Timing is Everything

By Dr . Joi Sutton|2018-09-07T14:27:54-04:00Updated: August 22nd, 2018|Pet Care, Pet Diabetes, Pet Newsletter|494 Comments
  • Cats and dog eating food

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 of 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 the insulin then waited an hour before feeding his pet. I don’t know where this client got this notion as I had told him what I tell all my clients, to 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 some period of time before (or sometimes after) will give the insulin. Sometimes folks give the insulin injections at times other than 12 hours apart. I am sometimes surprised at what folks do.

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

French Bull Dog with OwnerEvery diabetic pet is a unique experience. And yet, in general it is best to give equally portioned meals and equally portioned insulin injection every 12 hour 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 potential for errors when there is 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 the glucose less than a high carb food. 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 food is not given with the insulin the pet could become hypoglycemic.

How about the timing of meals?

The timing of insulin injection with cats and dogDoes 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 Pet

  • Pets can dive into their chow with such gusto you are lucky to get your hand away before setting down the food bowl.
  • Some diabetic pets are more finicky about if and how much they will eat.
  • A pet 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 a blood glucose every time they fed the pet and adjust the insulin dose based on the appetite.
  • The easiest to manage pets are very regular and predictable regarding 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 a 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 as 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 demetir). 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 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. 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 a 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 diabetics, why might a diabetic pet not want to eat?

The Timing of Insulin Injections

  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 of Zofran or Cerenia to see if it helps the appetite. Regularity of appetite makes it so much easier to treat a diabetic pet.
  2. Additionally, pancreatitis is a common cause of diabetes in pets. The pancreas is, afterall, 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 can affect the function of white blood cells, so infections such as kidney or bladder infections could cause a poor appetite.

The 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.

Life sometimes get is 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.

About the Author: Dr . Joi Sutton

Dr. Joi Sutton is a 1993 graduate from Oregon State University. She has practiced both in emergency medicine and general practice. Dr. Sutton has done extensive international volunteer work though Veterinary Ventures, a nonprofit organization that takes teams of veterinarians to undeveloped countries for humane medical care. She also runs a small animal practice in South Florida. Connect with Dr. Joi on LinkedIn

494 Comments

  1. Kevin March 20, 2024 at 7:29 pm - Reply

    We have a 7 1/2 year old beagle mix, diagnosed 10/23. Started at 6u humulin n up to 11 now. Food was science diet 7yr old now on the diabetic version. Since switching food and going back to 11 u from 12 u her numbers are better but she still spikes just before meals, like 300 to off the scale. Comes down gradually shortly after meal / insulin. I can share the graph if I can upload. All she eats is her food at 7 and 7 with insulin right after or maybe with the meal, she’s a good eater. Any idea on the spikes before she eats?

    • Dr . Joi Sutton March 25, 2024 at 7:59 pm - Reply

      It sounds likely that the insulin just isn’t lasting the full 12 hours which is common for humilin N. How we adjust a dose is based on the “nadir” (where the blood glucose bottoms out). If She spends a lot of time with elevated blood glucose your vet might consider changing to a longer acting insulin. Different pets metabolize different insulins at different rates. This unique response by each pet is why we do blood glucose curves. Do share the curve with your vet who has examined your sweetie.
      Remember, if you have a pet who is having a blood glucose spike you can always take your pet for a walk to lower the blood glucose. One habit we should all do (diabetic or not) is to take a walk after a meal. Our muscles utilize the glucose from the meal and help blunt a spike after eating. If I had a diabetic dog I would feed at the time of the insulin injection then after each meal take the pet for a 15 to 20 minute walk to help blunt the blood glucose spike. It is a good habit for the diabetic pet owner, too! (Of course not all folks have the luxury of doing this with our busy schedules.)
      It sounds like you are doing a great job!! 🙂 Joi

  2. Stacy February 14, 2024 at 10:55 am - Reply

    My Shizu Chihuahua mix dog was diagnosed with diabetes about a month ago and I’ve been really good about feeding him 12 hours apart and injecting him during is meals (he’s food motivated). However, he’s now “caught on” that a shot is coming while he eats and it’s impossible for me to give it to him now. I’ve switched it up and injected him during and then right after his meals but I’m out of options now. I live by myself and don’t have anyone to help keep him still.
    Any suggestions? Distracting him with a toy is not an option, he’s just too smart.

    • Dr . Joi Sutton February 18, 2024 at 5:24 pm - Reply

      Hmmmm. This is a tough one. The injection at the time of the meal is the best, but chihuahuas are smarter than the average bear! I’m sure you’ve thought of asking a neighbor for help. If he doesn’t like the injection and is wary of you, he’ll soon catch on to a soft muzzle as well. You could wrap him in a big blanket and give the injection into a hind leg—away from his mouth if he is being nippy. Be sure to rub the area of injection before and after the injection so that the injection doesn’t hurt so much.
      Ask your vet who has met your doggy. Injecting during the meal is usually the best way to distract a food motivated pet. Do chat with his veterinarian.

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