it is thought that this happens to CRF cats too. Warming the food makes it smell stronger, which may filter through to the cat and encourage him/her to eat.
We microwave the food on a plate for about 4-5 seconds on High, but your oven may vary. If you use the microwave, stir it thoroughly afterwards and make sure it is not too hot - food cooked in the microwave may cook unevenly and contain "hot spots" which could burn your cat if you are not careful.
We have also tried warming the food by adding hot water - again, be sure it is not too hot. Some cats prefer the mushy texture of food that is watered down.
The Feline Advisory Bureau mentions that cats tend to prefer food at a temperature of around 35° C, which happens to be the same temperature as freshly killed prey.
Some cats suffer from stomach acid if they have to eat from a bowl on the floor. For tips on how to raise the bowl, see Treatments.
These are items which you can sprinkle on your cat's food in order to make it more tempting for your cat. I have had good luck with Liv-a-Littles.
Fishy Extras
Fish can be a bit of an issue for cats (see Which Foods to Feed), but a little sprinkled on the food each day to tempt your cat to eat should not be a problem.
Meaty Extras
Although these tend to be pure meat and therefore relatively high in protein and phosphorus, you use so little when you sprinkle them on food that it should not be a problem.
Some people have found homemade chicken broth (just boil the chicken in water, there is no need to add any vegetables, definitely not onions) very helpful for their CRF cats. It can either be added to food, particularly prescription food, to make it more appetising, or simply given to the cat to drink.
When buying chicken to make the broth, make sure that it does not contain added broth, which may contain sodium and onion. Many commercially sold chickens have a lot of salt, The Center for Science in the Public Interest has more information about this. You can check how much sodium is in a chicken by looking for sodium in the nutritional information on the packaging: anything over 100mg of sodium means that broth has been added.
Some people have tried a simpler approach and simply add lots of water to their cat's tinned food in order to make it soupy. You can use a blender if necessary to make it fairly smooth. Cats with mouth ulcers in particular may prefer food with this texture.
I am sometimes asked if it is acceptable to give catnip to a CRF cat. It is fine, and in fact may act as an appetite stimulant in some cats. However, not all cats react to catnip - this is a genetic trait. Cats International has some information on catnip. The Feline Advisory Bureau also has information on catnip.
Whilst tuna itself is not appropriate for cats (see Which Foods to Feed), one possible compromise is to add the water in which tuna is packed to your cat's prescription or other diet in order to moisten it and make it more palatable. Tuna packed in water may actually be packed in a type of broth, which may contain onion; and other brands may contain high levels of sodium, so you need to be very sure the brand you use is acceptable. Starkist Low Sodium Tuna contains only tuna and water and is popular with Feline CRF Information listmembers in the USA.
When my cat began having acupuncture (for his arthritis), there was a noticeable improvement in his appetite. I don't know if this was a direct result of the acupuncture itself, or whether being in less pain from the arthritis made him feel better generally; but I know of a couple of cats who receive acupuncture solely for appetite stimulation, and it seems to work for them. Holistic Treatments has more information on acupuncture.
You will probably have times when your cat refuses to eat. Naturally, you must try to address all possible causes of inappetance, such as stomach acid, mouth ulcers and nausea (see Index of Symptoms and Treatments), and the suggestions above to make the food seem more appetising. But if all else fails, there are a couple of other things you can try.
We found this helpful with both Tanya and Thomas. We would sit by them encouraging them to eat, praising each mouthful. It does work for some cats. If Harpsie was lying near us on the sofa, we also used to place a plate of food nearby, also on the sofa, so he did not have to move far to eat.
This is the next stage, where you lift the food out of the bowl and encourage your cat to lick it off your finger or a spoon. It can take hours, and your cat will probably drop lots of the food, but we found this really helped persuade both Tanya and Thomas to eat.
Syringe (Assisted or Force) Feeding Finally, you can try what many people refer to as force feeding, but what I prefer to call assisted feeding. This entails placing your cat's food into a syringe and syringing it gently into the cat's mouth. Hill's a/d in particular can be made into a mush with water and syringed in easily. Alternatively, you can puree tinned food (prescription or standard food) using a mixer or blender, add water to make it more liquidy (otherwise it is hard to squeeze out of the syringe), then draw it up into a syringe. Using warm water can make the food more attractive to your cat.
