Fleas on your dog? How to get rid of them and prevent them from coming back

Reading time: about 18 min

Some time ago, a client called me and said she suspected her dog had fleas. To be honest, my first thought was probably the same as that of many dog owners: is this really still a problem in Estonia? It is. Fleas are not only a “country-life problem” and they are not a sign of a dirty home. They can arrive via another animal, the environment, a car, a shed or even brief contact, and a centrally heated home suits them perfectly well even when it is cold outside.

The client’s question was very practical: can fleas be eliminated with gentler and more natural approaches, or should you move straight to more intensive parasite control? Based on what we know today, a one-word answer makes little sense. With a low-level infestation and a healthy dog, you can start much lower: flea combing, bathing, environmental cleaning and close monitoring. If there are many fleas, the dog is allergic to flea bites, the dog is a small puppy or there is no clear improvement trend, it is not wise to keep stretching home measures indefinitely.

If you find one flea, deal with the dog and the environment at the same time

This is the most important point in the entire article. The adult flea is only the part of the problem you can see. Eggs fall from the animal’s coat into the environment, larvae hide in carpets, under furniture and in cracks, and the pupal stage can persist for a long time when a suitable host is absent. That is why a dog can have a completely “clean” day and then pick up a new flea the next day even though nothing new has been brought into the home.

ESCCAP points out that the most common flea on dogs and cats in Europe is actually the cat flea, Ctenocephalides felis, rather than the dog flea the name might make you expect. A female C. felis can lay an average of about 20 and a maximum of 40-50 eggs per day, and those eggs rapidly fall into the environment. Under favourable conditions development from egg to adult can be fast, but a flea inside the pupa can delay emergence for months. Merck’s 2026 guidance therefore also emphasises that fully clearing an established infestation may take up to three months.

How can you tell whether your dog has fleas?

Sometimes you really will see a fast-moving or jumping flea. Much more often, however, you will see tiny black-brown specks in the coat, especially around the lower back, tail base, abdomen or thighs. These may be flea faeces, or digested blood.

Use a fine-toothed flea comb and comb the dog slowly over white paper or a light-coloured towel.

If you find black specks, place them on damp white paper. Flea faeces dissolve into a reddish-brown stain because they contain blood.

Check the tail base, lower back, backs of the thighs and underside of the abdomen especially carefully. In a dog with flea allergy, the skin damage can be far more extensive than the number of fleas would suggest.

If the dog is extremely itchy but you cannot find fleas, that does not rule out flea allergy. A hypersensitive dog may remove fleas quickly through licking and chewing.

Why are fleas more than just an annoying itch?

A flea bite may cause simple itching, but in some dogs flea saliva triggers flea allergy dermatitis, or FAD. Put simply, this is allergic skin inflammation: the immune system reacts too strongly to flea saliva, and in a very sensitive dog even one or two bites can trigger intense itching. A very small flea burden can therefore cause a disproportionately strong reaction: the dog licks, chews and scratches, the coat thins and the skin can become inflamed. Self-trauma may then lead to hot spots and secondary bacterial or Malassezia infections.

With small puppies or a very heavy infestation, blood loss and anaemia also need to be considered. Fleas are also intermediate hosts for the tapeworm Dipylidium caninum. The goal is therefore not simply to “relieve the itch”, but to break the infestation while also treating any skin damage that has already developed when necessary.

Treatment options at a glance

Method	What it is useful for	Weight of evidence	When to expect change	When to escalate
Flea comb	Detecting a low flea burden and mechanically removing adult fleas	Good adjunct, not treatment of the whole life cycle	Flea numbers should decrease within days if the environment is also under control	If there is no clear downward trend within 7-14 days or itching is severe
Bathing	Rapid mechanical reduction of adult fleas and cleaning the skin	Adjunctive measure	The flea burden may drop immediately after bathing	If frequent bathing dries the skin or fleas return quickly
Vacuuming + textiles	Reducing eggs, larvae and environmental flea biomass	Important part of integrated control	Over weeks; fully clearing the environment may take 2-3 months	If infestation persists despite consistent cleaning
Natural adjuncts	Selected low-risk situations and supportive use	Limited and highly variable by method	Only within a monitored trial period	If there is no clear effect or skin/respiratory irritation develops
Veterinary ectoparasite medicine	Heavy, recurrent or rapidly controlled infestation; flea allergy dermatitis (FAD)	Strongest evidence for rapid flea control	Depends on product, often hours to days for adult fleas	Adverse effect, unsuitable product or lack of control despite correct use

1. Flea comb: the simplest place to start

If the dog has only a few fleas, the skin is calm and the dog is otherwise healthy, a fine flea comb is a very reasonable first step. Comb at least once a day and keep a bowl of soapy water beside you. After each pass, dip the comb into the water so the flea you removed cannot simply jump back into the room. Combing also gives you the simplest possible measure of progress: are the number of fleas and the amount of flea dirt actually decreasing?

