27 | The top 5 things you need to know about canine diabetes
Diabetics are some of the most common endocrine patients we see, and the good news is they benefit from SO much nursing care
However, to give the best care we can, we need to understand how diabetes affects our patients, the signs we see, and how we manage it. If you want to feel more confident advising your diabetic pet parents and really feel like you understand canine diabetes, this episode is for you.
But before we get into that, I have some VERY exciting news for you.
I am SO pleased to announce that I’ll be hosting a webinar to accompany this podcast series, and you’re invited! Join me for a 90-minute session demystifying diabetes on July 10th, where we’ll explore:
How the endocrine pancreas is supposed to work, and what happens when it goes wrong
How diabetes differs between cats and dogs, and why this is important in how we treat and nurse them, and in the advice we give our clients
What signs we see in diabetic patients, the typical findings on their physical examination, and the conditions and lifestyle factors that can cause diabetes
The common tests performed with diabetic patients, how to interpret them, and what they tell us
The treatment options for diabetes and how they differ between cats and dogs - including the different insulins available, how to use new SGLT2 inhibitors for cats, what to feed your diabetic patient, and more
How to monitor your patient’s response to treatment, including advanced monitoring options like continuous glucose monitoring and haemoglobin A1c monitoring
How diabetic ketoacidosis occurs, and how we diagnose, treat and manage this diabetic emergency
The nursing skills we can use when managing diabetic patients
The session will be hosted live at 7.30 pm (UK time), and the recording, quiz and CPD certificate will be available to everyone registered after the event.
I can’t wait for this—it’s the first public webinar I’ve hosted in over a year, and I’m jam-packing it with SO much information—you won’t want to miss it!
Let’s dive into diabetes
Diabetes is, as we know, a common endocrinopathy in dogs. It has an overall prevalence of up to 1.5% across all dogs and is usually seen in older dogs (7+ years).
The most common form of diabetes in dogs is type 1. This is associated with the destruction of or a deficiency in pancreatic beta cells, causing an absolute insulin deficiency. This means that type-1 dogs lose the ability to secrete insulin permanently.
What causes diabetes in dogs?
We don’t know exactly what causes diabetes in dogs, but we suspect it is multifactorial. Around 50% of diabetic dogs have immune-mediated destruction of the beta cells in the pancreas, whereas around 30% have pancreatitis-associated beta cell damage.
The other 20% have varied causes, including a congenital form of diabetes where the pancreatic islets don’t develop correctly or have insulin-resistant diabetes due to things like Cushing’s disease, oestrus or gestation, or the administration of certain medications.
In most cases, canine diabetes is permanent. That’s because most of these patients have an absolute insulin deficiency requiring lifelong treatment. In patients with insulin-resistant diabetes these cases, withdrawing any contributing medications or managing the underlying disease may allow the patient to enter remission - as long as it’s done quickly enough. Long-term hyperglycaemia will result in permanent beta cell damage (known as glucose toxicity), making diabetes permanent.
What signs do we see in these patients?
Polyuria, polydipsia, polyphagia, and weight loss are the classic signs of canine diabetes.
We see polyuria and compensatory polydipsia due to glucosuria, causing osmotic diuresis and polyuria.
We see polyphagia and weight loss due to an inability to use glucose correctly for energy since this process requires insulin. These patients also end up lethargic and weak because they can’t utilise energy normally and are often dehydrated.
Dogs also frequently develop diabetic cataracts, causing progressive visual deficits and blindness.
And if they present with DKA, they’ll have signs ranging from mild-to-moderate dehydration and vomiting to hypovolaemia and collapse - but we’ll cover DKA in its own episode later this series.
So, you suspect your patient is diabetic. How do we diagnose them?
Of course, as nurses and technicians, we won’t be diagnosing these patients, but that doesn’t mean we can’t know how to interpret the results!
We will be performing many of these tests for our vets, and it’s important we know what to look for, especially if you’re dealing with a diabetic emergency and need to intervene quickly.
What tests will we perform?
