Safe Flea Treatment For Dogs – Is Revolution Toxic To Dogs?

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Safe Flea Treatment For Dogs

Safe Flea Treatment For Dogs – Is Revolution Topical Treatment Safe For Dogs?


We have been using flea treatment called Revolution for our dog. Revolution is applied topically on dogs monthly. However, it seemed that our dog didn’t like Revolution when we applied topically on him. He seemed to be a little depressed on the day that Revolution was applied on his skin. It is a medication with a chemical smell. We hated giving our dog chemicals that we don’t even know what they are made of. Therefore, I wanted to research further if Revolution is safe for dogs. After all, fleas and ticks can transmit diseases to people and pets. Therefore, it is necessary to control and treat dogs for them. When we forgot to apply Revolution more than a month one time, fleas were present in our dog. Is there any non toxic treatment available for fleas and ticks?  In this post, I share with you if Revolution is safe for dogs and if any safe flea treatments are available.



Ways To Treat Dogs For Fleas and Ticks

There are two ways to prevent and treat dogs for fleas and ticks with medication. You can apply medication topically on dog’s skin (spot on treatment) or have a dog ingest a flea pill. Pills are taken daily until fleas and ticks are gone. Topical treatment is only done once a month since it lasts up to 30 days.  Topical treatments provide fast relief whereas flea pills are stronger and more effective. There are also flea and tick treatment shampoos, sprays and powders but they only last a short time and are temporary so they must be applied often usually daily to weekly.



Toxic Pesticides In Flea And Tick Products

The main ingredients of most flea and tick control products for pets use pesticides to kill fleas, ticks and other insects and worms.  Most conventional flea and tick products including collars, sprays, spot-on products, powders are registered as pesticide products and regulated by the EPA.  Pills are regulated by the US Food and Drug Administration.  Pyrethrum-based pesticide chemicals such as pyrethrum, pyrethroid, or permethrin are most common ingredients found in many flea and tick products.  However, they could be harmful for pets if not used correctly.  Toxicity in pets can occur from over-application or overdose of topical flea and tick products and overusing the products in wrong species.  It can cause muscle tremors, staggering, vomiting, diarrhea, difficulty breathing, excessive drooling, an agitated or over excited state, hyperthermia and possibly seizures. 

Many pet products including flea and tick control collars are also made with organophosphate insecticides (OPs). According to the report by The Natural Resources Defense Council,  seven organophosphate insecticides (OPs) are found in many flea control products such as flea collars. The seven OPs are chlorpyrifos, dichlorvos, phosmet, naled, tetrachlorvinphos, diazinon and malathion.  Dose responses of OP pesticides by pets have a narrow margin of safety. Therefore, if incorrectly used, it can cause diarrhea, vomiting, hypersalivation, dyspnea, colic, muscle fasciculations and weakness, seizures. It also affects respiratory, reproductive and developmental, organ, cardiovascular, hepatic, and immune systems. In acute poisoning, it can cause death. 

Health problems in humans may also arise from chronic exposure to organophosphate insecticides. The Natural Resources Defense Council suggested that even at low levels, organophosphates may be dangerous to human health, especially small children.  Tetrachlorvinphos is classified as possibly carcinogenic and malathion and diazinon were classified as probably carcinogenic to humans by the International Agency for Research on Cancer (IARC). WebMD also recommends to avoid all organophosphate.  

Each flea and tick control product uses different pesticide chemicals as active ingredients. Some ingredients are safer than others.  Pyrethrum-based pesticides and organophosphate insecticides should be avoided.  They can be toxic to both animals and humans particularly pregnant women or small children.  Pets can also be affected by licking other pets treated with above chemicals.



How Revolution Can Be Harmful To Dogs

So then, is Revolution safe? Revolution is one of the most well known flea and tick treatment for dogs. It is a topical treatment and applied once a month on the skin of a dog. Revolution works by penetrating the skin and entering your pet’s bloodstream. The active ingredient of Revolution is selamectin, an insecticide.  It kills fleas, ticks, ear mites. It also prevents heartworm disease and flea eggs from hatching.  Studies have found that slamectin is safe for dogs at recommended minimum dosage.  Large enough amount of Revolution, on other hand, can have effects on the central nervous system. In pre-approval clinical trials, less than 1% of cats and dogs have side effects such as vomiting, loose stool or diarrhea with or without blood, salivation, anorexia, muscle tremors, lethargy and tachypnea.  Selamectin seems to be considered to be safe when used at recommended minimum dosage but in large enough quantities, it can cause hair loss at the site of application, salivation, vomiting, diarrhea with or without blood, fever, lethargy, urticaria, ataxia, tachypnea, pruritus and erythema. There has been also rare reports of seizures followed by death with acute overdose.

