Tree House Feeding and Nutrition Program
Benefits of Canned-only Feeding
Kidney and urinary tract health
Weight benefits
Many factors can contribute toward undesirable weight gain, including inactivity,
neutering, free-feeding, and food type. Recently, the focus has been on diet – particularly the high-carbohydrate dry foods commonly fed for convenience.
Studies have shown that overweight cats lose weight while maintaining muscle
mass on a low-carbohydrate canned diet better than the high-fiber low-calorie “Lite” diets. Interestingly, underweight cats may also gain weight
on low-carbohydrate canned foods, as they contain more protein. The concept
is similar to why humans may lose weight on a low-carbohydrate diet – yet athletes may use a high-protein diet to gain weight and muscle mass.
Dr. Deborah Greco coined the phrase “Catkins” for a low-carbohydrate
diet. At the 2003 AVMA conference, she noted that 35% to 40% of cats are obese.
She noted that "obese cats are four times as likely to develop diabetes
mellitus and five times as likely to develop lameness." Overweight cats
more frequently show signs of non-allergic skin disease, probably caused by
their inability to groom as effectively. In a study, Dr. Greco noted weight
normalization in both overweight and underweight cats on the “Catkins” diet.
Unfortunately, the newer lower-carbohydrate dry foods aren’t as effective
for weight loss. It’s possible this is because these dry foods are very
high in calories.
Blood Sugar
As noted in the diabetes article in this issue, low-carbohydrate diets may aid
in the prevention and treatment of feline diabetes. Most canned foods are naturally
lower in carbohydrates and less glycemic than dry foods. The manufacturing of
dry foods necessitates the inclusion of a starch, in the form of rice, corn,
potatoes, tapioca, etc., in order to “puff up” and form dry food
“kibbles”.
As obligate carnivores, cats are extremely efficient at producing glucose from
protein. However, they have difficulty processing carbohydrates. On a high-carbohydrate
diet, the cat releases more and more insulin in an attempt to reduce blood glucose
levels. When that fails, the cat may develop Type II diabetes mellitus. Dr.
Greco recommends a canned food diet, avoiding diets with rice or corn starch,
as they have a high glycemic index.
Low-fiber diets may also benefit cats with pancreatitis.
Gastro-intestinal health
Gastro-intestinal disorders such as chronic diarrhea, constipation, and vomiting
are on the rise, and many blame the grains in many commercial pet foods. Canned
foods may be easier to digest and less likely to contain ingredients that aggravate
gastro-intestinal conditions. Dry foods may be more acidic than canned foods,
and the acidity may cause stomach upset. The moisture in canned foods may also
prevent dehydration secondary to diarrhea.
Dr. Lisa Pierson writes there are an impressive number of anecdotal reports
of cats that were terribly ill with IBD (inflammatory bowel disease) exhibiting
dramatic improvement when all dry food was removed from their diet. Dr. Debra
Zoran speculates that a high carbohydrate diet affects the number or species
of bacteria in the gastro-intestinal tract.
Kidney and urinary tract health
Moisture is imperative for good kidney and urinary tract health. Many veterinarians
are recommending all cats with renal (kidney) insufficiency be fed all wet food
to maintain hydration and assist in flushing toxins out of the kidneys.
Canned food is naturally higher in moisture, and studies have shown cats on
all-wet diets are less apt to develop bladder/kidney stones. In fact, of cats
with a history of stone formation, the cats fed prescription dry foods had recurrence
of stones, while the cats on all wet diets did not.
While cats fed dry food drink more water, they don’t drink enough additional
water to make up for the lack of it in their food. Studies show cats fed wet
food have more dilute urine. As cats evolved from a desert species, they naturally
have low thirst drives as nature intended them to get most of their moisture
from their prey.
Some recent studies have also shown urinary crystal formation may be related
to carbohydrates in the diet. Dry foods tend to be higher in carbohydrates than
canned foods.
Older cats may need administration of sub-cutaneous (or sub-q) fluids less often
when they consume more water in their food.
Behavior
Meal-feeding gives caregivers more of an opportunity to determine if cats are
eating well and their appetite is normal. Meal-feeding can also be used as a
socialization technique. By providing food in meals, rather than free-feeding,
cats may associate a good thing (food) with human presence.
