Diabetes in cats and dogs

Diabetes is the most common hormonal disease in pets.  It is caused by a lack of insulin in the body which results in very high blood sugar levels.  It is more likely to occur in older, overweight pets and the primary symptom is an increase in their drinking.  It is treated with daily insulin injections and for well controlled patients, the prognosis can be very good and they can lead a normal life.  

What is Diabetes?

• There are actually two forms of Diabetes, Diabetes Mellitus and Diabetes Insipidus.  Diabetes Mellitus is by far the most common and the one we will be discussing here.
• It is caused when the pancreas, an organ in the abdomen, stops producing the hormone Insulin.
• Insulin allows glucose to move out of the blood stream and into the rest of the body tissues. Without it the glucose is unable to leave the blood and so the levels become very high.
• There are two kinds of Diabetes Mellitus; Type One and Type Two
• Type One is more common in dogs. It occurs when the pancreas is faulty and stops all insulin production.  It can occur in younger animals who have a congenital fault with the pancreas and it is irreversible.
• Type Two is more common in cats and older, overweight animals.  It occurs when the body becomes resistant to the effects of insulin and despite the fact the pancreas is still producing it, the blood glucose levels do not fall.  It can be reversible if the things which have caused it, such as obesity or a high fat diet, can be reversed.  It is very similar to Type 2 diabetes in people, which is more common if a person is over-weight.

What are the symptoms of Diabetes?

• The main symptom of  Diabetes in cats and dogs is an increase in drinking and urination.  Often this can be very dramatic with the animal drinking several water bowls a day and having urinary accidents in the house.
• The normal water intake for a pet is 50ml water per kilo of weight per day.  Diabetic pets will drink far in excess of this.
• Diabetic pets will often have a big appetite and seem hungry all the time. As the sugar cannot move out of the blood and into the body, the body is effectively starving and so gives signals to the animals to eat more.
• If Diabetes is left untreated for a long period of time, the animal can become very thin as the body uses up its fat and muscle reserves for energy.
• Dogs with this disease are very vulnerable to developing cataracts.  These cause the lenses in the eyes to go white and leads to blindness.  They cannot be reversed but surgery can be performed to remove them.
• Some cats with Diabetes develop what is know as a 'Plantigrade Stance'.  The back legs become weaker and the cat will walk with their hocks almost touching the ground, making them look very flat footed.  It often corrects when the disease is brought under control.

How is Diabetes diagnosed?

• The mainstay of diagnosis for Diabetes Mellitus is blood and urine tests.
• In a normal animal, the blood sugar levels rarely rise about 10mmol/l but in a diabetic pet they can reach 20mmol/l or greater.  A high blood sugar level is usually diagnostic for Diabetes but most vets will run other tests as well.
• Other changes that can be seen on blood tests include high liver enzymes, the liver has to try to process all the extra sugar in the blood which puts it under extra strain.  These usually settle down once the Diabetes is under control.
• Most vets will also test an animals urine.  Diabetic pets will have high levels of glucose in their urine as well as their blood and this helps to confirm the diagnosis.  They are also prone to bladder infections (the high sugar levels make it easy for bacteria to survive) and dip stick urine tests will also pick up on these. 

Treating Diabetes

• The vast majority of Diabetic animals are treated with regular, either once or twice daily, injections of insulin.
• In dogs this treatment is usually life long but in cats, especially if it is combined with a controlled diet and weight loss, the disease can go into remission and the insulin is no longer required.
• All Diabetic pets will also need their food intake carefully controlled and, in the case of dogs, their exercise as well.
• Entire female dogs should be neutered as soon as their condition is stabilised.  The hormone fluctuations which occur when they are in season will affect the action of insulin and can cause their Diabetes to become uncontrolled.
• There are tablets called 'Oral Hypoglycaemics' which can be used to lower the blood sugar levels.  However, they are not often used as they don't tend to be very effective and rarely negate the need for the animal to be injected with insulin.

Insulin is the mainstay of treatment for Diabetic pets, most will need injecting with it once or twice daily.  This can seem like a daunting task at first but really it is fairly easy and with practice, most people find it no problem at all. It is always worth looking at cover for life pet insurance policies to help cover the costs of treatment of long term illnesses such as diabetes

Injecting your pet with insulin

• Your vet will give you the dose of insulin your pet needs.  It is in 'International Units' IU, rather than mls.  This dose will start fairly low and then usually rises as your vet monitors your pet's condition and changes the doses accordingly.
• The insulin syringe has graduations printed on the barrel, so drawing up the correct dose is easy. Sometimes, they can be quite small but some makes of syringe come with a magnifying glass which can be attached or in lower volumes where the graduations are more spread out.
• The needle of the insulin syringe is tiny, your pet will hardly feel it, so you mustn't worry about hurting them.
• It is very important, especially in dogs, that the animal has eaten before the injection is given. So, one good tip is to inject your pet while their head is in the food bowl!
• Your vet will be able to talk you through the injection process, show you to how to do it and also let you practice.  Many will clip the hair from the back of your pet's neck, this is helpful in the early stages while you learn to inject the insulin as it means you can see the skin you are injecting without the fur being in the way.
• It is important that the insulin is stored in the fridge and discarded once it has been open for 30 days.  Some types of insulin are available in small volumes, which is more economical for little dogs or cats who are on low doses, as you do not have to throw away nearly full bottles of medication.
• Once the insulin syringe has been used (and if your pet is on twice daily injections the same needle is usually used for both), it should be safely disposed of in a medical sharps bin. Your vet will be able to supply you with one of these. 