We had to do this with Tanya occasionally at our vet's suggestion; luckily it was usually only necessary for a day or two, although some people on the Feline CRF Information list do this on an ongoing basis. If you are doing this on an ongoing basis, you may as well assist feed prescription food.
You can feel really mean when you assist feed, and it doesn't help that some vets claim that if a cat stops eating, it's time to let go. All I can say is, I'm glad that doesn't apply to humans too because I would have been dead years ago if so! I saw in the new millennium with a nice bout of flu during which I was unable to eat a thing. It was just while I was feeling ill, and it's usually the same for most cats, it's a short term thing.
Tanya was a very independent cat, but she coped far better with assist feeding than we would have expected, and your cat might be the same. Assist feeding can actually reduce stress for both of you. You know your cat has eaten enough rather than watching anxiously and trying to ascertain if his/her food intake has been sufficient that day. Your cat is not being hassled by you waving twenty different foods under his/her nose. Plus you will also save money by not having to throw away twenty different rejected foods each day.
Of course, if you do this, you have to aim to feed a reasonable amount of food to your cat; two teaspoonfuls a day won't suffice (see average feline calorie needs). It is also important to assist feed properly: make sure the food is reasonably mushy so it flows smoothly, go slowly, try to stay calm. Insert the syringe in the side of the mouth, not directly in the front, so as to reduce the risk of the food going down the wrong way; and give your cat time to swallow each mouthful. You must also only syringe in a little food at a time and give your cat time to swallow it. All this is in order to avoid the risk of aspiration pneumonia. Pet Place has more information on this.
Don't worry if your first session doesn't go too well, you and your cat both need time to get used to this new routine. It may be more comfortable for your cat if you warm the food but be careful not to have it too hot, you don't want to burn your cat's mouth.
Sandy and Boo's story has detailed instructions on how to assist feed. Medi-vet in USA sells syringes which you can use to assist feed your cat, search for Syringe. Lambriar Animal Health Care in USA sells syringes with an "O-ring" which last longer and which some people find easier to push than standard syringes. Pippins Roost sells ringless syringes which are supposed to last the longest. Pharma Systems sells ringless syringes in Canada.
The size syringe you should choose depends upon how strong your hands are - the smaller and weaker your hands are, the harder it is to push a larger syringe. I have weak hands and found a 10ml one worked best for me with Tanya.
If all else fails, your vet may suggest a feeding tube. This is a device which is implanted into your cat under general anaesthetic and you then simply pour food and medications into it. These tubes can last for up to a year. My vet is opposed to them for CRF cats, believing that if a cat reaches this stage, it is cruel to keep them alive; but some people on the Feline CRF Information list have had good results with them.
There are two main types of feeding tube. The oesophageal tube, which can normally be inserted with sedation only, is inserted at the neck and runs down to the oesophagus. Usually food fed through such a tube must be blended. Your vet can tell you how much and how often to feed.
The gastrostomy tube (sometimes called a PEG tube) is placed directly through the cat’s side into the stomach. It normally has to be inserted using a general anaesthetic. This tube is less likely to interfere with the cat’s swallowing mechanism than the oesophageal tube, but neither type seems to bother cats particularly.
Occasionally vets use a naso-gastric tube, which can be inserted without anaesthesia. This tube is placed in the nose and runs down to the stomach. Unfortunately, these tubes are narrow so can only be used for liquids, plus they are really only suitable for short-term feeding of several days. If your cat is given such a tube, the throat can be a little sore for a few days after removal, so you will need to continue to feed smooth, easily swallowed food during this period.
Vetcentric has more information on feeding tubes. Long Beach Animal Hospital is also very helpful on this topic. Zora's feeding tube shows how her human, Shoshannah, tube fed her. Zora is now eating without a tube.
The Assist Feed Website has tips and advice on assist feeding. Feline Assisted Feeding List covers many of the above topics and may be of help to you in trying to persuade your cat to eat.
Appetite Stimulants: Use of Drugs to Induce Eating
Since it is important that cats eat regularly because of the risk of hepatic lipidosis, vets may prescribe a drug to stimulate appetite. However, you should not reach for these alone, because many cats may eat because of these drugs yet still feel dreadful; plus these drugs have potential side effects. Therefore you should definitely try to treat any possible causes of inappetance (see Index of Symptoms and Treatments) and try the other tips mentioned here, rather than only opting for appetite stimulants.
Unfortunately, appetite stimulants do not always work on cats who have completely stopped eating; they tend to be more effective at persuading a cat who is still eating, but not enough, to eat more.
