Ultimate Guide to Fleas on Dogs: Signs, Treatments, and Prevention

19 Minute Read
Updated May 13, 2021

If your dog’s got that seasonal itch, you might be dealing with fleas. Read on to learn all there is to know about fleas on dogs - how to spot them, treat them, and prevent them in the first place! As we head into warmer weather and bask in the long-awaited sunshine, the joy of leaving winter months behind might be clouded by one teeny-tiny little shadow…


Fleas are a nightmare for pet owners and furry friends alike, leaving a wake of itchy destruction that is as hard to get rid of as fleas are to catch.

For a creature that’s so small, fleas can have devastating consequences. Aside from being a pain in the neck (literally), fleas can lead to flea-related illnesses such as anemia from blood loss or tapeworms if left untreated. 

If you suspect your pet has fleas, your best bet is to take them to the vet who does a proper exam and recommends the right treatment to get them back to their best furry self.

In the meantime, to help put your mind at ease, we put together this guide to go over all things fleas - what they are, how to spot them, what to do when you think you have an infestation, and most importantly, how to prevent them in the first place. 

What is a Flea

Adult-flea-closupAside from being a total nuisance, of course - the scientific name for fleas is Siphonaptera, which includes about 2500 different species of fleas. Fleas are ectoparasites, meaning they live outside of their hosts and feed on their blood to survive. 

Historically, fleas have played a role in spreading some pretty terrible diseases, like the bubonic plague - Yikes. While common flea species in Canada aren’t packing that kind of a punch anymore, they can still spread diseases and parasites, like tapeworms in dogs. 

This is why you need to know how to recognize, treat, and prevent fleas on dogs. 

Anatomy of the Flea

Fleas are small, flightless insects that feed off of mammals’ and birds’ blood. These little brown bugs usually grow to be only about 1.5-3 millimetres in length or about the height of a penny or two. 

Their flattened shape allows them to run around easily through fur and feathers, evading even the sharpest of eyes, so you may not notice the fleas themselves. Instead, you’ll see the effects of fleas.

Fleas make up for their inability to fly with strong claws that grip onto their host and powerful back legs that let them jump distances up to 50 times their size. That tiny speck you practically need a magnifying glass to see can jump vertically up to 7 inches and horizontally up to 13 inches. Yikes!

Additionally, their little bodies are covered in plates that allow them to withstand the effects of scratching, which is frustrating news for you and your pup.

Life Cycle of the Flea

The flea life cycle goes through four stages: egg, larva, pupa, and finally, adult. When a flea hatches, it needs blood before it can mature and reproduce. 

Flea Eggs

A female can lay between a hundred to several thousand eggs in her lifetime, meaning it’s important to catch these suckers quickly! The eggs might be laid on their host, aka your poor pet, or can fall onto the ground. This means that wherever your friend walks around and shakes off or lays down could end up becoming a flea-hatching hotspot. 


When these eggs hatch into larvae, they prefer dark, humid places such as outside in your yard in dirt and sand or the crevices, carpets, and bedding in your home. 

Even though they feed off of blood, they actually do best when they have a varied diet that includes other organic material, your dog’s food, as well as nonviable flea eggs. Yuck!


The larva stage lasts between 4 to 18 days before it transitions into the pupa stage. In the pupa stage, the flea spins a cocoon in which it moults into its final adult form, which can take just 4 days but is ultimately dependent on a viable host. 

No host means the flea just hangs out in the cocoon, which is all fine and peaceful until a nice host comes along… and a mass flea exodus occurs.


Once that unsuspecting host shows up and triggers the flea to emerge, it has two goals: find blood, and reproduce. If it fails, it’ll only live a few days, but with enough food, an adult flea will usually live about 2 months. 

This doesn’t sound too bad until you remember that females can lay thousands of eggs in their lifetime, meaning that each female born will add to the infestation exponentially in a very short amount of time.

Types of Fleas in Canada


While you might hear of dog fleas and cat fleas, either species can get both. However, the most common type of flea you’ll find in Canada (and North America) is cat fleas, so if you suspect your dog has fleas, this is most likely the culprit.

Since these fleas aren’t too picky about their hosts, they’ll also feast on other animals and even you if given the chance. Cat fleas, scientifically named Ctenocephalides Felis, have been known to go after humans from time to time, though we aren’t a “complete and balanced” diet for them, so they would need a dog or cat host to complete their life cycle. 

