IS A CONSIDERABLE FOE TO POTBELLIED PIGS
BY: BRUCE LAWHORN, DVM, MS
When The Duchess Fund
(http://www.duchessfund.org) asked me if I would write an
article about obesity in potbellied pigs (and the problems
associated with obesity) I promptly responded.
Any feeding strategy
for the pbp should furnish adequate nutrition by a balanced
ration and prevent excess weight gain. Although sizes and
weights of mature pbps may vary greatly, generally speaking,
the heaviest mature weight for even the largest frame pbp of
today should not exceed about 125-150 pounds. Of course, there
are many small frame pbps today compared to a decade ago. The
feeding goal is the same no matter what the frame size. So
what is obese? When a pbp is so heavy that walking is
difficult, the eyelids are forced closed by facial fat and the
tailhead is buried in its behind, this is obvious obesity. I
generally think that an additional 25 pounds is considered
overweight or fat. Greater than this is obesity. I have seen
some pbps that are 125-150 pounds heavier than their frame
size will allow. This is insane obesity. It is a miracle that
these pbps can walk around, and many can’t.
It is too late for the
owner to be sorry for all the medical problems their obese pbp
has suffered once an illness crisis arises. The most skilled
pbp veterinarian may not be able to remedy the situation. Why
Other than the animal
description and problem history, making a diagnosis in the
sick, obese pbp is extremely challenging. The physical exam,
which includes temperature, pulse and respiration is probably
the easiest to evaluate but the slightest exertion increases
the temperature and causes the pulse and respiration to race
due to the excessive weight burden.
Evaluating the color of
the mucus membranes, capillary fill-time and pupillary
response are more difficult because access to the oral cavity
and orbit is reduced. The so-called entropion seen in obese
pbps should be re-evaluated after weight loss which may make
the condition disappear.
Collection of body
fluids for diagnostic tests is even more difficult. This
includes blood sampling and intravenous therapy. Cut downs
through the skin to access veins may have to be performed.
Even routine blood draws from the cranial vena cava (lower
neck area) are challenging since all the anatomic landmarks
are obscured by fat deposits.
Values for routine
serum enzymes and complete blood counts require good blood
sample quality and may be distorted as the degree of
difficulty in obtaining samples increases. For example, pig
blood rapidly clots and is easily hemolyzed (red blood cells
easily ruptured). Hence, these diagnostic tests become harder
Urine collection in the
obese male is difficult because the abdomen drags the ground.
Midstream catch samples of urine from the female is somewhat
easier but woe unto the veterinarian if catheterization of the
urethra is necessary. An endoscope (which many veterinarians
do not have easy access to) is required to visualize the
urethral recess since the massive amount of fat collapses all
normal anatomic structures and makes blind passage of a
catheter difficult to impossible.
If all this were not
enough, ultrasound and radiographs are hindered by the extreme
thickness of the body walls.
Any type of anesthesia
puts the obese potbellied pig at high risk due to its inherent
small chest and lung capacity. Many veterinarians use face
masks to induce and maintain gas anesthesia because pigs in
general are hard to intubate and irritation from repeated
attempts at intubation may cause throat swelling and reduced
air movement after surgery. The time required to situate an
endotrachael tube into an obese pbp is increased due to
reduced visibility from compression of the oral cavity by fat.
An oral speculum and endoscope may even be necessary.
Obese pbps are also at
higher risk for fatal post surgical complications such as
heart, kidney or multi-organ failure. Veterinarians do not
know all the reasons for this higher risk, but a leaner pbp
would be much less of an anesthetic risk. Embolism and death
has occurred post surgically from orthopedic procedures in the
normal weight pbp: the risk may be higher for the obese
Both kidney failure, a
common cause of death in geriatric pbps, and lameness are
probably accelerated by obesity.
So you see, these are
many, many medical reasons to keep your pig fit and trim!