Revolution also contains isopropyl alcohol and the preservative butylated hydroxytoluene (BHT) as inactive ingredients. According to the Environmental Working Group (EWG), BHT is not classified as a carcinogen but it could cause cancer in animals and developmental effects and thyroid changes in animals.  It may disrupt animal’s endocrine signaling.  Isopropyl alcohol is rubbing alcohol. Small amounts of isopropyl alcohol wiped on skin is safe. In large amount, it can penetrate skin and cause harm. It shouldn’t be used with organophosphate pesticides since it will make it penetrate skin easily. Although Revolution’s active ingredient is not pyrethrum-based pesticide chemicals or organophosphate insecticides (OPs), we don’t know its full list of inactive ingredients or how much of each ingredient is used. Inactive ingredients are proprietary and are considered to be a trade secret. Therefore, manufacturers are not required by law to list their inactive ingredients.



How Revolution Can Be Harmful For Human

When Revolution is applied to a dog, it usually leaves residue on the skin and hair coat for a month. One study shows that gloves contained significant transferable residue of selamectin after Revolution was applied to dogs wearing gloves. The highest concentration of selamectin was detected 24 hrs after Revolution application. The residue lasted about 4 weeks, with less residue found on week 2, lesser amount of residue found on week 3 and the least amount found on week 4. The study suggests that repeated exposure to selamectin can pose potential health risks to people who apply medication including dog owners. Since dogs have an insecticide residue after Revolution application, this exposure can have consequences to people especially small children.  

Insecticides are a type of pesticide that kill insects. Studies have suggested that small children are a lot more vulnerable to negative health effects from pesticides than adults. Their body and organ systems have not grown fully and matured that a children’s body can’t process toxic chemicals as adult’s’ body can.  A child’s brain, developing organs, reproductive, endocrine systems and immune systems can be damaged from toxic chemicals. A child can suffer the same injuries as an adult at lower level of exposure. Children also spend more time indoors than adults do and infants and toddlers sit and crawl on the floor.  Carpets and floors would most likely have pesticide residues from pet, dust or other sources. Children’s hand to mouth behavior also contributes to children’s exposure to pesticides.  

WebMD recommends to use topical products including selamectin (Revolution) sparingly, especially when pets are around pregnant women or small children.  They suggest that orally administered products have less exposure to other pets and children.  In Revolution’s warning label, it says Revolution may be irritating to skin and eyes in humans. It also warns that reactions such as hives, itching and skin redness have been reported in humans in rare instances. 

In my research, Revolution, on the other hand, is safer than other well-known spot on products such as Frontline (active ingredient: fipronil) or Advantage (imidacloprid) or Advantix (imidacloprid and permethrin).  Fipronil is classified as a possible human carcinogen by the United States Environmental Protection Agency. Advantix contain permethrin which is pyrethrum-based pesticide chemical. Permetrin is classified by the Environmental Protection Agency as a possible human carcinogen when ingested.  It is also very toxic to cats so it shouldn’t be used for or around cats.   According to the Pesticide Research Institute, imidacloprid may be toxic to the nervous systems of pets and people.  Insects are more susceptible and it is highly toxic to bees.  Pesticide Research Institute, lists fipronil, imidacloprid and permethrin as pesticide flea treatments to be avoided. Regular use of these ingredients can result in unsafe exposure from residue to pets and human especially to children and pregnant women.  Revolution is listed in the lower toxicity pesticide treatments. However, there is still concerns of residue on dog’s fur.



Non Toxic Flea Treatments For Dogs

Unfortunately there is no real organic, natural flea and tick treatments that are proven to be effective. Natural flea and tick treatments include bathing your dog, vacuum regularly, washing beddings regularly for pets and human, combing pets for fleas often.  You can also build your dog’s immune system and health by giving a dog healthy raw meals. Also, garlic (I wouldn’t feed my dog garlic though since it is supposed to be bad for dogs.) and B-vitamins are recommended for dogs since they make dog’s blood less attractive to fleas. There are always possibility of fleas and ticks and you have to be really diligent in keeping up with washing, cleaning, combing and feeding. It could be hard to be on top of flea and tick control naturally for some people.  For us, once we forgot to give Revolution to our dog, he had fleas right away.  