Dog fleas are less picky (surprise, surprise!). Though they aren’t as common as cat fleas, dog fleas, or Ctenocephalides Canis, will feast on dogs, cats, and humans if we are convenient. 

When is Flea Season in Canada?

Fleas thrive in warmer climates, so even though Canada’s average peak flea season is August to October, it will depend greatly on the regional weather.

Areas of Canada with moderate climates, like Ontario, have a more typical flea season, but the prairies tend to have longer and colder winters that can bump peak flea season back a few months to that short period we call summer (shout out to my Albertans 😢). 

BC, who barely have a cold season, may have to worry about fleas all year round if the weather is right. To be safe, it’s best to treat spring and summer as prime flea season. Any warmer weather can allow fleas to reproduce quickly. 

Unfortunately, flea season tends to line up with popular camping and hiking seasons, so before you head for the trails, make sure you know how to protect your adventure companion from these pests. 

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Flea Bites On Dogs 

When a flea ends up on your pooch, it’ll puncture their skin with those sharp pincers so that it can draw blood to feed and reproduce. This bite leaves a raised nodule that is itchy and inflamed and can last for weeks. In some dogs who are particularly sensitive to fleas, all it takes is one bite to send them into itchy misery. 

Unfortunately, this annoying itch is just the beginning.

Where did my dog get fleas from?

So you saw the fleas hoppin’ all over your pet with your own eyes, or you went to your veterinarian who was able to confirm a flea diagnosis. 

You might be wondering to yourself how this happened. Even if you bathe your pooch regularly and they’re mostly home-bound, it doesn’t take much to get an infestation started.

Since fleas like other mammals and birds, it isn’t hard for your pet to pick them up from another furry critter. It’s possible that a squirrel, rodent, neighbourhood cat, or another dog shed the flea onto the ground, and it happily hopped right onto your pet. 

Anywhere where pets gather is an opportunity to swap fleas. For example, your pet could have picked it up from the dog park or at a playdate and been none the wiser.

Additionally, a mouse or rat could have gotten into your house and brought fleas along with them. 

Perhaps you had dormant flea pupae hiding in a crevice somewhere in your home, such as on a couch. Your dog could have been lying there and picked it up, continuing the life cycle.

Since the pupae can remain dormant for a long time, it is important to do a thorough deep clean of your house and all of your belongings after you take care of a flea infestation. The only thing worse than having fleas is getting them again because you didn’t take the right precautions!

7 Signs of Fleas on Dogs

beagle puppy scratching chin S

You might become suspicious of a flea infestation when your dog starts scratching themselves more than usual. They might also bite and lick at the sites of irritation. 

Since fleas like dark, humid areas, they’ll go for the neck, ears, lower back, abdomen, and tail base. However, they might be hard to spot because of their size and brownish colour, especially in dogs with darker, denser fur, so this likely won’t be the first sign.

To make it even trickier, it is rare to see live fleas on your pet because they typically only stay on their host to feed.

After the initial bite and itchiness, there are a few possible symptoms and outcomes that can torment your canine. 

1. Flea Bite Marks

This might be one of the first signs you think to look for when you notice your pet scratching. Flea bites will often happen in clusters, as well as in rows. In addition, you might notice a single puncture mark in the middle, similar to a mosquito bite. 

These bites will likely be hard to spot depending on the density of your dog’s fur, so it’s important to be paying attention to the other more overt signs.

2. Flea Dirt

It may look like regular dirt, but it is actually feces left over by the bugs. Flea dirt is one of the easier-to-spot signs and can often be found in hidden and warm areas, like their belly, armpits, and neck. 

To tell it apart from actual dirt, put it on a wet paper towel. The “dirt” will turn from brown to red - this is digested blood that was excreted.

3. Scabs

You might notice some scabs where your pet has repeatedly been scratching and biting. Whether or not the cause of the scratching is fleas, it is important to bring this up to your veterinarian, as the repeated reopening of these wounds can cause secondary infections and complications when bacteria get in the opening.

When bacteria get under healed skin, it can fester and form an abscess which is a much bigger issue. Proper wound and infection treatment is important, so talk to your vet to make sure you are using the right treatments. 

