Some signs of aging in cats can be mitigated, while others need to be treated. However, as age does affect cats in life-altering ways, you may wonder if senior cats lose their sense of smell and what can be done about it.
Older cats may lose part or all of their senses. In large part, this is degenerative as the body ages and loses its ability to replicate cells. However, a cat is unlikely to lose its sense of smell solely due to aging. That said, health issues can affect a cat’s ability to smell, such as dental disease, cat flu, and scarring due to trauma.
Cats have an excellent sense of smell. Three separate organs work together to allow cats to detect even trace scents and pheromones in the air. These organs are called the vomeronasal system and include the vomeronasal, the accessory olfactory bulb, and the vomeronasal amygdala.
How Do Cats Smell?
The olfactory sense of cats is far stronger than that of humans and even rivals most dogs. Alongside roughly 2 million odor-sensitive cells, cats also have a scent organ called the vomeronasal. This is sometimes also referred to as the Jacobson organ.
The vomeronasal organ is on the roof of a cat’s mouth. This organ detects and analyses chemicals in the air, allowing the cat to pick up even the smallest scent trails. This organ is also one part of the larger vomeronasal system. The Journal of Anatomy describes this system as the vomeronasal organ, the accessory olfactory bulb, and the vomeronasal amygdala.
A cat will breathe through its nose to smell. If there is an interesting scent, it will also open its mouth to draw more air over its tongue and the vomeronasal organ. This action appears almost grimace-like and is called the flehmen response. The cat deliberately exposes its mouth to the air, using its tongue to trap airborne pheromones against the roof of its mouth.
A cat’s sense of smell remains intact throughout its life. Except for in the case of illness or injury, age will not directly affect a cat’s olfactory senses.
What Is Considered Old Age for Cats?
Cats can be quite long-lived. It is not uncommon for a healthy domestic cat, given a high-quality diet and kept indoors, to live up to 20 years of age. Although, Ecological Management and Restoration have a more conservative estimate of 15 years.
A cat is considered a senior between 7 and 10 years of age. This is when it will likely undergo physical and behavioral changes related to aging. So, a 10-year-old cat is the equivalent of a 57-year-old human.
What Happens As Cats Age?
As a cat ages, it will experience several changes. These changes can be physical and behavioral and may require you to adjust how you care for them. Certain physical changes leave a cat more prone to illness or injury.
These changes are also largely responsible for behavioral changes. For example, if it suffers from stiff joints, it may be less likely to play or run around the house. As a cat ages, it may experience:
- Hearing loss
- Dental issues
- Blindness and partial loss of sight
- Overgrown claws
Do Older Cats Lose Their Appetite?
A cat’s sense of smell triggers its hunger response. A loss of smell can cause a cat to be pickier about its food or have a decreased appetite. There are many other reasons why an older cat may have a lower appetite. This includes illness, injury, and a lower metabolism.
Older cats may need more pungent food to trigger a hunger response. There are a few methods you can try to entice your cat to eat. You can:
- Offer wet food, or a different type of wet food
- Mix wet food through kibble
- Add specially formulated cats treats and/or sauces to its usual food
- Heat the food (although not too hot) to make it smell stronger
A vet may suggest medications/supplements that trigger a hunger response.
How A Cat Uses Smell
A cat will use its sense of smell to navigate the world around it. The wild ancestors of your cat would have relied on smell to hunt prey, patrol territory, avoid predators and threats, and for social interactions.
Cats mark territory using pheromones and scents. A cat will do this by urinating or defecating in its territory. This behavior is typical of unneutered cats. Using its sense of smell, a cat can detect its own territory, other cats’ territories, and if a foreign cat has entered its territory.
A cat also marks places, objects, and beings by bunting. Bunting is the label given to the action of a cat pushing, rubbing, or head-butting its face and forehead against someone or something. Bunting marks the receiver with the cat’s scent. In this case, a cat may feel comforted and secure if it detects its own scent on you. The same goes for its home, toys, and bed.
A cat will use scent to interact with others. A domestic cat will regularly smell its family members. Mother cats will monitor their kittens through their scent. Kittens will rely on their sense of smell (and sound) to recognize their mother during their first weeks of life. This is because kittens do not open their eyes until roughly two weeks of age. A kitten will use its sense of smell to find its mother and her teats.
Cats will typically greet other cats by smelling them. A lot can be learned through scent alone. Male cats will also use the vomeronasal organ to pick up the pheromones of female cats in heat.
