Dog odor
Dogs have natural and un-natural odors that dog owners may find objectionable or noticable. One factor to be considered is some people are not used to being exposed to the natural odor of a non-human species living in close proximity to them.
Natural dog odors
Natural dog odors are most prominent near the anus, near the ears, and from the footpads. Dogs naturally produce secretions the function of which is to produce odors allowing for species and individual animal recognition by other dogs.
Dogs do not produce sweat for thermoregulation. However, they do have sweat glands, called apocrine glands, associated with every hair follicle on their body. The exact function of these is not known, but it is suspected that these are meant to produce pheromones or chemical signals for communicatation with other dogs. These sweat secretions probably produce an individual odor signal that is recognizable by other dogs.
Dogs also have sweat glands on the pads of their paws and on their noses. These are eccrine glands. When these glands are active, they leave the nose and pawpads slightly moist and help these specialized skin featues maintain their functional properties. On the pawpads, natural micro-organisms living in the surface layers likey contribute to the typical odor of dog paw pads, which has been likened to the odor of Cheese puff snacks. This odor is much more noticable on dogs with moist paw pads than on those with dry pads.
Dogs also have numerous apocrine glands in their external ear canals. In this location they are referred to as ceruminous glands. The ear canals also have numerous sebaceous glands. Together these two sets of glands produce natural ear wax, or cerumen. Micro-organisms live naturally in this material and give the ears a characteristic slighty yeasty odor even when healthy.
Dogs, like all carnivores, also possess two anal sacs, or scent glands. These sacs communicate with the surface of the skin by ducts which open on either side of the anus. The sacs are lined with apocrine and sebaceous glands. They function to produce a natural secretion that varies from thin and yellowish to pasty and greyish; the secretion has a very strong musty odor. A small amount of this material is deposited when dogs defecate. A large amount may be extruded when a dog is frightened. It is thought that this secretion leaves a signal to other dogs allowing them to recognize the source of the individual fecal deposit. This odor is also likely the signal being sampled when strange dogs investigate one another by sniffing out the anal area.
Another source of odor that can be considered natural results from a common dog behavior. Dogs like to roll in and mark themselves with some natural products of other animals in their environment, including fecal deposits of natural prey animals. One of their favorites is rabbit droppings. It is thought that this might be a method of communicating with pack members about the other animals that are active in the pack home territory.
Un-natural sources of odor on pet dogs
Poor grooming of dog with long, thick or corded hair can cause the haircoat to be a source of unpleasant odor. A coat that is not kept clean and groomed can trap dirt and other substances with unpleasant odors.
Skin diseases can cause a dog to have increased or abnormal odor. Allergy can cause increased production of apocrine sweat, which imparts a musty odor. This condition, termed hyperhidrosis, can encourage yeast infection or bacterial skin infection and these micro-organisms produce odors as well. Dogs with seborrhea or keratinization defect, and dogs with deep skin folds(such as on the face of an English bulldog), are very subject to secondary proliferation of bacteria or yeast on the skin surface, and these produce odors.
Ear disease (otitis) can be a source of odor that varies from yeasty to one resembling sewage as either cerumen or pus accumulates in the diseased ear canal. Anal sac disease or excessive anal sac production can cause a very musty pungent odor. Anal sacs can become abscessed and infecting micro-organisms produce odor.
Dental disease or mouth ulcers can produce rotten smelling breath (halitosis). Dental calculus harbors numerous bacteria which produce odor and foul breath. Dental disease can also lead to excessive drooling, and the skin around the mouth can become infected, leading to more odor production.
Some medications, such as antibiotics, taken by mouth or antiseptics or medicated shampoos used on the skin can produce odors that owners may find unpleasant. Chlorhexidine is a common disinfectant incorporated in skin medications that some individual owners find to have an unpleasant odor. Likewise, some food ingredients, most noticably fish meal or fish oil, can produce skin odor in dogs.
Flatulence can be a problem for some dogs, which may be diet-related or a sign of gastrointestinal disease. This, in fact, may be the most commonly noticed source of odor from dogs feed cereal-based commercial dog foods.
Skunks and dogs often have aggressive encounters and a dog may be sprayed by a skunk. This results in an over-powering musky acrid odor that remains apparent in the 'skunked' dogs coat for many days or even weeks until steps are taken to neutralized the odor.
Reference
Scott, Danny W. (2001). Muller & Kirk's Small Animal Dermatology 6th Edition. Philadelphia, PA: WB Saunders Company. ISBN 0-7216-7618-9. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)