Monitoring diabetes in cats
If your pet has been diagnosed with diabetes they will probably need life-long monitoring. Ongoing monitoring is even recommended for cats that achieve remission of their diabetes and do not require insulin for a time. If diabetes is well controlled your pet can live a long and healthy life free from many of the problems that the disease can cause. Your vet will want to see your cat regularly to check on its progress but there are many things that you can monitor at home which will help to provide a complete picture of your cat’s health for your vet. At intervals your vet may want to take blood samples from your pet to see how well the diabetes is controlled. If you have any concerns about any aspect of your cat's treatment, discuss them with your vet.
Why do I need to monitor my cat if it has diabetes?
If your cat has diabetes they are unable to regulate their blood sugar (glucose) levels naturally. Your pet will probably have been prescribed insulin injections or special tablets by your vet to prevent blood sugar levels going too high.
High levels of sugar in the blood can result in consequences which can severely impact your pet’s quality of life. These include the problems you probably first noticed in your pet such as weight loss, drinking excessively and increased appetite. Cats with poorly controlled diabetes also tend to have poor general health and low immunity, which can increase the risk of infections. The presence of diabetes can also lead to complications when a cat develops another health problem, whether it is a simple gastrointestinal upset or something more serious. In that case, diabetic pets may become suddenly very ill with high blood sugar levels and they might develop a condition called ketoacidosis or ketosis. This is a life-threatening emergency and urgent veterinary help might be needed to save your pet’s life. Therefore it is recommended that your pet receives prompt veterinary attention at the first sign of any illness.
Diabetic cats are fortunately not prone to the same long term complications as people with diabetes. However, high blood sugar over a long period of time can lead to reversible neurological damage which can cause weakness.
On the other hand, if blood sugar levels drop too low (this is often called a ‘hypo’), your pet may have episodes of wobbliness, confusion and ultimately could collapse. Some diabetic cats are more prone than others to low blood sugar. The majority of episodes of low blood sugar are associated with no signs or only mild signs; however, in some cases, low blood sugar levels can result in more serious signs of seizures, coma and death.
What can I measure at home?
The most straightforward thing to monitor at home is your pet’s overall general health. Take note of how your cat seems and if they are out of sorts or show any unusual signs or changes in appetite always consult your vet.
If you are able to measure how much your cat is drinking this can provide very useful information for your vet. It is often difficult to accurately measure a cat’s water intake because, if they go outside, they will often drink from ponds and puddles or other water sources in preference to drinking from a bowl at home. However, water consumed at home gives a guide to changes in how much your cat is drinking overall. When you fill your pet’s water bowl in the morning measure how much you put in. If they drink all this in the day record also how much more you have to add. If they don’t drink the whole bowl in one day then the following morning you can measure how much is left and use this to calculate the total volume drunk over 24 hours. Once you know roughly how much your pet normally drinks in a day you can simply provide them with a bit more than that in the bowl each morning and establish a routine of monitoring water intake each day. It will then be very easy for you to spot if they suddenly start drinking more. If your diabetic cat shares the water bowl with other pets, then it is often still useful to measure the volume drunk by all the animals each day. It is not generally recommended to separate the pets to measure water intake. Owners of cats fed wet cat foods often do not see them drink at all. Try to be aware of how often you see your cat drinking - if you notice a change in how much your pet drinks, contact your vet for advice.
Diabetes may start in obese animals but in untreated diabetics there is often weight loss (due to loss of calories in the urine). When you first start treatment your vet will want to get your pet’s weight into an ideal range; therefore thin animals will be fed so that they gain weight, whereas calorie restriction will be recommended for overweight cats. Once their ideal weight is achieved their food intake will be adjusted to ensure that their weight remains the same. If you have scales at home, it is recommended that you weigh your pet on a weekly basis and keep a record of the weight. Your vet will also weigh your pet every time they see them for a routine check, and many veterinary practices have scales in the waiting room and will allow you to take your pet in to regularly weigh them at your convenience. Try to keep food intake the same because any treatment your pet is getting will be closely balanced with their food intake. If, despite the same feeding regimen, you notice a change in your pet’s weight then contact your vet for advice. Weight loss may be an indication that the diabetes is getting out of control, whereas weight gain can indicate that adjustment of the insulin dose and/or food intake is required.
