A dog at rest takes about 10 to 30 breaths per minute.
Breathing at a faster rate suggests fever, pain, anxiety, or a
problem with the lungs or chest. Rapid breathing should be distinguished from
panting. Panting is the primary way a dog lowers her body temperature; water
evaporates from the mouth, tongue, and lungs, and warm air in the body is
exchanged for cooler air in the atmosphere.
A dog may vomit simply because he’s eaten something disagreeable or gobbled down too much food, too fast. But vomiting can also indicate something far more serious-your dog may have swallowed a toxic substance, or may be suffering from a condition that requires immediate medical attention. Vomiting can also be associated with gastrointestinal and systemic disorders that should be evaluated by a veterinarian.
Dogs with rapid, labored breathing should be seen by a veterinarian.
Noisy breathing indicates an obstruction in the nasal passages, the back of
the throat, or the larynx. Snorting and snoring are typically heard with the
brachycephalic syndrome. If your dog normally breathes quietly but suddenly
develops noisy breathing, this is a cause for concern. She should be checked by
Stridor (Croupy Breathing)
Croupy breathing, or stridor, is a high-pitched raspy sound caused by air
passing through a narrowed voice box. It may be heard only when the dog
exercises. When the onset is sudden, the most likely cause is a foreign body in
the voice box. When croupy breathing has been present for some time, laryngeal
paralysis is a possible cause.
A wheeze is a whistling sound heard when the dog inhales or exhales, or
both. Wheezing indicates spasm or narrowing in the trachea or bronchi. Wheezes
in the lungs are best heard with a stethoscope. Some causes of wheezing are
chronic bronchitis, congestive heart failure, and tumors of the larynx,
trachea, and lungs.
Shallow breathing is seen in dogs with broken ribs and severe bruising of
the chest wall. Blood, pus, or serum in the chest cavity (called pleural
effusion)restricts breathing by interfering with the range of motion of the
chest and expansion of the lungs. A dog with shallow breathing compensates by
breathing more rapidly.
WebMD Veterinary Reference from "Dog Owner's Home Veterinary Handbook"