TANYA'S

COMPREHENSIVE GUIDE TO

FELINE CHRONIC KIDNEY DISEASE

 

    

ALL ABOUT CONSTIPATION

 

ON THIS PAGE:


What is Constipation?


Causes


Symptoms


Treatments for Acute Constipation: Suppositories, Enemas and Manual Evacuation


Treatments for Chronic Constipation: Fluids, Slippery Elm Bark, Fibre (Pumpkin, Psyllium), PEG3350 (MiraLAX), Lactulose, Cisapride


Cautions: Hairball Remedies, Mineral Oil


 

Join

Tanya's CKD Support Group Today

 

HOME


Site Overview


What You Need to Know First


Alphabetical Index


Glossary


Research Participation Opportunities


Search This Site


 

WHAT IS CKD?


What Happens in CKD


Causes of CKD


How Bad is It?


Is There Any Hope?


Acute Kidney Injury


 

KEY ISSUES


Nausea, Vomiting, Appetite Loss and Excess Stomach Acid


Maintaining Hydration


The Importance of Phosphorus Control


All About Hypertension


All About Anaemia


All About Constipation


Potassium Imbalances


Metabolic Acidosis


Kidney Stones


 

SUPPORT


Coping with CKD


Tanya's Support Group


Success Stories


 

SYMPTOMS


Alphabetical List of Symptoms and Treatments


Fluid and Urinary  Imbalances (Dehydration, Overhydration and Urinary Issues)


Waste Product Regulation Imbalances (Vomiting, Appetite Loss, Excess Stomach Acid, Gastro-intestinal Problems, Mouth Ulcers Etc.)


Phosphorus and Calcium Imbalances


Miscellaneous Symptoms (Pain, Hiding Etc.)


 

DIAGNOSIS: WHAT DO ALL THE TEST RESULTS MEAN?


Blood Chemistry: Kidney Function, Potassium, Other Tests (ALT, Amylase, (Cholesterol, Etc.)


Calcium, Phosphorus, Parathyroid Hormone (PTH) and Secondary Hyperparathyroidism


Complete Blood Count (CBC): Red and White Blood Cells: Anaemia and Infection


Urinalysis (Urine Tests)


Other Tests: Ultrasound, Biopsy, X-rays etc.


Renomegaly (Enlarged Kidneys)


Which Tests to Have and Frequency of Testing


Factors that Affect Test Results


Normal Ranges


International and US Measuring Systems


 

TREATMENTS


Which Treatments are Essential


Fluid and Urinary Issues (Fluid Retention, Infections, Incontinence, Proteinuria)


Waste Product Regulation (Mouth Ulcers, GI Bleeding, Antioxidants, Adsorbents, Azodyl, Astro's CRF Oil)


Phosphorus, Calcium and Secondary Hyperparathyroidism (Calcitriol)


Miscellaneous Treatments: Stem Cell Transplants, ACE Inhibitors - Fortekor, Steroids, Kidney Transplants)


Antibiotics and Painkillers


Holistic Treatments (Including Slippery Elm Bark)


ESAs (Aranesp, Epogen etc.) for Severe Anaemia


General Health Issues in a CKD Cat: Fleas, Arthritis, Dementia, Vaccinations


Tips on Medicating Your Cat


Obtaining Supplies Cheaply in the UK, USA and Canada


Working with Your Vet and Recordkeeping


 

DIET & NUTRITION


Nutritional Requirements of CKD Cats


The B Vitamins (Including Methylcobalamin)


What to Feed (and What to Avoid)


Persuading Your Cat to Eat


Food Data Tables


USA Canned Food Data


USA Dry Food Data


USA Cat Food Manufacturers


UK Canned Food Data


UK Dry Food Data


UK Cat Food Manufacturers


2007 Food Recall USA


 

FLUID THERAPY


Intravenous Fluids


Subcutaneous Fluids


Tips on Giving Subcutaneous Fluids


How to Give Subcutaneous Fluids with a Giving Set


How to Give Subcutaneous Fluids with a Syringe


Subcutaneous Fluids - Winning Your Vet's Support


Dialysis


 

RELATED DISEASES


Heart Problems


Hyperthyroidism


Diabetes


Polycystic Kidney Disease (PKD)


Pancreatitis


Dental Problems


Anaesthesia


 

OBTAINING SUPPLIES CHEAPLY


UK


USA


Canada


 

SAYING GOODBYE


The Final Hours


Other People's Losses


Coping with Your Loss


 

MISCELLANEOUS


Early Detection


Prevention


Research


Canine Kidney Disease


Other Illnesses (Cancer, Liver) and Behavioural Problems


Diese Webseite auf Deutsch


 

SITEOWNER (HELEN)


My Three CKD Cats: Tanya, Thomas and Ollie


My Multi Ailment Cat, Harpsie


Find Me on Facebook


Follow Me on Twitter


Contact Me


Home > Key Issues > Constipation

 


Overview


  • Many CKD cats suffer from constipation, and treating or preventing it can make a big difference to your cat's quality of life.

  • Which treatments you use depend largely upon how severe your cat's problem is, and whether it is an acute problem or a chronic problem.

  • Obviously the ideal is to prevent constipation from ever happening, but that is not always possible.

  • It is important to keep a close eye on your cat's litter tray and to deal promptly with any signs of constipation or straining.


What is Constipation?


