Diabetes Mellitus in Cats: A Guide to Treatment at Home

What is Diabetes Mellitus?

Diabetes mellitus is caused by a decreased ability by the body to provide enough insulin, a hormone that is made by the pancreas. Insulin moves glucose (sugar) from the blood and in to the cells (which use it as an energy source). Because the glucose cannot get into the cells, the levels in the body rise and spill over into the urine where it is lost from the body. When the cells are not getting their energy source, the body attempts to make even more glucose, not understanding that it cannot get into the cells. Fat supplies are also mobilised to provide energy.

Cats start to drink lots of water as the loss of glucose into the urine makes them urinate more. They also lose weight despite an increased appetite, because without sufficient insulin, the body is unable to process utilise the nutrients in the food your cat eats.

What are the clinical signs of Diabetes Mellitus in cats?

Diabetes can exist for a while before it begins to make a cat obviously ill. The clinical signs that the cat exhibits may vary depending on the stage of disease, but they can include any or all the following:

Increased drinking/thirst
Increased urination
Urinary “accidents” in the house
Weight loss
Increase or decrease in appetite
Vomiting
Dehydration
Lethargy (tiredness)

Aims of treatment

1) Control the clinical signs

If the clinical signs are well controlled, then it is likely that the diabetes is well-regulated. Unlike humans in which very tight diabetic control is required to prevent complications in the long-term, in cats, if adequate diabetic control is able to be obtained, then the long-term outlook is generally good.
When adequate diabetic control is obtained in cats, their clinical signs return to normal.
The best way to monitor your cat's clinical signs is by observing them at home.
Cats with poorly-regulated diabetes drink a lot of water, eat a lot of food but lose weight.
When cats have well-controlled diabetes, the amount of food they eat and water they drink will naturally drop to a normal amount, and their weight will remain steady or increase to normal values.
We recommend keeping a journal documenting the food intake (e.g. decreased, normal, increased) and water consumption. Ideally, measure your cat's water consumption, but if this is not possible, then describe it as decreased, normal or increased based on how frequently your cat is drinking
If your cat uses a little tray, monitor the number of times your cat needs to urinate as this is an indication on how much your cat is drinking.

2) Prevent hypoglycemia

Hypoglycaemia occurs when the blood sugar drops too low. This can be life-threatening when it happens, and can cause collapse, seizure and death.
For this reason, it is very important that if your pet stops eating or becomes unwell, contact your veterinarian BEFORE giving the insulin. If your cat is not eating, they will not be getting the normal sugars from their diet and that can mean that a normal dose of insulin can be a relative overdose.
If you are ever concerned about whether your cat is tolerating the insulin injections well, it is safer to skip an injection until you hear from your veterinarian on how to proceed.
If your cat goes to a boarding cattery, it is extremely important to pass this information on to the care staff.

3) Remission from insulin

High blood sugar levels can cause further damage to the pancreas, which is an organ responsible for making insulin. In some cats, once the diabetes is under control, the pancreas recovers some ability to make insulin and the need for insulin injections may change.
This may mean that some cats may eventually end up only needing insulin once a day or no longer need insulin injections a all.
If this happens, it is important to remember that the pancreas will never fully recover to normal, and your cat may need treatment with insulin again in the future.
The diagnosis of remission should only be made by a veterinarian.

How to give insulin injections

Insulin can be given using disposable needle and insulin syringe or an insulin injection pen. It is personal preference which one you use. If you would like to switch between the needle/syringe system to the injection pen system or vice versa, please let us know and we will assist you in locating what options are available for your cat.

