What To Do With Insulin When Your Diabetic Pet Is Vomiting Or Not Eating

By |2018-06-21T15:38:10-04:00Updated: June 25th, 2015|Pet Care, Pet Diabetes, Pet Diet & Nutrition, Pet Newsletter|10 Comments

Once you have your diabetic pet regulated on insulin it’s smooth sailing, right? Well, not necessarily. Even a well-regulated diabetic doggie may mischievously get into the trash and subsequently vomit. Or Fluffy might toss up a random hair ball. Just because your pet is diabetic doesn’t mean it can’t have a dietary indiscretion or gastroenteritis the same as non-diabetic pets!

Even if you are new to having a diabetic pet, if you understand the basics of diabetes (most importantly that insulin drops the blood sugar levels) you can work your way through a short-term treatment plan. You know that insulin allows sugar (from the food we eat) to enter our cells. Without food, giving the usual dose of insulin could drop the blood glucose to dangerously low levels. However, if the blood glucose is still quite elevated, you might consider giving a lesser dose of insulin even if a diabetic won’t eat. You know your pet… Some have a sensitive stomach whereas others might have the constitution as sturdy as a goat. Some have ravenous appetites whereas other pets may be finicky. None of us have a crystal ball when it comes to predicting if a pet will vomit more.

Not eating and vomiting are both situations that put us in the same boat in regards to insulin dosing. No food in the tummy means there is nothing for the insulin to utilize. Of course, vomiting is worse than simply not eating because we don’t know why the pet is nauseous nor if there will be more vomiting to follow. Not eating may simply be that a pet isn’t hungry.

Obviously you need a good relationship with your veterinarian to help you work through contingency plans for these situations, but I want you to understand in general what we might do. Of course making choices to alter the insulin dose mandates that you have a blood glucose meter at home. I think the vast majority of our readers do have a blood glucose meter for their pets. You likely use it to run periodic blood glucose curves so that you and your vet can evaluate your pet’s insulin dose and recommend the usual insulin dose for your pet. However, if your pet doesn’t eat or if your pet eats and then vomits, you can use the meter to run a spot check of the blood glucose.

Here’s where the tricky part comes in: Just how much less insulin shall we give if a pet doesn’t eat or if a pet vomits? This depends on the pet’s blood glucose. If the blood glucose is sky high in the 400s or more, you might give half the regular dose even if the pet is vomiting or not eating. If the blood glucose is normal or only mildly elevated you would clearly skip the insulin dose. In between I’d advise you to be very cautious with insulin doses. As a short period of a high blood glucose level is much safer than a short period of a low blood glucose level! Contact your veterinarian. And if the anorexia or vomiting persist until the next dose, you better get your pet into the vet office pronto.

Years ago when I was an ER vet, I recall numerous times when clients got confused as to course of action for a diabetic pet who was vomiting or not eating. I recall several times when clients gave their diabetic pets extra insulin in these situations instead of backing off on the dosage. Don’t be that pet owner. If you have any doubt, contact your veterinarian. Otherwise you may just end up with a pet in a hypoglycemic crisis, hospitalized on IV fluids spiked with dextrose.

You know I like hearing from our readers. Don’t hesitate to email me at joi.suttondvm@adwdiabetes.com.

NOTE: Consult your veterinarian to confirm that my recommendations are applicable for the health needs of your pet.

About the Author:

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.


  1. Liza January 8, 2018 at 3:19 am - Reply

    Thank you so much for sharing this. It has been very helpful.

  2. Anonymous April 3, 2018 at 11:05 pm - Reply

    Thank you so much for your advice. I feel so much better now. I am glad that this has happened to other cats, too. Thanks again !!!

  3. Linda Rodriguez June 5, 2018 at 12:36 am - Reply

    Thank you so much! My cat had to go without her insulin for 16 hours. I worked that long yesterday. She was so Hungry when I got home she ate way too fast and ended up vomiting everything up. I held off on the insulin until I thought she could keep some food down. Since she is only on 1 unit I did not decrease it. She did eat a small amount of the Hill’s dry food. By morning she was back to normal. Unfortunately my carpet is not. 🙂

    • Dr . Joi Sutton June 10, 2018 at 8:40 pm - Reply

      Good job. That’s a pity about the carpet. :/

  4. John W Craft October 1, 2018 at 5:21 am - Reply

    Great information and advise. This morning Jordan threw up. Prior to that she ate grass. After throwing she was very weak and did not want to eat, very abnormal for her. We finally got her to eat. I’m going to reduce her shot this
    AM and watch her. Thank You

    • Dr . Joi Sutton October 17, 2018 at 8:52 pm - Reply

      Thank you! Be sure to chat with your vet about a plan in case this happens again. And having a blood glucose meter will help you make choices about her insulin. 🙂

  5. Darren g Briscoe November 19, 2018 at 11:27 pm - Reply

    My comfort companion aka my cat first started to clean himself perfusely after using the litter box which is usual a sign of the runs, Then he throw up a regular size hairball. The he proceeded to vomit all over the flooring and poop in sequence between all 3 of my litter boxes . So it was puke, poop, puke, poop in sequence ( I have 2 cats and my Parents have 2 cats, Mine are Indoor only and theirs are Indoor/outdoor so I check for outside influence on my felines constantly) My cat has both UTD and Diabetes so I vigilantly keep an eye on his urination and bowel movements so I am rarely surprised.This incident was very surprising, I am now going to have to invest in a meter so I can make sure its a blood sugar issue when he gets sick like this, He lacked an additional symptoms for Hypoglycemia and last dose of 2 units of Insulin was 11 hours ago. I was able to access this site and got enough cursary information to be able to accertain that he probally a more mundane reason for his illness. That being the wet food he keeps getting from my father who overfeeds most cats too much wetfood. I decided to refrain from giving the insulin shot until later when he eats and drinks because his stomach is upset enough he refuses to eat or drink which in itself is very unusual. Thank you again for the information it did come in handy.

    • Dr . Joi Sutton November 23, 2018 at 11:36 pm - Reply

      Yes, please do get a pet glucose meter! I can’t fathom having a diabetic pet without the ability to measure the blood glucose. Without a meter it is all guessing. My favorite meter is 5e Alphatrak 2 meter. It is very user friendly.
      Feeding too much is bad, but feeding a diabetic cat canned food is a good thing. Canned food is much lower in carbohydrates than kibble. I advise against dry food for diabetic cats.
      Best to you! Joi

  6. Joanne June 15, 2019 at 10:10 am - Reply

    Dear Dr Joi Sutton,

    My diabetic dog vomited out the food after injecting insulin , what should I do now ?
    Unable to contact my vet , can you please help , thanks

    • Dr . Joi Sutton June 16, 2019 at 4:27 pm - Reply

      First of all, this is an excellent reason to have a blood glucose meter at home. It helps you make wise choices. Without knowing the blood glucose you don’t know if there is hypoglycemia. You may need to go to the ER if your pet shows signs of hypoglycemia for IV dextrose. Or, if your pet only vomited once, you might try feeling a small snack of some bland food say an hour or 2 later.
      It’s a good idea to discuss this scenario with your vet. Perhaps they have an after hours service for your clinic or someone on call. If your pet is prone to stomach upset you might have a prescription of an anti nausea medication at home as it is a weekend. If there is further vomiting, do please head to the ER. Or if your pet shows any signs of a low blood glucose also you must go to the ER until you can contact your vet. Best, Joi

Leave A Comment

Go to Top