When Extra Sweet Turns Sour: Supporting Cats with Behavior Changes Related to Feline Diabetes

Written by T Hamboyan Harrison, CCBC, ACSB-C, FFCP

Summary: Diabetes in cats is not uncommon, and can be managed with the appropriate veterinary care. There are, however, often some challenging behaviors that accompany a cat’s experience of the symptoms of diabetes. If these behaviors are not managed, the cat-human relationship can become strained, which can makes providing the consistent care a diabetic cat needs more difficult. This article introduces the most common behavioral issues reported in diabetic cats and suggests interventions a behavior consultant could make to improve them.

What is feline diabetes and why does it matter?

Feline diabetes can be very challenging for cat caregivers to manage.1 Similar to human diabetes, feline diabetes is an inability of the body to absorb and manage glucose (sugar) and is often treated with dietary management and insulin therapy. The idea of giving cats injections can be intimidating for many owners! In addition, especially when a cat is newly diagnosed or their diabetes is not yet under control, feline diabetes can present a host of challenging behavioral issues, with common symptoms of PU (polyuria: excessive urination), PP (polyphagia: excessive eating), and PD (polydipsia: excessive drinking).2 These symptoms can present as behaviors such as: constantly screaming for food, urinating outside the litter box, seeking inappropriate water sources (such as the toilet), and more. The behaviors associated with the diabetes symptoms can have a negative effect on the cat-human bond, as the caregivers feel overwhelmed by the diagnosis and frustrated by the behaviors. These behavioral issues can be so difficult for caregivers to manage that these cats can end up surrendered to shelters or rescues—or even euthanized.

Prior to beginning my work as a cat behavior consultant in 2022, I was a non-veterinary volunteer tasked with overseeing feline medical at a local rescue from 2016-2020. During that time, I was responsible for managing the care of 20 diabetic cats. While serving in that role, I observed that not only were diabetic cats frequently at risk of medical euthanasia at partnering shelters, but we were also contacted directly by local vets’ offices who were unwilling to euthanize otherwise healthy cats. One example was a cat named Ming, whose owners requested euthanasia because he was peeing on their bed. The vet insisted on doing diagnostics prior to euthanasia, which led to the diabetes diagnosis.

Sadly, this scenario isn’t uncommon; unfortunately, diabetic cats can also be difficult to find homes for—even diabetic cats that are otherwise healthy and friendly can spend months in shelters or rescues waiting for adopters. My experience with the rescue led me to join Diabetic Cats in Need—a national nonprofit dedicated to assisting low-income caregivers of diabetic cats—first as a case manager in 2020, and then as a member of their Board of Directors, starting in 2022. I have also had two diabetic cats of my own, Snowcrash and Emily, who have both sadly passed due to cancers. These experiences have allowed me to better assist clients in managing cat behavioral issues related to feline diabetes, as I can often personally relate to the challenges they are experiencing.

As cat behavior consultants, we must stay in our behavior lane and not advise about, diagnose, or offer treatments for medical issues. However, as Dr. Johnson pointed out in the IAABC Foundation Journal Article “Make the Most of Your Lane: Why to Stay Involved in Medical Cases,” just because a cat has a medical condition doesn’t mean behavior consultants can’t be helpful.3

Indeed, many cat medical conditions come with a host of behavioral challenges that we, as behavior consultants, are equipped to help owners manage. We can thus help to repair the bond between cats and caregivers by giving the owners the tools they need to manage the behavioral challenges.

Behavior concerns in diabetic cats

Since the symptoms of diabetes are associated with behaviors that we can help clients manage, one of our first roles as behavior consultants can be helping clients learn how to monitor their cat’s behaviors and encouraging them to share that information with their veterinarian. As my veterinarian, Renee Rucinsky, DVM, DABVP, says, “Owners know their pets. If they think something isn’t right, make sure the vet listens!”4 We can assist owners in learning how to monitor, log, and share behavior information with their veterinarians. This habit can be lifesaving for diabetic cats! Not only can monitoring these behaviors increase the bond between owner and cat, sharing the information with their veterinarian can result in better control and management of the cat’s diabetes. Please encourage your clients to contact their veterinarian if any new behaviors arise, as assuming a behavior MUST be caused by feline diabetes can lead to missed diagnoses and possibly dangerous outcomes.

To better understand the effect of feline diabetes behavior challenges, I posted an informal poll in a Facebook Feline Diabetes support group. The poll question was “Please fill out the poll below about behavior issues you’ve had with your diabetic cat; and feel free to add poll options too.” The “Big 4” feline diabetes behavior challenges as reported by this poll were: polyphagia, polyuria, polydipsia, and mobility issues secondary to diabetic neuropathy.