Steroids (as Appetite Stimulants) Your vet may offer you a steroid if your cat is not eating very much. There are two classes of steroids, corticosteroids and anabolic steroids, and both may help stimulate appetite.
Corticosteroids Commonly prescribed corticosteroids include prednisone and prednisolone (usually abbreviated as pred), which usually are used in pill form. Cats metabolise prednisolone better than prednisone (they have to convert prednisone into prednisolone in their bodies anyway before they can use it) so it is usually better to give prednisolone in the first place. Vet Contact reports on a study entitled Bioavailability and activity of prednisone and prednisolone in the feline patient (2004) Graham-Mize CA & Rosser EJ Veterinary Dermatology 15 (s1), pp 10 which supports this view.
However, corticosteroids can have serious side effects with long-term use (including triggering diabetes, fluid retention and resulting hypertension, and masking infections), and may also increase stomach acid, which is not ideal for a CRF cat.
If your cat develops congestive heart failure (CHF) within a week of starting corticosteroids, the steroids may be the cause. One study, Corticosteroid-associated congestive heart failure in 12 cats (2004) Smith SA, Tobias AH, Fine DM, Jacob KA, Ployngam T The International Journal of Applied Research in Veterinary Medicine 2 (3) pp159-170 found that some cats developed a unique form of congestive heart failure (CHF) within seven days of starting steroids. Five of the cats died, but the seven that survived did much better than the typical CHF patient once taken off the steroids.
In any event, it is recommended that corticosteroids should not be used in the renally impaired.
If for some reason you are using corticosteroids, these should never be suddenly discontinued: the dose must be tapered because using corticosteroids may suppress the adrenal glands' ability to produce cortisone naturally. Tapering the dose minimises the risk of adrenal insufficiency occurring as a result.
There are links about corticosteroids below.
Anabolic Steroids Anabolic steroids can help stimulate appetite, and may also be beneficial for CRF cats with muscle wasting and mild anaemia. If you are using steroids as an appetite stimulant, particularly longer term, anabolic steroids are a much safer choice than corticosteroids. Your vet may prescribe anabolic steroids in the form of either tablets or injections. Commonly used anabolic steroids in Europe are Nandoral (Ethylestrenol in tablet form) or Laurabolin (injectible Nandrolone). Winstrol-V (stanazole) was popular in the US but unfortunately, it appears to have been unavailable since September 2004, which apparently is related to some type of FDA regulation. It may still be obtainable from some compounding pharmacies. Pet Education warns that Winstrol-V may cause severe liver disease in cats. Thomas took anabolic steroids whilst he had CRF. He received a monthly shot at the vet's. We were able to reduce Thomas's steroid dose, but he still seemed to do better overall when he was taking his steroids. If you are using steroids as an appetite stimulant only, I suggest trying the other ways of encouraging your cat to eat first, keeping steroids in reserve for later on in the disease. If you do use steroids, opt for anabolic ones and your vet should monitor liver values, because these sometimes increase with steroid use, in which case the steroids should be discontinued.
Veterinary Partner explains how corticosteroids work. Newman Veterinary has helpful information about steroids. Mar Vista Vet discusses the potential problems of ongoing steroid use. Washington State University College of Veterinary Medicine advises against the use of corticosteroids in CRF cats. University of Georgia also advises against the use of corticosteroids in cats - go to Section IV, point 4 on page 23.
The most common appetite stimulant used in cats is cyproheptadine (Periactin), an antihistamine which in cats may have the side effect of stimulating appetite. Unfortunately it can also have several other side effects, such as making the cat agitated, causing howling, making the cat breath faster, or having the opposite effect of causing lethargy. In a small number of cats it may cause reduced urination or an increased heart rate or temperature. If you see such symptoms, check with your vet - the dosage you have used could well be too high.
Since cyproheptadine is not really designed to be an appetite stimulant (and indeed may not work for all cats), dosage can be rather hit and miss, so you should be guided by your vet. Since the body of a cat with CRF eliminates cyproheptadine more slowly than that of a healthy cat, you should start with a low dose, increasing it only if necessary – you are aiming for a dosage which stimulates your cat to eat whilst ideally not making the cat agitated or lethargic.