A flea comb does not, however, deal with eggs, larvae or pupae in the home. So “I found no fleas today” is a good sign, but it is not yet proof that the problem has gone for good.

2. Bathing can help, but do not turn it into a new problem

Bathing can reduce the number of adult fleas on the dog and, in a very itchy dog, remove irritants from the skin. In a small dog, an ordinary bath combined with careful combing can be a very effective mechanical step. At the same time, there is no need to bathe the dog automatically every week for months if the skin is becoming dry or the flea burden has already disappeared. Watch the skin and reduce the frequency as soon as bathing starts to cause dryness, redness or more itching.

3. Cleaning the home is not extra work: it is part of the treatment

If one animal in the household has fleas, check every animal. ESCCAP stresses that common reasons for treatment failure include not treating all animals at the same time and overlooking “hot spots”. Those areas are not limited to the dog’s bed; they can include the sofa, car, carpets, spaces around skirting boards, a shed or any other place where the animal rests.

At the beginning of an active infestation, vacuum every day in the areas where the dog spends the most time. Do not make only an “aesthetic circle” across the middle of the floor: go under furniture, along edges and into cracks as well.

Wash the dog bed, blankets and other washable textiles on the hottest programme the material can safely tolerate.

Empty the vacuum cleaner container or bag after a thorough clean and do not keep the collected debris in the living area.

If the dog spends a lot of time in the car or sleeps in a shed or garage, treat those as part of the infestation environment too.

Complete disappearance may not be linear. New fleas can continue to emerge from pupae for weeks after adult fleas have disappeared from the dog. Consistency therefore matters more here than one enormous cleaning day.

4. What about natural options?

One distinction is important here. “Natural” does not automatically mean effective or automatically mean safe, but “the evidence is limited” does not mean every low-risk option is pointless. FendaF uses the same logic here as elsewhere: if the potential benefit is realistic, the risk is low and quickly noticeable, and trying it does not delay necessary treatment, a gentler option can be reasonable to test. But with an active flea infestation, you need both a measure of progress and a stop-rule.

Apple cider vinegar

With apple cider vinegar, two claims need to be separated: does it kill fleas, and can it be used as a low-risk repellent adjunct? There are no good dog-specific studies showing that apple cider vinegar kills fleas. At the same time, several integrative veterinary sources recommend it as a topical repellent.

Dr Karen Becker recommends a 50:50 mixture of raw apple cider vinegar and water for the dog’s coat, and Balance Veterinary Care describes the same dilution for skin and coat care and for repelling fleas, ticks and biting insects. The 50:50 solution therefore remains in this article as an integrative practical recommendation, not as a proven flea treatment.

Practical use: mix 1 part apple cider vinegar with 1 part water. Lightly spray onto healthy coat or apply with your hands. Avoid the eyes, nose, mucous membranes, ear canal, open wounds and severely inflamed skin. For sensitive skin, test a small area first or begin with a weaker dilution. If redness, stinging, licking or scratching increases after use, rinse it off and stop. Apple cider vinegar may serve as a repellent adjunct, but in an active infestation it does not replace flea combing, environmental control or, when needed, effective ectoparasite treatment.

For oral use, Dr Becker gives a practical guideline of about 1 teaspoon of apple cider vinegar per 20 lb, or roughly 9 kg, body weight mixed into food. She does not recommend putting it into the dog’s only drinking water because the taste may reduce water intake. This is an integrative veterinarian’s practical guideline, not a flea-control dose confirmed by a study. Stop if the dog develops gastrointestinal irritation or refuses the food.

Diatomaceous earth

Food-grade diatomaceous earth works physically: the dry particles damage and bind lipids in the insect’s outer layer and promote desiccation. NPIC emphasises that diatomaceous earth works only when dry. At the same time, its very fine dust can irritate the nose and respiratory tract when inhaled. This is exactly why the method of use matters as much as the substance itself.

In the environment, use only food-grade diatomaceous earth and apply a very thin layer. Avoid creating a dust cloud during application, wear a mask if necessary, keep animals and children away from freshly dusted areas, and focus on cracks, around skirting boards and other dry places. Bark & Whiskers’ 2026 recommendation is to leave the powder in place for 24-48 hours and then vacuum it up thoroughly. Its effect is reduced or lost in a damp environment, so applying it to a wet surface and expecting immediate action makes little sense.

