How do we smell?
The human nose and brain is capable of discriminating roughly 1 trillion scents, according to a study by Leslie Vosshall of Rockefeller University in New York City, and that is a conservative estimate.
We “detect smells by inhaling air that contains odor molecules, which then bind to receptors inside the nose, relaying messages to the brain.”
The specialized sensory cells inside the nose are called the olfactory sensory neurons. We have 10 to 20 million olfactory receptor neurons and each olfactory neuron has one odor receptor.
Most scents that we experienced are composed of many odorants. A single whiff of fresh cup of coffee, for example, hundreds of different odor molecules will be traveling to your olfactory sensory neurons.
Many factors can affect our ability to smell smells. Diet, genes, how hungry we are, the time of the day (our sense of smell is better as the day progresses) are just a few of them. A 2007 research found that your sense of smell decreases in higher pressure (e.g. when you’re on a mountain, in high altitude). And your sense of smell increases when it’s more humid.
Removing pet odor: Which method/ ingredient is most effective and safe?
Odor treatment technologies
According to a European Commission publication, technologies for treating odor usually fall under one of two categories, physical/chemical or biological.
Physical or chemical technologies “remove bad-smelling emissions by changing them with chemicals (chemical scrubbers), burning (incinerators) and by adsorbing the emissions with carbon.”
Biological technologies, on the other hand, remove odor using filtration systems that are “made partially or completely from organic materials (biofilters)”. In the home setting, most of the deodorizing methods are using physical/chemical technologies.
Masking odor vs. neutralizing odor: What’s the difference?
What’s the difference between masking odor and neutralizing? Which is better? A large number of household products for odor elimination use a combination of both masking and neutralizing to combat odor.
As this article puts it “[t]he main goal of odor removal must be to eradicate the vaporous odors at their molecular level, not mask them with powerful fragrances”
Masking odor, instead of neutralizing odor, is “a temporary fix for a permanent problem”.
Masking odor often means you’ll need a stronger scent to overpower the malodor.
Fragrances that’s been used in cleaning products vary in the type and concentration, and “[a] single scent may contain anywhere from 50 to 300 distinct chemicals.”
According to an article by The Guardian on the dangers of fragrance in consumer products cites that “[b]esides common reactions to fragrance – about 35% of people report migraines or respiratory problems because of fragrance – health advocates have more serious concerns.”
Besides that, the masking of odor is simply not effective. You might even end up with a funkier concoction of smells, as the malodor bends with the fragrance.
Let’s explore some of the common ingredients and methods for getting rid of pet odor indoors.
Baking soda
How does baking soda work?
Baking soda is an ingredient that is well-loved for its versatility. It can be used for a myriad of tasks: cooking, baking, deodorizing, cleaning, etc. Baking soda, sodium bicarbonate, is made from soda ash.
Soda ash is derived from an ore called trona or processed by “passing carbon dioxide and ammonia through a concentrated solution of sodium chloride (table salt)”.
When soda ash is dissolved into a solution, carbon dioxide is released (that’s the bubbles you see) and sodium bicarbonate is released. Malodor comes from either strong acids or strong bases. Baking soda deodorizes by neutralizing “bringing both acidic and basic odor molecules into a neutral, more odor-free state.”
Baking soda is a common ingredient in homemade DIY recipes for cleaning and deodorizing. These homemade recipes usually are a combination of baking soda and some kind of essential oils or dry plants as a source of fragrance.
You can find these homemade recipes all over the internet, but this and this caught our eyes. They usually cost much less than store-bought formulas, and some people swear by their effectiveness and safety.
Is baking soda safe for pets?
This multi-purposed ingredient is also commonly used for cleaning and deodorizing products. Many carpet powders are baking soda based. Carpet powders are tiny granules that you spread on the carpet to treat the smell in the carpet fibers. After letting it sit for some time, you’ll need a vacuum to extract the granules out from the carpet.
There are quite a few formulas on the market that specifically target pet odor on carpets, and they are usually scented. There are debates about how safe it is to use carpet powders.
The main concern is the residue granules that can cause skin irritation and allergies. Some of these powders can be quite fine, and there is risk of inhalation into the respiratory system.
However, baking soda itself is relatively safe unless ingested in large amounts. To be even more cautious, use baking soda only on non-porous and smooth surfaces. This makes it much easier to rinse off any residue baking soda. Use it to clean and deodorize the cat litter box in between litter change.
You can also sprinkle baking soda in the cat litter box after each round of daily cleaning. You can also add baking soda into your pet grooming routine. Using it as a dry shampoo or during a wet shower. However, you should always consult your veterinarian before using baking soda directly on your pet.
