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> 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.
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 (see below).
There are two considerations with constipation: prevention and treating it if it is present
Obviously the ideal is to prevent constipation from
ever happening, but that is not always possible.
If a cat has an
acute case of
constipation, you will have to use a more powerful treatment.
Cautions
discusses treatments that are usually best avoided.
Causes
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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.
Feline Constipation is a detailed and helpful website
about constipation.
Pets Canada
has information on
the different colours of cat poop.
The Feline Advisory Bureau has a helpful overview of
constipation.
Merck Veterinary Manual has a helpful
overview of the mechanisms by which many of the treatments described below work.
Symptoms
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Some of the symptoms of constipation are:
Some of the
symptoms of constipation are not what you might expect. Occasionally a cat
may urinate outside the litter tray when s/he is constipated - our Karma
peed on the sofa so we 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.
Sometimes a
cat will appear to have diarrhoea but in fact has constipation, and the
runny stool is simply what can squeeze around the solid dry stool.
Harpsie
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.
Newman Veterinary mentions that
constipation may cause vomiting (scroll down a bit).
Treatments for Chronic Constipation
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MiraLAX
How MiraLAX Works
MiraLAX is a human constipation treatment
containing polyethylene glycol 3350, also known as PEG. (This is not
the same as ethylene glycol, or antifreeze, which is toxic to cats).
MiraLAX
was recently made OTC in the USA, and perhaps as a result of this, it is an
increasingly popular treatment for CKD cats in the USA.
MiraLAX is an osmotic laxative like lactulose,
but unlike lactulose, it 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 chronic constipation
(2007) Dean L reports that MiraLAX 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. I am not aware of any
veterinary links about MiraLAX as yet, but most people using it for their
CKD cats seem to have had good
results.
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. In addition,
since MiraLAX is OTC, you do not need a prescription for it, though
please do not use it without your vet's knowledge and approval.
MiraLAX
Dosage
Unlike lactulose, which is a sticky syrup,
MiraLAX comes as an odourless
and tasteless powder which can be mixed with water or food. A common
starting dose is 1/8 of a teaspoon per day, though if you don't see an
improvement in your cat's constipation after three days, you can increase
to 1/4 of a teaspoon if necessary. If this still doesn't work, ask your
vet about increasing the dose. MiraLAX is supposed to be mixed with water,
and can be given via a dropper, though some people mix it with baby food.
You can also divide it between your cat's meals over the course of a day
if you prefer, it is not essential to give the day's dose all in one go.
MiraLAX and Renal Failure 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.
MiraLAX 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 MiraLAX to a CKD cat in order to prevent
constipation becoming a problem, you are using MiraLAX in a different way
which should not affect electrolytes in any way. But of course do check
with your vet anyway before using MiraLAX.
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.
Obtaining
MiraLAX
USA
MiraLAX is widely available in the USA from
drugstores and supermarkets.
UK
In the UK, MiraLAX is not available but it can often be
bought from
Amazon,
though supplier links change often, so if the link I give doesn't work,
search for MiraLAX. The price
varies depending upon the supplier. It is usually shipped from the USA,
so shipping costs can be relatively high.
Other
products containing MiraLAX's active ingredient (polyethylene glycol 3350, or
PEG) are widely available. Two such brands are Idrolax and Movicol. Unfortunately
Idrolax
contains orange oil, which is potentially
problematic, and which is unlikely to appeal to your cat (most cats
find citrus repellent).
Movicol unfortunately contains added
electrolytes. This is presumably to offset the electrolyte imbalances
which may result from using these products pre-endoscopy, but since CKD
cats are not receiving Movicol for this purpose, the added electrolytes
mean this product is unlikely to be appropriate.
There is also another type of polyethylene
glycol available, which is polyethylene glycol 4000, known as Macrogol
4000 and also sold under the Idrolax brand name. As far as I can tell,
this does not appear to contain electrolytes, but since it is also
Idrolax, it may also contain orange oil. In addition, I do not know if
this higher strength is suitable for cats. It might be acceptable given at
a reduced dose, but this is something you would need to discuss with your
vet before using it.
Net Doctor has some information about
Macrogol 4000.
Canada
MiraLAX is sold in Canada under the name of
RestoraLAX, and is widely available in pharmacies.
Australia
Biovea sells MiraLAX in Australia.
Lactulose
Lactulose - How It Works
Lactulose is
a popular
treatment to prevent constipation on
Tanya's CRF Support Group. It 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 is
available OTC in Europe and Canada, but requires a prescription in the
USA.
A 1997 review of renal failure in humans
(Lactulose
and renal failure
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, 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.
Lactulose Dosage
Lactulose is a "dose to effect" treatment, so you should start with a
low dose, and work your way up only if necessary (so as not to cause the
opposite problem of diarrhoea). A possible starting dose is 0.5ml once a
day, but this may need to be adjusted with your vet's approval; Plumb's
Veterinary Drug Handbook says that cats may be given up to 1ml per kg
(0.5ml per lb) of bodyweight per day. It does take a couple of days for lactulose to work, so do not give too much too soon. I found out the hard
way that, if you syringe it 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 babyfood each day for this
purpose.
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.
Since lactulose is so sticky, you might wish to
ask your vet about a new form of it called
Kristalose. This is a powder which can be dissolved in water,
and which therefore eliminates the stickiness problem. I do not know
anybody who has used it for a cat yet, but it is available from
Drugstore or
in smaller quantities 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. You
may therefore wish to avoid lactulose if your cat is already
hypercalcaemic. A possible alternative would be
MiraLAX.