4. Hair Loss

The fleas themselves don’t cause hair loss - this is from the repeated itching and biting over the same areas. However, a bald spot could indicate that your dog has fleas, especially if the spot is in the “flea triangle” near the base of the tail on their lower back.

Hair loss can result from overgrooming, like licking and scratching, but can also be a result of inflammation at the bite sites. The next symptom on our list can cause this type of severe reaction. 

5. Flea Allergy Dermatitis

Some dogs react more strongly to flea bites than others. Therefore, if your pet has significant scabbing, hot spots, or hair loss, it is important to take them to the vet so they can run the appropriate tests to determine whether your dog has a hypersensitivity to flea bites.

Flea allergies are often mistaken for dog food allergies or environmental allergies. Unfortunately, this often leads to you treating the symptoms instead of the cause and prolonging your pet’s suffering. 

Pets with flea bite allergies need to take even more precautions to limit exposure to fleas. But first, talk to your vet to make sure you are doing everything you can to prevent flea bites and treat them quickly should they still happen. 

6. Tapeworms

Sometimes when your dog bites and licks in response to a flea bite, they end up swallowing a flea that’s been infected with tapeworm larvae. This is a common side effect of dog fleas. 

Once it’s ingested, the tapeworm can develop into an adult, where it matures in the intestines. Signs of tapeworms include visible segments of the worm that get passed in fresh stool.

Luckily, tapeworms don’t usually cause immediate harm to the infected pet, and your veterinarian can easily treat them with the right medication. 

7. Anemia

Anemia refers to a low red blood cell count. Since fleas feed on their host’s blood, it makes sense that significant flea activity could lead to anemia. This is especially true in puppies and small dogs with less blood volume, but thankfully anemia due to fleas is rare. 

Check the colour of your pet’s gums - if they are lighter than usual or white, take them to your veterinarian as soon as you can.

Anemia can be dangerous. If left untreated, anemia could lead to organ damage, brain damage, or death. If your pet is anemic because of fleas, they will need an aggressive intervention that addresses both the blood loss and persistent flea problem.

Confirm Your Dog Has Fleas

Even if you’re positive that your little friend has fleas, it can be hard to be sure of a diagnosis on your own. However, your veterinarian will know exactly what questions to ask, how to check for signs of fleas, and what to do to help them get better. 

Even if you’re 99% sure your pet has fleas, there’s always a chance that there is another underlying cause of the horrible itchiness that will go undiagnosed, and therefore untreated.

You don’t want to mess around with the wrong treatment by guessing as a diagnosis.

Your vet can also advise you on the best solution to quickly manage your dog's flea problem. The longer the fleas are allowed to hang out, the more they multiply. This means more fleas, not just on your dog but in your home. Talk about an unwanted guest!

One of the best indicators that the source of the problem is indeed fleas is the wet paper towel test. Take a wet paper towel to some of the suspected flea “dirt.” If it turns from brown to a reddish colour, then you’re most likely dealing with a case of fleas. Off to the vet!

If your veterinarian confirms that your pet has fleas, they’ll be able to prescribe the right treatment to nip it in the bud and get their tails wagging again!

How to Get Rid of Fleas on Dogs 


Fleas suck! (Literally!) Since you want to get rid of them ASAP so you can get your pet and your home free of these nasty parasites, you need a treatment that’s going to work and fast. Remember that the longer you leave the fleas untreated, the longer they’re allowed to multiply.

Be wary of using a remedy that isn’t meant for fleas. You don’t want to just take care of the problem halfway using a treatment that isn’t verified or by not doing it quite right. Not only could you prolong the problem, but you could unintentionally hurt your pet.

Additionally, don’t use a flea treatment prescribed for your cat on your dog, and vice versa. Use only as directed! The chemicals used to kill the fleas and eggs can be dangerous if used improperly. 

Here are some common treatments, in addition to those prescribed by your veterinarian, that you might use to get rid of fleas on your dog.

