Monthly Letters to Pulmonary Patients by Thomas L. Petty

Thomas L. Petty, M.D.

Professor of Medicine, 
University of Colorado

Chairman, National Lung Health Education Program (NLHEP)


National Lung Health Education Program
A collaborative project with



HealthOne Center
1850 High Street
Denver, CO 80218
Phone: 303 839 6755
Fax: 303 832 8137

Dogs Don't Sweat!

January 2005

Second Wind
Lomita, California

Dear Friends;

Have you ever noticed that dogs don't sweat no matter how heavy their coat may be? The reason is that they don't have any sweat glands. The only way dogs can lose heat is by panting. Thus they breathe at an extremely rapidly rate to lose heat through evaporation from their tongue and air passages. In this process they also lose water. Your dog must have plenty of water during hot days or while exercising.

Dogs are born hunters. They can chase their prey for long distances, but they finally get tired and have to rest and pant. Dogs may be descendants of wolves. Early wolves learned to organize into community groups and, in fact, may well have helped primitive man in achieving some social organization.

Also "dogs don't sweat the small stuff." Your dog will forever be your loyal companion. This happens in spite of your unintentional failings, such as, at times, lack of enough attention, proper food and shelter. Dogs are always forgiving. Dogs love you unconditionally!

Most dog owners share their love equally with their dogs, which they often regard as a spiritual animal very much like a brother or even child. Dogs are to be admired as lifelong companions. Dogs are, indeed, man's best friend.

I'll be in touch next month. Happy New Year!

Your friend,

  Thomas Petty, MD

Last update:
25 March 2005