Diabetes in Cats and Dogs: Symptoms, Insulin and Daily Care

Medically reviewed by: Kinga Wojtczak, Doctor of Veterinary Medicine, specialist in canine and feline diseases

Has your cat or dog been diagnosed with diabetes? Are you sure you know everything about it and can recognize the signs of diabetes in your pet? Do you know how to monitor glucose levels, what a blood glucose curve is and how to give insulin correctly? Did you know that a quick response can save your pet from death, and that honey can save its life?

If you don't know the answer to any of these questions, this article is for you!

What is diabetes in cats and dogs?

Diabetes is a systemic disease. It is associated with disturbances in protein, fat and carbohydrate metabolism. The signs are caused by a deficiency of insulin, the hormone produced by the β cells of the pancreas. Diabetes in dogs and cats may also be associated with impaired insulin secretion and insulin resistance of the target organs.

An insufficient amount of insulin in the body causes a cascade of signs:

1. An increase in blood glucose concentration.
2. Acidosis.
3. Without treatment—coma and death.

The disease mainly affects middle-aged and older dogs, more often females—mainly intact or obese ones. In cats, the disease can occur at any age, but in my practice I see that it mainly affects obese female and male cats over 6 years of age. You need to be aware that treatment of diabetes in a dog or cat is lifelong. Whether it involves giving insulin, oral medications or only a change of diet, your pet will always need your special supervision.

Types of diabetes in animals

1. Primary diabetes 1. Type 1 diabetes—insulin-dependent diabetes—results from absent or insufficient insulin secretion due to infection, the formation of antibodies against pancreatic islet cells in autoimmune diseases, or genetic predisposition. It may also be drug-induced (streptozocin) or result from alcohol poisoning or the action of carcinogenic substances. Treatment requires ongoing insulin administration. Insulin-dependent diabetes occurs most often in dogs. 2. Type 2 diabetes—non-insulin-dependent diabetes—is associated with impaired (delayed) insulin secretion and insulin resistance of the target organs. The cause may be a hereditary predisposition, obesity, or the deposition of amylin, which is secreted together with insulin, as amyloid in the pancreatic islet cells. Non-insulin-dependent diabetes occurs most often in cats.
2. Secondary diabetes—develops secondary to an underlying disease, for example: 1. Pancreatitis. 2. Pancreatic tumors. 3. Cushing's disease. 4. Overactive thyroid (hyperthyroidism). 5. Acromegaly. 6. Excess progesterone. 7. Administration of drugs that raise blood sugar levels, for example glucocorticoids, STH (growth hormone), progestins, i.e., contraceptives.

Symptoms of diabetes in dogs and cats

In my practice, I see that the course and nature of diabetes differ between dogs and cats. The initial signs, however, are common to both, and they are often the only ones you are able to notice.

These are:

• excessive thirst (polydipsia),
• increased urine output (polyuria).

If you have to top up your pet's water bowl more often than usual, take it out for walks more often, or change the litter in the litter box more often, these may be the first signs of diabetes in a dog or cat.

Symptoms of diabetes in cats

With feline diabetes, the signs look a little different.

You may notice:

• loss of appetite,
• decreased physical activity,
• less attention to grooming.

The cat's coat becomes dull, the hair looks ruffled, and dandruff may appear on the skin. In advanced feline diabetes left untreated for a long time, diabetic neuropathy may be seen. In this condition, the cat walks abnormally—on the whole foot (a plantigrade stance), which looks a bit like a rabbit's gait, and this is called a "bear foot." In cats I have not actually encountered signs of cataracts, but they cannot be ruled out.

Symptoms of diabetes in dogs

U psów obserwujemy dodatkowo znacznie zwiększony apetyt ale paradoksalnie silny spadek masy ciała. Często właściciele zgłaszają lekarzom spadek formy i kondycji na spacerach. W większości przypadków, które trafiają do lekarza weterynarii i na podstawie której rozpoczynamy diagnostykę cukrzycy u psów, to pogorszenie widzenia. Pojawia się tak zwana zaćma u psa – czyli widoczne białe zmętnienie soczewki.

Diagnosing diabetes in cats and dogs

Worried, you have taken your pet to the veterinarian. Based on the signs you observed at home, together with a physical examination and a glucose measurement in the clinic, a preliminary diagnosis is made: diabetes in a dog/cat. Fortunately, diagnosing diabetes is not particularly difficult. The tests of choice are routine blood work and a urinalysis. In advanced and complicated disease, an abdominal ultrasound is recommended.

Urinalysis

It is best to bring the urine sample in the morning (see how to collect urine from a cat).

The sample will be analyzed, and a result confirming diabetes will show the following on urinalysis:

• glucose in the urine,
• sometimes ketones,
• protein,
• increased specific gravity.

Blood tests

On blood tests, performed after fasting (a minimum of 8–10 h), we always detect an elevated glucose level, and we may see increases in values such as:

• AST,
• ALT,
• ALP,
• urea (BUN),
• creatinine,
• cholesterol,
• fructosamine (which reflects a persistently high blood sugar level over at least the last 3 weeks).

