04/12/2024
Tracking dogs vs Airscent dogs – a bacteria primer
The prowess of a dog’s nose is another subject, so let’s consider the “target” that search and tracking dogs are trained to locate.
A search dog (SAR air scenting) is trained by a human to identify and approach the highest concentration of the “human target scent” and then to perform a specific action. (sit, speak, dig, bump, etc.)
A “tracking dog” is trained by a human to follow a “scent picture” a combination of human scent and crushed vegetation scent in combination with disturbed ground scent. Both valuable dogs are using their noses to detect the differences in the excretions of ever-present bacteria.
Bacteria growth is a subject that dog trainers of scent work must understand fully to professionally train dogs to be successful.
Bacteria, those tiny, remarkable organisms, can indeed produce a variety of distinctive smells.
Let's delve into the fascinating world of microbial odors:
1. Metabolic Factors and Volatile Compounds:
Microorganisms themselves do not inherently have a smell, but they can generate various metabolites that carry their own distinct scents.
When these microbes metabolize substances, they produce volatile compounds that contribute to characteristics smells. These compounds depend on the specific organism's metabolic processes.
For instance, when anaerobic bacteria (like Clostridium) break down organic matter (especially proteins), they create foul-smelling, incompletely oxidized compounds such as:
Hydrogen sulfide (H2S): Known for its rotten egg smell.
Methyl mercaptan: Smells like rotten cabbage.
Cadaverine and putrescine: These smell like decaying flesh.
Interestingly, the odor produced by these microorganisms can sometimes provide essential clues for identifying specific microbes. For example, the smell of diarrhea can help distinguish between giardiasis and other types of diarrheas.
Laboratory technicians have been known to "smell the difference" between bacterial cultures, although some consider it a biohazard.
2. Other Notable Microbial Smells While bacteria themselves do not inherently smell, their metabolic byproducts create distinct odors:
Spoiled seafood owes its odor to trimethylamine oxide (TMAO) produced by bacterial action.
The earthy scent of soil results from geosmin, a complex metabolite produced by Streptomycetes.
Cyanobacteria contribute to earthy odors and flavors in freshwater environments.
Here's a glimpse of some characteristic smells associated with specific microbes:
Alkaligenes faecalis: Freshly cut apples.
Citrobacter spp.: Dirty sneakers.
Corynebacterium spp.: Fruity.
Eikenella corrodens: Bleach or cracker.
Haemophilus spp.: Wet fur.
Staphylococcus spp.: Dirty sneakers.
Streptomyces spp.: Musty basement
3. Body Odor and Bacteria: Our own body odor is influenced by bacteria too. As bacteria metabolize our sweat, they produce byproducts that contribute to body odor. Different bacteria digest sugars and create varying odors.
So next time you catch a whiff, remember that it's not just you—it's the microbial world at work! Remember, microbial smells are a fascinating blend of science and mystery, revealing the hidden world of these tiny life forms.
No written test at this time! Haaa!
Canada's foremost E Collar Trainer and only "ProStaff" rep for DogTra in Canada. No trainer today has the experience of all facets of dog work than Bill.