 

Constipation means the cat has difficulty passing a stool. This can actually take many forms:

  • The cat may not pass stool as frequently as before

  • The cat strains in the litter tray

  • Stools are hard and dry

In the most severe cases, the cat does not pass stools at all. Eventually the stool becomes impacted, which is called obstipation.

 

Cats with repeated constipation or obstipation may suffer from reduced motility related to a distended colon which can no longer push stool towards the rectum ready to be passed. This condition is called megacolon.

 

Feline Constipation is a detailed and helpful website about constipation.

International Cat Care has a helpful overview of constipation.

Mar Vista Vet discusses constipation and megacolon.

 


Causes


 

Chronic renal insufficiency and its associated disorders: kitty kidneys and the kitchen sink (2007) Scherk M The 2007 Nestlé Purina Veterinary Symposium on Companion Animal Medicine says "For the most part, constipation is a clinical sign of dehydration." This is certainly a major factor in CKD cats.

 

In addition to concentrating urine, a cat's body also tries to conserve water by reabsorbing it from the stool through the intestinal wall. This mechanism is very efficient, and remains so even in CKD cats, and since CKD cats are largely on the edge of dehydration most of the time, the intestine will wring every drop of water out of the stool that it can, leaving it quite dry. The lack of moisture as a lubricant makes it more difficult for the cat to have bowel movements and can lead to constipation. 

 

Some cases of constipation are caused by low potassium levels or by high calcium levels. Treating these problems may resolve or improve the constipation.

 

Some of the medications commonly used in CKD cats, such as phosphorus binders  or sucralfate, may also cause constipation.

 

Constipation is sometimes caused by external factors, e.g. if you put the litter tray up two flights of stairs and your elderly, arthritic cat finds it hard to get up the stairs to it, or if the tray is where your family dog can disturb the cat in the tray.

 

All bunged up: unclogging the constipated cat (2015) M Scherk Veterinary Medicine discusses the causes of constipation.

 


Symptoms


Some of the symptoms of constipation are pretty obvious, as mentioned above:

  • Frequent visits to the litter tray

    This may sometimes be a sign of constipation but may also be a sign of a urinary tract infection. It may also be a sign of a very serious problem, i.e. the inability to pass urine. I made this mistake myself with one of my cats when I saw this symptom and thought he was constipated when in fact he had a urinary tract blockage (luckily, despite my ignorance, I still got him to the vet in time to save him). If your cat cannot pass urine, this is a medical emergency and you need to go to the vet immediately.

  • Dry and hard stools

  • Straining in the litter tray

You may also see some symptoms which you might not necessarily associate with constipation:

  • Lying in the litter box

  • Loss of appetite

  • An ungainly walk

  • Pooping outside the litter tray

    Perhaps next to it or you will find small bits of poop lying around the house.

  • Vomiting before, during or immediately after using the tray

    Newman Veterinary mentions (scroll down to Constipation) that constipation may cause vomiting because "stretch receptors within the serosa in the colon (or even serosal surfaces of other abdominal viscera) respond to distension and transmit signals to the vomit center of the brain inducing the vomit reflex."

  • Urinating outside the litter tray

    Most people assume this is because of a urine-related problem (e.g. a urinary tract infection) or a behavioural problem, but it can actually be a sign of constipation. My Karma peed on the sofa so I took her to the vet for a suspected urinary tract infection, but in fact she did not have one, her problem was constipation. Once the constipation was under control, her inappropriate elimination ceased. The University of California at San Francisco Department of Urology states "There is a close relationship between the muscles and nerves that control bladder functions and those that control bowel movements. In addition, the bladder and the colon are close together in the body. Large amounts of stool in the colon can put pressure on the bladder which can cause the bladder to not fill as much as it should, or cause the bladder to contract when the bladder is not supposed to contract. This large amount of stool can also cause the bladder to not empty well. All of these problems can lead to daytime wetting, nighttime wetting, urinary tract infections."

  • Diarrhoea

    You see a runny poop in the litter tray so you think (reasonably enough) that your cat has diarrhoea but in fact the true problem is sometimes constipation, and the runny stool is simply what can squeeze around the solid dry stool.

  • Fast breathing and fast heart rate

    One of my cats once had an episode of fast breathing and fast heart rate. He had severe constipation, and his problems resolved once he had been given an enema. If a cat is very severely constipated, toxins can back up in the cat's system causing such problems; pain or discomfort can also cause fast breathing, and severe constipation can be extremely uncomfortable. Alternatively you might see lethargy and fainting, known as vasovagal syncope - syncope means to faint. Medicine Net discusses this.

Obviously you do not want your cat to have such severe constipation that these problems arise!

 

The vet can usually feel the backed-up stool when s/he palpates the cat's abdomen, but sometimes an x-ray is necessary to confirm the problem.

 

Here is a video from Dr Margie Scherk on how to recognise constipation in your cat, courtesy of DVM360.

Here are some links on the different colours, sizes and textures of cat poop. I uploaded these just after eating a rather gooey chocolate brownie. Bad move.

 

Pets Canada

 

Bristol stool form scale for humans but hey, poop is poop.

 

The Cat Doctor Maine

 

Fecal scoring system

 


Treatments


 

Which treatments you use depend largely upon how severe your cat's problem is, and whether it is an acute problem or a chronic problem. Acute problems will usually need treatment at the vet, but you should then hopefully be able to maintain your cat at home with one or several of the treatments described below.