Jeśli ten parametr będzie znacznie podwyższony, a wykluczone zostaną inne choroby metaboliczne mogące prowadzić do wahań cukru w organizmie, to lekarz weterynarii przedstawi Wam możliwości leczenia cukrzycy. Uprzedzi jak wygląda przebieg choroby i możliwe powikłania braku leczenia – a te mogą być bardzo poważne.  Przedstawi plan stosowania insuliny lub doustnych leków przeciwcukrzycowych.  Wyjaśni też znaczenie diety i ruchu a także uprzedzi o ryzyku zbyt wysokiej, lub zbyt niskiej dawki insuliny.  Podpowie jakie objawy w trakcie leczenia powinny budzić Twój niepokój.

Treatment of diabetes in dogs and cats

Diabetic diet for dogs and cats

I hope you realize how enormously important diet is in diabetes. Sometimes proper nutrition can bring about remission of the disease or significantly reduce the amount of medication (insulin) needed. Several companies on the market offer foods for animals with diabetes. They contain a limited amount of simple carbohydrates, more protein and fiber, and an appropriate amount of fat.

All foods for diabetic cats and dogs are made as veterinary therapeutic diets (prescription diets)—you won't find them in an ordinary pet store, because they too should be used under the guidance of a veterinarian.

Remember: there is no point in switching to a food your pet won't even want to sniff. If insulin therapy is being given at the same time, this can lead to hypoglycemia. Any change in food composition should be made carefully and gradually. Many owners use a so-called home-cooked diet. Formulating such a diet for cats or dogs with diabetes is a real challenge, and it is better not to try to put one together on your own.

More and more veterinarians have a solid background in nutrition and, after taking a dietary history, are able to formulate a properly balanced diet for an animal with diabetes. So it is a good idea to ask your veterinarian for advice on diet and feeding amounts for your pet.

Oral treatment

It is mentioned in connection with treating cats, but in practice it does not achieve satisfactory results. The most commonly used drugs are sulfonylurea derivatives, which stimulate insulin secretion by the pancreatic cells.

Insulin injections

Unfortunately, it is most often necessary to start regular insulin injections (once or twice a day) given by the owner.

The most common way to start treatment after a diagnosis of diabetes:

1. Starting insulin dose: 0.25–0.7 IU/kg body weight twice a day.
2. The first blood glucose check is recommended 3–5 days after starting treatment.
3. Performing a daily blood glucose profile, the so-called blood glucose curve—glucose is measured every 2–3 hours, starting with a measurement just before the insulin injection.
4. Adjusting the insulin dose. At the beginning of treatment, the dose must be changed often, as needed and after consulting your veterinarian, by 0.25–1.0 IU per animal.

Insulin treatment for diabetes

There are several types of insulin. They differ in origin (porcine, bovine, mixed, synthetic) and in duration of action. Short-acting insulins (1–8 h) are reserved for in-hospital treatment, while long-acting ones (up to 28 h) are used for daily long-term therapy. In practice, the most commonly used insulins are Caninsulin and Lantus (insulin glargine).

Caninsulin is used as the first-line insulin in dogs, and Lantus (insulin glargine) in cats. Insulin is given once or twice a day, depending on its effect. Your veterinarian will always set the dose and frequency individually for your pet.

• Ultra-short-acting insulins—intended for treating complicated diabetes, in diabetic ketoacidosis (DKA) and at the very start of treatment under veterinary supervision. They are used together with intravenous fluid therapy. Onset of action is seen 15–30 minutes after injection, peak action after 1–4 hours, duration of action 3–6 hours.
• Intermediate-acting insulins—intended for treating uncomplicated cases and for long-term therapy. Onset of action 0.5–3 hours after injection, peak action after 2–10 hours, duration of action 4–24 hours.
• Mixtures of short- and intermediate-acting insulins—intended mainly for patients with marked hyperglycemia after eating.
• Long-acting insulins—onset of action 1–8 hours after injection, peak action after 4–16 hours, duration of action 8–28 hours.
• Insulins between intermediate- and long-acting (lente insulin, Caninsulin)—onset of action < 1 hour after injection, peak action after 2–10 hours, duration of action 6–24 hours.

What should you do if the insulin isn't working?

Your pet is getting insulin, but you don't see any improvement? Your pet doesn't feel better, and the signs are even getting worse? What could be causing this?