Which of the “Big 4” would you expect to be the most challenging for caregivers: excessive peeing, excessive appetite, excessive drinking, or mobility issues? While excessive peeing may be the best-known symptom of feline diabetes—and is a very common behavioral reason for surrenders to shelters/rescues—these committed cat caregivers in the Facebook group answered that the excessive appetite (PP) was their primary behavior concern with their cats. Out of 874 responses, 25% were hunger related: “extreme hunger,” “hanger–not just hungry, but angry and aggressive about it,” “chewing through packages to get into human or cat food,” etc.

A pie chart of the results of the author's Facebook poll about behavior issues in diabetic cats

A pie chart of the results of the author’s Facebook poll about behavior issues in diabetic cats

Polyphagia: Excessive hunger

Why is polyphagia such a challenge for diabetic cat owners? Quite simply, the level of hunger with diabetic cats can be extreme. One of my former behavior clients was being pestered by her diabetic cat screaming and pawing at her for food all day long, which is a behavior I also observed in my own diabetic cats. Additionally, as diet control is often part of feline diabetes treatment, diabetic cats are sometimes prescribed a diet change at diagnosis. Changing a cat’s diet can be enough of a challenge for both cats and owners even when the cat isn’t diabetic, but can be even more challenging with the extreme hunger of a diabetic cat. After a diet change, some diabetic cats will search for forbidden food by breaking into cabinets, chewing through packages to get to food, or eating food meant for another pet (such as the dog’s food). While the extreme hunger will likely continue until the diabetes is better controlled, there are ways we can help owners manage these behaviors while they continue to work with their veterinarian to manage their cat’s diabetes. We can help clients by encouraging them to monitor and share information about hunger symptoms with the veterinarian, and we can help clients manage these behavior challenges.

A tortoiseshell cat with their face in a bowl of salad

A diabetic cat trying to eat salad

Before we can start working on modifying the behavior challenges, we need to acquire more information from the client about how and when the behaviors are occurring. This is especially relevant with hunger-related behaviors for diabetic cats, as the severity of hunger can be affected by the time of day—especially for a diabetic cat receiving insulin therapy, as changes in blood glucose levels can affect the cat’s hunger. As part of our work with the client, we can help them start a behavior log, which should include time of day, behavior noted, and action taken (if any). This behavior log should be shared with the client’s veterinarian. The behavior log can help us notice patterns that can influence how we design our behavior modification plans for these cats. For example, if a client observes their cat consistently becoming hungrier four hours after insulin administration, attempting clicker training at that four-hour mark may result in a cat too distracted by hunger to focus on anything other than food.

As behavior consultants and trainers, we must respect any and all diet restrictions during training—any food used as reinforcers must fit into the cat’s prescribed diet. If food must be used as a reinforcer, instead of traditional crunchy treats (which are often too high in carbs to be appropriate for diabetic cats), consider using a freeze-dried raw single-ingredient treat or another veterinarian-approved treat. Another concern with using food as a reinforcer for diabetic cats is that their hunger may make the food too powerful a motivator, as the cat may be so focused on the food that they are unable to focus on any training. Even if we try to schedule training for the time of day when the hunger behaviors are at their least intensity, the intensity of the hunger may still not be low enough for the cat to be able to focus on training.

While we often reach for food as our first reinforcer for training, it is worth exploring if other reinforcers may be sufficiently motivating for your client’s cat. If the cat especially enjoys being brushed, for example, that could be used as a reinforcer for training instead of food. Other non-food reinforcers could include affection, play, loose catnip, or praise; be creative! Ask the client what is that cat’s favorite thing to do—other than eating—and see if there’s a way to use that as a reinforcer. Using a non-food reinforcer for training can also give our clients flexibility in when they train, so that training doesn’t need to be as restricted by the time of day.

One very basic training method that can be helpful is for clients to NOT feed until the cat has stopped yelling, as feeding the cat when they are screaming will encourage that behavior. Vocalizing for food can also be managed with reinforcing quiet moments through clicker training (click/reward in between meows or when the cat is taking a breath) or pattern games (such as “take a breath”). I like to think of teaching cats habits instead of tricks and to focus on “What can we do to change this habit?” Other pattern games such as “1-2-3” may help the cat learn patience; if food is the reinforcer, this pattern game may be especially helpful for the cat to learn patience around food.5

If the cat is not restricted to two meals a day, using an automatic, timed feeder to add meal-times between injections may be helpful. Using an automatic feeder can also help by removing the human element, as the cat will learn they get food from the “magic device” instead of from their people. This should decrease the amount of screaming at people for food. Using food puzzles such as LickiMats to slow down how fast the diabetic cat eats their meals can also help, as long as the food puzzles don’t create frustration for the cat.

