Close your eyes for a minute. Imagine yourself in a barn. What do you smell? Hay? Corn? Molasses? Manure? What about in a vet clinic? The tangy smell of iodine, perhaps?

 

My job as a large animal vet takes me to lots of different locations, where any number of smells await. Sometimes that’s nice and sometimes that’s not so nice. Sometimes it’s diagnostic. Let’s break it down.

 

Nice Farm Smells

 

Hay, particularly alfalfa hay, has such a sweet smell it’s like perfume — seriously. Good hay smells so good that you can tell without too much trouble when hay is bad. Hay can mold if it stays damp for long periods. And you don’t want to feed moldy hay to animals. While most fungus on hay is harmless, a few are trouble-makers. Some molds produce toxins called mycotoxins, which can cause problems such as intestinal upset and abortions in pregnant livestock like horses and cows. Other molds can instigate respiratory issues. Because you can’t tell the good from the bad mold just by visual appearance, the best rule of thumb is to throw out any moldy hay you find.

 

Bad Farm Smells

 

Aside from the obvious (e.g., infected wounds, diarrhea, etc.), there are two smells that I encounter on a fairly regular basis that I find particularly malodorous. One is the male intact goat. When male goats become sexually mature, their scent glands go into overtime and produce a smell that I understand is supposed to be attractive to female goats, but for humans — pew!

 

The second noteworthy stink is the smell that accompanies alpaca or llama spit. Irate camelids can and do throw a mean spit ball — be it at a pasture mate that is out of line or a veterinarian simply trying to do her job and give a vaccination or dewormer. There’s just something about those globs of half-digested grass and gastric juice that stays with you for the rest of the day.

 

Diagnostic Farm Smells

 

Ketosis is a metabolic condition commonly seen in dairy cows when their diets aren’t providing them with enough energy to make milk. As a result, they become glucose deprived and their bodies make ketones for energy instead. This is something that can happen to human diabetic patients, as well. Excess ketones in the blood sometimes produce a sweet smell to the cow’s breath. Although I must confess I’ve never noted sweet breath on a ketotic cow I’ve been treating, it’s an interesting additive to the diagnostic picture.

 

One other smell that I give honorary mention to doesn’t really fall into any of the above categories. DMSO (dimethyl sulfoxide) is the king of solvents and is used sometimes as a therapeutic in horses in leg wraps to decrease swelling, or in an IV drip to help with neurological disease. This stuff has a unique smell that some describe as “garlicky” but you wouldn’t think Italian restaurant if you smelled it in a barn.

 

Whenever I use it in practice, its smell takes me back to vet school, where I remember learning about it for the first time and being able to tell a patient was receiving it at the large animal clinic because the entire ward would reek. Smell as a trigger for memory? Maybe that’s the most distinct category of all.

 

Dr. Anna O'Brien

 

Image: Evgenia Pashkova / Shutterstock