Feeding a diabetic pet

• Getting the diet of a diabetic pet right is almost as important as their insulin injections and have have a huge impact on the control of their disease.
• Dogs, like humans, have a spike in the blood sugar soon after they have eaten.  This means it is important to match their meals to their insulin, so it is active in the system when it is needed the most.
• Dogs who have twice daily insulin injections should be fed just before they are injected.  Dogs who have insulin only once a day should be fed one third of their food after the injection and the rest 8 hours later, when the insulin should be at its peak in their system.  For this reason, most dogs given once daily insulin should be injected in the morning.
• It is very important that the dog has eaten (or is eating) before they are injected.  If they are injected and then they don't eat, the sugar levels could fall dangerously low.
• Diabetic dogs should not be allowed any treats or snacks between their meals as these will affect their blood sugar and make the control of the Diabetes more difficult.
• Cats are different in the way they process the sugar from their diet and they don't have the post-eating spike in blood glucose like dogs.  This means it is not as vital to ensure they have eaten before their injection.
• However, it is important they do eat at some point to ensure their blood sugar levels do not fall too low.
• Cats are naturally grazing feeders and would rather nibble on food regularly through the day rather than eating meals, so the easiest way to feed a Diabetic cat is to leave a bowl of dry food available all day.
• Like dogs, it is important in cats that the food intake is consistent, so it is a good idea to weigh or measure the food daily.
• Diabetic cats are often over-weight, which is a big factor in triggering the disease, so putting them on a controlled diet and getting some weight off can be very helpful and, in some cases, even put the Diabetes into remission.
• There are commercially prepared Diabetic diets for both cats and dogs on the market, your vet will be able to discuss these with you.  They can be very helpful for promoting Diabetic remission in cats and lessening the insulin doses required in dogs.

Exercise

• In Diabetic pets, their levels of daily exercise should be consistent.  Exercise will use up the glucose in the animals system and lower the levels. So, to ensure their condition remains controlled, their daily exercise levels should be the same.
• This is only really relevant to dogs.  Cats will regulate their own exercise levels, generally doing very little indeed!

Monitoring Diabetes

• It is very important that a Diabetic pet is regularly monitored, especially in the early stages of the disease when your vet will be deciding on the correct dose of insulin for them.
• The best way for your vet to monitor your pet is to perform a 'Glucose Curve'.
• This is a simple procedure which involves taking regular blood tests over a 12 or 24 hour period and tracking how the blood glucose levels change.
• These are usually performed in the surgery but can, with practice, be done at home.
• Your vet will be particularly interested in the 'peak' (highest) and 'trough' (lowest) levels of blood sugar.  They will be aiming to maintain the levels between 9 and 15mmol/l and if they are going above or below this  then it is likely the insulin dose will need to change.
• During the initial period after diagnosis these curves are likely to be run every 2-4 weeks to ensure the right dose of insulin is used but once the animals condition has stabilised, most pets only have a curve every 3-4 months.
• Another monitoring blood test measures the levels of Fructosamine in the blood.  This is an indicator of the average blood sugar levels over the previous 2-3 weeks and can be useful in patients who find glucose curves too stressful.  However, it is not a substitute for glucose curve, which is by far the most useful test.
• It can also be helpful to take regular urine samples from a Diabetic pet, but it is important it is remember it is normal for them to have low levels of sugar in the urine.  What is of more use in urine testing is monitoring for urinary infections.  These are common in Diabetic animals and can destabilise their condition, so it is important they are picked up on quickly. 

Diabetic Complications

• The two most important, and potentially life threatening, complications to Diabetes are when the blood sugar goes either too low or too high.
• Hyperglycaemia is when the sugar levels in the blood are too high.  The body is very tolerant of high blood sugar and the animal can survive without any problems for a while but if the symptoms of Diabetes are not picked up on quickly, or are ignored, then the animal can go into 'Ketoacidosis'
• Ketoacidosis is a very serious problem and can be fatal.  The main symptoms are a huge water intake and urine out-put, lethargy, an inability to stand or walk properly, vomiting and collapse.
• Affected pets should see a vet immediately where, once the diagnosis has been confirmed, they will start treatment to quickly lower the blood sugar levels.
• Hypoglycaemia occurs when the blood sugar levels fall too low.  The body is less tolerant of this and low blood sugar will cause problems more quickly than high blood sugar.
• Signs of Hypoglycaemia will include; weakness, lethargy or a staggering walk, collapse and a coma.
• Causes of Hypoglycaemia are often related to the insulin treatment.  Often they are caused by the pet giving too much insulin, or being injected despite the fact they didn't eat.  Episodes can also be triggered by over-exercising in dogs.
• Affected pets should be taken to the vets immediately but you can act to raise the blood sugar at home by rubbing honey on their gums or syringe feeding them an oral glucose solution.

Owning and caring for a Diabetic pet is demanding but it is also hugely rewarding. In the early stages after diagnosis there can seem to be a lot of testing and trips to the vets but once the disease is under control and you are comfortable with injection your pet, it is fabulous to see them get better and become their old selves again.  It is a condition where you should develop a close relationship with your vet and always call them if you are at all concerned or have any questions.