Depending on the individual patient, we’ll likely perform:
Biochemistry
Haematology
Urine analysis, including culture
Ketone measurement (blood and/or urine)
Venous blood gas (if available)
+/- Pancreatic lipase
+/- Thoracic and abdominal imaging - especially if your patient is anorexic, hyporexic or is a hard-to-stabilise diabetic
Fructosamine
And what do we usually see on our results?
Biochemistry reveals persistent hyperglycaemia, with or without increased liver enzymes and lipaemia (increased cholesterol and triglycerides). Fructosamine, where measured, will be elevated - indicating hyperglycaemia that has persisted for at least 2-3 weeks. Persistent hyperglycaemia is required for diagnosis, alongside glucosuria (but more on that in a second).
Looking at haematology, this can be normal or may show evidence of infection/inflammation or haemoconcentration secondary to changes in fluid balance.
Glucosuria is present on urine analysis. Clinical signs in diabetes are seen when glucose crosses the renal threshold and enters the urine, so we need to have glucose present on our dipstick. Ketones are usually negative but may be present if your patient presents in DKA.
That’s our patient diagnosed - but how will we treat them?
There’s a lot to consider when it comes to treating diabetes. Our primary goal in treating diabetic dogs is to resolve clinical signs while avoiding clinical hypoglycaemia.
We know that nearly all of our dogs will require lifelong treatment and don’t have the ability to enter diabetic remission, but we can still significantly improve quality of life by:
Providing exogenous insulin
Feeding them an appropriate diet to reduce pancreatic demand
Withdrawing contributing medications
Managing contributing conditions
Let’s start by looking at insulin
All type 1 dogs require lifelong insulin, and there are two main options for long-term diabetic dogs (dogs not in DKA) - these are lente insulin (Caninsulin/Vetsulin) and protamine zinc insulin (Prozinc).
Each insulin has a different onset and duration of action, so it can take some trial and error to find the correct insulin and the right dose for each patient. We first need to examine how long these last and how quickly they’ll reach their nadir (peak effect).
Lente insulin is an intermediate-duration porcine insulin given every 12 hours in most cases, though it can be used once daily in some patients. The nadir is usually seen around 4-8 hours after administration.
Protamine zinc insulin is a slower-release, long-acting insulin given every 12-24 hours. The insulin crystallises with protamine and zinc to cause a slow-release formulation.
Other insulins are sometimes used in dogs, but this is typically either neutral insulin in a DKA patient or a very long-acting off-license insulin in dogs who have not stabilised on either lente or protamine zinc insulin.
Where does diet come in?
Nutrition is vital to managing many medical conditions, and diabetes is no exception. We could argue that nutrition in diabetes is especially important since the foods we eat have a direct effect on insulin demand in the body.
Nutritional recommendations also differ between dogs and cats since the pathophysiology of their diabetes differs. So, it’s essential that we, as nurses and technicians, know what recommendations are appropriate for each species.
In dogs, we recommend feeding a complete and balanced palatable diet free of simple sugars. Some dogs show better diabetic control with higher fibre diets since these control glucose absorption from the GI tract and minimise spikes in blood glucose. They also promote weight loss, which enhances diabetic control.
Food choices in diabetic dogs are much less critical than in cats - so with dogs, it’s more important that they eat regularly and in sufficient amounts rather than limiting them to a specific diet.
The timing of their meals is also important since we need to coordinate this with the timing of their insulin injections carefully. In dogs receiving twice daily insulin, we give ½ their daily requirement every 12 hours, coinciding with their injection time. In dogs on once-daily insulin, the requirements are slightly different - we want to give them half their requirement at the time of injection and the other at the time their insulin is at its peak effect (the nadir).
What about nursing care?
So you’ve diagnosed your patient, and now it’s time to think about nursing care. Well, in most of our ‘stable’ diabetic patients, we’ll deliver this care on an outpatient basis, explaining insulin administration and helping with diabetic monitoring.
The veterinary nurse plays a vital role in this process - a new diagnosis is a challenging time for our clients. They’ve just been handed a daily injection schedule and told their pet will need treatment for the rest of their life (in most cases).
