I may receive a commission if you purchase through links in this post. I am not a doctor; please consult your practitioner before changing your supplement or healthcare regimen. As an Amazon Associate I earn from qualifying purchases.
This post shares an Alternative to Flea Medicine for Cats: Colloidal Silver, and shares how I use it. This change started two years ago when my vet suggested I try a new flea medicine, and my cats all ended up sick from it. It turns out, he hadn’t had much experience with it himself, but it was a new product, so he recommended it. One of my cats disappeared for days after the dose, with digestive problems after he returned, and another was very sick for weeks, with throwing up and compromised digestion.
Of course, I spent hundreds of dollars on that appointment and the medicine.
The following summer, I thought about what causes fleas in house cats, and that’s what led to my discovery that colloidal silver is a better choice for our family.
In this article, I share how much colloidal silver I add to cats’ drinking water for flea prevention.
Is it safe for cats to take colloidal silver
Yes, in fact, holistic vets use colloidal silver for various symptoms: wounds, abscesses, sore throats, colds and flu, cystitis, diarrhea, eye and ear infections, removing plaque on teeth, boosting immunity, skin infections and breakouts, reducing ulcers and some types of tumors, hot spots, feline herpes, ringworm, candida, yeast infections and toe nail fungus!
It makes sense that colloidal silver is an easy remedy for chronic seasonal issues like worms and fleas.
What causes fleas
I learned from one vet that ongoing flea problems are actually caused by internal worms. He acted like this was so obvious and everyone knew it, so I didn’t think at the time to ask more questions. But it was an epiphany that caused my discovery about colloidal silver.
He told me that products like Revolution, yes, kill fleas and flea larvae, but their most important role is killing intestinal worms, that allow fleas to flourish.
Sadly, it turns out, this information is not readily accessible. Perhaps it’s because the flea problem is too easy to stop if we 
understand how, and then we’ll stop buying expensive products.
But it took me a lot of digging to even speculate how fleas benefit from worms.
How worms benefit from fleas is easy to find information:
Fleas and worms are closely linked as the lifecycle of certain worms involves fleas harboring worm eggs in their gut. Cats eat fleas when they groom themselves and end up with worms in their stomach. The worms flourish, and cats end up with two parasites, one external and one internal.
But how do worms support fleas
This part is truly my own speculation, because I can’t find the information directly, but here’s what I currently guess:
Worms of all kinds produce significant amounts of carbon dioxide. Fleas and other parasites are extremely attracted to carbon dioxide. In fact, it’s one of the main ways they choose their hosts. Fleas choose their hosts based on the amount of CO2 coming off the animal.
As one study reports, “CO2 is an essential host-seeking cue for these parasites.”
Another source states, “Studies have shown that fleas will jump wildly when CO2 is introduced into an enclosed test environment. Other studies indicated that flea activity increased when CO2 was released in short bursts…”
We see this even in humans. Anyone who has a parasite infestation can observe: They attract more bugs than people who do not play host to invasive pathogens. Whether mosquitos, bed bugs or fleas, parasites are attracted to parasites.
If we can kill internal parasite overgrowth, in this case worms, our cats are no longer attractive hosts for external parasites.
If fleas can’t smell potential hosts, and in so doing grab food and shelter, they’ll die. As Wiki says, “Without a host to provide a blood meal, a flea’s life can be as short as a few days.” We can see here how easily a flea population will die down if we make potential hosts “invisible” by smell.
How I introduced colloidal silver for fleas
Having used colloidal silver for years for our family, and knowing it kills worms, and is safe for pets, I knew it logically could work as a flea preventative.
Last summer, I did not give my cats flea medicine because of the injury caused to them the prior year by the new flea medicine.
Instead, I started putting colloidal silver in their drinking water. The result: zero fleas all summer.
Wow, what freedom, how cheap and how convenient.
No expensive vet appointment — and an effective easy alternative!
This summer, the weather’s been very hot for many weeks, and warm for a while. I started colloidal silver in their water about a month ago, and not one flea yet.
This method works so well. I just can’t get over it.
How much colloidal silver to add to cats’ drinking water for flea prevention
I put 1/2 to 1 teaspoon colloidal silver per cat — in 1-1/2 to 2 cups of drinking water for my cats daily (so up to 1 tablespoon total in 2 cups water, because we have 3 indoor/outdoor cats). During the summer, they’re very thirsty, so they drink most of that.
If I use colloidal silver on them other times during the year, (for example, if worms are suspected), I use a higher ratio in their drinking water, because they don’t drink as much.
I am not a vet, and I don’t pretend to have the perfect recipe for you. Rather I am sharing what I do, and that it absolutely works great, and it’s cheap.
My cats haven’t had any health issues since their problem with the flea medicine two years ago. My cat with the chronic digestive issues has improved digestion since I began the silver. I think he tends toward pathogen overgrowth, so the silver really helps to keep him free of invaders.
How to dose colloidal silver for acute symptoms
If I see worms on my cats (which I did once this past year), I use 1 teaspoon per cat in cat’s water (or feed with syringe if acute situation presents — up to 2 to 3 times daily).
For those of you with dogs, who are wondering how this applies to your canine, 2 teaspoons are recommended for dogs weighing 26 lbs to 40 lbs, 3 teaspoons for 56 lbs to 80 lbs, 4 teaspoons for 101 lbs to 150 lbs — all 2 to 3 times daily. (source)
Can you use colloidal silver year round in cats’ water
While colloidal silver is considered gentle and safe, I don’t think it’s ideal to give year round constantly.
What I do is use it all summer long, and as soon as the weather cools off, I stop. If I notice worms the rest of the year, I’ll use it again for a month or so, and then stop again until summer.