Treatments for Acute Constipation


 

If your cat has obstipation (i.e. the stool is impacted), your vet will have to remove the stool for you.

 

Obviously you want to avoid the need for such treatments if at all possible, but if they become necessary, they do tend to work well and should make your cat much more comfortable. You can then take steps to avoid the need for such treatments in the future.

 

Your vet should be able to tell by palpating (feeling) your cat's abdomen whether your cat is blocked up but this is not always reliable, so an x-ray can also be helpful. 

Feline constipation, obstipation, and megacolon: prevention, diagnosis, and treatment (2001) Washabau R Presentation to the World Small Animal Veterinary Association World Congress has information about rectal suppositories and enemas.

 

Fluid Therapy


Since constipation is associated with dehydration, fluid therapy can help. If your cat is receiving treatment for acute constipation at the vet's, your vet may well put your cat in intravenous fluids to help, or may give a smaller amount of fluid subcutaneously.

 

Suppositories


Paediatric suppositories containing only glycerin are usually safe to give to cats, though of course check with your vet first, and ideally ask your vet to teach you how to give them.

 

I had to use a paediatric suppository on Harpsie once when my vet was not available. It didn't work (he needed veterinary treatment) but it was easier than I expected, and not stressful for either of us.

 

Feline Constipation advises that if you are using a liquid glycerin suppository, after you have squeezed on the bulb to inject the suppository into your cat, you should keep squeezing the bulb until you have removed the tip from your cat.

 

Enemas


Some enemas are not safe to use in cats (see immediately below), but your vet will use one that is safe for your cat.

 

Enemas can be messy so are normally given at the vet's, but some members of Tanya's Support Group whose cats need enemas regularly have been taught how to give them at home. One popular brand in the USA is Feline Pet-Ema, which is designed especially for cats.

 

Medi Vet sells Pet-Emas for US$4.82 each.

Thriving Pets sell the Pet-Ema for US$4.95 each.

Vet Depot sells Pet-Emas for US$5.52 each.

Amazon sells the Pet-Ema for US$7.99 each.

 

Enema Cautions: Sodium Phosphate (Fleet)


Enemas containing sodium phosphate (one common US brand is Fleet) should be avoided because they are extremely dangerous for cats.

 

The Merck Veterinary Manual states "Phosphate-containing enemas must be avoided in cats."

Constipation in cats Duddy J MSPCA Angell says "Do not use enema solutions containing sodium phosphate (Fleet™) as they predispose to life-threatening electrolyte imbalances (hypernatremia, hyperphosphatemia and hypocalcemia)."

Electrolyte abnormalities induced by hypertonic phosphate enemas in two cats (1985) Jorgensen LS, Center SA, Randolph JF, Brum D, Journal of the American Veterinary Medical Association 187 pp1367-8 reports on two cats who suffered severe problems after such enemas, and advises against their use for cats with renal problems in particular.

Troublesome toxicoses in cats (2011) Dowers K Veterinary Medicine explains more about this problem, including symptoms and treatment options should a cat accidentally be given such an enema.

 

Manual Evacuation


If an enema does not work, the stool may be impacted and have to be removed manually by your vet.

 

Water or saline is introduced into the colon while the vet palpates the cat's abdomen in order to break up the mass. Feline constipation, obstipation, and megacolon: prevention, diagnosis, and treatment (2001) Washabau R Presentation to the World Small Animal Veterinary Association World Congress explains more about this and mentions that it can be safer to do this over a period of several days.

 


Treatments for Chronic Constipation


 

If your cat has constipation quite regularly, you want to control it as much as possible, so as to prevent it reaching the stage where it needs veterinary help. If your cat already has obstipation (i.e. the stool is impacted), your vet will have to remove the stool for you, see Acute Treatments, and you can then try to maintain your cat at home. If you are ever concerned though, always contact your vet.

 

All bunged up: unclogging the constipated cat (2015) M Scherk Veterinary Medicine discusses the various treatments available for constipation.


Maintaining Hydration


If your cat is dehydrated, which is quite common with CKD cats, getting the problem under control should help. Indeed, if you don't ensure your cat is properly hydrated, the other treatments discussed below will only be of limited use. Chronic renal insufficiency and its associated disorders: kitty kidneys and the kitchen sink (2007) Scherk M The 2007 Nestlé Purina Veterinary Symposium on Companion Animal Medicine says "primary treatment should address rehydration and the underlying cause of dehydration, rather than stool passage( e.g., with laxatives). Promotility agents, laxatives, osmotic agents, and fiber-enriched diets should be used only after the patient is rehydrated."

 

Please ensure there are plenty of water drinking opportunities available for your cat. Water fountains can be helpful. See Oral Fluids for more information.

 

Also consider feeding canned food in preference to dry foods.

 

Most CKD cats will eventually be receiving sub-Q fluids regularly to maintain hydration, and these may also help with constipation. However, they are not normally given solely to assist with constipation. Please see Subcutaneous Fluids for more information on this treatment.

 


Slippery Elm Bark


Slippery Elm Bark is a natural treatment which can be sufficient to keep some CKD cats regular; there is more information on this treatment in Holistic Treatments

 


Vitamin B12 (Methylcobalamin)


Some people whose cats have megacolon (a bowel disorder which causes severe constipation) have found that giving vitamin B12 in the form of methylcobalamin is a helpful preventative treatment.

