"Intravenous" means the
fluids are given into a vein.
As with humans, this
treatment is usually only used in a hospital setting.
fluids are therefore normally reserved for acute situations. In the case
of a CKD cat, this would often be when a cat is severely dehydrated
They may also be used for cats with kidney stones or kidney infections.
Intravenous fluids (IV) are a form of fluid therapy
whereby the fluid is administered via a drip feeding
into a vein (intravenous). If you've ever been in hospital, you were
probably on intravenous fluids, which are sometimes referred to as "a
drip." The fluid used is not simply water, it also contains the correct balance of electrolytes,
which are salts required by the body.
This is a skilled form of treatment, and great
care needs to be taken to ensure the rate of fluid flow is correct for the
cat - too fast a flow can be dangerous (it can overtax the heart), too
slow a flow may not rehydrate
the cat quickly enough.
Because of this, IV fluids are usually only given at the
vet's office, where the cat can be carefully monitored. If you are
giving fluids at home, you are probably giving
not IV fluids.
As explained on the
Fluid Therapy page, intravenous fluids are
often used to treat acute problems e.g. to stabilise
a critically ill animal who has lost a life-threatening amount of body
fluids, perhaps following a road traffic accident. They are also used to
treat cats who are critically ill for other reasons, such as our
George on the left who was extremely ill at this time, but with liver disease, not
In terms of
CKD cats, IV fluids are commonly used for
severely dehydrated sick cats (cats who "crash").
In most cases cats in this situation will have high bloodwork (creatinine
over 550-650, or in US terms over 6 to 7). The IV fluids are being
employed as a kind of flushing through of the kidneys to correct an acute crisis situation of severe dehydration and any resulting electrolyte imbalances, and
to remove toxins from the
IV fluids are also used for cats who have suffered some kind of
acute insult to the kidneys (acute
kidney injury), such as a kidney infection or kidney
In some cases, they may succeed in flushing out kidney stones.
On the other hand, I have heard recently of some vets putting cats
with low or medium level numbers (creatinine around 260-300, or US 3-3.5) on
IV fluids. In most cases this is unlikely to be necessary, because most cats
would not be dehydrated at this level. However, it may be
appropriate if a cat is very dehydrated despite the low bloodwork, perhaps
from vomiting or diarrhoea, and/or has a kidney
infection or kidney stones.
IV fluids are not a suitable treatment for ongoing hydration purposes:
they are too taxing on the kidneys and, since they increase the GFR (see
CKD?), they could accelerate the loss of kidney function if done for
too long; plus of course they entail a stay in the vet's office, which
many cats find very stressful and which is also very expensive.
Fluid therapy for critically ill dogs and cats
(2005) Schaer M Presentation to the 30th World Small Animal Veterinary
Association World Congress discusses the use of IV fluids. This is a
rather technical presentation for the layperson.
the cat feel better i.e. to correct vomiting, lethargy and poor
appetite, which are commonly seen symptoms in a dehydrated cat.
stabilise the kidney values.
The goal is not to lower the bloodwork values as such, but this usually
will happen, because the dehydration is making the bloodwork look artificially
If you agree to
have your cat put on IV fluids, ask for him/her to be put in a quiet area
as far away as possible from any canine in patients. Leave a blanket or an
old item of clothing with your smell on it in the cage to comfort your
How much fluid to give each day and the drip rate (how fast the fluid
flows into your cat) is a complex calculation, based on various factors
such as your cat's weight and the degree of dehydration. Your vet is
trained to do this. If you would like some idea of what might be
Dechra Veterinary Products
has an online calculator for working out an appropriate drip rate
over a 24 hour period.
Most CKD cats stay on IV fluids for 2-4 days. For a severely dehydrated
cat, the first 2-4 hours are used to rehydrate the cat i.e. the severe dehydration is
quickly corrected. Cats stay on IV for longer than this though, usually
for several days: this is the "maintenance" phase which is
designed to give the cat a chance to
IV fluids should not be stopped suddenly, but should be reduced gradually
so as to give the cat's kidneys time to adapt. Most vets will start this
weaning process once there are no longer any improvements in the cat's bloodwork.