Lactulose is usually of limited use if a cat is so constipated as to have
impacted stool; this may need to be removed by the vet before starting
lactulose.
Although lactulose is indigestible, since it is
composed of sugar molecules,
Mar Vista Vet advises against using it in
diabetic cats.
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.
Lactulose Links
Lactulose - the
manufacturer's website.
Mar Vista Vet
discusses lactulose.
Drs Foster and Smith have some
information about lactulose.
West Shore Endoscopy Center also has information about lactulose.
Fibre
Sometimes it is also necessary to add fibre to your cat's diet in order to
bulk up the stool so that it moves easily through the cat's system. These fibre-based treatments are intended to help prevent constipation, but they
cannot cure it once it is present.
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.
Pumpkin and Other
Vegetables
Some form of vegetables such as baby or
tinned peas or pumpkin (not the pie filling) may suffice. 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.
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.
I sometimes hear from people that pumpkin is high in
phosphorus but that is not the case. 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, but there was a shortage in the summer of 2010; if
this happens again, you could consider trying baby food containing squash.
Amazon sells Farmer's Market Organic Pumpkin
online, as well as
other brands, including Libby's.
Vitacost also sells Farmer's Market Organic
Pumpkin.
UK
Tinned pumpkin is hard to find in the UK, but
some branches of Waitrose and Sainsburys sell American canned pumpkin with no
additives in the canned vegetables aisle.
Cyber Candy sells the Libby's brand online in
the UK.
If you cannot find tinned 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.
Psyllium
A popular fibre-based treatment which is available OTC
in the USA is
psyllium. You only need to
give a tiny amount - the maximum dose is 1/8th 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.
In the USA psyllium is commonly sold under the name of Metamucil, however,
be sure not to buy Metamucil Clear and Natural (blue container) because this
does not contain psyllium.
If you are
in the UK, your vet may offer you a standardised pharmaceutical-grade fibre
called Nutrifyba.
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.
Pet Education has some information about
pysllium use in cats.
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.
Other Treatments
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Fluid Therapy
Fluid therapy can help reduce constipation, but should not be used solely
for this purpose. There is more about fluid therapy and when it is appropriate
to use it here.
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 tratment. See
Food
Composition & Nutritional Requirements for more information.
Ranitidine
(Zantac 75)
Ranitidine
(Zantac 75) is commonly used to help treat excess
stomach acid in cats.
However, it may help also 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.
Feline constipation, obstipation, and megacolon: prevention, diagnosis,
and treatment Washabau RWorld Small Animal Veterinary Association
World Congress 2001 has information about this aspect of
ranitidine.
Acute
Treatments: Enemas and Supppositories
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If at all possible, you want to avoid the need for an enema or manual
evacuation of the bowel by your vet. However, sometimes this becomes a
necessity.
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.
Enemas and Suppositories
Paediatric suppositories containing only glycerin are usually safe to give to cats, though of course check
with your vet first, and ideally get taught how to give them by your
vet. I used a paediatric suppository on Harpsie. It didn't work
(he needed veterinary help) but it was easier than I expected, and
not stressful for either of us.
Enemas containing sodium phosphate
(one common US brand is Fleet) should be avoided because they are extremely dangerous for
cats. See below
for more information. However, there are some enemas which are
safe to use in cats.
Feline Pet-Ema is an enema in the
USA designed especially for cats.
Vet Depot
sells Pet-Emas for US$2.99 each.
Medi Vet sells Pet-Emas for about
US$3.50 each.
Feline constipation, obstipation, and megacolon: prevention, diagnosis,
and treatment Washabau R Presentation to the World Small Animal Veterinary Association
World Congress 2001 has information about rectal suppositories
and enemas.
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 Washabau RWorld Small Animal Veterinary Association
World Congress 2001 explains more about this and mentions that
it can be safer to do this over a period of several days.
Constipation
Cautions
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Cisapride (Propulsid)
You may be offered a drug called cisapride (trade names are Prepulsid or
Propulsid) to treat your cat's constipation, but I would
suggest only using this as a last resort since it has been withdrawn from the
human market because of serious heart-related side effects which have caused
some human deaths.
Rx
List
has more information about this issue in humans
Pet Education
has some information about the implications for animals.
Hairball Remedies
Many vets seem to routinely prescribe Laxatone or Petromalt, but
these are really intended for the treatment of hairballs and are not ideal
- or particularly effective - for the ongoing constipation problems
suffered by many CKD cats.
In addition, they may prevent the absorption of nutrients if used
longer-term. The
Merck Veterinary Manual
has some information about this.
However, such a product may be of use if given for a short period to try
and soften the hard stool often seen at initial diagnosis.
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. If given regularly,
it may also interfere with the absorption of nutrients.
Merck Veterinary Manual
explains more about tha absorption
problem with these products.
Pet Place has more information on
aspiration pneumonia (no nee d to
register to read the article, just click on Close at the bottom of the
registration pop-up).
Enemas
Enemas containing sodium phosphate (one
common US brand is Fleet) should be avoided because they are extremely dangerous for
cats.
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.
The Merck Veterinary Manual also
advises against the use of such enemas.
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This page last updated: 05 September 2011
Links on this page last checked: 29 July
2010
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