Originally written
for DogWatch, a newsletter for the general public from the Cornell University
College of Veterinary Medicine
When I took my rottweiler in for
her annual check-up, I asked my veterinarian about bloat because her litter
mate died from it and I wanted to know what I could do to prevent it. We
discussed different feeding strategies, but he also told me fearful dogs
were at higher risk. Can my dog's personality really affect her health?
The study of gastric dilatation-volvulus (GDV or bloat) in dogs conducted
by Lawrence Glickman and his team of researchers at the Center for the Human-Animal
Bond at Purdue University did indeed show that dogs judged nervous or fearful
by their owners were at higher risk than happy, easy-going ones. But how
could this be? Unfortunately, currently studies of disease or injury don't
take the role of the animal's behavior or its relationship with the owner
into account. However, hopefully the increased interest shown in the links
between behavior and health by human health professionals and the general
public will stimulate more research in this aspect of veterinary medicine,
too.
Beyond that, though, we can get some hints regarding what might occur in
domestic animals from what we know happens in wild ones. When frightened
by a predator, a wild animal will immediately empty its bladder and defecate
to decrease its weight to enable it to fight or run more efficiently. Consequently,
the normal fear response involves a period of hypermotility or increased
activity of the gut to empty it, followed by hypomotility which allows the
animal to channel maximum energy to the skeletal muscles for flight or fighting.
In the wild, the prey animal which finds itself in this situation usually
either gets away from the predator or gets caught and eaten. within a relatively
short time. If the animal gets away, normal gut motility becomes re-established
and may remain so for a fairly long time. Although nature films sometimes
give the impression that animals spend most of their time fighting or fleeing
predators, such encounters make up a comparatively small part of the wild
animal's day.
Compare this to the life led by the average timid dog in a complex suburban
environment. Every time fearful Freddy hears a strange noise during his owner's
absence, he wants to run and hide. Shortly after his owner goes to work,
the sound of the school bus sets him off. His ancestral brain sends a message
to the smooth muscle of his gut to empty out and prepare for the great fight
or escape. However, house-trained Freddy wouldn't dream of doing that, or
maybe his gut is empty because he only gets fed in the evening. Whatever
the reason, the hypermotile phase comes to a screeching halt when he bolts
for the door and begins barking frantically. Freddy survives that assault
and his gut starts functioning normally again. But then an hour later the
mail arrives. An hour after that, the UPS man leaves a package. Then the
kids next door start playing ball, and a dog starts barking on the next block.
Each time something frightens him, Freddy's gut speeds up, shuts down, then
starts up again. Perhaps after repeated episodes of this, it loses its ability
to contract normally and dilates, just like a balloon that's been repeatedly
inflated and deflated eventually loses its elasticity.
But what about dogs like Clementine who drool, vomit, or get diarrhea when
they get scared? Instead of their guts shutting down, they go into overdrive.
In reality, Freddy's and Clementine's responses probably represent variations
on the same theme. Freddy can muster the courage to get beyond the gut-emptying
freeze state, but Clementine remains stuck there. Perhaps her gut just keeps
churning until it can't churn any more.
In both cases though, when the dogs eat that night, the digestive juices
flow as usual but their stomachs don't contract to mix things to aid digestion
and gas builds up. At some point before or during this process, and added
by a body type that lends itself to this, the stomach flips and GDV results.
Again, this all remains speculation based on wild animal behavior. Still,
it serves as yet another good reason to keep our dogs' minds as healthy as
their bodies.
The above information is simply informational. It's intent is not
to replace the advice of a veterinarian nor to assist you in making a diagnosis
of your pet. Please consult with your own veterinarian for confirmation of
any diagnosis. Your pets life may depend on it.