There are also some natural products that uses natural ingredients. However, you have to be careful before using natural products as well. Some pets and humans are allergic to natural essential oils such as clove, geraniol, wintergreen, and thyme. They can cause skin irritation and can be toxic to dogs if swallowed.  Pennyroyal oil is also highly toxic to dogs if swallowed.  Oil extracts from lemons and orange are not safe for dogs. They contain limonene and it is a skin irritant and can cause liver damage in cats and dogs when ingested.

Safe ingredients for natural home remedies include apple cider vinegar, lavender stems, lemon balm, cedar, juniper oil, garlic, diatomaceous earth (DE), fleabane, brewer’s yeast, citrus peel and essential oils.  They may or may not work for your dog and your dog’s current flea situation. When we forgot to apply Revolution on our dog during the summer he got fleas right away. I’m not sure if these natural home remedies may have worked when he had a lot of fleas. I think these natural ingredients certainly helps with fleas but I just don’t know how much.  Therefore, I am not certain that natural remedies should be used as a sole means of controlling fleas.



Low Impact Pesticide Flea Treatments

Then, are there any flea and tick treatments that are safer?  There are some low impact pesticide flea treatments available. They still use pesticides to kill fleas and ticks but their active ingredients are safer or less toxic than the ones that are recommended to avoid.  However, they are still pesticide products. Therefore, they shouldn’t be considered to be completely safe or harmless. According to the Pesticides Research Institute, the following are low impact pesticide flea and tick treatments. Some of them are prescription only treatments. 

*You should consult your vet regarding the below treatments. Some pesticides that are safe for dogs can be toxic to cats. Some pesticides that are safe for one species can be toxic to another species. Each pesticides also have different limits on dosage used depending on size, weight, type, age and health of dogs.



Spot On Treatments

Selamectin (Revolution) prescription only

Selamectin is an active ingredient in Revolution. It kills fleas, ticks, ear mites. It also prevents heartworm disease and flea eggs from hatching.  It is considered to be safer than other toxic pesticides that are also carcinogens.  However, there are still dangers of residue on dog’s fur. 




Nitenpyram (Capstar

Capstar is a pill flea treatment. It is given daily. Each pill is only effective for 24 hours. Capstar’s active ingredient is nitenpyram. It kills adult fleas and it doesn’t kill young fleas, larvae, or eggs. It also does not offer protection against ticks, mosquitoes, flies, heartworms or lice. Capstar works within 30 minutes and 90% effectiveness is achieved within 4 hours for dogs.  According to the book ‘Antiparasitic drugs‘, nitenpyram has a high margin of safety in dogs. Toxic syndrome such as salivation, vomiting, soft stools, tremors, lethargy and tachypnea is shown at 100 times higher than the recommended use rate. Capstar is also safe for pregnant or nursing dogs and cats.



Spinosad  (Comfortis)

Comfortis is a pill for flea treatment.  Its active ingredient is spinosad. It can kill fleas within 30 minutes and 100% effective within 4 hours.  The pill lasts for one month and it is taken monthly. According to the general fact sheet of spinosad by National Pesticide Information Center, spinosad is low in toxicity and other mammals. In one study, one dog out of 28 dogs vomited when fed low to moderate doses of spinosad. There were no spinosad related effects in other dogs.

In multiple studies, animals were fed low to moderate amounts of spinosad and no cancer or alter/ damage of genes were observed.  It is classified as not likely to cause cancer by EPA.  A common side effect of spinosad is vomiting so eating the tablet with food is recommended.



Methoprene  or S methoprene (Direct Protect Plus)

Methoprene is an insect growth regulator. It is safer than traditional insecticides. It kills flea eggs and prevents flea pupae and larvae from growing into adults.  According to a pesticide information project of cooperative extension offices of Cornell University, methoprene is relatively non-toxic when ingested or inhaled and slightly toxic by dermal absorption. Methoprene is not carcinogenic, mutagenic or teratogenic. It also doesn’t cause reproductive harm. It has very little danger or risk to humans or other non target species. In addition, it is not a skin or eye irritant. It can be used in spot-on treatment, spray, collar, pet shampoo, etc.  Some products contain methoprene with higher toxicity insecticide such as fipronil or permethrin which should be avoided. Direct Protect Plus, for example, is a brand that uses methoprene and fipronil as an active ingredient.