Enzyme cleaners
How does enzyme work?
Enzymes have been for cleaning, degreasing and deodorizing a variety of things. There are different classes of enzymes. The most commonly used in households are proteases, amylases, lipases and cellulases. Each of them are used to tackle a specific type of mess.
Proteases target protein-based mess like blood, urine, and food. Amylases targets starch-based mess like ice-cream and sauces. Lipases break down lipid-based messes like oil and grease. And finally, celluloses are used to lift dirt by softening fabrics (that’s made up of cellulose material).
According to the Encyclopedia of Life Sciences, “[e]nzymes are highly specific” and that “degradative enzymes [are] extremely restrictive in the reactions they catalyse.” Meaning different enzymes are needed to break down different substances. Understanding how enzymes work to break down a substrate will help us understand why.
The lock and key analogy is used to describe how enzymes work. “In this analogy, the lock is the enzyme and the key is the substrate. Only the correctly sized key (substrate) fits into the key hole (active site) of the lock (enzyme).”
This means that a more specialized cleaning product will generally do a better job than a general formula. If the formula is developed for getting rid of urine stain and odor, then using it to degrease a surface will not yield good results.
Many household products targeted at pet odor are enzyme-based. Some are more specifically targeting pet urine smell, but general formulas are more common. These formulas come in ready-to-spray, laundry formulations as well as concentrated solutions.
The ready-to-spray formulas are usually safe to be used on most hard surfaces, carpets and upholstery. Carpet cleaning formulas are concentrated solutions that need to be diluted with water, and are used in carpet cleaners.
Are enzyme cleaners safe for pets?
A 2012 research published a risk assessment of enzymes in cleaning products. It found that the enzymes used have “an excellent safety profile, with little ability to cause adverse responses in humans.”
However, caution needs to be taken when using these cleaning products. It goes without saying that following the manufacturer’s instructions on the product label is highly recommended.
There are two concerns that the researchers point out. First, high concentration of the enzyme protease can cause irritation in the eye, skin and respiratory system. Second, strict limits need to be established to limit airborne exposure.
But both can be avoided if one sticks to the guideline given by the manufacturer and sticks to the recommended amount of enzyme-based cleaner. Also, make sure to dilute the formula as instructed.
Essential oils
According to Dr Jennifer Coates, “[e]ssential oils are simply aromatic oils (fatty liquids) naturally produced by plants that are extracted and concentrated using various techniques.” Essential oils are sold as just one oil, lavender oil for example, or can be packaged into a blend of different oils.
They’re usually used in aromatherapy and also direct application to the skin. Some essential oils can be used topically in its concentrated form, sometimes even undiluted, by humans, without much adverse effect.
Some of the common uses of essential oils is to introduce a pleasant smell indoors and deodorize the area. This can be done via:
- Passive diffusers: Works by evaporating the essential oil. This includes reed diffuser, heat diffuser (plug-in electric diffuser), non-motorized, personal evaporative diffusers (necklace pendants, bracelets, etc.), and motorized diffusers.
- Apply directly on pet mess: Essential oil is used as part of the cleaning process. The oil can be added to the cleaning solution. Or the oil is added at the end of the process to freshen up the space. Some cleaning products are infused with essential oils. But most of the time, a homemade cleaning recipe is used, so the concentration of the essential oil used is unclear.
Is essential oils safe for pets?
The dose makes the poison. This is one of the basic principles of toxicology. It “means that a substance that contains toxic properties can cause harm only if it occurs in a high enough concentration.”
Even common food items, like fruits or coffee or even water can become dangerous to the human body if taken at a high enough concentration.
The concentration is of course proportional to the body weight of the human. That’s why some essential oils can be used by humans safely (in the correct dosage, of course), but it’s deadly to say a small animal.
A 2014 study looked at the data collected from the ASPCA Animal Poison Control Center database from 2002 to 2012. The data covered a total number of 443 cases of toxicosis in dogs and cats caused by concentrated tea tree oil. 89% of the reported cases were intentional application of 100% concentrated tea tree oil, while the rest were accidental use.
The study notes that the concentration of tea tree oil used in most pet skin care products is low, usually around 0.1% to 1.0%. While undiluted tea tree oil can be used “topically in humans by most individuals without adverse effects.
Animal owners sometimes knowingly or accidentally use 100% TTO [tea tree oil] to treat various skin conditions in their dog or cat.”