1. Flea Shampoo

Flea shampoo is an easy, low-risk first step in getting rid of the little devils. Zodiac Double Action Flea & Tick Shampoo for Dogs & Cats is fast-acting and will kill adult fleas, in addition to killing flea eggs for up to four weeks. This gentle formula uses coconut oil, lanolin, aloe, and oatmeal to help soothe angry skin and is suitable for sensitive types. It is recommended to use the shampoo monthly for residual problems and weekly for severe cases. The last thing you want after getting rid of the fleas is for them to come back because you didn’t get them all!

2. Diatomaceous Earth

Diatomaceous earth is a topical treatment made up of silicon dioxide, a powder made from fossilized aquatic organisms called diatoms. Baie Run Diatomaceous Earth is odourless and non-staining and can be applied to an affected area. However, when fleas or other bugs crawl over the powder, it destroys their exoskeleton and kills them.

While diatomaceous earth is a safe and natural formula, it isn’t always as effective as chemical flea treatments. Find out more about it in Diatomaceous Earth for Dogs

3. Flea Treatment

Flea treatments designed to get rid of infestations come in many formats, some more effective than others. Flea shampoos and flea sprays are one way to kill off any live pests that are causing your pooch discomfort, but they do have limitations. It's easy to miss spots and the infestation could return. 

Flea medications that are applied topically are the most effective option for getting rid of fleas at all life stages. They contain ingredients that not only rid your pet of fleas but also inhibit the eggs from hatching, causing them to die off too. 


Flea collars are a popular treatment method, but it's worth noting that flea collars aren't always effective. Flea collars repel fleas, but only from the area that the collar sits. They can deter flea infestations, but more often, the fleas are smart enough to avoid the collar and stick to your dog's belly and hindquarters. 

The last part of preventing a recurring flea infestation is to treat your house. These little bugs can live in warm soft fabrics like carpet and furniture, so a flea treatment for your house can help evict these pests for good. 

Shop All Flea & Tick Solutions

3. Oatmeal Treatment

An oatmeal treatment like Tropiclean OxyMed Medicated Oatmeal Treatment can help soothe itching and flaking from fleas. In addition, it can help hydrate your pet’s coat and bring some much-needed relief!

One thing to consider before using an oatmeal-based treatment is that dogs with yeast issues will likely have an adverse reaction to these grooming products. This is because yeast feeds on sugar, so oatmeal or any grain-based grooming product will only feed the yeast and worsen the itch. 

4. Flea Combs

Flea combs are small combs with really close teeth that allow you to physically pick out live adult fleas. Of course, this won’t get rid of the infestation, but it can help to reduce some of the annoying and uncomfortable bites while other treatments work to kill any developing fleas.

In addition to your veterinarian’s prescribed treatments and the treatments listed above, it is extremely important to make sure your home is cleaned and sanitized before bringing your pet back inside. The last thing you need after dealing with a flea infestation is to have some pupae hanging behind. Remember that all they’re waiting for is a host… Don’t give them the opportunity!

Your veterinarian will be able to discuss the best options for making sure your house is spick and span and ready for your friend to come back home. They may also recommend products for your outdoor space. Make sure to follow their instructions to completion! 

Misused flea treatments are one of the easiest ways to welcome those pesky fleas back into your home.

When cleaning, make sure you pay careful attention to cracks and crevices where fleas like to hang out, such as under baseboards and heaters. Wash all bedding several times over the next few weeks, as it can take up to three months to eliminate an infestation. Then, vacuum daily, and dispose of the vacuum bag in a sealed bag immediately outside.

Bayer Advantage II

Flea Prevention for Dogs

Ultimately, the best flea treatment is prevention. You’ll definitely agree with this if you’ve already dealt with a case! Seasonal flea treatments, regular grooming, and random spot checks will all help to reduce the possibility of flea infestations on your dog. 

Once you start noticing the signs of fleas, they’ve likely already started laying eggs. So get to them before they get to your dog using these preventative measures!

1.  Bug Spray

A bug spray with natural essential oils can help ward off bugs, including fleas. Citrobug Insect Hunt for Dog and Horses Spray is made from camphor, pine needles and geranium while being free from deet, harmful ingredients, and paraben so you can feel more at ease while your dog plays outside! 

These sprays are not 100% effective, so on their own may not completely protect your dog from infestations, but when combined with other preventative measures, they can further reduce your dog’s contact with fleas and other pests. 

Note that while this product is safe for all dog breeds, it is not safe for cats. Keep this in mind if you have a multi-pet household. 