1. You are using inactive insulin—it was stored incorrectly or is expired, or the storage temperature was wrong.
2. You are giving the medication incorrectly—for example, the animal runs away and you are not sure whether it went under the skin or into the fur, into the muscle or into fat tissue.
3. The dose is poorly matched to the baseline glucose level.
4. Somogyi effect (rebound hyperglycemia)—despite an appropriate insulin dose, blood glucose drops rapidly and sharply, which leads to the release of stress hormones followed by a large rise in blood glucose concentration. This is a transient condition, often related to the body getting used to insulin; it most often occurs from a week to 3 weeks after starting insulin therapy.
5. Impaired insulin absorption due to excess body fat or severe emaciation of the animal.
6. A dosing frequency that does not match the glucose curve results and the so-called peak action.
7. Excess anti-insulin antibodies, which form in response to the insulin being given.
8. Diabetogenic drugs—e.g., corticosteroids given for skin infections or orthopedic problems.
9. Other metabolic diseases—hyperadrenocorticism (Cushing's disease) and hypoadrenocorticism (Addison's disease).
10. Diestrus  (faza cyklu następująca po rui u kotki lub suki)
11. Infections, especially of the mouth and urinary tract.
12. Hypothyroidism.
13. Kidney failure.
14. Liver failure.
15. Heart failure.
16. Constant stress—new household members, new animals, renovations, moving.
17. Pheochromocytoma.
18. Chronic inflammation, especially pancreatitis.
19. Exocrine pancreatic insufficiency.
20. Severe obesity.
21. Hyperlipidemia.
22. Pancreatic tumor.
23. Diabetogenic drugs—those that raise blood sugar levels—should be discontinued: glucocorticoids, progestins (contraceptives). I also recommend having an ovariohysterectomy (spay) performed in female dogs and cats as soon as possible.

If your veterinarian does not see the therapy and diet working, additional tests will most likely be needed to rule out the factors listed above.

Your pet is responding well to insulin, but you feel something isn't right?

Your veterinarian will probably teach you how to measure glucose from the ear—this is the most reliable and fastest way to check. You will also need this skill to do a glucose curve calmly at home, without stressing your pet at the clinic and thereby skewing the results. So if you notice that an hour or several hours after an insulin injection (most often closer to the insulin's peak action, between hours 4 and 8) your pet is lethargic, vomiting, staggering, not responding to your voice or lying unconscious, the first thing you should do is measure the blood sugar from the ear with a glucometer.

If the result shows H or Ketosis, this means a very high blood sugar level and a risk of hyperglycemic coma due to an excess of glucose circulating in the blood. In this situation, be sure to get to your veterinarian as soon as possible! Your pet's life is in danger. If, on the other hand, the meter shows glucose below 70 mg/dL and you notice the signs described above, you may be dealing with hypoglycemia. In that case, apply dissolved sugar or pure honey to the gums or the lining of the mouth, and measure the blood sugar from the ear again after 5 minutes.

If it has not risen, give a larger amount of honey, or sugar dissolved in water at a higher concentration, and contact your veterinarian immediately.

What do you need to know about treating your pet's diabetes?

You are probably wondering what this glucose curve is and why it is done. A glucose curve is a graph of blood glucose measurements taken over the course of a day. Measurements are taken as needed—typically every 2–3 hours, starting with a measurement before the insulin injection. In some cases it is necessary to measure as often as once an hour. The measurements are taken in conditions that are comfortable for the animal—ideally at home, measuring the glucose value from a drop of blood taken from the ear.

Each measurement is recorded with the exact time it was taken, and the veterinarian then plots blood glucose against the action of the insulin and determines the so-called peak insulin action. This makes it possible to adjust the insulin dose and timing precisely. For example, if according to the curve the insulin's peak action is at hour 3, this means the animal should receive insulin three times a day, or changing the insulin should be considered.

Likewise, if the peak action is not reached by hour 10–12 after the insulin injection (this can happen in diabetes in cats), the insulin should most likely be given once a day. You should agree on every step with the veterinarian who is supervising your pet's treatment!

Food for diabetic pets

When it comes to food, it all depends on how much of it your furry friend eats 😉

A very large bag of food for a dog with diabetes lasts 1.5–3 months for a medium-sized dog.

How do you give insulin to a cat or dog?

Before each injection, the insulin should always be gently mixed, but it must not be shaken.

The most common injection sites in animals are:

• the skin fold between the shoulder blades,
• the thigh fold area.

Your veterinarian will probably explain everything when teaching you how to give the medication at home. Before using insulin for the first time, you should always read the storage and administration instructions.

How can you help a cat or dog with diabetes?

Have you forgotten that exercise means health? Of course, let's not force a pet that has so far been a dedicated couch potato or house sloth into sprints or long-distance runs! Exercise should be introduced slowly and increased gradually—in dogs as longer and longer walks, playing frisbee or playing ball outdoors. In cats, we gradually increase activity through play with toy mice, a laser pointer and wand toys.

Cats that are not afraid of a harness can be tried on walks. This will probably have a positive effect on your whole family.

Remember that diabetes is a disease that, if left untreated, leads to serious complications and ultimately to the death of the animal. Treating diabetes right after diagnosis is a challenge for many owners, but once your initial reluctance about injections and changing your way of life is just a memory, you will soon be enjoying your pet's stable health. Diabetes therapy, its monitoring and watching your pet will continue for the rest of its life. Even if diabetic remission is achieved (as seen in cats), its diet and lifestyle changes will last for the rest of its life.

Remember that when it comes to treating diabetes, your pet's life is literally in your hands. If you are looking for information on this topic, it means you want to help your pet, and that is already 50% of the battle 🙂 I hope that after reading this article you now know how to recognize diabetes in your dog or cat and how you can help. If you have questions about diabetes or want to share your experiences, leave a comment below the article now.

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