It can be really easy for them to see their pet as a patient and for this to interfere significantly with their relationship—and as nurses, we’re often the support, taking away these concerns, helping them to deliver this care at home, and helping them see their pet as a companion again.
So how do we do this?
Let’s start when they’re diagnosed
Get your nursing support early - the discharge is the ideal time for us to be introduced and take the lead in supporting them at home. The diabetic discharge should include:
How to store, handle and administer insulin
A practical demonstration of drawing up and administering insulin, specific to the administration method the client is using (pen or syringe and needle)
How much and how often to feed, and how to time this around insulin injections
Any specific recommendations regarding exercise
Instructions on what to monitor for at home (including providing a diabetic diary or monitoring tool for clients to use each day)
Any first-aid steps to take at home (eg how to spot the signs of a hypoglycaemic episode and what to do if one is suspected)
Any at-home testing you need them to do (eg how to perform urine dipstick testing and what results you expect)
I also like to follow up with a call a couple of days later to see how they’re finding things and provide any additional advice and support needed.
And then don’t let it stop there
The real magic when nursing these patients comes from regular nursing support. Clinics are a fantastic way to do this. Long gone are the days when these patients would only see the vet—the truth is that nurse clinics complement the vet’s consultations perfectly. Seeing both the vet and nurse allows us to provide tailored, individualized care to both the patient and client and help stabilise their diabetes more quickly.
We can provide ongoing support with things like:
Nutrition
Exercise and mobility
Glucose monitoring
Quality of life
Really effectively via nurse clinics. In fact, a couple of the academy members are doing this more and more with their own patients who come in and see them specifically. This has helped their patients and clients, given them tremendous job satisfaction, and made their careers more rewarding.
So there you have it! The top 5 things to think about when managing canine diabetes - first, we need to know how the disease works and how it differs from feline diabetes (which we’ll discuss in our next episode). Then, we need to spot the signs and know what to look for on our examination before thinking about the diagnostic tests we’ll perform. Once our patient is diagnosed, it’s all about treatment (and that’s not just insulin, but things like diet and managing contributing diseases, too) and then providing ongoing nursing care. Nursing care makes a massive difference in the long term, so if you’re not currently offering diabetic clinics, work with your team to start doing them!
Did you enjoy this episode? If so, I’d love to hear what you thought - screenshot it and tag me on Instagram (@vetinternalmedicinenursing) so I can give you a shout-out and share it with a colleague who’d find it helpful!
Thanks for learning with me this week, and I’ll see you next time!
References and Further Reading
AAHA, 2023. Insulins commonly used in dogs and cats [Online] AAHA. Available from: https://www.aaha.org/aaha-guidelines/diabetes-management/treatment/insulin-therapies/
Boehringer Ingelheim, 2023. ProZinc Recombinant Human Insulin [Online] BI Animal Health. Available from: https://bi-animalhealth.com/pets/canine/products/therapeutics/prozinc-for-canines
Caninsulin, 2019. Diabetes Stabilisation Protocol [Online] MSD Animal Health. Available from: https://www.msd-animal-health-hub.co.uk/sites/default/files/content/media/diabetes_stabilisation_protocol.pdf
Caninsulin, 2009. A Guide to Successful Management of Diabetes Mellitus in Dogs and Cats [Online] MSD Animal Health. Available from: https://www.caninsulin.com/offload-downloads/canisulin-technical-brochure/
Kipperman, B. and Rogers, B. 2012. Endocrinology. In: Merrill, L. ed. Small Animal Internal Medicine for Veterinary Technicians and Nurses. Iowa: Wiley-Blackwell, pp. 11 - 68.
Nelson, R W. and Couto, C G. Small Animal Internal Medicine. 5th ed. Missouri: Elsevier Mosby, 2014.
Tabor, B. 2019. Understanding and Treating Diabetic Ketoacidosis. VetFolio, available from: https://www.vetfolio.com/learn/article/understanding-and-treating-diabetic-ketoacidosis
Ward, C. 2019. Nutrition and diabetes mellitus [Online] Today’s Veterinary Practice. Available from: https://todaysveterinarypractice.com/nutrition/nutrition-and-diabetes-mellitus/