Sources disagree about use directly on the dog. Dr Becker has recommended applying food-grade diatomaceous earth very lightly along the dog’s back, while conventional veterinary sources warn against direct dry-powder application because of possible skin, eye and respiratory irritation. FendaF’s practical compromise is that, if it is used on the dog at all, a wet application that reduces dust is preferable: the old FendaF practical guideline is 1 tablespoon of powder per 1 litre of water, lightly sprayed onto the coat and allowed to dry completely. The mixture does not work while wet; any effect can begin only after it dries. Wet application may be less effective than dry dusting, but it reduces airborne dust during application. This mixing ratio is a FendaF practical guideline, not a clinical-study dose.

Safety limit: do not spray the dog’s face or around the nose, avoid the eyes and inhalation, use only on healthy skin and stop if dryness, redness, coughing or sneezing develops. Diatomaceous earth is not a good first choice for a dog with very dry or inflamed skin. And because it does not cover the entire flea life cycle, it should not be used as the sole method if the infestation persists.

Garlic

Garlic is another topic where both extremes are too simplistic. Yes, a very large amount of garlic can cause oxidative damage to a dog’s red blood cells. In a classic study, dogs were given 5 g of fresh garlic per kilogram of body weight every day for seven days and clear changes appeared in the blood. That is, however, a very large amount. In another study, a standardised aged garlic extract given for 12 weeks at 45 or 90 mg/kg caused no clinical or haematological changes. Form and amount therefore really do matter.

Flea control is a separate question. A 2020 Veterinary Evidence review found no in-vivo studies in dogs that could establish what oral or topical garlic dose prevents, repels or kills fleas. If you use garlic as part of the diet for another reason, that is a separate question of dose and safety, not the primary treatment for an active infestation.

Essential oils and homemade sprays

The right conclusion with essential oils is not “remove them all”, but “the right oil, a very low concentration, the right species and a clear stop-rule”. A 2026 critical review found biological activity against fleas and ticks for several essential oils, but standardised field data on efficacy and safety remain more limited than for medicinal products. Pet Poison Helpline also emphasises that risk rises with concentration and that concentrated essential oil should not be applied directly to the skin of a dog or cat.

Dr Becker’s homemade dog repellent spray recipe is: 235 ml clean water + 118 ml organic unfiltered apple cider vinegar + 20 drops neem oil. If the dog tolerates essential oils, only 5 drops of ONE essential oil may be added. Her listed options are lemon, lemongrass, eucalyptus or geranium. For FendaF’s home version, I would favour geranium or lemongrass from that list; Pet Poison Helpline includes eucalyptus oil among oils associated with poisoning in dogs and cats, so I do not see a reason to add that particular risk to a DIY mixture.

Essential oil must always be diluted. In this recipe, 5 drops are dispersed through roughly 350 ml of base liquid, so the concentration is very low; never add the same oil undiluted directly to the dog’s skin. Because essential oils do not dissolve evenly in water, shake the bottle very thoroughly immediately before every use. Spray lightly onto the body, not onto the face or around the eyes, nose, mouth, genitals or damaged skin. Test a small area the first time. If skin irritation, intense licking, drooling, vomiting, tremors, loss of balance or breathing difficulty develops, wash the product off and contact a veterinarian.

Much greater caution is needed with cats. Cats metabolise several essential-oil compounds less effectively and can also ingest them by licking their coat. A DIY spray containing essential oils and intended for a dog must not be transferred to a cat. In a multi-species household, do not allow a cat to lick a wet, freshly treated dog. With neem, too, do not assume that “not an essential oil = automatically safe for cats”: NPIC describes adverse effects in cats after neem use as well. Choose a separate species-specific solution for cats.

Natural flea-control and safety

5. When is it sensible to move straight to more effective parasite control?

A mechanical and environmental plan makes the most sense when the infestation is small, the dog is otherwise healthy and you can monitor the situation very consistently. With a heavy infestation, the advantage of a veterinary ectoparasite medicine is predictable and rapid control of adult fleas. Merck and ESCCAP treat effective flea control on the animal together with environmental control as standard management, especially in flea allergy dermatitis (FAD) or a heavy infestation.

Medicines are not risk-free either, and they should not be treated as one large category. The active ingredient, route of administration, duration of action, dog’s age, weight, health conditions and other animals in the household all affect the decision. The FDA considers isoxazolines safe and effective for most dogs and cats, but warns that neurological adverse events have been reported in some animals, including tremors, ataxia and seizures. This risk is especially worth discussing if the dog has a history of neurological symptoms.

