Can dogs lose their sense of smell? Many dog owners may find it surprising that dogs can become "scent blind" and lose their sense of smell. Perhaps this fact is quite surprising because we mostly hear about dogs who become blind or deaf, but rarely about dogs who lose their sense of smell. Because we think of dogs (especially scent hounds) as "noses on four legs," we would imagine the negative impact losing such an important sense would have on dog lives!
In most cases though, it appears that dogs lose their sense of smell only partially, making it sometimes difficult for dog owners to take note of such changes. A decline in a dog's sense of smell most likely would show up as alterations in appetite and food preferences, according to The Ohio State University College of Veterinary Medicine.
A for Anosmia
The medical term for a dog, other animal or human losing his sense of smell is "anosmia."
The term may be used to depict an animal or human who is unable to perceive odor or whose sense of olfaction is no longer functioning.
The loss or decrease in sense of smell may be either temporary or permanent. Fortunately, in dogs, in most cases, the loss of smell is only temporary; it's rare for it to be permanent, explains Dr. Pete a veterinarian with a Bachelor of Veterinary Science from the University of Melbourne, Australia.
A Part of Aging
Just like people, dogs undergo several changes as they reach their golden years. Along with reduced activity levels, loss of muscle mass, hearing loss and decreased visual acuity, dogs may also undergo changes in the way they smell and taste food, explains veterinarian Melody Foess Raasch. This loss of smell can reduce an older dog's interest in food which can lead to weight loss.
Let's remember that "a dog’s ability to “taste” food resides in her nose," explains veterinarian Randy Kidd in an article for the Whole Dog Journal. Increasing the palatability of foods for older pets might therefore be something to consider. Consult with your vet or veterinary nutritionist for advice.
Respiratory Tract Problems
Just as people temporarily lose a bit their ability to smell when they get a cold, dogs can lose their sense of smell due to upper respiratory problems.
The most common causes for loss of smell in dogs include infections of the nasal passages, blockages of the nasal passages, either due to an irritation or presence of mucus, and less likely, polyps or tumors of the dog's nasal passages that reduce airflow, explains Critical Care Vet, a Board Certified Specialist in Emergency and Critical Care.
Injuries to the Head
When dogs sustain some form of head trauma, their ability to smell may deteriorate because a specific part of the brain controls their sense of smell. According to the Merck Veterinary Manual, an injury to the dog's cerebrum can cause an impairment to the dog's ability to see and smell along with other neurological complications such as seizures, coma, circling behaviors, and their inability to recognize their owners.
Any injuries to a dog's olfactory nerve, one of the dog's 12 cranial nerves traveling from the nasal cavity to the brain, can also lead to loss of smell, according to Wikivet. The good news though is that, this nerve has shown the remarkable ability to regenerate when damaged.
Other Possible Causes
For what other reasons may dogs lose their sense of smell? Dogs affected by distemper, a serious viral disease, may develop alterations in their sense of smell. In a study conducted by Myers LJ, Hanrahan LA, Swango LJ et al, a loss of smell was found in 5 or 6 dogs who recovered from a case of acute distemper 10 to 26 weeks earlier.
If a dog inhales something toxic or caustic, this could scar the mucous membranes of the nose and lead to a loss of smell, adds Critical Care Vet.
Brain cancer can also trigger dogs to lose their sense of smell according to Vet Arena. Also, chemotherapy to treat tumors may alter the dog's sense of smell or taste resulting in reduced interest in food.
Did you know? The sense of smell is one of the first senses puppies are equipped with at birth, along with the sense of touch and taste.
The latter though requires still a few weeks to sharpen and completely mature, explains Stanley Coren, Professor Emeritus in the Department of Psychology at the University of British Columbia, in article for Psychology Today.
Disclaimer: this article and any other articles on this website are not intended to be a substitute for professional veterinarian advice, diagnosis, or treatment. If your dog appears sick, in pain or is not acting as his usual self, contact your veterinarian immediately. By reading this article you automatically accept this disclaimer.