Case Examples of Tight Regulation
“Maggie” is a 10-year-old female white long-haired cat.
Like almost all of my patients, she had eaten dry food since she
was a kitten. Occasionally her owners would feed her some canned
food as a special treat, but during the day she ate many small meals
of a” premium quality” dry cat food. She had been healthy
for 10 years and was not overweight at 8 pounds. One day, Maggie’s
owners noticed that she seemed to be losing weight. Her backbone
seemed more noticeable to them, even through her long coat. She
wasn’t eating very well and was drinking a lot of water. When
I saw Maggie, she was dehydrated and weighed only 7 pounds. A blood
test showed that her blood sugar level was 410 mg/dl (this is a
measure of how much sugar is in each one-tenth liter of blood; a
liter is about a quart). Normal resting blood sugar levels for the
cat range between about 50 mg/dl and 120 mg/dl. Maggie also had
sugar in her urine.
We hospitalized Maggie and started feeding her canned food only.
Maggie was ecstatic; she was getting her special treat food twice
a day and she loved it. By the second day Maggie’s average
blood sugar was 180 mg/dl and by the third day it was 100 mg/dl.
We sent Maggie home with no insulin and told the Dunbars to feed
only canned food to her. A week later, Maggie had been completely
normal at home and her blood sugar level was 90 mg/dl on average.
With her owners only feeding her canned food twice a day, Maggie
remains normal to this day (two years later) and has never needed
insulin injections. She has gained back the lost pound and is doing
“Goldstein” Murphy is an 8 year old neutered male domestic
shorthaired tabby cat whose owner is completely devoted to him.
Mr. Murphy is single and Goldstein is his roommate and best friend.
Mr. Murphy adopted Goldstein from the local animal shelter as a
kitten; the two had spent 8 years hanging out together and keeping
each other company, and Goldstein ate commercial dry food exclusively
all his life.
One day, Mr. Murphy noticed that Goldstein was spending a lot of
time near his water bowl. This was very unusual for the cat as he
usually spent his days sunning near a large window in the house.
Goldstein was going to the litter box almost every hour as well.
This also was not usual for him, so Mr. Murphy brought Goldstein
to me for examination. Goldstein was overweight at 14 pounds (I
told Mr. Murphy he should weigh about 11 pounds) but was in good
condition otherwise. He was still eating his dry food well and was
We took a blood and urine sample for analysis; Goldstein was very
diabetic with lots of sugar in his urine and a blood sugar level
of 490 mg/dl.
We hospitalized Goldstein and started feeding him canned food. He
liked the new food and ate it well. By the next day Goldstein’s
blood sugar level was down to 300 mg/dl without insulin. The diet
alone had helped him a lot. We added 1 unit of insulin twice daily
(I always use a special kind called protamine-zinc insulin, or PZI,
which works best in cats) and by the third day Goldstein’s
blood sugar was between 100mg/dl and 150 mg/dl throughout the day.
We sent Goldstein home with Mr. Murphy on I unit PZI insulin every
12 hours and a canned-food-only diet.
A week later, at Goldstein’s weekly blood sugar check, we
discovered that his sugar level was 60 mg/dl. This meant that Goldstein
was in the low normal range for blood sugar, and needed to have
his insulin reduced or even stopped. We stopped his insulin for
24 hours, rechecked his blood sugar, and it was still 60 mg/dl.
We sent Goldstein home and instructed Mr. Murphy not to give any
more insulin until we checked Goldstein again in one week. One week
later, Goldstein’s blood sugar was still low normal. He has
not needed any insulin injections for over a year now. He is healthy
and happy and has lost almost two pounds in that year. Mr. Murphy
knows never to feed his cat any dry food ever again. The following
story shows why…
My own cat “Punkin,” the one whose out-of-control diabetes
had caused me to start thinking about what we veterinarians might
be doing wrong with our feline diabetic patients, was doing great.
His blood sugar levels had been in the low-normal range for almost
two years without any insulin injections. He ate low-carbohydrate
canned cat food happily and had lost a pound from his earlier12
pound frame. My husband and I decided to board Punkin at a local
cat boarding facility while we took a week-long vacation. We instructed
the manager of the facility that we wanted Punkin to eat only canned
food that we brought along for him and nothing else during our time
When we returned from our vacation, we took Punkin home. We immediately
noticed that he was very thirsty and filled up his litter box with
urine the first night he was home. I tested his blood for sugar
and found his level was 400 mg/dl! Punkin was diabetic again! I
was devastated. I started giving him small doses of insulin again
and called the boarding facility to ask about Punkin’s stay
After much discussion, the manager of the kennel told me that she
had been concerned that Punkin wasn’t getting enough to eat
with just the canned food we asked them to feed him morning and
night. She thought that cats needed to “graze” (a term
that applies to cattle, not cats) during the day as well, so she
gave him some premium quality dry food along with his canned food.
She had meant well, and I appreciated her concern for my cat, but
she had caused him to become diabetic again, and very quickly.