 

Methylcobalamin is a popular choice for CKD cats too, and many people find that it seems to help with constipation.

 


Fibre


 

Adding fibre to your cat's diet can help to bulk up the stool so that it moves easily through the cat's system. Fibre-based treatments are intended to help prevent constipation, but they cannot cure it  once it is present, so should not be used if the cat is blocked with faeces..

 

All bunged up: unclogging the constipated cat (2015) M Scherk Veterinary Medicine states "Moderately fermentable fibers such as beet pulp are preferable to a highly fermentable, high-gas-forming fiber source." See Nutritional Requirements for more information on fibre, including beet pulp.

 

Be careful if using additional fibre in diabetic cats, because fibre may reduce blood sugar levels.

 

Some vets in the USA recommend a product called Benefiber. This used to contain a type of fibre called guar gum, but it now contains wheat dextrin. I think there are better choices available for cats.

 

Fibre-Enriched Foods


I have heard from a couple of people that a Royal Canin product, Veterinary Diet Gastrointestinal Fiber Response (the Canadian version is this one) is helping with their cats' constipation. I have not been able to obtain any information on its phosphorus or protein levels as yet, but will try again. The people I have heard from do not feed this food exclusively. 

 

One vet told me that Hill's i/d food can help some cats. The canned version contains 0.8% phosphorus and 40.6% protein on a dry matter analysis, which are not unreasonable levels for most CKD cats.

 

Pumpkin and Other Vegetables


Some  forms of vegetables can be helpful for constipated cats. Popular choices include pumpkin or squash or peas.

 

You can use pumpkin (not the pie filling) or canned peas (with no additives). Many cats seem to quite like the taste of pumpkin, but different brands can contain different types of pumpkin, so your cat may prefer one brand over another. Some people have found Gerber's baby food pumpkin or squash helpful; it keeps in the fridge for about two days.

 

If you cannot find canned pumpkin, you could consider using Applaws Chicken & Pumpkin cat food and see if that helps. I am awaiting details of the phosphorus content of this food. There are a number of other cat foods available containing pumpkin (see Canned Food USA), and many of them seem to have reasonable levels of phosphorus, though unfortunately they tend to have rather high levels of protein.

 

You do not need to cook the pumpkin if you buy the products listed below. You should start gradually, say with half a teaspoon of pumpkin once or twice a day (it can be mixed with food), and increase as needed.

 

You can freeze un-used pumpkin in ice cube trays and just take out what you need for each day, though freezing it can change the texture somewhat.

 

Pumpkin itself is low in phosphorus. According to the USDA National Nutrient Database, pumpkin cooked, boiled and drained without salt contains 0.48% phosphorus on a dry matter analysis basis. Pumpkin canned without salt contains 0.35% phosphorus on a dry matter analysis basis.

 

USA


In the USA canned pumpkin is usually widely available in supermarkets, though there was a shortage in the summer of 2010.

 

Amazon sells Farmer's Market Organic Pumpkin online, as well as other brands, including Libby's.

Vitacost also sells Farmer's Market Organic Pumpkin.

Pumpkin Patch Up! is a pumpkin product for cats from Weruva.

 

UK


Tinned pumpkin can be harder to find in the UK, but some branches of Waitrose and Sainsbury's sell American canned pumpkin with no additives in the canned vegetables aisle.

 

Amazon sells the Libby's brand online in the UK.

 

Psyllium


Psyllium is a fibre-based treatment which is widely available. Uncontrolled study assessing the impact of a psyllium-enriched extruded dry diet on faecal consistency in cats with constipation (2011) Freiche V, Houston D, Weese H, Evason M, Deswarte G, Ettinger G, Soulard Y, Biourge V, German AJ Journal of Feline Medicine & Surgery 13(12) pp903-11 found that a psyllium-enriched diet was effective at controlling chronic constipation in cats.

 

In the USA psyllium is commonly sold under the name of Metamucil. Drugs has some information about this. Be sure not to buy Metamucil Clear and Natural (blue container) because this does not contain psyllium.

 

You may prefer to buy a veterinary product such as Vetasyl fiber capsules. Drugs has some information about this product. The usual dose is ½ to 1 capsule, depending upon the size of the cat. The product can be mixed with food. I don't recommend Animal Essentials Colon Rescue because it contains liquorice, which may raise blood pressure.

 

In the UK, your vet may offer you a standardised pharmaceutical-grade fibre called Nutrifyba. Neals Yard Remedies also sell psyllium husks.

 

If you are using loose psyllium, you only need to give a tiny amount. The maximum dose is ⅛th of a teaspoon, but you should start with an even smaller dose.

 

With fibre-based treatments, it is very important to ensure that the cat drinks plenty of water, otherwise the fibre can bulk up in the body and make the constipation worse. Therefore if you mix it with your cat's food, it is probably wise to add a litttle water too.

 

Be careful how you handle psyllium: Psyllium: keeping this boon for patients from becoming a bane for providers (2006) Hoffman D The Journal of Family Practice 55(9) reports on the case of an asthmatic nurse who died after inhaling psyllium powder, and recommends spooning it rather than pouring it.