When sugar levels in the blood get very high the sugar starts to spill into the urine. It is helpful for urine samples from your cat to be tested regularly for the presence of sugar (glucose). The results from these samples will help your vet to monitor your cat's progress and ensure that the treatment is correct. When you first start treating your cat with insulin your vet will probably ask you to monitor urine samples regularly and record results from a dipstick test. However, it is even more important to record findings from urine tests in the long term – especially when your pet’s diabetes seems to be stabilized. This is because insulin requirement often decreases in cats once there is good diabetic control, and some cats might even need to stop insulin treatment altogether for a time (diabetic remission).
It can be easier than you might think to collect urine samples in cats! If your cat is happy to use a litter tray then you can get special beads or gravel to use instead of litter when you want to collect a sample and then the urine can easily be collected from the tray. Alternatively, tap water can be added to urine soaked litter, even if the urine patch has completely dried out, to produce a solution that can be tested with a dipstick. There are also test granules that can be mixed with litter that change colour when glucose is present. If you can, collect a urine sample a couple of times a week; this may be done at any time of the day that is convenient. Measure the glucose levels in the urine with a dipstick and record the results in a diary. The dipsticks are not very expensive but, to save money, it is possible to very carefully cut some strips in half long-ways (so that there is still half the detection pad on each stick) which allows you to get 2 sticks for the price of one.
It is important to contact your vet for advice if there are several days in a row when there is no detectable sugar in your cat’s urine. Otherwise take all your records with you to your routine veterinary check-ups.
Depending on the needs of your cat (and how confident you feel) your vet might ask you to take some blood glucose readings at home. These can be made using a simple machine that measures sugar levels in a tiny drop of blood collected using a pin prick on an ear tip. Your vet would show you how to collect the blood and use the machine. The advantage of measuring blood glucose at home is that it allows you to rapidly obtain this information when your pet is unwell or has a problem, and also provides an additional means of monitoring your cat’s progress. An important point is that it is generally not recommended to adjust the diabetes treatment based on single blood glucose measurements.
Continuous glucose monitoring
Monitors that continuously measure interstitial glucose (the sugar content of the fluid immediately below the skin) are also used to monitor diabetes in cats. They typically comprise a small adhesive patch that can be scanned with a reader or smart phone App. The adhesive patch may be applied by your vet, or you may wish to learn how to do this yourself. These monitors can provide a lot of information about your cat’s diabetes. This provides valuable feedback for the owner of the cat as well as for the vet. It is important to work closely with your vet to get the most value from this information as it is often complex.
Why does my vet need to do additional tests?
Your vet will need to examine your pet regularly and review your home monitoring notes to follow their progression. Your vet will be looking to see if the diabetes is currently well controlled, or if it is advisable to adjust the insulin treatment, meals or monitoring methods. However, when they take a blood sample during a routine health check, they can only get a snapshot of the blood glucose levels at that particular time. For example, if the glucose level is high when a blood sample is taken this does not mean that blood glucose levels are not normal or low at other points of the day. The act of taking your cat to the vet can be very stressful and this means that blood glucose measured at the surgery may be much higher than it would normally be at home. Your vet can measure other substances in the blood (such as fructosamine) which give a broad picture of whether glucose levels in the blood have been regularly high over weeks or months and they may run this test at regular intervals to assess your pet’s diabetes.
What is a glucose curve?
Because a single blood glucose measurement only gives a snapshot indication of your pet’s diabetes, it is often recommended to use a continuous glucose monitor, or to take multiple blood samples at regular intervals through the day and view the glucose values on a graph. This creates a ‘curve’ that typically shows blood/interstitial glucose levels rising and/or falling in response to insulin administration To make sure the glucose curve shows what happens in a normal day the normal routine must be followed. This is always complicated if your pet will be hospitalized for the duration of the tests because the environment of the veterinary surgery can trigger a stress response which means the insulin doesn’t work quite as well as normal. Therefore it is usually preferable to generate a blood/interstitial glucose curves at home, when meals and insulin injections are given at the normal times.
How often should testing be done?
Your vet will set a regular pattern of routine visits for you and your pet. This may be more frequent immediately after diagnosis or when problems develop, and then may be reduced to every 1-4 months if your pet’s diabetes becomes more stable.
Diabetes is an illness that will be with your pet for life. However, by carefully monitoring your pet at home you can help your vet ensure that treatment is the best it can be and that your pet is able to lead as happy and healthy a life as possible.