The study found that the “use of 100% TTO [tea tree oil] in dogs or cats to treat various health conditions can lead to serious clinical signs, including signs of CNS depression, paresis [muscular weakness], ataxia [very uncoordinated gait], and muscle tremors.
Younger and smaller body weight cats are at greater risk of developing major clinical effects from TTO [tea tree oil]. Until more studies are available to determine the safety and efficacy of 100% TTO, its use in dogs or cats is not recommended.”
But it’s not just tea tree oil that’s dangerous to pets. Dr Kia Benson is an associate veterinarian in clinical toxicology writes that essential oils that’s known to be poisonous to cats include “oil of wintergreen, oil of sweet birch, citrus oil (d-limonene), pine oils, Ylang Ylang oil, peppermint oil, cinnamon oil, pennyroyal oil, clove oil, eucalyptus oil, and tea tree oil.”
Some of the most common essential oils toxicities in dogs are “Melaleuca or Tea Tree Oil, Pennyroyal, Oil of Wintergreen, and Pine Oils.” Pets can be affected by dermal contact (topical application on the skin, for example), oral administration, and also inhalation.
In general, the higher the concentration of the essential oils, the higher the risk for the pet. Prevention is the best medicine in limiting essential oil toxicities in pets. You should always discuss with your vet before using any essential oils on your pets.
The Pet Poison Helpline is an excellent resource to help identify potential poisoning situations.
Steam
Is steam cleaning effective on pet odor?
According to a study on the effectiveness of steam cleaning for disinfection in veterinary hospitals, “[h]eat kills microbes by denaturing and damaging cellular proteins.” The study concludes that “Steam disinfection may prove to be an effective alternative or adjunct to chemical disinfection within veterinary practices”.
But how does this apply to the house setting? Steam cleaning in residential settings will no doubt help reduce the number of microbes. This cleaning method is targeted and effective, and can be used on practically any surface.
But is it effective to get rid of pet odor? Whenever we smell something, it is because of the microscopic molecules that are floating in the air that get swept into our noses (reaching the olfactory sensory neurons) by airflow.
Steam cleaners (producing high heat and pressure) can kill the bacteria that’s producing these molecules. This reduces the amount of molecules floating in the air. And the atmosphere can technically become less smelly.
But at the same time, steam can aggravate the odor issue. Steam produces moisture and heat, both of which will make odor smell worse. According to researcher Victoria Henshaw, “[t]he combination of heat and humidity allows bacteria to grow faster and smells to travel farther”.
Another way it worsens the smell is that humidity and temperature “increase molecular volatility”, meaning the substance turns into a gas easier. And once the substance is in a gaseous state, it floats into the air.
Here’s an example: Cleaning pet urine out of the carpet by shooting a jet of hot steam at the spot. When the hot steam is directed at the urine spot, the heat will turn some of the urine into a gaseous state.
This is why you would want to position a towel around the spot as you’re doing this. The towel is to catch any urine that’s vaporizing. Otherwise, tiny droplets of urine will be floating around in the air.
Is steam cleaning safe for pets?
Compared to the other options above (baking soda, enzyme, or essential oils), steam cleaning is undoubtedly the safest option. The caveat: use only water in your steam machine. You really can’t get even safer than this.
Some steam cleaners allow you to add detergent to the water tank. If you want to play it very very safe, don’t use the detergent function on your pet’s bedding and their favorite spots around the house.
Be aware of hot steam that will burn the skin. Keep your pets away from the area while you’re cleaning. The steam can go up to 347°F/ 175°C in some of the commercial grade steam cleaners.
The surface can stay very hot to the touch, so remember to allow a few minutes after the steam treatment for the surface to cool off.
How to get rid of different sources of pet odor
If it’s a flat, non-porous surface, then the job is easily done. Simply clean the surface. But if there’s nook and crannies, and the pet mess has seeped into the porous surface, then you need a better plan.
A good rule of thumb is to completely saturate the area with the cleaning agent. The idea is to flood the same nooks and crannies and porous area with the cleaning agent. This strategy aims to do two things.
The first is to reach every spot where there’s urine/vomit/etc in order to let the cleaning agent neutralize the smell. Secondly, it aims to flush out the nasties and replace them with nicer smelling solutions.
We’ll now look at how to tackle each type of pet soil odor.
Pet urine odor
Pet urine odor is one of the most common problems, even in homes without carpets or rugs.
“Urine is a concentrate of metabolic waste and is comprised of urea, creatine, uric acid, various detoxified substances, sodium chloride and other electrolytes.” according to Joe Schwarcz, PhD. of McGill University. The compound urobilogen gives urine its characteristic yellow color.