For clients with multi-cat households, diabetic cats may benefit from being fed separately from other cats. As many inter-cat aggression issues revolve around resources6 and food resources can have an increased value for diabetic cats, diabetic cats can be more likely to fight with other cats for food (especially if the other cats are fed a “forbidden” food, which then can have an even higher value for the diabetic cat). Feeding the diabetic cat separately will also help the client be better able to monitor their diabetic cat’s food intake, which is especially important for any diabetic cat receiving insulin therapy.

A client’s diabetic cat vocalizing for food

Polyuria: Excessive urination

For cat behavior consultants, helping owners work through litter box issues is not uncommon. What makes helping an owner of a diabetic cat with a litter box issue unique? Diabetic cats—especially when uncontrolled or newly diagnosed—urinate a lot, both in quantity and frequency; they can produce as much urine as two to four non-diabetic cats! As noted above, urinary issues in diabetic cats can be persistent and can even result in owners surrendering their cats to shelters or requesting euthanasia. Behavior issues related to urine were 21% of the Facebook poll results: “Excessive urinating in the litter box” (109), “Not urinating in the litter box” (73).

The following factors are important to be aware of:

  • Clumping clay litter may become stuck to diabetic cats’ paws due to the frequency and volume of urine.
  • Non-clumping litter may result in large puddles of urine in the litter box.
  • Diabetic cats are likely to struggle to make it to the litter box in time.
  • Because these cats urinate both a large quantity and frequently, litter box hygiene is even more important; scooping MUST happen at least once a day.
  • Additionally, diabetic cats are more likely to have urinary tract infections (UTIs). If there is an increase in urinating outside of the litter box, encourage your client to schedule an appointment with their veterinarian ASAP.

How can we help these owners? Here are some management options:

  • Increase the quantity of litter boxes
  • Decrease the distance the cat has to travel to litter boxes within their living space. Especially important to have at least one litter box per floor!
  • Scoop more frequently. (Important note: any organic matter with lots of sugar can grow things like mold!)
  • If the client is using clumping litter that’s sticking to their cat’s paws, consider non-clumping clay litter or soft clumping non-clay litters like OkoCat.
  • If the client is using non-clumping litter, a clumping litter may make scooping easier to manage.
  • Consider the use of pee pads with trays if the client is averse to the idea of extra litter boxes or if the cat is missing the litter box.

We must also educate clients on the importance of proper cleaning of cat urine and working with their veterinarian to check for any worsening of diabetes or concurrent medical conditions (such as urinary tract infections). Any male cat, especially, should be monitored closely by the veterinarian for any urinary symptoms.

While urinary challenges in diabetic cats can persist, the intensity of the behavior concerns often will reduce once the cat’s diabetes is better controlled. Encouraging the client to be patient as they continue working with their veterinarian to control their cat’s diabetes can reassure the client that this issue is possible to improve over time.

Client cat urinating in litterbox with pee pad already saturated outside of it. This client was already scooping and replacing the pee pads more than once a day.

Neuropathy and mobility issues

Though this issue came last in the “Big 4” results from the Facebook group poll, with 8% of the total responses—”Trouble walking or jumping” (76)—I am mentioning it now because this issue can also affect litter box use. Cats with diabetic neuropathy will have trouble jumping, landing on their feet (these cats can have a characteristic THUD when jumping down), and getting in and out of litter boxes. One difference between cats with diabetic neuropathy and cats with other mobility challenges is diabetic neuropathy can cause numbness, which can make these cats more likely to slip, slide, skid, or lose their balance on hard or slippery surfaces.

Environmental modification is the primary tool we can use to help owners whose cats are struggling with diabetic neuropathy mobility issues. Low-entry litter boxes and adding extra litter boxes in more locations can be a HUGE help to these cats! These cats may also struggle with extra-fine, soft litter substrates, as they may not be able to keep their footing in such slippery substrates; using pee pads or substrates with a rougher texture may be helpful. Even with modified litter box setups, these cats may still have difficulty squatting in the litter boxes and may “miss”; using pee pads around the litter boxes may make clean-up easier for their owners. In addition, adding non-slip mats around litter boxes can help these cats be better able to get in and out of the boxes; if pee pads are necessary, they can be placed on top of these mats.