 

Too much fibre may prevent your cat from absorbing sufficient nutrients or calories from his/her food. In humans, fibre may also bind calcium in the small intestine and lead to an increase in calcium levels in the body (hypercalcaemia). If you are only giving a small amount to prevent constipation, your cat will probably be fine, but be careful if your cat already has hypercalcaemia.

 

Drugs states that "Psyllium may interact with other medications if given at the same time. This can cause your other medications to become less effective. In general, all oral medications should be administered at least 2 hours before or 2 hours after dosing of psyllium."

 

Pet Education has some information about psyllium use in cats.

The University of Maryland Medical Center explains more about psyllium.

 


Osmotic Laxatives: Polyethylene Glycol (PEG) 3350 (MiraLAX) or Lactulose


 

These work by drawing water into the stool, making it softer and easier for the cat to pass. They are very effective treatments for most CKD cats, but for optimum effect your cat should not be dehydrated.

 


Polyethylene Glycol (PEG) 3350 (MiraLAX)


What is Polyethylene Glycol 3350?


Polyethylene glycol 3350, also known as PEG 3350, is an osmotic laxative which is commonly used in cats. I am sometimes asked about the name: polyethylene 3350 is not the same as ethylene glycol, an ingredient in antifreeze, which is toxic to cats.

 

Both PEG3350 and lactulose (see below) are osmotic laxatives, but unlike lactulose, PEG3350 retains water in the colon rather than pulling it into the colon from the rest of the body. The US National Library of Medicine explains more about how it works.

 

Comparing drugs for constipation (2007) Dean L reports that PEG3350 is more effective than lactulose for treating chronic constipation in humans, and another study, Single and multiple dose pharmokinetics of polyethylene glycol (PEG3350) in healthy young and elderly subjects (2008) Pelham RW, Nix LC, Chavira RE, Cleveland M VB & Stetson P Alimentary Pharmacology & Therapeutics 28(2) pp256-65 found that it started working in some people within a day. Most people using it for their CKD cats seem to like it, finding it easy to give and effective, with no side effects.

 

Another advantage is that it does not have the potential to cause hypercalcaemia (high calcium levels) which lactulose has, plus it is safe to give to diabetic cats.

 

Since PEG3350 is OTC, you do not need a prescription for it, though please do not use it without your vet's knowledge and approval.

 

Polyethylene Glycol 3350 Formulations


MiraLAX is the most widely known brand of PEG3350 in the USA. This is a human brand which only contains PEG3350.

 

PEG3350 is often used in human patients to empty the bowel before an endoscopy. If you use it for this purpose, it may cause an imbalance in the body's electrolytes, particularly potassium and sodium. Therefore some varieties of PEG3350 have added electrolytes to offset the electrolyte imbalances which may result.

 

Since cats are not receiving PEG3350 for this purpose, the added electrolytes are not necessary, and may not be appropriate for CKD cats. Safety and palatability of polyethylene glycol 3350 as an oral laxative in cats (2011) Tam FM, Carr AP and Myers SL Journal of Feline Medicine & Surgery 13 pp694-7 used a version containing added electrolytes, and found that although it seemed to be an effective laxative in cats, it did cause increased potassium levels in some cats. These were not clinically significant, but I would recommend trying to obtain PEG3350 without added electrolytes. If you have to use PEG3350 with added electrolytes, I would ask your vet to monitor your cat's potassium levels.

 

Polyethylene Glycol 3350 Dosage


PEG3350 is a dose to effect medication. Safety and palatability of polyethylene glycol 3350 as an oral laxative in cats (2011) Tam FM, Carr AP and Myers SL Journal of Feline Medicine & Surgery 13 pp694-7 says "Effective doses varied widely in experimental cats, so individualized dosing is important." Since your cat may respond well to the drug, it is better to start off with a low dose and increase only as necessary.

  • Plumb's Veterinary Drug Handbook states "As a laxative (extra-label): ⅛ to ¼ teaspoonful twice daily in food."

  • A common starting dose is ⅛ (one eighth) of a teaspoon per day.

  • If you don't see an improvement in your cat's constipation after three days, you can either give ⅛ of a teaspoon twice a day, or increase to ¼ of a teaspoon once day.

  • If this doesn't work, consider giving ¼ of a teaspoon twice per day.

  • If this still doesn't work, ask your vet about increasing the dose.

In humans, PEG3350 is only supposed to be given for up to seven days, but many humans and cats do use it on an ongoing basis.

 

Polyethylene Glycol 3350: How to Give


PEG3350 under the trade name of MiraLAX comes as an odourless and tasteless powder. Plumb's Veterinary Drug Handbook says the "powder should be dissolved in liquid before using."

 

MiraLAX can be mixed with water, and can be given via a dropper, though some people dissolve it in water and then mix it with baby food or add it to their cat's canned food. Some people just sprinkle it on their cat's food and mix it in.

 

It is not essential to give the day's dose once or twice a day, you can divide it between your cat's meals over the course of a day if you prefer.

 

Polyethylene Glycol 3350 and Kidney Disease Warning


I have been asked why there is a warning on MiraLAX stating that it should not be used in patients with renal failure, particularly since this warning is not on generic products.

 

PEG3350 is often used to empty the bowel before an endoscopy. If you use it for this purpose, it may cause an imbalance in the body's electrolytes, particularly potassium and sodium. Since CKD patients have a tendency towards electrolyte imbalances anyway, this could be risky for a CKD patient. However, when giving PEG3350 to a CKD cat in order to prevent constipation becoming a problem, you are using PEG3350 in a different way which should not affect electrolytes in any way. But of course do check with your vet anyway before using PEG3350.