Always read the label of the specific spot-on product. Some permethrin-containing products intended for dogs are highly toxic to cats, so in multi-species households contact with a treated dog also has to be considered. If a reaction develops after a topical product, the EPA recommends washing the animal with mild soap and plenty of water and contacting a veterinarian promptly.

The goal is not to choose the “most natural” or the “strongest” option. The goal is to use as little intervention as possible and as much as necessary, without making the dog pay for experimentation through itching, skin inflammation or anaemia.

Practical FendaF 14-day flea plan

1. Day 0: comb the dog thoroughly, give one bath if needed, check every animal in the household and vacuum the dog’s main resting areas. Wash washable textiles.
2. Days 1-7: comb every day and keep a simple count of how many fleas or how much flea dirt you find. During an active infestation, clean the dog’s resting areas, furniture edges and cracks every day.
3. If you use a gentler adjunct such as a 50:50 apple cider vinegar spray, diatomaceous earth or a diluted essential-oil repellent spray, change only one thing at a time. That way you can tell whether it helped or irritated the skin. The same stop-rule applies to all of them: if the dog becomes itchier, the skin reddens, coughing/sneezing appears or any other new reaction develops, stop and rinse the product off if necessary.
4. Days 8-14: you should be seeing a clear downward trend in adult fleas, flea dirt and itching. An occasional new flea may still emerge from the environment, but the overall picture should be moving in the right direction.
5. If there is no clear downward trend, there are many fleas, the dog is damaging its skin or the dog has flea allergy dermatitis (FAD), meaning allergic skin inflammation triggered by flea saliva, do not continue the same plan indefinitely. Move to the next level and choose effective flea control together with your veterinarian. Continue environmental cleaning even when you use medication.

When should you contact a veterinarian?

• • A puppy or very small dog is lethargic, the gums are pale, breathing or pulse is faster than usual, or there are very large numbers of fleas. These may be signs of anaemia.
  • The itching is so severe that the dog cannot sleep, chews the skin until it bleeds, or develops extensive hot spots, weeping wounds or a bad smell.
  • There is no clear improvement trend within 7-14 days despite consistent combing and environmental cleaning.
  • The dog has a history of seizures or other neurological symptoms and you are considering an isoxazoline-containing product.
  • There is a cat in the household and you are planning to use a topical product on the dog. Check the active ingredient and label first because some dog products can be dangerous to cats.

In summary

With fleas, it is easy to make mistakes in two opposite directions. One is to reach automatically for the strongest product without assessing the dog, the risk and the product separately. The other is to stay with home measures too long when the dog is already suffering. A practical middle ground works better: start low when the situation allows it, measure the real treatment response and escalate promptly if the result is not sufficient.

And do not forget the environment. A flea is not only the little jumping creature on the dog. An infestation is dog + other animals + home + time. If you deal with all four at once, you have a much better chance of actually breaking the cycle.

Sources used

• Merck Veterinary Manual – Fleas in Dogs and Cats (2026)
• Merck Veterinary Manual – Flea Allergy Dermatitis in Dogs and Cats (2026)
• ESCCAP Guideline 03 – Control of Ectoparasites in Dogs and Cats
• Companion Animal Parasite Council – Fleas
• FDA – Potential adverse events associated with isoxazoline flea and tick products
• US EPA – Controlling Fleas and Ticks on Your Pet
• EMA – Activyl Tick Plus (indoxacarb/permethrin; cat risk)
• Buckley LA. Can garlic prevent, repel or kill fleas that infest dogs? Veterinary Evidence. 2020
• Lee KW et al. Hematologic changes associated with the appearance of eccentrocytes after intragastric administration of garlic extract to dogs. AJVR. 2000
• Safety and efficacy of aged garlic extract in dogs. BMC Veterinary Research. 2018
• Bark & Whiskers – Looking for a More Natural Way to Fight Fleas? (2026)
• Bark & Whiskers – All-Natural Pest Deterrent for Pets (Dr. Karen Becker, 2024)
• Bark & Whiskers – Spritz This on Your Pet to Nix These Pesky Parasites (2018)
• Balance Veterinary Care – Apple Cider Vinegar for Dogs?
• National Pesticide Information Center – Diatomaceous Earth Fact Sheet
• Korunic et al. – A review of natural insecticides based on diatomaceous earths (2016)
• Pet Poison Helpline – Updates on Essential Oils
• Essential Oils for Flea and Tick Control in Companion Animals: A Critical Review (2026)
• Adverse reactions from essential oil-containing natural flea products in dogs and cats (2012)
• National Pesticide Information Center – Neem Oil Fact Sheet

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