Have you noticed how fresh urine usually doesn’t smell as bad as old urine?
This is because the process of decay that’s releasing the smelly molecules. Urine decomposes in two stages.
In the first stage, bacteria decomposes urea (of the compounds in urine) and this gives off an “ammoniacal odour characteristic of stale old urine”.
The second stage releases mercaptans, which is what gives skunk spray its smell.
Cats typically have more concentrated urine than dogs, according to the International Renal Interest Society (IRIS). It’s been observed that “[i]n healthy animals, urine concentration can change substantially over time, and 2 to 3 fold variations have been observed within 2 hours in some dogs.”
The urine odor can vary between species, but also animal to animal. Older animals who have lost kidney efficiency will produce smellier urine. Male cat “also tends to smell worse than female urine, due to the presence of certain steroids.”
Now let’s see how we can get rid of the smell of pet urine in your home.
Finding the pee spot
Finding where the urine spot is sometimes half the battle. Even in a small bathroom area where we place the cat litter boxes, we don’t spot it as quickly as we think we would. This becomes even more difficult when the pee spots dry up.
Although the liquid of the urine has dried up, the smell lingers. And will in fact develop an even very strong odor as the second stage of decay kicks in.
To start spot cleaning, we must first locate the pee spot. Shining a blacklight will help you do that. The wavelengths in a blacklight will cause protein and phosphorous to glow in the dark.
Do this in the dark, otherwise you wouldn’t be able to see the glow. More expensive blacklight devices emit a greater wavelength providing a better visibility of the glow.
Removing the urine residue
One of the most common solutions for pet urine cleanup is to use a ready-to-spray formula. These formulas are usually enzyme-based.
Because of how enzymes are very substrate specific – only a specific enzyme will work on a specific substrate – opt for a more specific formula when possible. It will be more effective than general use formulas.
Ready-to-spray formulas are typically suitable for most surfaces, but absorbent surfaces like carpet will need more than that. We’ll talk about how you can eliminate pet urine smell from your carpet in the next section.
This study on storage of human urine sheds some light on why popular cleaning agents like white vinegar or enzyme-based cleaners work well. The study found that “acids could be used to prevent the decomposition of urea into ammonia”.
White vinegar and enzymes are naturally acidic and that can inhibit the decay process, and therefore prevent the release of smelly molecules.
The reason why pet urine odor is especially tough to get rid of is because of urine salt crystals. If the cleanup has not been thorough, you will leave behind urine residue. And these residues will dry up into urine salt crystals when the liquid dries down.
In its crystal form, it doesn’t release as much odor as it will when in liquid state. If moisture is available in the area, it reactivates the salt crystals and releases its odor.
This makes the salt crystals particularly hard to catch because our noses can’t detect them after the cleaning is done, and the area has dried up. The only foolproof way to weed them out is by using a blacklight to shine on them.
Stopping repeat occurrence
There are steps you can take to correct these behaviors in dogs. Housebreaking training and crate training are some of the top things to consider. Submissive urination is “a normal canine communication”.
It is something that occurs more during puppyhood, but some dogs don’t grow out of it even when in adulthood.
There are ways to help your dog improve this behavior, and greeting them outdoors (instead of indoors) is one of them. So if they do pee in excitement, at least it’s still an easier cleanup when it’s outdoors.
But there are also times when your dog might need medical attention for it. You would want to rule out any medical causes to this behavior.
For cats that urinate outside of the litter box, it could be due to multiple different reasons: such as litter box location and size, litter box hygiene, substrate material, and even territorial behavior that can happen in a multi cat household.
For male cats that spray, neutering is recommended. Neutering will help with tomcat spray odor. It will also reduce the cat’s motivation to spray. However, a very small percentage (10% in males, 5% in females) will continue to spray.
This article on cat spraying and marking by Dr Debra Horwitz looks at helps you understand the behavior by looking at the location, frequency, duration and number of locations.
There are also drugs, like Feliway, to help address the underlying problems such as stress, anxiety and depression. However, always consult your vet before administering these drugs.
You can also prepare your home in anticipation of these incidents. You can use fabric protectant like Scotchgard to prevent liquid from seeping into the fabric and carpet fibers as quickly.
They help make cleanups easier, but you’ll still need to clean the pet urine out as soon as possible. They make the fabric/carpet surface slightly water resistant, but not waterproof.
Dr Debra Horwitz writes that if you need to compromise with the spraying behavior, you might as well be prepared. She suggests using a shower curtain to cover the wall area and place litter boxes directly under to catch the liquid.