 

One study, Single and multiple dose pharmokinetics of polyethylene glycol (PEG3350) in healthy young and elderly subjects (2008) Pelham RW, Nix LC, Chavira RE, Cleveland M VB & Stetson P Alimentary Pharmacology & Therapeutics 28(2) pp256-65, found that 66% of the elderly people in the study had mild renal impairment but their bodies did not appear to have any problems processing the treatment compared to the other people in the study.

 

Feline constipation believes the warning "is a caution for humans with a tendency to self-diagnose and self-treat for months without consulting with a doctor, humans who think if a little is good, a lot is better. Provoking the Kitten equivalent of diarrhea by use of any laxative causes water and electrolyte loss which can lead to dehydration which is more risky for those with kidney disease than for healthy individuals."

 

Polyethylene Glycol 3350 and Other Safety Concerns


I sometimes hear from people who are concerned by reports about the safety of PEG3350 when given to autistic children. The FDA investigated the concerns about PEG3350 and concluded ""FDA decided that no action is necessary at this time based on available information."

 

Autism speaks has an interview with the gastroenterologist who was quoted as having concerns about PEG3350 who says "Miralax remains the most-effective medication for many children with autism and severe, chronic constipation. So if you and your pediatrician have worked through other approaches without success, I would still strongly consider using Miralax based upon current safety information. At the same time, however, I strongly recommend that the family and physician work together to find the lowest effective dose. This is true with any stool softener or other type of laxative."

 

Safety of polyethylene glycol 3350 solution in chronic constipation: randomized, placebo-controlled trial (2016) McGraw T Clinical & Experimental Gastroenterology 9 pp173–180 found PEG3350 was well tolerated and appeared to be safe in the human patients in the trial.

 

I know of hundreds of cats who have used PEG3350 over the years, some of them for years, and cannot recall any cats who had problems with it. If you are concerned, talk to your vet about the best way forward.

 

Polyethylene Glycol 3350: Interactions


Drugs mentions a moderate interaction between cisapride, another treatment for constipation (see below) and PEG3350 which I am sometimes asked about. The site states "cisapride can cause an irregular heart rhythm that may be serious and potentially life-threatening, although it is a relatively rare side effect. The risk is increased if you have low blood levels of magnesium or potassium, which can occur with bowel cleansing preparations or excessive use of medications that have a laxative effect. Do not exceed the dose and duration of use of polyethylene glycol 3350 recommended on the product label or prescribed by your doctor."

 

This warning does not concern the ingredients in PEG3350 but rather the fact that PEG3350, when used for bowel cleansing, may also remove electrolytes such as potassium, and this may increase the potential risks of using cisapride. This will not apply to most cats, who are using PEG3350 but not cisapride. Even if your cat is receiving both medications, you are unlikely to be giving PEG3350 in high enough doses for this to be a problem, but discuss with your vet if you are using both products.

 

Polyethylene Glycol 3350 Sources


 

USA


MiraLAX is available without prescription in the USA, so it is widely available from drugstores and supermarkets. Generics are also available, but check that the product you wish to use does not have added electrolytes (see above).

 

Amazon sells it for US$16.98 for 17.9 oz. Other sizes are also available.

 

Thriving Pets sells the same size for US$24.95.

 

UK


MiraLAX is not available in the UK. It used to be available on Amazon but no longer seems to be available.

 

Polyethylene glycol 3350 is widely available under the name of Movicol. Unfortunately Movicol contains added electrolytes (see above).

 

eBay has a seller offering MiraLAX for around US$15 plus US$9 shipping (from the USA). One member of Tanya's CKD Support Group used this supplier with no problems.

 

Thriving Pets sells MiraLAX for US$24.95. They will ship it to the UK but you will have to pay a customs paperwork fee of US$10 and a non US credit card fee of US$5, plus shipping, and any import duties and taxes.

 

Canada


PEG3350 is sold in Canada under the name of RestoraLAX or Lax-A-Day, and is widely available in pharmacies. Generics may also be available, but check that the product you wish to use does not have added electrolytes (see above).

 

Australia


PEG3350 is known as macrogol-3350 in Australia aid should be available in most pharmacies. Brand name include OsmoLax and Movicol. Unfortunately, as in the UK, many of these products seem to contain added electrolytes (see above).

 

VivaLAX appears to contain the active ingredient only, but the product has disappeared from the manufacturer's website, so I suspect if it has been discontinued.

 


Lactulose


Lactulose - What is It?


Lactulose is a syrup of long chain indigestible sugars (derived from lactose, a milk sugar) that pulls water into the colon and softens the stool. The US National Library of Medicine explains more about how it works.

 

Lactulose and renal failure (1997) Vogt B & Frey FJ, Scandinavian Journal of  Gastroenterology Supplement 222 pp100-1 indicated that lactulose may help promote the excretion of BUN and creatinine through the faeces in humans, and some people have found that this effect is sometimes seen in CKD cats; but lactulose is not usually given specifically or solely for this purpose because of the obvious side effects of causing diarrhoea in non-constipated patients. 

 

The British Medical Journal reports on a 2001 study of human patients that indicates that lactulose may also help to prevent urinary tract infections.