Fortunately, after 2 weeks on doses of insulin that I decreased
as his blood sugar levels started to become normal again, Punkin
was able to keep his blood sugar in the normal range all by himself
and I stopped giving insulin. Punkin never got dry food again and
never needed insulin again, either. This was an important lesson
for me and all of my diabetic patients. Cats that have been diabetic
will always tend to become diabetic again quickly if they eat high-sugar
foods, even if they have been “normal” for long periods.
They don’t have the ability to resist the effects of high
sugar foods, even for short periods, like they did before they became
diabetic. We have seen many cases like Punkin’s where a “recovered”
diabetic cat eats dry food again and immediately starts to need
insulin again. I make it a point to emphasize to my clients that
their recovered diabetic cat will never be able to have high carbohydrate
foods again in its lifetime.
While many cats recover from their diabetes quickly, as Maggie,
Goldstein and Punkin did, some are much slower to become normal.
Unfortunately, cats that have been diabetic for a long time seem
to take longer to improve. Many of these will still go off insulin
eventually, but the longer a cat is diabetic before its diet is
changed to low-sugar foods, the harder the process of recovery:
“Rascal” was a 6-year-old neutered male short-haired
cat that weighed 20 pounds when I first saw him. He was at least
8-9 pounds overweight for his frame. Rascal had been diagnosed as
a diabetic by a veterinarian 2 years earlier in another state where
the Simons lived at the time. Rascal had been getting 6 units of
Humulin™Lente insulin (this is a type of human insulin, not
PZI that I prefer) twice a day and was eating one of the high-fiber,
high-carbohydrate dry foods for diabetic cats. Rascal’s owners
were not happy with his lack of progress during the two years of
his treatment for diabetes. His previous veterinarian would check
his blood glucose once each month and adjust Rascal’s insulin
dose depending on those tests. Sometime Rascal’s blood sugar
was very high, as high as 520 mg/dl, and the insulin dose would
be increased. Sometimes his blood sugar would be lower, as low as
100 mg/dl, and his insulin dose would be decreased. Once, Rascal
even had a seizure because his blood sugar dropped all the way to
35 mg/dl! When this happened, Rascal’s owners rushed him to
the vet’s and he was hospitalized for 3 days while his doctor
gave him IV fluids and adjusted his dose of insulin again. It was
a never-ending see-saw. The Simons were about to give up when they
moved to Orange County, California and a neighbor told them to bring
Rascal to my clinic.
When I first saw Rascal, he weighed 18 pounds, and was still obese.
His coat was dull and he had dry flaky dandruff coming off his skin.
The Simons told me that Rascal drank lots and lots of water and
went to the litter box to urinate at least 10 times a day. Every
day they had to empty all of the litter and what seemed like quarts
of urine from the box. Rascal was always starving; he begged for
food whenever his bowl was empty and would steal any human food,
even pretzels and potato chips that he was able to get to. He never
seemed content and didn’t socialize with the family at all.
The Simons were giving him 6 units of Humulin insulin every 12 hours.
We hospitalized Rascal and found that his blood sugar ranged between
300 mg/dl and 450 mg/dl throughout the day, even though he was getting
so much insulin every day. We stopped giving Rascal any insulin
at all and changed his diet to low-carbohydrate canned food only.
At first, he ate only a small amount of the canned food. Rascal
was “carbohydrate-addicted” and wanted his dry food.
Even so, his blood sugar the first day off dry food and with no
insulin ranged from 250 mg/dl to 375 mg/dl, a respectable improvement
for a cat without insulin injections. We started him on 2 units
of PZI insulin every 12 hours and within 2 days his blood sugar
levels ranged from 125 mg/dl to 200 mg/dl. His excessive thirst
and urination stopped altogether and he started eating the canned
food well. We sent Rascal home with his owners on 2 units of PZI
injected under the skin every 12 hours and canned food as an exclusive
diet. We taught the Simons to hometest Rascal’s blood glucose
2 to 3 times per day.
One week later, we rechecked Rascal’s glucose and found it
ranged during one 12-hour period between 60 mg/dl and 150 mg/dl.
We stopped giving insulin for one day and his blood sugar started
rising to over 200 mg/dl at the highest. We started insulin back
at 1 unit PZI every 12 hours and sent him home for two weeks. This
process of readjusting Rascal’s insulin as he responded better
and better to the canned diet and insulin continued for another
2 months. Eventually he was getting less than one-half unit of PZI
every 12 hours, and finally, after 3 months of proper diet and the
right insulin, Rascal went off insulin altogether. He has been off
insulin for eight months now, has lost 3 of the 8 pounds he needed
to lose, and his coat is starting to shine. He uses the litter box
3-4 times daily, and drinks very little water because his food has
most of the water he needs. The dandruff is gone, and the Simons
can’t believe how active Rascal has become. He no longer begs
for food all the time, eats his canned food at mealtime only, and
is more affectionate than ever. Rascal’s owners continue to
home-test him every few days.