If you live in a place where the weather never cools off, you might consider pulsing colloidal silver, for example: Two weeks on to start, one week off, then one week on, one week off, or similar, to find the right balance.
What colloidal silver to use
I like this brand the best, but other products will work, too.
We make our own, which is why it’s extra cheap. This is the machine we use.
Flea medicines aren’t good for us or the environment
A lot of us with pets just ignore this issue, because we love our pets, and we don’t know an easy alternative to keep fleas at bay. But as long as we have that alternative with colloidal silver, it’s a great time to be honest.
The risks posed by parasiticides are significant:
Recently, concerns have been raised that some of these medicines are contaminating the environment. Parasiticides could be reaching rivers through wastewater from homes or other premises where animals are kept, or from animals entering rivers. Parasiticides may also be excreted in urine and faeces, and therefore deposited in gardens and open spaces, and absorbed into soil. As parasiticides are harmful to a wide range of invertebrates, this could be highly detrimental to wildlife and ecosystems. This in turn could impact on public health. (source)
One more reason to use an alternative to flea medicine.
I’d love to hear your results with using colloidal silver for preventing fleas!
You can Pin Alternative to Flea Medicine for Cats: Colloidal Silver here:
Skye says
This so timely and appreciated as we just got two kittens a couple of months ago and discovered a flea two days ago! My holistic vet said I could try Revolution, which is selamectin (a parasite treatment like ivermectin), but silver would be even better! Thank you for sharing, Megan! My dog once had a terrible adverse reaction to Frontline, and my husband’s brother’s family lost their gorgeous young dog to cancer after giving her oral flea medicine, so I will never use either of those conventional flea treatments.
Question – my cats and dogs share the same water bowls. Would you dose the water for cats or dogs?
Thank you, Megan!
Megan says
Hi Skye, thank you for sharing your experiences (including your family members’). Those are valuable warnings. I would dose for cats, so they don’t get too heavy of a dose, but then I would also hand dose the dogs maybe once a week during flea season, meaning, use an oral syringe to give them a larger dose. I would even do this a few days in a row to start, 2 times daily, to kill off any initial worms, and then perhaps weekly the larger oral dose as maintenance. Of course they’ll slurp up more of the water from the water bowl, too. You might have to kind of figure it out intuitively as you go, to see what works just right. I’m so glad the article came at the right time for you!
Emily Marx says
Hello Skye ~ lovely name !
There is an animal sanctuary called Dr.goodpet.com ~ they also have a line of amazing homeopathic remedies for animals. We tried their product “ Flea Relief homeopathic liquid”
(you put a few drops in your pets daily water).
We’ve been doing this for 30 years and haven’t seen a flea yet.
It’s also extremely cost-effective and the frosting on the cake is there are never any side effects from using homeopathy and you can’t overdose either.
if you call their fone number
staff will answer questions about your pet for free, they’re all very kind and helpful..
Truly a wonderful organization !
If you have pets, you should check out their extensive list of remedies.
we recently had our senior cat, develop a rash on his spine, and after trying their product,” scratch relief,” his rash is now all gone.
There’s also a remedy for when your pet gets scared and anxious due to storms rain, being alone whatever.
Their list is quite extensive for wonderful remedies that have no side effects whatsoever because it’s all homeopathic and you don’t have to go incur the expense of going to a Vet and getting toxic prescriptions. For more information on homeopathy for humans see the wonderful book: “ The Family Guide To Homeopathy” by Dr. Alain Horvilleur, M.D.
Kind regards all around,
~ Nell
Megan says
Awesome, Nell, thanks for sharing all of that!
Kevin V. says
Interesting research, thank you for your ideas!
I am on the Gulf Coast and fleas are always a problem but this year we have been getting them as early as late February. I have four household cats who never go out, but I track them in from my feral cat rounds. One cat in particular has had terrible dermatitis from reactions to flea bites, a second one not quite as bad and two with short, thick hair very little.
I have used Advantage II in the past without bad reaction from the cats, but it no longer seems effective. Two weeks after they are treated I start seeing them again. I am using virgin coconut oil now to kill the ones that are crawling, and then I use food grade diatomaceous earth as a residual to both control later flea that are born and it also dries out the coconut coated hair : )
Re colloidal silver: I have used it for years myself and it is as close to a miracle compound as anything I’ve found. Cuts, styes, burns etc., plus disinfecting surfaces, it does it all. I have used liberal amounts of CS on tom cats who were terribly beat up in fights, bloodied badly. A week after using it liberally, they are getting pink skin back, no sign or smell of infection. It is amazing.
Just on a whim, I tried using the colloidal silver I make on the two cats’ dermatitis, to try to help heal them as they of course are scratching the wound a lot. They both immediately let me apply it and gently rub in, and then I noticed they both were falling asleep without the incessant scratching. I don’t think it was killing fleas, I think it was soothing the lesions from the flea bites. I’m sitting here watching them and they both are in deep sleep now.
I am going to be going with the CS a lot more regularly on them topically, and based on your information, more consistently in the drinking water. I have a small fountain they love to drink from so getting them to take enough should not be a problem.
Thanks again for you info. You are right over the target with the reco for colloidal silver. Anyone who is skeptical should try it for him/herself. It will make a believer out of them.
Megan says
Thanks for sharing all your uses and success with CS, Kevin! Great to hear. I finally got a water fountain for my cats, too, and it’s a huge hit: finally clean water daily without feeling sabotaged by all the dust and bits about, not to mention stray cat food. Thinking about the CS in there is comforting, too, when I think about it killing any slimy things that may want to grow in the pipe work of the machine where it’s hard to clean.