Pyriproxyfen  or Nylar

Pyriproxyfen (often sold under another name nylar) is also an insect growth regulator. It disrupts the life cycle of the flea by preventing eggs and larvae from developing into adults. It affects young insects and eggs of fleas. It doesn’t kill the adult fleas or ticks. It has low toxicity in humans and other mammals.  It has very low acute oral and dermal toxicity in mammals. It is classified as not likely to cause cancer in humans by the EPA. Some studies have shown some health effects when fed in high amounts of pyriproxyfen or in long term feeding.  The National Resources Defense Council (NRDC) recommends s-methoprene or pyriproxyfen as safer ingredients as long as they are not mixed or used with other more harmful pesticides such as imidacloprid or dinotefuran.  VetGuard® Plus contain pyriproxyfen but it also contains permethrin which is pyrethrum-based pesticide chemical and has higher toxicity. 



Lufenuron -prescription only

Lufenuron is also an insect growth regulator. This insect regulator disrupts insect hormones and prevents eggs and larvae of fleas from developing into adults.  It doesn’t kill adult fleas, ticks, mites or parasites. It is administered to animals orally once a month. According to the People for Ethical Treatment of Animals (PETA), insect growth regulators are a safe alternative to pesticides. Although side effects are usually rare, some sensitive animals have experienced vomiting, diarrhea, itchy skin or lethargy. 


Final Thoughts

It is truly unfortunate there are no natural products or natural ways to treat and control fleas and ticks fully. Without any prevention or treatments, your dog can be easily infested.  Therefore, it is necessary to prevent and control ticks and fleas.  There are some natural ways to prevent and treat ticks and fleas such as regular vacuuming, bathing your dog, combing and brushing dog’s hair and maintaining dog’s good health with good diet. There are also sprays, shampoos, powders that are made from natural ingredients.  However, they should also be used with caution since some natural ingredients are allergens or toxic to dogs. Some natural methods may work. However, they also may not work or may not be effective enough to treat tick and flea infestations.

If you decide to use chemicals to treat and control ticks and fleas, be aware that these chemicals are pesticides. Some pesticides are toxic and can cause adverse reactions to your pets. There are pesticides that are safer and less toxic than hazardous ones. However, they are still pesticides and they are not completely safe.  Some chemicals have a narrow safety margin. Therefore, ensure the amount used is not over the recommended dosage. Also, some chemicals are toxic to cats or different species of dogs. Therefore, research if the chemicals are safe for your pets.  Dog’s age, size, weight, type all should be considered when choosing a chemical treatment.  

Try to mix and rotate between natural methods and chemical ones to minimize the use of chemicals on your dog.  We don’t use Revolution on our dog during the winter season. We only use Revolution when the weather starts to get warm.  We also wash beddings & blankets, vacuum, brush dog’s hair more often when we don’t use Revolution.  Revolution is considered one of the safer spot on treatments. However, it does leave residue on the dog’s fur and it could affect our 3 year old child.  We considered switching to a pill treatment. My husband and I have been discussing this, however, we are not sure if feeding our dog pesticide chemicals is a better option.  For now, we are going to stick to Revolution during the warmer seasons. We told our daughter not to pet our dog on his back and wash her hands if she pets any dog.  We have been diligently combing our dog’s hair, vacuuming our place and washing beddings and blankets.   Although our dog is not ingesting a pesticide, it is still applied to his skin and goes through his blood stream.  This still concerns me.  I will be further exploring if there are better options for our dog. Hopefully, there are better solutions than using pesticides in the future. 




If you are interested in cruelty free make up products, please read ‘Cruelty Free Cosmetics – Organic, Natural, Cruelty Free Make Up Brands.’

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If you want to find out which company test on animals, please see my next post ‘Companies That Test On Animals – Don’t Buy From These Companies.’




  • go_new_mommy

    Isabelle has been an entrepreneur for last 16 years in retail and educational industry. She is also a mom. She is a mom entrepreneur who is always trying to find a better, easier way to run her business. She also tries to provide organic and non-toxic living environment for her child. She likes to research for the most non-toxic products or safe alternatives and share them with parents. In addition, she is against animal testing and supports cruelty-free products.


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