 

Drs Foster and Smith have some information about lactulose.

 

Lactulose Dosage


Lactulose is a "dose to effect" treatment, but as with any medication, it is better to start off with a low dose and increase only as necessary, so as not to cause the opposite problem of diarrhoea.

  • Plumb's Veterinary Drug Handbook says that cats may be given 0.5ml per kg (0.25ml per lb) of bodyweight per day up to 2-3 times daily. This would mean a daily total of 1.0-1.5ml per kg or 0.5-1.0 ml per lb of bodyweight.

  • This means you would give a 5kg (11 lb) cat 5.0-7.5ml daily.

  • Some people start at just 0.5ml (per cat) once a day, but this may well need to be adjusted depending upon the cat's response.

  • It does take a couple of days for lactulose to work, so do not give too much too soon.

Lactulose: How to Give


I found out the hard way that, if you syringe lactulose in to your cat's mouth, it's a good idea to wipe your cat's chin with a damp cloth after using it, because, being sugar-based, it is incredibly sticky. You may find it easier to mix the lactulose with food; some people use a little baby food each day for this purpose.

 

Lactulose: Sources


Lactulose is available OTC in Europe, Canada and Australia (one brand in Australia is Duphalac), but it requires a prescription in the USA. 

 

Since lactulose is a prescription item in the USA, it can be rather expensive, but Walmart and Target both sell it for US$4 a bottle.

 

Kristalose


Kristalose is a powdered form of lactulose which can be dissolved in water, which eliminates the stickiness problem found with standard lactulose.

  • Kristalose comes in packets of 10g and 20g. The 10 g packet contains 15 ml of lactulose.

  • Plumb's Veterinary Drug Handbook says that "one gram of the crystals is equivalent to 1.5 mL of the liquid. An anecdotal suggested dose for constipation in cats is ½ teaspoonful (2.5 ml) to ¾ teaspoonful (3.75 ml) twice daily."

  • This is a daily total of lactulose of 5.0-7.5ml a day.

  • This is in line with the standard lactulose dose for a 5kg (11lb) cat. If your cat is smaller than this, discuss with your vet, because as discussed above, many cats may do fine on less than this.

As with MiraLAX, you should mix it with water before giving.

 

If you are giving 7.5ml a day, a 10g packet would only last two days. I heard from one person who used Kristalose for her cat, but she gave up because it was so expensive.

 

Kristalose is available from Vet RX Direct in the USA.

 

Lactulose Side Effects and Interactions


Some people have found that their cats developed hypercalcaemia (high calcium levels) after using lactulose regularly, which then improved when they stopped using lactulose. The same thing occurs in humans: Effect of lactulose on calcium and magnesium absorption: a study using stable isotopes in adult men (2007) Seki N, Hamano H, Iiyama Y, Asano Y, Kokubo S, Yamauchi K, Tamura Y, Uenishi K & Kudou H Journal of Nutritional Science & Vitaminology (Tokyo) 53(1) pp5-12 found that "lactulose enhance the absorption of calcium and magnesium in adult men." You may therefore wish to avoid lactulose if your cat is already hypercalcaemic.

 

Although lactulose is indigestible, it is composed of sugar molecules, so Mar Vista Vet advises against using it in diabetic cats because it may raise blood sugar levels.

 

Antibiotics may reduce the effectiveness of lactulose. 

 

Lactulose may exacerbate the effects of diuretics. Drugs has more information about this.

 

I have heard from a couple of people who found that their IBD cats did not seem to do too well  on lactulose. This may be because, as mentioned in Update on the non-invasive monitoring of intestinal disease in dogs and cats (2000) Batt R Revue Médicine Véterinaire 151(7) pp559-563, more lactulose is absorbed by a damaged gut than by a healthy one. If your IBD cat seems to worsen on lactulose, speak to your vet about switching to another treatment.

 


Prokinetic Medications


 

Most CKD cats with constipation will respond to the treatments outlined above, but some cats may need medications for reduced motility. These medications help stimulate contractions in the colon to move the stool.

Ranitidine (Zantac 75)


Ranitidine (Zantac 75) is commonly used to help treat excess stomach acid in CKD cats. However, it may also help with constipation caused by low motility in the colon, so is certainly worth considering if your cat needs treatment for both constipation and stomach acid. See the link in the first line of this paragraph for dosage.

 

Feline constipation, obstipation, and megacolon: prevention, diagnosis, and treatment (2001) Washabau R Presentation to the World Small Animal Veterinary Association World Congress has information about this aspect of ranitidine.

 

Cisapride (Propulsid)


Cisapride is another medication used for cats with constipation caused by reduced motility. Trade names are Prepulsid or Propulsid.

 

Cisapride works by activating certain muscle receptors. The Merck Veterinary Manual says "Anecdotal experience suggest that cisapride (0.1–0.5 mg/kg, PO, bid-tid) effectively stimulates colonic propulsive motility in cats with mild to moderate idiopathic constipation."

 

According to Pet Education, cisapride was withdrawn from the human market in 2000 because of serious heart-related side effects which caused some human deaths. Rx List has more information about this.

