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, 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 baby food each day for this
purpose.
Since lactulose is a prescription item in the
USA, it can be rather expensive, but
Wal-Mart 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
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. In such cases you could consider using
MiraLAX instead.
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, 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.
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.
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.
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 Sainsbury's sell American canned pumpkin with no
additives in the canned vegetables aisle.
Amazon sells the Libby's brand online in
the UK.
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.
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
psyllium use in cats.
The University of Maryland Medical Center
explains more about psyllium.
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.
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 for
Chronic Constipation
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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
treatment.
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 (2001) Washabau R Presentation to the World Small Animal Veterinary Association
World Congress has information about this aspect of
ranitidine.
Acute
Treatments: Enemas and Suppositories
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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 ask your vet to teach you how to give them. 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, but check with your vet first.
Feline Pet-Ema is an enema in the
USA designed especially for cats.
Vet Depot
sells Pet-Emas for US$2.27 each.
Medi Vet sells Pet-Emas for about
US$3.50 each.
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.
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.
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 the 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.
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.
The Merck Veterinary Manual also
advises against the use of such enemas.
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This page last updated: 05 December 2013
Links on this page last checked: 27 April 2012
