Flea and Tick Products that are poisonous to some pets ... Some cats are especially sensitive and most of the problems we vets see is when people apply over the counter flea products designed for dogs on cats.

The active ingredients that cause the problem in sensitive pets are Pyrethrin, Permethrin, and other Pyrethroids such as etofenprox, allethrin, fenvalerate, resmethrin, and sumethrin,

Common brands names include Adams, Bio Spot, Duocide, Happy Jack, Hartz, K9 Advnatix, Mycodex, Ovitrol, Proticall, Raid, and Zodiac.  These products are available as collars, sprays, shampoos, foams, and spot ons.

When Pyrethrins first became available they were very effective and in general much safer than the organophosphate poisons we had be using in the 1970's and before.  Pyrethrin based flea products smelled nice and was a "natural" product coming from the Chrysanthemum family.  Mums and Marigolds.

It didn't take long, though, for the fleas in South Carolina to become resistant to natural pyrethrin and more potent, more stable, longer lasting synthetic variations became available.  These types of compounds affected the nervous system of insects and were very effective when applied on a regular basis.

But these more potent forms of pyrethrin and permethrin also affect the nervous system of pets and smaller dogs and many cats will get very sick with these products.

DO NOT use permethrins on cats and DO NOT use any product on a cat unless it is specifically made for cats.

Another problem is that these products aren't working nearly as well as they used to.  They seem to work well for only a few days and that means more frequent application to be effective and that means more expense and more exposure to the toxic effects.  Please click here to go to our page about recommended flea control products.

The most common signs are excessive salivation, tremors, twitching, lack of appetite, vomiting, diarrhea, incoordination, hyperactivity, disorientation, vocalization, depression, difficulty breathing, and seizures and Death.


Bathe and thoroughly rinse the animal if dermal exposure occurred.

If ingested, induce vomiting if the product does not contain petroleum distillates.

Get to your vet. We have the antidote (atropine) for many of the symptoms.  Additional treatment is likely to include repeat bathing if the poison was applied to the skin, induction of vomiting, gastric lavage (stomach pumping), activated charcoal or other absorbants, seizure control medications, control of hypothermia, and supportive care

Prognosis is usually fair to good but some of these patients die.

Organophosphate and Carbamate Pesticides .... often the poison used to kill
ants, termites, wasps, garden pests and many other nuisance insects.

Unfortunately, these products present a risk to our household pets when a dog or cat is accidentally exposed to the poison, usually by eating the bait or poison.

Although there are a host of different active ingredients found in these preparations, many of them can be grouped into two categories:

Organophosphates and carbamates.

Both organophosphates (known as OP's) and carbamates have similar toxic effects which involve disruption of the normal nervous system function by causing an excess of the neurotransmitter, acetylcholine, to accumulate in the body. Although acetylcholine is a necessary body chemical for normal nervous and muscular function, this excess or overdose, causes severe clinical signs that can result in the death of the animal.
If an animal is exposed by eating a poison containing OP's or carbamates (or, less frequently, absorbing the substance through the skin in a dip product) it can experience a number of clinical signs.

These include excess saliva production, lacrimation or tearing of the eyes, excessive urination, diarrhea, muscle twitching, weakness, difficult breathing and collapse.

It is critical than an animal potentially exposed to these insecticides be evaluated by veterinary personnel as quickly as possible in order to provide treatment if necessary before signs become severe, at which point treatment is often ineffective.

Bring in the container, if possible, so we can see what specific poison is involved.

Treatment is the same as for Pyrethrin poisoning discussed above but the
Prognosis is only fair to good.

Metaldehyde Based Poisons

Snail, slug, or rat poison, or ingestion of a poisoned snail, slug, or rat. Sometimes metaldehyde is also present in the heating fuels used in small heaters.

Anxiety, twitching of the muscles and eyes, acting drunk, muscle tremors, dilated pupils, panting, drooling, seizures, fever, trouble breating, and death.

The pet may survive the early stages of the poisoning and then succumb to complications such as organ failure in the next 3-5 days.

Induce vomiting by giving your pet oral hydrogen peroxide, very salty luke warm water, or ipecac syrup.

Give milk, cream, Milk of Magnesia, or PeptoBismol to help absorb the toxin and prevent absorption into the blood stream.

Get to your vet.  Treatment will probably include gastric lavage with milk, activated charcoal, seizure control medications, hospitalization for several days, IV Fluids and other supportive care.

Prognosis is fair to guarded.


Rotenone; a natural poison made from the root of the Derris plant, also known as the tuba root or aker tuba.

Rotenone is a common insecticide in many sprays, powders, dips, and topical medications. These include Duradip, DuraKyl Pet Dip and Spray, Ear Miticide, Goodwinol Ointment, and KC Ear Mite Drops.