Draw up the prescribed amount of insulin. For cats, this is usually a very small amount and is often right at the bottom of the syringe – it is such a small volume that sometimes you may question whether you actually gave the dose to the cat! If you are unsure, it is best NOT to give another injection as you could end up overdosing your cat. The starting dose of the insulin will vary from cat to cat and is largely dependent on their bodyweight and pre-feeding glucose levels. Very importantly - use only the insulin needle/syringe or injection pen provided by your veterinarian. This is because there are a number of different insulin needle/syringes and injection pens; and using the wrong delivery system may mean that your cat could receive the wrong insulin dose.
The injection can be given anywhere under the skin. You can rotate locations where you give the injection. Or, if you find that your cat tolerates injection in only one place or if you struggle to give the injection in other places, stick with the place that works for you. If you haven't given many injections before, the easiest place to learn to give them is in the scruff at the back of the neck/shoulder region.
Some people find that it is easiest to give the injection while the cat is sleeping or distracted (e.g. while he or she is eating).
Often cats go through a period where they absolutely detest injections. If you persevere through this, most cats improve.
See the next section on caring for the diabetic pet at home.

Caring for the Diabetic Pet at home

Here are some helpful tips when caring for a diabetic cat at home:-

Always feed your pet and administer insulin at the same time of the day.
Split daily feeding into two meals, approximately twelve hours apart.
Your veterinarian may also recommend a special prescription diet to assist with your pet's blood sugar control.
Offer your pet a meal, ensure that he/she has finished the allocated amount, then give the insulin.

Never give insulin without food, and never give food without insulin.
Always keep the bottle of insulin refrigerated & stored upright.
Ensure you are using the correct insulin syringe for the type of insulin your pet has been prescribed.

e.g. Caninsulin needs to be drawn up with the 40iu/ml insulin syringe, whereas Glargine uses the 100iu/ml insulin syringe.

Date the bottle of insulin on the day you open it, as different insulin products are stored for different lengths of time once opened

e.g. Caninsulin should be discarded 6 weeks after opening; whereas Glargine pens/cartridges should be discarded 28 days after opening.

Ensure that you gently agitate (shake) the bottle of insulin before giving it to your pet.
Before administering the insulin, always check that the colour and consistency of the insulin solution has not changed or have little precipitates "floaties" that do not dissolve upon shaking the bottle lightly - if you are concerned about the appearance of the insulin solution, please check with your veterinary team if it is still safe to be used
When you inject the insulin under your pet's skin, be sure to "suck back" on the syringe to check for blood as the insulin must not be injected into a skin blood vessel. If blood is obtained upon "suck back", withdraw the needle completely and find a different location to administer the insulin.
After administering the insulin injection, feel the skin/coat for any wetness. If you suspect that some of the insulin may have come out during the injection, do not give another dose - make a note of this in your diary and only administer the next insulin dose only when it's due.
Do not change the insulin dose without first consulting your veterinarian.
Bring the used insulin syringes/needles back to us at Cahill’s and we will dispose them for you
Should you accidentally injury yourself with the insulin needle/syringe (that has already been used), please seek immediate medical attention with your family doctor or at an urgent care clinic
Please phone is approximately 1 week in advance to order your pet's next insulin prescription and insulin syringes before they run out.

Summary of appropriate handling and storage of insulin

Always keep the bottle of insulin refrigerated upright
Ensure that you gently agitate (shake) the bottle of insulin before giving it
Before administering the insulin, always check that the insulin solution is clear and colourless. Caninsulin may be a very light white opaque consistency.
Do not administer the insulin if you notice that the colour of the insulin solution has changed, become cloudy or have little precipitates ("floaties") in it. In that scenario, please contact us at the clinic to arrange a pharmacy script for a new bottle.
Always date the bottle of the insulin on the day you have opened it as different types of insulin will need to be discarded after different periods of time once opened.

