Timing is Everything

Key Takeaways

• Consistency in meal portions, insulin doses, and injection timing can make diabetes management more predictable for many pets.
• For pets receiving insulin, meals are generally coordinated closely with injections so owners can confirm that the pet is willing and able to eat.
• Changes in appetite, unexpected glucose readings, or difficulty maintaining a consistent routine should be discussed with your veterinarian.

A friend recently told me that she always comes up with the perfect comeback. Her problem is that she thinks of it 20 minutes too late. Yep, sometimes timing is everything, especially the timing of insulin injections in pets.

When it comes to diabetes care for our pets, timing can make the difference between a well-regulated diabetic pet and a “mostly” regulated diabetic pet. Routines may not be exciting, but routines make for a well-regulated diabetic pet! After two-plus decades practicing veterinary medicine, I sometimes think I have heard it all. Then a client comes along and proves me wrong. Recently, one of my own veterinary clients told me he routinely gave his cat insulin, then waited an hour before feeding his pet. I don’t know where the client got this idea, since I told him what I tell all my clients: feed and give insulin at the same time every 12 hours.

I also hear from diabetic pet owners all the time about what they do. I often hear that they want to feed a variety of foods so the pet doesn’t get bored with the food. I sometimes hear that a client gives the food and then, after some time (or sometimes before), gives the insulin. Sometimes folks give the insulin injections at times other than 12 hours apart. I am sometimes surprised at what folks do.

Because insulin needs can vary by pet, insulin type, diet, and health status, your veterinarian’s specific instructions should always take priority over general scheduling advice.

So, let’s chat about my preferred order of events for diabetic pets and why:

Every diabetic pet is a unique experience. And yet, in general, it is best to give equally portioned meals and equally portioned insulin injections every 12 hours as the norm. That is the ideal. Diabetic cats on tight diabetic control or pets who are tough to regulate may be a different story, but for the majority of diabetic pets, this is my preference. There is less room for error with a routine!

Humans usually ponder what they are going to eat, check their blood glucose, then give themselves a dose of insulin based on their blood glucose level and the type and quantity of food they are about to ingest. Diabetic humans are in control of their actions. And they know how they will likely react to a particular food. Clearly, low-carb foods will affect glucose less than high-carb foods. They know if they feel hungry before they inject themselves. We hope they make good food choices, but they can and will alter their insulin dose based on those food choices. Humans like variety in their food choices. They are in control of their actions and know if they will eat. They have an opposable digit and give themselves insulin injections. Pets can’t do this.

If we wish to minimize the variability of how much insulin to give, we must give the same diet in the same portion repeatedly to pets. Until pets can figure out how to inject themselves, please don’t change your diabetic pet’s diet on a day-to-day basis. Yes, pets do like treats and variety, but they would prefer to “feel good” by having good glucose regulation over a variety of foods.

Now, whether one waits to see if Fluffy is eating before giving the injection is another story. For folks who have a pet with a hearty appetite that couldn’t imagine missing a meal, they may give the injection as the pet dives into dinner. A feeding frenzy is definitely a distraction to the quick poke of an insulin needle. For folks who have a finicky eater, they might watch to make sure the pet truly eats before giving the injection. Nonetheless, I would feed the pet essentially at the same time as the injection rather than waiting any length of time. The insulin needs something to work with. If you don’t give food with insulin, the pet could become hypoglycemic.

How about the timing of meals?

Does it matter if a pet eats in between insulin injections? Yes. Just as giving insulin without food can cause a low blood glucose reading, giving food without insulin will cause an elevated blood glucose test result. If you give a snack in the middle of the day, the blood glucose will likely rise due to the snack.

Different Eating Habits of Diabetic Pets

• Pets can dive into their chow with such gusto that you’d be lucky to get your hand away before setting down the food bowl.
• Some diabetic pets are far more finicky about if and how much they will eat.
• Some pets can have erratic blood glucose numbers and are more difficult to regulate.
• Hard-to-manage pets are so difficult that their humans are forced to check blood glucose every time they feed the pet and adjust the insulin dose based on the appetite.
• The easiest-to-manage pets are very regular and predictable with their blood glucose.
• No two diabetic pets are the same.