This tends to be measured over 1-2 days, so if a cat's creatinine level is
unchanged on Day 3 from Day 2, that is when the vet would start gradually
reducing fluids with a view to discharge probably on Day 4 if the cat
One day on IV is unlikely to be sufficient for most cats to restore hydration
and some degree of balance; so I am growing increasingly
concerned recently at the number of vets who offer just one day on IV, tell
the person their cat's numbers have not improved after that short stint, and
recommend euthanasia. In most cases this is inappropriate in my opinion. Yes,
not every CKD cat can be saved; but euthanasia is an irrevocable decision so
you need to be very sure, and for most people that means giving their cat
every chance. For a severely ill cat, one or two days on IV are simply not
going to be long enough, so I would recommend that you make sure that your cat
is given a reasonable stint on IV of 3-4 days if you can afford it. If your
cat's bloodwork is still improving, your cat may stay on IV even longer,
occasionally cats are on IV for as long as a week.
IV catheters can usually remain in place for 72 hours before there is any risk
of infection; after this, a catheter can be placed in the other paw if
Don't be too
despondent if your cat's bloodwork does not improve after a few days on
IV. In fact, sometimes the bloodwork actually worsens after 1-3 days on IV.
Some vets may recommend euthanasia if this occurs, but don't feel obliged
to agree to this. Further improvement may occur gradually once you take
your cat home and use sub-Q fluids.
Thomas is a good
example of a cat who did not respond dramatically to IV fluids, but they did
help stabilise him, and he continued to improve once he came home. Initially
Thomas was on IV for four solid days and nights, and only began to eat a
little on day 3. He had urea of 89 (BUN: 241) at diagnosis, and it did not
actually improve after four days and nights of IV either. But he was acting
better in himself by the end of the four days, and with home treatments over a
few weeks we eventually reduced his numbers to urea 27 (BUN: 76) and creatinine 316 (US: 3.57), where they stabilised for some months.
Cats on IV fluids need
close monitoring to ensure they do not become overhydrated, which is a
strain on the heart. The cat should be checked once an hour, and heart and
lungs should be checked every 3-4 hours. The cat should be assessed by a
vet at least once every twelve hours and weighed regularly. The following
should be routinely monitored:
the weight of the cat
such as potassium and sodium levels
fluid output (urination)
many American vet offices do not have anybody
their premises overnight, so some of these tests cannot be performed for
several hours, which is
potentially very risky. I personally would not feel at all comfortable leaving
a cat on IV fluids unattended. If your vet recommends IV fluids for your cat,
but s/he would be left alone overnight, a possible compromise is for your cat
to be on IV fluids at the vet's office during the day, but to come home (with
catheter still in paw) overnight. Ideally though, your cat should be on
IV fluids continuously but under supervision.
A litre of lactated ringers contains only around 10 calories, so if your
cat is on IV fluids at the vet's, make sure that s/he is also being fed. Many
practices place food in front of a cat on IV but do not make sure the cat eats.
Your cat will do better if s/he keeps his/her strength up by eating. The vet
may add treatment to the IV fluids against
excess stomach acid, so
ask if this is being done.
Some people believe that they should not visit their hospitalised cat
because the cat may find it distressing. I don't agree with this, I think
it is better for both the cat and the caregiver if regular visits take
place, preferably daily. This also enables you to feed your cat yourself during your visits. The
Persuading Your Cat
to Eat page has tips on getting food into your cat.
When your cat comes home from a session on IV in
hospital, don't expect him/her to bounce back immediately. Most cats are
exhausted - if you've ever been in hospital, you'll know how hard it can
be to sleep well there - so fatigue and lethargy are normal. Your cat will
probably not drink much either - s/he will be well hydrated from the IV
fluid. Many cats hide, which indicates they are not feeling 100%. Give
Most cats need a few days at home convalescing before they
begin to act better.
Appetite may take some time to return, or your cat may
need a little help in this department, perhaps treatment for stomach acid
or an appetite stimulant.
Most CKD cats who have been on IV fluids will need sub-Q
fluids at home if they are to avoid crashing again. You probably won't
need to start sub-Qs as soon as you return home because your cat will be
nicely hydrated from the IV fluids. You will probably need to start sub-Qs
a couple of days after returning home. Bring a few basic supplies home
from the vet, and then check
Supplies Cheaply to find sources for obtaining the supplies you need
If your vet believes IV
is the best treatment for your cat, you should give it very serious
consideration - it really can be lifesaving.