Diabetic diet and feeding your cat

It is best to stick with a consistent food type to avoid sudden changes in the amount of sugar (carbohydrate) in the diet, as this may alter your cat's insulin requirements.
Your veterinarian can prescribe a commercial-type of food that is lower in carbohydrates and suitable for diabetic cats such as the Hill's m/d diet or Royal Canin Feline Diabetes diet.
For most cats we recommend ad-lib feeding, that is, leaving a bowl of food constantly available and they can help themselves.
If your cat is overweight, we may recommend controlling the amount into dedicated meals to prevent overeating and also to promote weight loss. This is because being overweight can cause insulin resistance, meaning that the insulin doesn't work as well as it should. Therefore, it is important that if your cat is putting on too much weight, do contact your veterinarian about feeding advice.

Monitoring

There are different ways that we can monitor diabetic cats. We will discuss various options with you during your cat's revisits at our clinic; if there are cost constraints we can adjust the monitoring plan to suit your budget. For all at home monitoring options, we can train you how to do these.

1. Observation of clinical signs

As mentioned above, keeping a record of clinical signs at home is very important. This doesn't need to be done every day, several times per week should be fine.
Keep a record of food intake/appetite and water intake (measured if possible). Keeping this record provides us with a lot of important information about your cat's condition.
As your cat's diabetes becomes more controlled, you will notice the water and food intake dropping. A well-controlled diabetic should have a food and water intake similar to a healthy cat.

2. Blood glucose curves

Ideally, before we change the amount of insulin given, we will perform a blood glucose curve to ensure that the blood glucose (sugar levels) do not fall too low. Blood glucose curves can be performed either at our clinic, or at home if you felt comfortable and confident in performing them. At-home blood glucose curves are usually more accurate as they are not affected by stress.
To do blood glucose curves at home, you will need your own glucometer. If you felt comfortable in performing this on your cat at home, do let us know and we can order in a glucometer for you. Obtaining a small blood sample for the glucometer is straightforward; either your veterinarian or veterinary nurse will demonstrate the correct technique to you. A small, sharp prick is made in the ear or footpad with a needle or lancing device, and the blood is used by the machine. There is little pain in taking the samples unless you are doing it very frequently and there is bruising. Samples are taken every 2-3 hours for an 8-12 hour period.
If you are doing a blood glucose curves at home, please provide your veterinarian with the results. Based on the blood glucose cuves, your veterinarian will be able to assess your cat's response to insulin, and whether any dose changes are required.
If you do notice that the blood glucose drops below 3.5mmol/L, contact your veterinary clinic immediately for advice.

3. "Spot" blood glucose

This option is for petswhodo not tolerate a whole blood glucose curve.
A once-off blood glucose measurement can be taken 6-8 hours after insulin administration. This is when we would expect the blood glucose to be at its lowest.
This can be done at our clinic or at home with a glucometer as described above.
Again, contact a veterinary clinic immediately for advice if the blood glucose drops below 3.5mmol/L.

4. Urine glucose strips

These are little dipsticks that can be dipped in urine and it will show a rough estimate of how much glucose/sugar is in the urine.
When there is no glucose/sugar detected on the test strip, it means that your cat's blood glucose is likely consistently low and may indicate that your cat is going into diabetic remission and may need less, or no insulin at all.
Once your cat is on a stable dose of insulin, we may recommend doing urine dipsticks every couple of weeks at home.
To collect urine at home, fill a clean and empty urine tray with a non-absorbable litter. We do sell non-absorbable litter at the clinic that can be reused - please enquire with a veterinary nurse. Alternatively, you make your own non-absorbable litter by shredding plastic bags. This urine can then be collected and used for the test strip.
Note: If you are using reusable cat litter, make sure that you wash it well to remove any residual sugars before you next use it.
If you are getting no glucose on the urine dipstick, contact the clinic for advice as your veterinarian may reduce your cat's insulin dose or discontinue insulin altogether. Your veterinarian may also check your cat's blood glucose or fructosamine (see below) levels to further confirm this negative urine test result before altering the insulin dose.
If you are using urine dipsticks that also checks for ketones in the urine, contact your veterinary clinic immediately if you notice any amount of ketones in the urine.