Pet feces and vomit odor
why smelly pet poop is not normal
We’re often advised to pay attention to our pet toilet behavior. How frequently are they eliminating, how much, the quality of it. When determining fecal quality, we will consider the “consistency, moisture, volume, odor, and color” of it.
We need to be familiar with what normal looks like, so any changes or abnormality is immediately noticed. A healthy dog poop should be “segmented, slightly moist, chocolate brown in color, and firm, with a mild odor. “
So stinky poop is not normal, generally speaking. There are a variety of reasons why poop becomes not normal/healthy. And a very common reason is diet.
According to Dr Ryan Yamka, the digestibility and bioavailability of amino acids of the protein source is important. And this is not measured by the amount of protein in the source.
The digestibility and bioavailability (available for absorption and utilization) of each amino acid is measured at the end of the small intestine.
And according to Dr Yamka “[a]ny amino acids or protein that are not digested or absorbed prior to leaving the small intestine will be fermented by microbes in the hindgut and produce fecal odors compounds.”
This is how diet can influence your pet’s fecal odor. The undigested protein is undergoing a fermentation process in the gut. The fermentation process releases odorous particles which are released when your dog poop or passes gas.
But aside from diet, not-so-normal looking/smelling poop can indicate other more serious health issues. From viral infection, intestinal parasite, bleeding in the digestive tract, to even liver, pancreas, or gallbladder problems. You can use a fecal scoring chart like this to help you describe your dog’s poop to your vet.
Like dogs, undigested food can cause cats to have smelly poop as well. If your cat uses the clumping type of cat litter, then you’ll need to pay extra attention. If the diarrhea is bad enough, the feces will be very watery and will clump up. This can be mistaken for urine clumping up.
Dr Yamka notes that there’s currently not much data on the digestibility and bioavailability of amino acids of the protein source in cats.
If your cat goes outdoors and has been known to hunt and eat their prey, that could also explain the occasional smelly poop.
Aside from that, bacteria and parasites can also cause smell stool.
According to Dr. Mike Paul, “mal-digestion and mal-absorption often result in rancid smelling stools. This can be associated with undigested and unabsorbed fats and starches.”
It seems that the smelliness in dog’s poop is mainly caused by undigested proteins. While it’s fats and starches in cats. If you’re using enzyme-based cleaning solutions, then it means you’ll need a specialized formula in order for it to be effective. Each type of enzyme works on very specialized substrates (particles that they break down).
Proteases are for protein based messes, and amylase for starches and lipases for oil and grease. Understanding the type of mess you’re dealing with will help you clean more effectively, and use the right type cleaning solution.
Vomit vs regurgitation: What’s the difference and why it matters?
According to Washington State University, “[v]omiting is the ejection of contents of the stomach and upper intestine; regurgitation is the ejection of contents of the esophagus.” This happened in both dogs and cats.
Determining whether your pet is vomiting or regurgitating will help your vet make a diagnosis quicker than it would otherwise take.
Vomit is food that has been further down the digestive tract, and have been digested to some degree. While the regurgitated material usually still looks like the food the pet has eaten.
“Vomiting is an active process. The pet is apprehensive and heaves and retches to vomit. If food is present in vomit, it is partially digested and a yellow fluid, bile may be present. Regurgitation is fairly passive. The animal lowers its head and food is expelled without effort. The food brought up by regurgitation is usually undigested, may have a tubular shape, and is often covered with a slimy mucus. The pet will often try to eat the regurgitated material.” according to Washington State University.
The key difference between vomit and regurgitated material, in terms of clean up, is the pH level. Vomit is usually acidic, while the regurgitated material usually has a higher pH. While these are definitely not strong acid or bases, taking note of the pH level will help you clean more effectively.
If it is vomit that you’re dealing with, you should try to avoid applying even more acidity. This can potentially worsen the sour smell of vomit.
To neutralize it, you’ll need a weak base. The opposite is true when cleaning up regurgitated material. You’ll need to neutralize it with a weak acid if the smell is too bad.
Wet dog musky smell
Smelly dogs often smell worse when they get wet. The musty scent intensifies also when it’s warm and humid. This musty scent is emitted from yeast and bacteria metabolizing secretions, especially the skin oils on the dog’s coat.
Skin folds, the month, ears and under the tails are not exposed to as much air flow and light.
These are places where you’ll find a higher concentration of bacteria and yeast. That’s why they’re usually smellier.
Moisture makes the smell worse in two ways.
Firstly, moisture breaks down the chemical bond of the yeast and bacteria compound. And with it the smelly particles are released into the air.