Threat And Prey Detection
Wild cats will use their fine sense of smell to hunt and track down prey. Domestic cats do not need to hunt. However, smell still plays a role in its eating habits. Scent is a key trigger of a cat’s appetite. How a food item smells is also vital information. Cats can detect if food is safe to eat or if it is tainted or rotten. This applies to both wild and domestic cats.
A fine sense of smell also provides cats with an early warning system for potential threats. These threats could be anything from fire, natural predators, or noxious chemicals. A cat will also mask its own scent while hunting by approaching prey from downwind.
Signs That A Cat Can’t Smell
The main indicator that a cat is losing its sense of smell is its response to food. A cat that cannot smell food may have little to no interest in eating. Test this by holding a plate of food where the cat cannot see. Watch how, and if, it picks up the scent. You can also try foods with stronger scents. If your cat doesn’t seem to notice the food, it may not be able to smell it.
Other indicators that a cat can’t smell are behavioral. Even in its home, a cat will usually pause and scent the air when it comes into a room. It will definitely do this when new items or people are brought inside, such as groceries or visitors.
If your cat shows no interest in exploring these new scents but would previously do so with eagerness, that might mean it is actually unable to.
What Affects a Cat’s Sense of Smell?
If a cat loses its sense of smell, it is a symptom of a larger problem. For example, dental disease and upper respiratory infections can impact a cat’s olfactory senses. As can cat flu. Cancer or trauma that has resulted in permanent scarring or nerve damage can also affect its ability to smell.
Upper Respiratory Infections
Upper respiratory infections, or URIs, can be caused by bacteria or viruses. The latter is the more prevalent. Bacterial infections in the respiratory system often develop because of a virus.
Feline calicivirus and feline herpesvirus count for 80-90% of contagious URIs in cats due to how easily they can be transmitted. Bacterial infections include chlamydia and Bordetella.
URIs impact a cat’s sense of smell due to some of the symptoms these infections develop, which include:
- Runny nose with clear or colored discharge
- Loss and decreased appetite
- Ulcers in the nose and mouth
- Irritated eyes, expressed through squinting and rubbing
Any form of congestion or fluid build-up in the respiratory systems can dampen or mute a cat’s sense of smell. It is not uncommon for a vet to examine a cat brought in for a loss of ability to smell. Most of the time, the cat is diagnosed with a URI.
Older cats can be more vulnerable to URIs, especially in multi-cat and/or stressful households.
Preventing Upper Respiratory Infections
Stay up to date with vaccinations. They will not make your cat immune, but they will make it more resilient to the URI’s effects.
Be aware that even if a cat is not showing symptoms of a URI, it can still be a carrier. Meaning that any outdoor cat in your neighborhood could be a carrier, even if it seems perfectly healthy. As such, especially with young or senior cats, limiting their exposure to other animals by keeping them indoors is recommended.
Minimize your cat’s stress. Consider your home environment and its other occupants. Are there any stressors that can be move or removed entirely?
Cat flu is somewhat like the common cold in people. It is incredibly infectious and is caused by the feline herpes virus and feline calicivirus.
Young cats, older cats, and cats with pre-existing illnesses are more vulnerable to cat flu and are more susceptible to permanent damage. Or even dying. Symptoms of cat flu include:
- Runny nose
- Loss of appetite
- Sore eyes
- Ulcers in the eyes and mouth
- Weight loss
Untreated cat flu can cause permanent damage to the nasal passages and sinuses. Thus, limiting its sense of smell.
Preventing Cat Flu
Staying on top of vaccinations is key in preventing cat flu. No vaccine grants complete immunity, so keeping your cat isolated from other cats is the next step.
Just like with URIs, cats can be carriers for cat flu and not show any symptoms. Keep your cat indoors, or create an outdoor enclosure that prevents it from interacting with other cats.
Cat flu is very contagious. At the first sign of symptoms, quarantine the cat from other animals in the house and make an appointment with the vet.
Trauma can result in permanent damage and scarring to the nose, sinus, and mouth. This trauma can result from injuries, infections, and cancer.
Although not overly common in cats, they do run a risk of developing nose and sinus cancer. Depending on the size and location of the tumor, and the type of treatment provided, a cat may lose its ability to smell.
A cat relies heavily on its sense of smell. Cats have noses several times stronger than those of humans. Cats also have a vomeronasal organ that can detect even the smallest traces of a scent.
An older cat can lose its sense of smell, although not solely due to aging. Elderly cats may lose their ability to smell due to illness or injury. This could include upper respiratory infections, cat flu, nerve damage from trauma, or dental disease.