Shop Citrobug

2. Flea Protection

Bayer offers several topical once-monthly flea protection products that can help prevent and control a flea infestation. There are several options to choose from according to the size of your dog. So whether they’re small, medium, large, or extra-large, know that you’re taking an extra step to protect your pet from fleas! This product starts working 12 hours after application and is waterproof after 24 hours.

3. Clean Often

Don’t forget to wash your pet’s bedding periodically in hot water and dry on high heat or in the sun to kill any eggs or larvae that might be present.

Vacuum your carpets often, especially wherever your pet likes to lounge around. Pay special attention to any crevices that are good hiding spots for fleas.

Diatomaceous earth can be used around your house to prevent fleas from spreading indoors. For example, you can treat carpets, furniture, and bedding with a light dusting of diatomaceous earth powder. 

Home Remedies for Fleas on Dogs


If you prefer a more natural approach for flea prevention on dogs, there are some safe options. Not all homemade flea remedies for dogs won’t work for every pet, but they are effective for some. 

Here are a few natural prevention methods that can help keep your dog flea-free:

1. Apple Cider Vinegar

A more acidic skin environment is unappealing to fleas, so applying a diluted apple cider vinegar solution to your dog’s skin can help to deter these pests from migrating onto your pet. Pure apple cider vinegar is too potent, so dilute the vinegar with water to at least a 50/50 ratio, but even weaker to reduce the strong vinegar odour. 

The dilution can be sprayed on your dog’s fur, but to avoid getting the acidic mixture near your dog’s face or any open wounds, you can more accurately apply the solution by pouring some on a soft cloth and gently rubbing the mixture onto their skin and coat.

Apple cider vinegar is also safe to ingest, though not all dogs like the taste. If your dog or another pet grooms after you apply the remedy, it isn’t harmful. 

2. Garlic

This one is controversial because it’s a common misconception that dogs can’t have garlic. To help clear this up, yes, garlic can be toxic to dogs if fed in large doses, but you would have to feed an unreasonable amount of garlic for your dog to have adverse effects. 

In more appropriate portions, garlic has many health benefits, one of which is an effective pest repellant. The best way to get this effect is to feed garlic to your dog—¼ cloves of garlic per 10 lbs of body weight. 

So a 50 lbs dog should only have about 1 ¼ clove of garlic per day. Start with half that and work your way up. Start feeding a few weeks before flea season and continue until fall. 

Other benefits of garlic include anti-bacterial, anti-viral, and anti-parasitic properties. 

3. Essential Oils

This one is especially tricky because essential oils can be very effective. But can also be used improperly. Essential oils can’t be used as-is, or they can be toxic. So instead, essential oil needs a fat or oil base, like MCT coconut oil. 

Here are a few essential oils that can help to repel fleas and other pests:

      • Lemon
      • Eucalyptus
      • Peppermint
      • Lavender

Check this helpful article from Dogs Naturally Magazine for more info on how to safely use essential oils for dogs. 

Prevent - Check - React


Fleas certainly aren’t fun, but they aren’t the end of the world. When you know what to look for and how to protect your pooch, you can go back to enjoying your favourite outdoor activities without the fear of a pesky infestation. 

When you pay attention to the signs and act fast, you can get you and your furry friend back to living your best, flea-free lives in no time! Just remember to prevent, check, and react. 

Routine flea prevention isn’t hard, but it needs to be consistent, especially during peak flea seasons. Find a method that works for you, and make sure you start your prevention treatments at the first signs of weather warming. 

Now that you know the signs of fleas on dogs make sure to add a regular flea check to your dog’s weekly routine. Daily brushing, weekly deshedding, and any other grooming routines are excellent opportunities to spot check for flea activity and other skin conditions. 

At first signs of flea activity, talk to your vet to get a diagnosis so that you can start treating as early as possible. The fewer eggs that are laid, the quicker the infestation can be resolved. 

If at any point you aren’t sure if your dog has fleas, if the treatments you are using are working, or if your dog has an adverse reaction, then it’s time to contact your vet again. It’s better to be safe than sorry, especially because fleas can cause complications and can quickly spread around your house and to other pets. 

What’s your go-to flea prevention method? Share your tips and success stories in the comments below!

Written by

Homes Alive Pets


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