Secondly, moisture also changes the compound chemically, which worsens the smell.
And according to this article by Wired, “humid air can hold more molecules (warm air does this too, and together heat and humidity can have a compounding effect on smell), and the higher concentration of molecules in the air means more can make their way into your nasal cavity to assault your olfactory receptor neurons.”
Yeast and bacteria are present in healthy dogs as well. But if you think your dog smells unusually offensive, something else could be at play.
As the animal grows older, the skin becomes less effective at managing the yeast and bacteria. So keep a look out for that.
The wet dog musty smell can be improved by increasing air flow and ventilating the space. If your car is smelling like your dog after a day swimming at the beach, air out the car.
When possible, open up the car doors and let the car interior dry in the sun. Air flow and sunlight will help dry the car interior out.
If the smell persists, a sprinkle of baking soda helps. Spread out a generous amount and let it sit. Vacuum up the baking soda residue.
How to eliminate pet odor from carpets
Carpet and rugs account for 54% of the flooring market in the United States. Although this is undoubtedly the trickiest flooring to clean, it still remains the most popular choice in American homes.
Soils on carpets are like icebergs. What you see at the surface is just the tip of the iceberg. The damage usually goes further down into the fibers. Liquid can flow down into the carpet backing and padding.
Source: https://www.sciencedirect.com/science/article/pii/S0360132319308017
In residential carpets, the backing is often made of latex, which is not very absorbent. However, the carpet padding is made out of “fiber, sponge rubber, or urethane foam.” If your carpet has a firm feel, it is most likely made out of fiber.
The fiber can be made with natural material like wool or jute, synthetic material like nylon and olefin or recycled textile fiber. These types of materials are more absorbent.
However, the majority of carpets would have the padding made of urethane foam which is not absorbent.
For carpets and rugs, you might need to use a combination of tools and cleaning agents. A winning combination of steam cleaner, carpet cleaner, enzyme-based cleaning solution and baking soda usually does the trick.
Step 1: Pick up the mess
Scrap out as much of the mess as you can. Start with some paper towel to scoop up the mess. Be careful not to apply too much pressure on it so you don’t push the mess further into the fibers.
Step 2: Use high pressure steam to saturate the spot with a steam cleaner
We recommend getting a canister-style steam cleaner that allows you to use a lance attachment. Stick steam cleaners are good for flooring, but only hard floor surfaces.
The lance tool will produce a very concentrated stream of hot steam, and you’ll have precise control of it.
If you have a thick, tight-woven carpet, you would need a steam machine that produces higher steam pressure. It is only with high enough pressure that it can penetrate the thick carpet fibers.
With one hand, direct the lance tool at the spot at a 45 degree angle. With the other hand, catch the steam that’s coming off the carpet surface with a microfiber cloth. The steam is to loosen the particles stuck deep inside the carpet fibers.
Some of the steam will start to evaporate, and the water droplets will contain some of the particles. You’ll need to catch it before it floats into the air.
Because liquid can flow further down into the carpet backing and padding layers, you’ll need to fully saturate the spot with steam. This is why stick steam cleaners are not very effective on carpets. The steam cannot penetrate deep into the carpet.
Step 3: Use a carpet cleaner
Once the carpet is properly saturated, use the carpet cleaner as a wet/dry vacuum to suck it all up. If you’ve applied a lot of steam to the carpet, you might want to start out with just extraction.
Extract as much of the liquid out of the carpet as you can. This will get some of the particles out of the fibers first, and will also make the drying process easier.
At this point, for tougher soils, you can pre-treat the spot with a more concentrated enzyme-based solution. Apply it to the surface and let it sit for at least 15 minutes. Don’t rub the cleaning solution, this will work the soils further into the fibers.
Now you’re ready to add hot water and enzyme-based cleaning solution to the water tank. Hot water, like steam, will do a better job at further loosening the particles.
Take your time to run the carpet cleaner over the spot several times. The motion is similar to using a vacuum cleaner, but at a much slower pace.
Allow the spot to dry down. Some carpet cleaners have features like blowing hot air onto the carpet to aid the drying process. Still, you’ll need at least a few hours to get the surface to be dry to the touch.
Step 4: Apply baking soda to further deodorize
In general, we recommend using baking soda over carpet deodorizing powder. Unless you’re confident that the carpet powder ingredients are safe for your pets, baking soda is usually the safer option.
On the dry carpet, sprinkle baking soda generously on the spot. Spread the baking soda around evenly, but try not to work it into the fiber. Let it sit for a few hours, overnight would be even better.