Cyproheptadine comes in 4mg tablets. Whilst Plumb's Veterinary Drug Handbook mentions a dose of 1 - 4mg once or twice a day for a cat, many people on my Support Group have found a dose of 0.5mg once per day works well, so you may wish to ask your vet if you can start at this level, increasing it only if necessary.
According to one study, Disposition of cyproheptadine in cats after intravenous or oral administration of a single dose (1998) Norris CR, Boothe DM, Esparza T, Gray C, Ragsdale M, American Journal of Veterinary Research 59(1) pp79-81, you may need to give cyproheptadine for approximately 2.5 days before it reaches a steady level in the cat, but some people have found that even one dose can take effect pretty quickly. Once the cat has been on cyproheptadine for a few days, it should certainly take effect within a couple of hours, although some cats develop appetite within 15 minutes, so be sure to have fresh food ready for your cat.
You may choose to use cyproheptadine for a few days and then see if you can manage without it, but if you find you need to use it on a longer-term basis, this appears to be safe, though its effectiveness may gradually reduce, and the cat may sneeze as the effects wear off. If you use cyproheptadine longer term, monitor BUN levels (which you are probably doing anyway), because these may occasionally increase when using cyproheptadine.
Cyproheptadine is available in the UK and Canada without a prescription, which is cheaper than buying it from your vet, but please do not use it on your cat without your vet's knowledge and approval.
Pet Education has information on the use of cyproheptadine in cats. Pet Place also provides an overview. Mar Vista Vet also has helpful information.
Plumb's Veterinary Drug Handbook mentions that cyproheptadine may have calcium channel blocking effects and thereby cause low blood pressure. There is a small risk that this in combination with a drug used to treat hypertension, Norvasc, which is also a calcium channel blocker, could reduce blood pressure too far, so be sure your vet knows this before you permit your cat to be on both drugs simultaneously.
Another drug sometimes used as an appetite stimulant is diazepam (Valium), a tranquilliser and muscle relaxant. Diazepam has a number of side effects, including affecting depth perception which can be dangerous for cats allowed outdoors. It may also cause ataxia (loss of co-ordination or an unsteady walk). In some cases, although it is a tranquilliser, diazepam may have the paradoxical effect of causing aggression.
The main problem with diazepam is that unfortunately a small number of cats develop acute liver failure after several days of use, so if you do choose to use this drug, your vet should check your cat’s liver values before starting it and a few days afterwards.
If you are using histamine H2 antagonists to control stomach acid, you should know that one drug in that family, cimetidine (Tagamet), may increase the effects of diazepam, so it would probably be safer to control stomach acid using Pepcid AC instead.
Fulminant hepatic failure associated with oral administration of diazepam in 11 cats (1996) Center SA, Elston TH, Rowland PH et al. Journal of the American Veterinary Medical Association 209 pp618-25 reports on the risks of using diazepam in cats, and concludes that some cats have an idiopathic (i.e. the precise reason is unknown) response to this drug. Some cats just appear to be sensitive to it, and it is hard to know beforehand which cats would react in this way. Mar Vista Vet has more information on using diazepam in cats, including a comment that diazepam may have a stronger effect if used at the same time as cimetidine (Tagamet), and conversely may heighten the effect of Digoxin, a heart medication. Pet Place discusses the pros and cons of using diazepam. Wedgewood Pharmacy recommends that diazepam should be used with caution in animals with decreased kidney function.
Although some people have had good results with diazepam, I personally would not risk it; if you choose to use it, I would suggest you do so as a last resort.
In recent years a drug called mirtazapine (trade name is Remeron in the USA and Zispin in the UK) has become increasingly popular as an appetite stimulant for CRF cats. Mirtazapine is actually an anti-depressant but in small doses it can cause an increase in appetite. It may also have anti-emetic properties.
Mirtazapine must be used with caution in anyone with renal problems. It should also be used with caution in cats with hyperthyroidism or liver problems.
A commonly used dose in CRF cats is ⅛ to ¼ of a 15 mg tablet every 3 days. However, a recently completed study at Colorado State University found that the half life of the drug (the time it takes to leave the body after taking it) is shorter than originally thought. The Veterinary Teaching Hospital at Colorado State University therefore considers it safe to give mirtazapine every other day, but always start with ⅛ of a 15mg tablet.
As a tetracyclic anti-depressant, mirtazapine may cause an increase in blood pressure and heart rate. It may increase cholesterol levels. Like cyproheptadine, it may make some cats restless and agitated, although around 50% of human patients on mirtazapine feel sleepy.
