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.
Obviously the ideal is to prevent constipation from ever happening,
but that is not always possible.
Which treatments to use depends largely upon how severe your cat's
problem is, and whether it is an acute problem or a chronic problem.
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.
Constipation is relatively common in CKD cats, but some vets do not seem
to realise this. Survey
of defecation habits in apparently healthy and chronic kidney disease
cats (2022) Jones SE, Quimby JM, Summers
SC, Adams SM, Caney SMA & Rudinsky AJ Journal of Feline Medicine and
Surgery24(2) pp131-141 states "Constipation can be a
significant clinical problem in cats with chronic kidney disease
(CKD)...Under-recognition of subclinical constipation in CKD cats is
likely."
This lack of recognition of the problem can lead to the constipation
becoming acute, which in some cases results in a trip to the ER. Retrospective
evaluation of risk factors and treatment outcome predictors in cats
presenting to the emergency room for constipation (2020)
Benjamin SE & Drobatz KJ Journal of Feline Medicine and Surgery22(2) pp153-160
looked at cats presenting to the ER with severe constipation and says
"cats with chronic kidney disease or previous episodes of constipation
were found to be at increased risk of constipation." Increased age or
obesity were also factors.
(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.
Constipation is sometimes caused by external factors, e.g. if you put
the litter tray up two flights of stairs so your elderly, arthritic cat
finds it hard to get up the stairs to it; or perhaps the tray is where your
family dog can disturb the cat in the tray.
Survey of defecation habits in apparently healthy
and chronic kidney disease cats (2022)
Jones SE, Quimby JM, Summers SC, Adams SM, Caney SMA & Rudinsky AJ Journal
of Feline Medicine and Surgery24(2) pp131-141 states "Causes
include dehydration, electrolyte abnormalities, gastrointestinal
alterations and medications prescribed."
Symptoms
Some of the symptoms of constipation are
pretty obvious, but others may come as a surprise.
Pooping Outside the Litter Tray
Perhaps next to it or you will find small bits of poop lying around the
house. This may also be a symptom of cognitive
dysfunction.
Vomiting Before, During or Immediately After Using the Tray
Survey of defecation habits in apparently healthy
and chronic kidney disease cats (2022)
Jones SE, Quimby JM, Summers SC, Adams SM, Caney SMA & Rudinsky AJ Journal
of Feline Medicine and Surgery24(2) pp131-141 found
that "more cats in the CKD group showed signs of vomiting, vocalising
and straining around the time of defaecation."
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.
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.
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 (click on Types).
Obviously you do not want your cat to have such severe constipation that
these problems arise!
Frequent Visits to the Litter Tray
Other possible symptoms include:
Dry and hard stools
Straining in the litter tray
Lying in the litter box
Loss of appetite
An ungainly walk
Here is a video from Dr Margie Scherk on
how to recognise constipation in your cat, courtesy of DVM360.
Diagnosis
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.
It can be helpful to know what normal stool looks like, so 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.
Emergency Vets USA discuss the meaning
of the different colours of cat poop.
Treatments
Which treatments to use depends 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.
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.
Since constipation is associated with dehydration, fluid therapy may
help. If your cat is receiving treatment for acute constipation at the
vet's, your vet may well put your cat on intravenous
fluids, or may give a smaller amount of fluid subcutaneously.
If your cat eventually receives subcutaneous fluids regularly at home,
this may help with constipation to an extent, though you may well also
need to use some of the other treatments described below.
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.
Some enemas are not safe to use in cats (see Enema
Cautions), 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.
MSD Veterinary Manual states
"Phosphate-containing
enemas must be avoided in cats due to the potential for developing
severe electrolyte imbalances and potentially life-threatening
hyperphosphatemia and subsequently, hypocalcemia, hypernatremia, and
hyperosmolality."
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 chronic constipation, you want to control it as much as
possible in order 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.
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 about 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)
Scherk M 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, is
helping with their cats' constipation. I have not been able to obtain
any information on its phosphorus or protein levels. 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 0.79% phosphorus and 40% 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 canned 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, and 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.
There are a number of cat foods available containing pumpkin (see Canned
Foods 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 canned 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.
If you buy fresh pumpkin, you will need to cook it before use. The
Pioneer Woman has an oven recipe, while A
Pinch of Healthy has instructions for cooking it in an
instant pot.
You can freeze unused 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.