Finally, thoroughly vacuum the area to remove the baking soda. Repeat this process again if necessary to completely remove the pet odor.
Ambient air care: More Ways to reduce pet odor in your home
Aside from addressing the soil spots directly, there are other ways to reduce pet odors in your home. Here are some ways to improve the air quality indoors, which will also help with malodor.
Ventilation, airflow and humidity
Well insulated modern homes need good ventilation more than ever. Old houses built with more traditional methods and materials tend to have more cracks, gaps and holes that air can flow through.
Ventilation was not a big deal back then because of that. But ventilation becomes an important aspect of indoor air quality nowadays. Ventilation systems are generally divided into two categories:
- Exhaust-only or supply-only mechanical ventilation: This type of ventilation system only allows one way airflow. The exhaust-only ventilation “exhaust stale air and moisture generated” by generating a small negative air pressure in the home. It is a very common feature in bathrooms to expel odor outdoors.
- Balanced ventilation: This type of ventilation has an inlet and exhaust fans. You can control where the outside air is pulled from, where to deliver the fresh air and where to exhaust air out. This system can also be fitted with a heat recovery system. A balanced ventilation system is a better option.
Airflow and humidity are some of the factors that affect the smell indoors. A well ventilated home will be able to exhaust out odor pollutants and be replaced with fresh air. It provides odor control at all hours of the day, but controls the indoor humidity as well.
With well placed exhaust fans in spaces that produce more pollutants and moisture, such as the kitchen or bathroom, you’ll be able to draw them out before they float into the other rooms.
And similarly, you would want to place the inlet fans in living and resting areas to improve the air quality where you’ll spend most of your time in.
And when the weather and outdoor temperatures allow, open up the windows to allow for natural airflow. Cross ventilation is even better to allow air to properly circulate the space.
Air purifier
Residential air purifiers are outfitted with a few layers of filters to help combat different types of pollutants in the air. The different layers of filters have different purposes. They each target and filter out different types of pollutants.
One of the filtration layers is the activated carbon filter. Activated carbon targets volatile organic compounds (VOCs), odors, and other gaseous pollutants from the air.
According to research engineer Phillip D. Myers, “[c]arbon air filters remove pollutants from the air with a process known as adsorption.“
This is a different process from absorption. During adsorption, the pollutant molecules are chemically bonded to the carbon molecules.
The activation process of the carbon material is crucial to increase the adsorption rate. It increases the surface area that’s available for the pollutant molecules to bind to the carbon molecules.
Dr Myers writes that in order for the activated carbon filter to filter out pollutant molecules from the environment, it needs to be used correctly. Here are 3 rules to stick by:
- Using enough carbon: The general rule of thumb is the more carbon, the better the adsorption rate. The more carbon means a bigger binding site.
- Air flow and carbon filter thickness. A higher rate of air flow will ensure air passes through the filter more times. A thicker carbon filter is also better than a thinner filter because air spends more time passing through the filters. This allows even more odor pollutants to be captured.
- Replace carbon filter is needed: The pollutant molecules binding sites on the carbon filter is limited. Once the carbon is saturated with pollutant molecules, the carbon filter is completely useless. It can no longer take in any more pollutant molecules.
Cleaning supplies
Vacuum cleaners: Vacuum cleaners can take up a funky smell after a few rounds of usage. Especially if you’re vacuuming areas that are slightly damp, the smell can really start to build up.
For households with pets, it’s almost unavoidable to have some drool, water/food spillage, or accidents around the house.
The smell doesn’t go away if your vacuum is with or without a bag. It’s advisable to read the manufacturer’s instructions on how to clean and maintain your vacuum cleaner.
And in general, here’s what you should do when you’re trying to get rid of the smell in your vacuum cleaner.
- Empty the dust cup (or replace the dust bag). Give the dust cup a good wash with mild soapy water. Make sure to let it dry completely before reassembling it. Very old or scratched up dust cups can harbor bacteria more easily, so replace the dust cup if necessary.
- Wash the filter, replace if necessary. There are usually two filters, pre-motor filter and post-motor filter. Give each a good wash under running water, tap dry it and leave to dry completely before putting them back.
- Wash the attachments. All the hose, wand, brushes and nozzles attachments are usually washable, if they’re made of hard plastic. Rinse them under warm soapy water. Leave them to dry before using.
It’s very important to let the parts dry completely before reassembling. A 24 hour or longer drying time is ideal.
Moisture in the parts will make it a breeding ground for bacteria and mold. Letting the parts dry down will break the cycle, and keep the vacuum cleaner smelling fresher.