If I had my way, diabetic dogs and cats would be fed twice a day with their insulin injections. That sounds all very good on paper, but the truth of the matter is that our pets may have different opinions. Cats especially are notorious for nibbling throughout the day. I joke that in my home pets get the same authority as humans – that it is a “democracy” in the Sutton household. In all honesty, however, the truth is that the cats wear the pants in my family. I have never had a dog boss me around so much as my cats do. If I were to feed my cats a mere two times daily, there would be no end to them telling me about it. My particularly food-motivated cat sometimes looks at the empty food bowl and then looks at me. I’m certain she is thinking, “Human, are you daft?”

My compromise for diabetic pets who think they are constantly starving is to try to get them to eat the majority of their calories at the same time as the insulin injection. For dogs who insist on a mid-day treat, I encourage a low-calorie veggie such as green beans as the snack. For cats, it is the same low-carbohydrate food that they receive as a meal, but hopefully the majority of food is given with the insulin. This stubborn food-nibbling preference of cats is likely why we tend to have greater success with longer-acting insulin for putty tats (i.e. glargine, PZI and detemir). Glargine has a relatively steady action over its duration and has been referred to as a “peak-less” insulin. Most dogs readily accept “meal” feeding twice daily, so we tend to go with intermediate-acting insulin as our first choice, such as Vetsulin and NPH.

If you have a diabetic pet with a healthy appetite, you are lucky! It is a blessing to have a food-motivated diabetic pet compared to a finicky diabetic pet. It makes it much easier to treat the diabetes because it’s easier to predict how much insulin to give. We evaluate the insulin dosage based on periodic blood glucose curves. You probably don’t need to check glucose before each and every injection once your pet is regulated IF you give equal portions and equal doses of insulin every 12 hours and IF your pet’s glucose is predictable. Of course, you must always use common sense.

Speaking of finicky diabetes, why might a diabetic pet not want to eat?

1. Hyperglycemia can cause nausea. If a pet isn’t well regulated, the pet may not be hungry due to nausea. Yes, diabetics are often hungry, but they can be hungry and nauseous at the same time. If I have a diabetic pet patient who isn’t eating well, I often send a prescription for Zofran or Cerenia to see if it helps the appetite. Regularity of appetite makes it so much easier to treat a diabetic pet.
2. Pancreatitis is a common cause of diabetes in pets. The pancreas is, after all, the organ that makes insulin. Pancreatitis causes nausea and abdominal pain. Many diabetic pets have chronic smoldering pancreatitis.
3. Diabetic pets are often immunosuppressed. A high blood sugar level can affect the function of white blood cells, so infections such as kidney or bladder infections could cause a poor appetite.

Above are discussion points with your vet if your diabetic pet is a finicky eater.

Timing of Insulin Injections: Before or After Meal?

Now, do you give the insulin injection before or after the meal? I typically wait to see if a pet will eat before giving the insulin injection. Again, diabetic humans usually give themselves the insulin a few minutes before they eat. The reason we wait until the diabetic pet is eating before we give insulin is actually pretty obvious: we wish to see if the pet will eat. If we give a pet an insulin injection and then the pet doesn’t eat, hypoglycemia may ensue. For good eaters who are well controlled, I will give the injection as the pet dives into the food bowl. For finicky pets, I’ll check the blood glucose and then decide how much insulin to give, taking into account how much the pet eats.

If your pet refuses a meal, vomits, appears weak or disoriented, or you are unsure whether to give the usual insulin dose, contact your veterinarian for individualized guidance rather than changing the dose on your own.

Life sometimes gets in the way of our plans, but do your best to give the injections every 12 hours. Occasionally I hear of clients giving insulin injections 10 and 14 hours apart or 11 and 13 hours apart due to their family’s work and sleep schedule. Strive for 12 hours apart. Consistency is key to diabetes regulation. I encourage consistency of timing of injections and consistency of portions fed. Every family has individual quirks and schedules, but we all do our best for the love of Fluffy.

Have a question or comment? Then post below! I always enjoy hearing from my readers!

NOTE: Consult your veterinarian first to make sure my recommendations fit your pets special health needs.