 

However, cisapride appears to be safe to use in cats. The Merck Veterinary Manual says "No significant adverse effects have been reported in cats treated with cisapride at dosages of 0.1–1 mg/kg, PO, bid-tid)." Plumb's Veterinary Drug Handbook states "Adverse effects appear to be minimal in veterinary patients; vomiting, diarrhea, and abdominal discomfort can occur." It does add "Although no reports have been noted in dogs or cats, prolonged QT intervals or other cardiac arrhythmias are possible but unlikely." You may wish to avoid cisapride if your cat has heart problems.

 

Dosage recommendations are as follows:

  • The Merck Veterinary Manual says "Anecdotal experience suggest that cisapride (0.1–0.5 mg/kg, PO, bid-tid):"  bid-tid means 2-3 times a day.

  • Plumb's Veterinary Drug Handbook says: "As a promotility agent (extra-label): Initially, 2.5 mg per cat PO twice daily preferably 15-30 minutes before food. Dosages may be titrated upwards, if tolerated, to as high as 7.5 mg per cat PO 3 times daily in large cats."

Cisapride can take time to work. Plumb's Veterinary Drug Handbook does mention that it can be given in conjunction with lactulose, psyllium or pumpkin, so you can continue to use these treatments while waiting for cisapride to work.

 

Because cisapride was withdrawn from the human market in the USA, cisapride is only available from compounding pharmacies in the USA, though it may be possible to obtain it commercially in other countries.

 

Cisapride interacts with a number of medications, including cimetidine (which according to Plumb's Veterinary Drug Handbook "may lead to increased cisapride levels with an increased risk for cisapride cardiotoxicity" and benzodiazepines such as diazepam (Valium), the effects of which may be made stronger. It also reduces the effects of ranitidine, but since both medications have similar mechanisms, you are unlikely to be giving both cisapride and ranitidine for constipation. If you need to give ranitidine for excess stomach acid, the injectable form may be acceptable.

 

Drugs mentions a moderate interaction between cisapride and PEG3350 (MiraLAX) which I am sometimes asked about. The site states "cisapride can cause an irregular heart rhythm that may be serious and potentially life-threatening, although it is a relatively rare side effect. The risk is increased if you have low blood levels of magnesium or potassium, which can occur with bowel cleansing preparations or excessive use of medications that have a laxative effect. Do not exceed the dose and duration of use of polyethylene glycol 3350 recommended on the product label or prescribed by your doctor." This warning does not concern the ingredients in PEG3350 but rather the fact that PEG3350, when used for bowel cleansing, may also remove electrolytes such as potassium, and this may increase the potential risks of using cisapride. This will not apply to most people using PEG3350 to control constipation in their cats, but discuss with your vet if you are using both products.

 

Drugs states that "Using cisapride together with ondansetron is not recommended. Combining these medications can increase the risk of an irregular heart rhythm that may be serious and potentially life-threatening, although it is a relatively rare side effect." This warning applies to humans, but check with your vet if you need to use both these medications.


Constipation Cautions


 

I don't recommend hairball remedies because they tend not to be particularly effective for chronically constipated CKD cats. I don't recommend mineral oil because it can be downright dangerous.

Hairball Remedies


Many vets seem to routinely prescribe hairball remedies such as Laxatone or Petromalt, but these are really intended for the treatment of hairballs. These products may be of some limited use if given for a short period to try and soften the hard stool often seen at initial diagnosis prior to using other treatment methods, but are not ideal - or particularly effective - for the ongoing constipation problems suffered by many CKD cats. Constipation in cats Duddy J MSPCA Angell says "Hairball remedies are only advised in very mild cases of constipation."

 

In addition, these products may prevent the absorption of nutrients if used longer-term. Pet Education says "May see a decrease in the absorption of fat-soluble vitamins (A, D, E, & K) when used frequently and long term."

 

Mineral Oil


Mineral oil (liquid paraffin) should not be used, because since it has no smell or taste, it can easily be aspirated and cause pneumonia. The Merck Veterinary Manual says "Mineral oil use should be limited to rectal administration because of the risk of aspiration pneumonia with oral administration."

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

 

Back to Page Index

This page last updated: 04 April 2017

Links on this page last checked: 04 April 2017

   

*****

 

TREATING YOUR CAT WITHOUT VETERINARY ADVICE CAN BE EXTREMELY DANGEROUS.

 

I have tried very hard to ensure that the information provided in this website is accurate, but I am NOT a vet, just an ordinary person who has lived through CKD with three cats. This website is for educational purposes only, and is not intended to be used to diagnose or treat any cat. Before trying any of the treatments described herein, you MUST consult a qualified veterinarian and obtain professional advice on the correct regimen for your cat and his or her particular requirements; and you should only use any treatments described here with the full knowledge and approval of your vet. No responsibility can be accepted.

 

If your cat appears to be in pain or distress, do not waste time on the internet, contact your vet immediately.

 

*****

Copyright © Tanya's Feline CKD Website 2000-2017. All rights reserved.

 

This site was created using Microsoft software, and therefore it is best viewed in Internet Explorer. I know it doesn't always display too well in other browsers, but I'm not an IT expert so I'm afraid I don't know how to change that. I would love it to display perfectly everywhere, but my focus is on making the information available. When I get time, I'll try to improve how it displays in other browsers.

 

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 site owner, who can be contacted via the Contact Me page.

 

This site is a labour of love, from which I do not make a penny. Please do not steal from me by taking credit for my work.

If you wish to link to this site, please feel free to do so. Please make it clear that this is a link and not your own work. I would appreciate being informed of your link.