Cleaning sponge: A used sponge is never the same as a brand new one. Even if it’s been used only once, you can never clean it enough to return it to its original pristine condition. And in fact, Mythbuster confirmed that a used kitchen sponge is one of the most nasty everyday items.
The kicker is that cleaning it does not make a difference. A 2017 study on used kitchen sponges shows that “[s]anitation by boiling or microwave treatment … did not contain less bacteria than uncleaned ones.”
Frequent cleaning of the sponges does not reduce the number of bacteria, but could “increased the relative abundance.. [because the] resistant bacteria survive the sanitation process and rapidly re–colonize.”
So the best way to reduce bacteria load in used sponges is to replace them frequently. The researchers suggest on a weekly basis.
Carpets and rugs
Now let’s address the elephant in the room: carpets and rugs. A 2018 market research revealed that carpet and rugs account for 54% of the flooring market in the United States.
Although its market share dropped by more than 10% from a decade ago, carpet remains the most preferred flooring by far, in American homes.
Carpets are the primary source of volatile organic compounds (VOCs) indoors. According to research on the implications of carpet on indoor chemistry and microbiology, “[t]he term primary refers to chemicals that are present in the material when installed and are then released indoors”.
It is also “well established that carpets can serve as reservoirs for allergens that cause asthma exacerbations”.
Multiple studies have also demonstrated that “[c]arpet removal interventions have been shown to be effective at lowering asthma prevalence when combined with other allergen reduction measures.
Aside from health concerns, carpets “may create conditions hospitable to microbial growth… mainly through increased moisture content.”
Pet body odor is partly due to microbial growth on the pet’s skin. The increased moisture content in the carpet will dampen your effort to get rid of the smell.
The study also found that vacuuming, even at very rigorous levels, cannot get rid of all the dust, dirt and other contaminants buried in the carpet fibers.
A sensible solution to removing pet odor from the carpet is to simply have less carpeting in your home. It has been shown to be better for your health and indoor cleanliness and sanitation.
Hard flooring is simply easier to clean and maintain, especially with pets around.
Are you fighting a lost cause: When to toss out a very soiled carpet?
The only true way you can completely get rid of pet odor from your home is to replace the soiled carpets, rugs and upholstery.
We can improve how we’re cleaning these surfaces, and drastically improve the outcome. But very small traces of pet mess will still be deeply embedded in the carpet fibers or the foam.
If you cannot live with the thought of having even traces of pet urine on the carpet, then you shouldn’t.
If you’re struggling with an extra tough spot, or the old pet spots that have been left behind by the previous occupants of the home, we recommend replacing the carpet altogether.
Or opt for hard flooring instead. This will be good for your sanity, really.
Sources
Bushdid, C., Magnasco, M. O., Vosshall, L. B., & Keller, A. (2014). Humans Can Discriminate More than 1 Trillion Olfactory Stimuli. Science, 343(6177), 1370–1372. doi:10.1126/science.1249168
Kuehn M, Welsch H, Zahnert T, Hummel T. Changes of pressure and humidity affect olfactory function. Eur Arch Otorhinolaryngol. 2008;265(3):299‐302. doi:10.1007/s00405-007-0446-2
Hellström, D., Johansson, E., & Grennberg, K. (1999). Storage of human urine: acidification as a method to inhibit decomposition of urea. Ecological Engineering, 12(3-4), 253–269. doi:10.1016/s0925-8574(98)00074-3
Nery J, Biourge V, Tournier C, et al. Influence of dietary protein content and source on fecal quality, electrolyte concentrations, and osmolarity, and digestibility in dogs differing in body size. J Anim Sci. 2010;88(1):159‐169. doi:10.2527/jas.2008-1666
Khan SA, McLean MK, Slater MR. Concentrated tea tree oil toxicosis in dogs and cats: 443 cases (2002-2012). J Am Vet Med Assoc. 2014;244(1):95‐99. doi:10.2460/javma.244.1.95
Wood CL, Tanner BD, Higgins LA, Dennis JS, Luempert LG 3rd. Effectiveness of a steam cleaning unit for disinfection in a veterinary hospital. Am J Vet Res. 2014;75(12):1083‐1088. doi:10.2460/ajvr.75.12.1083
Cardinale, M., Kaiser, D., Lueders, T. et al. Microbiome analysis and confocal microscopy of used kitchen sponges reveal massive colonization by Acinetobacter, Moraxella and Chryseobacterium species. Sci Rep 7, 5791 (2017). https://doi.org/10.1038/s41598-017-06055-9