Most people I have heard from have not had problems with Mirtazapine, but I have heard from a couple of people whose cats were on treatment for hyperthyroidism who did not seem to do well on mirtazapine. This is probably because methimazole, a commonly used medication for hyperthyroidism, reduces levels of a liver enzyme called CYP2D6 which helps to clear mirtazapine from the body. The University of Maryland Medical Center (click on Drug Interactions) has some information about this. If your cat is on methimazole and you want to use mirtazapine, I would talk to your vet about using a reduced dose of mirtazapine.
I also heard from a lady whose CRF cat had an extremely severe reaction to it, and since mirtazapine takes a long time to clear from the cat's body, her cat's reaction lasted for around three days. A poison centre was unable to offer any suggestions, so she just had to wait for the drug to work its way out of her cat's system. I have since learned that when cats react badly to mirtazapine, it is often because their bodies are creating too much of a hormone called serotonin. Mirtazapine is supposed to stop serotonin being bound to receptors in nerve cells, but this may cause too much serotonin to accumulate in the cat's brain, which leads to a condition called serotonin syndrome. Symptoms of this syndrome include fast heart rate, hypertension (including dilated pupils), excessive vocalisation, being "spaced out", walking strangely, stumbling, breathing problems such as panting or breathing very fast, and agitation.
Somewhat bizarrely, the antidote for mirtazapine is actually another drug commonly used as an appetite stimulant in cats, cyproheptadine. One possible dose would be 2mg given twice within the first 24 hours, followed by 1 mg given twice daily for the next 48 hours; but do not give this without your vet's knowledge and approval. I would recommend actually taking your cat to the vet if you think s/he is suffering from serotonin syndrome because other treatments such as IV fluids may also be necessary.
Mirtazapine does seem to work pretty well as an appetite stimulant in cats but for most cats I think I would try cyproheptadine first. If you do opt to use it with your vet's blessing, please be sure to monitor blood pressure.
Veterinary Partner has information about the use of mirtazapine in cats. It mentions that it may help with nausea as well as appetite. The Winn Feline Foundation is financing a study into the use of mirtazapine for cats with CRF at the University of Colorado (go to page 3). Net Doctor has some information about the use of mirtazapine in humans. Medicine Net also has information about the use of mirtazapine in humans.
Colorado State University are seeking participants for a new study into the use of mirtazapine (see above) as an appetite stimulant, which should commence shortly (March 2010). The study is a placebo-controlled double blind study where your cat will receive either mirtazapine or a placebo every other day for three weeks, and then cross over to the other group for an additional three weeks.
A vet visit is necessary at the beginning, middle
and end of the study and all visits and labwork
will be paid for at no cost to participants. These
visits may be with your own vet, there is no need to attend Colorado
State University for these tests. You will need to
record home observations regarding your cat's appetite and attitude. As
additional compensation, your cat will receive free Purina kidney
diet for six months (Purina are
sponsoring the study).
Cats with
a kidney infection
or other uncontrolled systemic diseases are not
eligible for the study.
The study should commence
soon. If you wish to participate, please contact Dr Jessica Quimby at The
Veterinary Teaching Hospital at Colorado State University and ask to be
placed on the waiting list. Her e-mail address is
jquimby@colostate.edu.
Thomas and Indie indulging in their favourite hobby!
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This page last updated: 27 August 2010 Links on this page last checked: 16 January 2008 Copyright Tanya's Feline CRF Website 2000-2010. All rights reserved. You may print out one copy of each section of this site for your own information and/or one copy to give to your vet, but this site may not otherwise be reproduced or reprinted, on the internet or elsewhere, without the permission of the siteowner, who can be contacted via the Contact Us page. If you wish to link to this site, please feel free to do so, and to use the banner ad on the Contact Us page if required. Please make it clear that this is a link and not your own work. I would appreciate being informed of your link. This site is best viewed using Internet Explorer. If you wish to print out the pages, I have found it works best if your margins are set to zero. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
My
cats were not keen on the Beechnut brand. The best food I found in the USA
was Gerbers 2nd Foods Meats. There are six different flavours, Beef & Beef Gravy,
Turkey & Turkey Gravy, Ham & Ham Gravy, Chicken & Chicken Gravy, Veal & Veal
Gravy and Lamb & Lamb Gravy. All my cats liked these foods, and they kept
Indie going when she had largely lost her appetite after extensive dental
surgery. 