5. Fructosamine levels

Fructosamine is a protein marker of the mean blood glucose concentrations, and the level of fructosamine in the blood is proportional to the amount of glucose in the bloodstream.
By measuring your cat's fructosamine levels, this provides your veterinarian with information of what your cat's "average" glucose concentration has been over the past 2-3 weeks, and gives us an estimation of how well-controlled your cat's the diabetes is.
Fructosamine can be measured from a single blood test.
The blood sample needs to be taken by a veterinarian at our clinic. We can coincide this test with a revisit appointment.
For most diabetic cats, your veterinarian may recommend measuring fructosamine every 3 – 6 months. We will discuss with you in which the frequency of fructosamine measurements is appropriate for your cat.

Complications of diabetes

Hypoglycaemia

Hypoglycaemia occurs when the blood sugar drops too low.
This is a very serious situation and can cause collapse, seizures and death. In the early stages, cats may just appear lethargic or quieter than usual.
If you have a glucometer at home, test your cat's glucose and if it is less than 3.5mmol/L, apply a sugary solution (e.g. golden/maple syrup, glucose solution) to the gums in the mouth and contact your veterinarian immediately for advice.

Diabetic Ketoacidosis

Diabetic ketoacidosis is a serious and potentially life-threatening complication of diabetes. It occurs when the body produces high levels ketones, of a type of acid in the blood. The condition happens when the body cannot produce enough insulin to keep up with its needs and can happen before adequate control of the diabetes is reached.
Sometimes, the condition can happen in diabetic cats who have previously been well-controlled. When it happens, this is often because there is another disease present that is causing stress hormone levels to rise (e.g. a bladder infection, dental disease, cat fight wounds). The reason why this happens is because stress hormones can cause an insulin resistance, meaning that the insulin is less effective.
If your cat appears unwell, lethargic, weak, or inappetant, please contact your veterinary clinic immediately.
Treatment of diabetic ketoacidosis usually consists of hospitalisation on intravenous fluids and infusions of insulin. Most cats need to be in hospital for at least several days. Any other diseases that triggered the diabetic ketoacidosis also need to be treated.

Peripheral neuropathy

Some cats with poorly-controlled diabetes can get a weakness due to nerve damage.
This causes the back legs to have a very sunken appearance.
Schedule an appointment with your veterinarian urgently if you suspect, or notice that your cat may be having a peripheral neuropathy.

Infections

Cats with poorly-controlled diabetes are predisposed to developing infections. The most common place to develop an infection is the bladder (urinary tract infection).
If you are concerned about your cat's urinary habits, please schedule your cat in for a check over with one of our veterinarians.

Poor diabetic control

It does take time to get to the right dose of insulin. This is because we want to do dosage changes slowly and by small increments to avoid overdosing (which can be fatal), and also allow enough time for the body to respond to the change in dose.
Some cats can have other diseases present which can make getting the diabetes under control very difficult.
If we are not getting adequate control of your cats diabetes, there are additional diagnostic tests that can be performed and there is also the option of referral to a medicine specialist.

Who to contact when concerned about your diabetic cat:

Cahill Animal Hospital is open 7 days a week, except for public holidays.
If you have any concerns, contact us immediately at (06) 3588675 during our opening hours
If your cat becomes very unwell outside our regular hours, phone our clinic number above and follow the voicemail instructions on how to contact the afterhours clinic.

The above information is provided for educational purposes only and not intended or implied to be a substitute for professional veterinary medical advice, diagnosis or treatment; and should not be relied on solely as veterinary advice. If you are worried your pet may have diabetes, please phone us on (06) 3588675 to book them in for a check over.

Published by Cahill Animal Hospital on 01 August 2016

The team at Cahill Animal Hospital is here to provide you and your pet with the best possible medical, surgical and supportive care. Our motto "We care as much as you do" is a very important part of our day to day work. We are committed to providing you and your pet with the best options for care.