Welcome to Brainstuff, a production of iHeart Radio Pay brain Stuff Lauren bog Obam. Here. When you take your dog for a walk, you know you're going to stop at every bush, fire, hydrant, mailbox, and any other marked item along the route. That's because dogs have highly sensitive sniffers. Their noses are constantly processing information left by other neighborhood dogs or critters that have passed through their turf. Scientists say a dog's sense of smell is ten thousand to
a hundred thousand times more accurate than humans. Dogs have been trained to sniff for bombs at airports, to participate in search and rescue, and to even detect certain diseases like diabetes and possibly the novel coronavirus. But just like any other of the senses, including site, hearing, or taste, that sense of smell can disappear for a whole host of reasons. If it does, it can be confusing for
the dog and challenging to diagnose. The loss or the decreased ability to smell is called a nasmia, and it's a fairly common symptom that people experience with illness or trauma. We heard about it most recently during the COVID nineteen pandemic. When it happens to people, we usually self report it. Unfortunately, dogs can't tell their people what's going on. Instead, they
may pick up their food or otherwise behave strangely. We spoke with Dr Sarah Moore, a veterinarian and professor in the College of Veterinary Medicine at the Ohio State University. More also specializes in veterinary neurology and neurosurgery, and she says that it takes a very astute owner to pick up a nasmia in dogs. She said, when we diagnosed or documented nasmia in a dog, we're doing it based on changes in behavior patterns or things they used to
do that they can't do anymore. It's quite hard, especially if it's just one side of the nose, if they can still smell out of the other can be really difficult for the owner to realize that there's something wrong. Owners typically bring dogs in when it's affected their work, for example, a police dog doing scentwork, or dogs the airport sniffing for explosives or drugs. More head a case of an osmia in a dog that was a bedbug sniffer.
She said, the dog went to people's houses and smelled out bedbugs, and the owners noticed a change in the way he did his job. That often triggers the visit to the vet, and by then it's usually a complete loss of smell because those dogs are so good at compensating for any loss of smell. But what causes anosmia? More said, the list of concerns is going to include things like infections of the lining of the nose or chemical irritants. Things that can cause inflammation of the nose lining,
whether that be infectious or otherwise. Also, problems of the brain can actually cause issues with smell. A dog's nose and the links between it and its brain are nothing short of astonishing for starters. When canines inhale, a fold of tissue inside the nostrils separates the air flow into two paths, one for old faction and one for respiration. About fifteen with the air is sent to the olfactory area as it's examined, recognized or not, and sorted before
it's exhaled. That examination happens in the canine nasal cavity or olfactory lobe, positioned directly behind the nose itself. This lobe is lined with all kinds of tiny nerve cells that connect directly to the brain. Dogs have up to three hundred million olfactory receptors depending on the breed, compared with only about six million in humans. More said, in dogs, the olfactory lobe is massive. If you were to look at a dog's olfactory lobe compared to a humans, it's huge.
In a dog, it's because their sense of smell is so highly developed. Problems in that area of the brain can cause altered smell, so tumors of the brain, strokes, head trauma, injury can all impact the sense of smell. That's a long list of potential issues. However, once the veterinarian knows what's causing the anosmia, it can usually be treated. Sinus infection is typically caused by bacteria and thus treated
with antibiotics. If the problem is brain related, such as a tumor, surgery may be an option, or if they can try radiation therapy. The loss of smell is temporary when caused by an allergic reaction to medication or exposure to chemicals or other irritants, and will usually wear off with time, though some loss of smell may linger. However, viral infections that cause loss of smell could become permanent
depending on what virus causes it. More says that questions about the link between aging and an osmia in dogs are fair because there is some evidence that the condition is linked with aging in people, though she has yet to see studies done linking the condition to aging in dogs.
For dogs with viral infections or those that can't otherwise be treated, the good news is is that if it's just a loss of smell, the dogs usually do pretty well with their lot in life, though of course, if their job utilizes that sense of smell, they may have to retire. And for pups with brain tumors or other brain related issues, the result is more complicated and unfortunately less cheery. More said, the problem with brain tumors is that they do get worse and tend to grow and
cause other problems. Eventually, there is some palliatee of care we can provide. Sometimes we can use steroids to help with inflammation around the tumor, and that can be helpful for a period of time, but it's not a permanent fix from a quality of life standpoint. If they're having a lot of other problems, owners might need to consider putting their dog to sleep, but More said that is definitely a worst case scenario and that in the vast majority of dogs, anosmia is a conditioned that will not
limit a dog's quality of life. She said, while it might cause a change in the dogs behave hear, the good news is that the most common cause of loss of smell and dogs is related to sinus infection, so most of those are going to be treatable problems. Today's episode was written by Patty res Mussin and produced by Tyler Clay. For more on listen lots of other curious topics, visit how stuff works dot com. Brain Stuff is production
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