WARNING: Rotenone is very toxic to pigs, snakes, and fish and should not be used if these species are in the household.

Vomiting, lethargy, depression, acting drunk, muscle twitching, seizures, respiratory failure, and death.

If the toxicity is due to skin contact, bathe the animal in warm water with dish soap. Rinse thoroughly and avoid allowing the animal to become chilled.

If ingested, induce vomiting.

Get to your vet.

Veterinary Care is likely to include gastric lavage, actived charcoal, hospitalization, seizure control medications, IV Fluids, Oxygen therapy, and supportive care until better.

Prognosis is usually good.


Amitraz is found in Mitaban Liquid Concentrate,  Preventic Tick Collars for Dogs, Cattle Dips for Mange, and The New Flea and Tick product called Promeris

Amitraz is a very potent and effective nerve agent insecticide.  It's the only available pesticide I know of that does a decent job of repelling and killing ticks.  It's also the only available pesticide I know of that does a good job on demodex mange.

But it's also potentially toxic to dogs if over dosed, if the dog is especially sensitive, or if by combining it with other nerve agent pesticides like some over the counter fleas sprays or spot on the dog is overdosed.

Cats are so sensitive to this poison, AMITRAZ CAN NOT BE SAFELY USED ON CATS

Another potential problem is that severe toxicity may occur if amitraz-containing collars are ingested.

Some dogs feel lousy for a day or act subdued after applying amitraz.  But this seems to self correct without treatment.

More serious side effects include low blood pressure, decreased body temperature, elevation of blood glucose, dilated pupils, slow heart rate, slowed intestinal rate, acting drunk, sedation, vomiting, diarrhea, and seizures. Death may occur.

Remove the source by removing the collar or giving a good bath and rinse.  Dry to prevent chilling.
If the pet ingested all or part of an amitraz-containing collar, induce vomiting.

Then get your pet to the vet.

Veterinary care for ingestion is likely to include forced vomiting or gastric lavage.  Veterinary care for Promeris or Dips will be repeat baths and rinsing.

Supportive care for the low blood pressure, low body temperature, control of nausea, seizures, and so forth.  That means hospitalization, IV fluids, and close monitoring.  The medication Yohimine may be given to help reverse the toxin.

Prognosis varies widely from poor to Good for dogs and very poor for cats.


Arsenic is not commonly available anymore in the U.S. but it's still found in some ant and roach poisons, herbicides, and wood preservatives.  Apparently, some types of insulation contain some arsenic.

Arsenic is damaging to the GI tract, kidneys, lungs, and skin.

Vomiting, restlessness, drooling, nausea, severe abdominal pain often with bloody diarrhea with mucous in it, muscle weakness, trembling, staggering, dehydration, shock, paralysis, coma, and death.

Induce vomiting

Get your pet to the vet.
Treatment there will probably consist of gastric lavage, activated charcoal, IV fluids, GI medications, control of nausea, Chelators, and prayer.

Prognosis is grave.  Most arsenic poison cases die.  If you're using Arsenic based products, take extra care to store and use these products very carefully.

Borate, Boric Acid, and Boron.

Ant and roach baits, flea products, herbicides, fertilizers, denture cleaners, contact lens solutions, antiseptics, disinfectants, cleaning compounds, and mouthwash.

These generally safe products weren't intended to be eaten, but you know pets ... they don't always read the instructions.  Ingesting boric acid compounds can damage the intestines, the nervous system and the kidneys.

Drooling, vomiting, abdominal pain, diarrhea, depression, acting drunk, over reactive reactions to noise or touch, muscle weakness, tremors, seizures, blood in the urine, decreased urine production, coma, and death.

Induce vomiting if ingested. Seek veterinary attention. If dermal exposure occurred, thoroughly wash the pet with warm soapy water. Dry thoroughly.

Activated charcoal, which is used in most other types of poisoning is unfortunately not very effective with boric acid cases.
Treatment will include IV fluids and other supportive care.

Lawn Chemicals
Lawn chemicals are sometimes dangerous to pets because they can cause contact rashes...but also fairly severe internal inflammation when the pet licks off the irritating chemical.    

Be careful.  The main treatment is to wash off the fertilizer, weed killer, or whatever ... and if the symptoms are serious .... get your pet to the vet.

What's On This Page:

A discussion about lots of common pesticides that are dangerous to pets.

Also about the dangers of using dog flea and tick products on cats

This is a very rough first draft ... please be patient

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Home; Poisons 

Antifreeze Poisoning

Poisonous Plants

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Grapes, Raisin, Chocolate and other foods that sometimes cause Poisoning   

Medicines that sometimes are poisonous including Tylenol or acetaminophen poisoning 

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Pesticide Poisoning
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