As jumping (both up and down) and climbing can be very challenging—and sometimes even dangerous, as these cats can be more at risk for falling—for these cats, adding pet stairs/steps near furniture the cat likes to spend time on could be very beneficial! Any cat trees the cat is currently using should have wide platforms that don’t require large jumps in between. Non-slip mats or rugs in other areas of the house may make walking around easier for these cats.

The client should be encouraged to share concerns about diabetic neuropathy and other mobility issues with their veterinarian, as medical treatments may also be available.

Diabetic cat at rescue intake vet appointment, showing extreme diabetic neuropathy in both front and back paws.

Drinking Behaviors

While water sources are often not high-value resources for most cats, they can be extremely important resources for diabetic cats, as excessive drinking is one symptom of feline diabetes. In the Facebook poll, 14% of the total results were about drinking behaviors: “Spending the entire day next to the water dish” (62), “Drinking from inappropriate places (toilets, human water glasses, etc.)” (59), “Pushing water dish across floor until it spills and licking it as it spills and doing it again and again” (5). The simplest way to manage this behavior challenge is to increase how many water sources are available and to offer a variety of water sources (such as fountains, dishes, water added to canned food, etc.). Increasing this resource can also help by reducing tension in multi-cat homes with diabetic cats, and reducing stress levels in diabetic cats by giving them more choices and easier access to this important resource!

Diabetic cat at a rescue enjoying a water fountain.

Additional Poll Results

In addition to the “Big 4,” the Facebook poll yielded the following results:

  • Behaviors related to high blood glucose: “Lethargic when high” (4), “Anger/Mean when high” (8)
  • Behaviors related to low blood glucose: “Standing in one position and staring into distance (hypo)” (1), “lethargic when low” (6), “Vocalizing and asking for food when blood sugar was low” (37)
  • Coat/hygiene issues: “Not grooming” (45), “Too big to clean themselves tush and body” (20), “Changing in coat color and bad fur health” (5), “Pulling out clumps of fur” (1)
  • “‘Cool seeking’ behavior (sleeping on concrete floors, in bathtubs etc.)” (44)
  • Reduction of Social Behaviors: “Decreased activity/social-ness” (34), “wants to spend a lot of time outside” (8), “Stopped sleeping in my bed” (3)
  • Increase of Social Behaviors: “needy, demanding attention” (12)

Similar tools as already mentioned (environmental management, positive reinforcement training, etc.) can be used to help clients manage these behavior issues. Discussions of blood glucose levels and behaviors that correlate with these should be between the client and their veterinarian, as the veterinarian may recommend treatment changes based on these observations.

Cooperative care and carrier training

While discussion of cooperative care and carrier training is beyond the scope of this article, these can be powerful tools for behavior consultants or trainers to teach their clients, as both can help reduce stress levels for cats. Cooperative care can make the medical treatments of feline diabetes (such as insulin injections and blood glucose testing) easier for both clients and cats, while carrier training can help the clients be better able to get their diabetic cats the veterinary care they need. Remember to choose your food reinforcer carefully for any training for a diabetic cat—and use a non-food reinforcer whenever possible!


As behavior consultants, we have many tools at our disposal that can be helpful for owners of diabetic cats. These tools can improve the cat’s quality of life and repair the bond between the diabetic cat and their owner. As long as we stay focused on helping manage behaviors, and not offer medical treatment advice, we can help these cats and owners live sweeter, less sour lives!


  1. AAHA (2023) Feline diabetes mellitus – The disease. American Association of Animal Hospitals [online]. Last accessed 10/7/2023.
  2. AAHA (2018) AAHA Diabetes Management Guidelines for Dogs and Cats [online]. Last accessed 10/7/2023.
  3. Johnson, D. (2022) Make the Most of Your Lane: Why to Stay Involved in Medical Cases. The IAABC Foundation Journal 25.
  4. AAHA (2023) The New Era of Feline Diabetes: What You Need to Know [podcast]
  5. Delgado M. & Dantas, L.M.S. (2020) Feeding Cats for Optimal Mental and Behavioral Well-Being. Veterinary Clinics of North America: Small Animal Practice. 50:5, 939-953.
  6. McDevitt, L. (2019) Control Unleashed: Reactive to Relaxed. MA: Clean Run Productions

TO CITE: Hamboyan Harrison, T. (2023) When extra sweet turns sour: Supporting cats with behavior changes related to feline diabetes. The IAABC Foundation Journal 28, doi: 10.55736/iaabcfj28.3

This article is dedicated to the memory of Carolina Grace

Carolina Grace