Dog Community

Digestion-Where does it begin

Posted : 11/16/2006 5:25:55 AM

Since there has been some discussion on another thread (and to prevent hijacking it), I felt it would be a good idea to start a new thread relating to the act of digestion in dogs.
Every thing I was taught says, digestion starts in the mouth (ingestion) where mastication occurs. Mechanical and enzymatic activity start the process and it continues throughout the alimentary canal. It ends when waste is voided.

What say you?

sandra_slayton

Posted : 11/16/2006 5:33:23 AM

That is what i was taught as well....starts in your mouth.

paulaedwina

Posted : 11/16/2006 6:23:33 AM

Digestion starts in the mouth for HUMANS because we have an enzyme called ptyalin or salivary amylase that breaks down starch. Dogs and cats do not have salivary amylase in their mouths so that is not where digestion begins for them.

http://www.wonderquest.com/DogSaliva.htm

Lends itself to the argument that dogs are carnivores not omnivores. They well maybe facultative carnivores (as opposed to cats who are obligate carnivores), but they lack any real ability to assimilate unaltered plant matter. It would have to be digested (stomach of prey), ground or cooked in some way.

Paula

ron2

Posted : 11/16/2006 6:41:09 AM

Lends itself to the argument that dogs are carnivores not omnivores

Actually, no it doesn't. I read the whole article. Dogs do produce amylase, just not in the mouth. So, they can still digest a starch, just not in the mouth. I didn't know that absence of amylase in the mouth defined whether or not a creature was omni or not.

As for cooked food being opportunistic, around here it is. On one street, with rented duplexes, the opposite of the street is a drainage to a 5 acre field. Some of those "classy" renters throw out their stew or something resembling it. Dogs will eat most anything that smells like food.

papillon806

Posted : 11/16/2006 8:40:10 AM

It is important to decipher the very substantial difference between "digestion" and the acutal "absorption" and utilization of nutrients...

You are right..."digestion" starts in the mouth with the enzymes that help begin the breakdown on food into compounds that can be digested. "Digestion" also occurs in the stomach to a degree where HCl and pepsin help break down compounds even further, so that nutrients can be absorbed....however, "absorption" of any nutrients doesn't occur until the small intestine.

paulaedwina

Posted : 11/16/2006 10:19:09 AM

ORIGINAL: ron2

Lends itself to the argument that dogs are carnivores not omnivores

Actually, no it doesn't. I read the whole article. Dogs do produce amylase, just not in the mouth. So, they can still digest a starch, just not in the mouth. I didn't know that absence of amylase in the mouth defined whether or not a creature was omni or not.

As for cooked food being opportunistic, around here it is. On one street, with rented duplexes, the opposite of the street is a drainage to a 5 acre field. Some of those "classy" renters throw out their stew or something resembling it. Dogs will eat most anything that smells like food.

Yes they produce it in the pancreas.

Paula

paulaedwina

Posted : 11/16/2006 10:19:55 AM

ORIGINAL: papillon806

It is important to decipher the very substantial difference between "digestion" and the acutal "absorption" and utilization of nutrients...

You are right..."digestion" starts in the mouth with the enzymes that help begin the breakdown on food into compounds that can be digested. "Digestion" also occurs in the stomach to a degree where HCl and pepsin help break down compounds even further, so that nutrients can be absorbed....however, "absorption" of any nutrients doesn't occur until the small intestine.

In dogs digestion - a break down of food by enzymes - DOES NOT occur in the mouth.

Paula

mudpuppy

Posted : 11/16/2006 10:59:30 AM

dogs don't even really chew. They slice the food into swallowable chunks and swallow. So for dogs digestion clearly doesn't start in the mouth.

M.W.Lewis

Posted : 11/16/2006 11:42:38 AM

This is a great topic [

]

papillon806

Posted : 11/16/2006 11:44:30 AM

In dogs digestion - a break down of food by enzymes - DOES NOT occur in the mouth.

Paula

Oh crap, you are right....I was thinking of the salivary amylase secreted by ruminants to begin the digestions of starch.

thank you for clarifying.

jenns

Posted : 11/16/2006 12:42:10 PM

I attended a lecture being given by a scientist who is a leading expert on the human digestive system - and he made it a point to clarify that digestion DOES NOT take place in the stomach like is commonly thought. He said do not believe any source that tells you otherwise.

paulaedwina

Posted : 11/16/2006 1:41:20 PM

ORIGINAL: jenns

I attended a lecture being given by a scientist who is a leading expert on the human digestive system - and he made it a point to clarify that digestion DOES NOT take place in the stomach like is commonly thought. He said do not believe any source that tells you otherwise.

Please clarify. The stomach has a very low pH (hydrochloric acid) so indeed digestion does occur there. Even some absorption occurs in the stomach but most happens further down the tubes but it's not like that burger you ate is still burger in the small intestine.

Paula

Edie

Posted : 11/16/2006 4:10:29 PM

In dogs digestion - a break down of food by enzymes - DOES NOT occur in the mouth.

This is what i have always been told,and read.Dogs digestions does NOT start in the mouth,like in humans.

kennel_keeper

Posted : 11/16/2006 7:37:45 PM

Mastication (the act of chewing, biting, or crunching food bits) IS a integral part of digestion.

Papillion made an excellent point in that digestion and absorbtion are two different things. Absorbtion of nutrients occurs (for the most part) in the small intestine, but digestion occurs all along the digestive tract, which INCLUDES the mouth and continues to the anus.

Also, dogs DO salivate, which helps to begin the digestion process by moistening the food bits for swallowing. It is really irrelevant if the saliva contains amylase or not, digestion DOES start in the mouth.

chelsea_b

Posted : 11/16/2006 11:30:38 PM

It is really irrelevant if the saliva contains amylase or not, digestion DOES start in the mouth.

Why start a thread asking what others think if you're already sure of what you think? [&:]