My cats had bad breath but since adding this liquid to the water, I have noticed a slight decrease in odor. The size of product isn't that large but since we only use a little, it should last a while. I'd say it seems decent value for money. There was no leakage was product arrived, it's simple to use. I just add the recommended dosage to water. Initially, my cats suspected there was something different because they sniffed around a few times and walked away. After a few days they got used to it and drank their water as usual. I did notice loose stool on one of my cats, since I had made no other changes to their diets, I suspect that she might have had a reaction to the water. However, the bottle stated that we can reduce the dosage if cats are sensitive to it. I'm still keeping an eye out but so far she seems to be tolerating the product. I'd still recommend because it really does reduce the bad breath without having to brush their teeth.

This product is easy to dispense and my animals were never aware of this product in their water.
I have a large dog am elderly cat and a two year old cat and I use it for all of them. Bad breath has vanished and gums and teeth are looking better.

If your dog suddenly has really bad breath/bleeding you should get his teeth checked out BEFORE using this product. I adopted a 13 yr old chihuahua mix who previously had some teeth taken out two years ago. His breath was stinking super bad suddenly and I noticed some blood on his greenies and toys so found out he had to get 7 more extractions and part of his jaw broke off during the process because his teeth/gum was so rotten . Even tho he has 6 teeth left I bought this to prevent any more extractions and to help his gums. He didn't have any more stinky breath after extractions but I'm hoping this will prevent any more tartar/plaque. He did not have any side effects from it and I started with a smaller amount than usual. He also drank water normally and didn't notice this in it. It has almost no flavor or smell to it seems like.

We have two chihuahuas, Frankie on the left and Sammie on the right (Rat Pack references), and if you know anything about small dog breeds, then you know they're prone to bad breath. As lovable and affectionate as these two are, their breath was so bad we could barely stand to let them near us. In fact, if they climbed on the couch and started grooming themselves, it smelled like a rotting corpse was laying next to you. We've tried a number of water additives over the years, with absolutely no success. However, in the spirit of not giving up, we decided to give this Oxyfresh Premium Water Additive a try, albeit with little hope that it would actually do anything at all. Much to our surprise it's worked miracles. Within a week we noticed a HUGE difference. While their breath doesn't smell minty fresh or anything like that, and what dog's does really, it has rid their breath of about 90% of the stench, which is now entirely tolerable. Now we don't cringe when they jump on our laps and get in our faces. They are both such affectionate members of our family, and this stuff makes getting and giving them that love a real joy. I know some people have voiced concerns in the comments about some of the ingredients, but after two solid months of use, we've noticed absolutely no adverse side effects whatsoever. We asked our vet, and she said she has no concerns with them ingesting this water additive, as long as we stick to the recommended dosage. If your dog suffers from really bad breath, I can tell you this stuff has really worked for us.
UPDATE: 8/23/2021
So I've seen a number of reviews claiming that this product contains toxic ingredients, so I spoke with my vet today and did a bit of research. I also responded to someone who had a question about this product, so I'll just paste my response here, and hopefully it will answer a lot of concerns others are having about some of the ingredients in this product.
We've been using this with our dogs for a couple of months now, with absolutely no issues whatsoever. However, today one of my dog's rabies shots were due, so I showed this to the vet. To paraphrase our conversation after showing her some of the comments on Amazon, she basically said the following regarding Sodium Hydroxide being toxic: "Well yeah, if you consume unhealthy amounts of it, then yes, absolutely. But then again so is toothpaste. HOWEVER, Sodium Hydroxide is used in a number of human and pet products in very low amounts to regulate the acidity. It helps regulate the pH balance. It's also used in a number of medications for humans and pets, as well as human and pet foods."
So after our conversation I went home, did a little more research and here's what I found. "Sodium hydroxide is used to help manufacture a variety of medicines and pharmaceutical products, from common pain relievers like aspirin, to anticoagulants that can help to prevent blood clots, to cholesterol-reducing medications. Municipal water treatment facilities use sodium hydroxide to control water acidity and to help remove heavy metals from water. Sodium hydroxide is also used to produce sodium hypochlorite, a water disinfectant. Sodium hydroxide is used in several food processing applications, such as curing foods like olives or helping to brown Bavarian-style pretzels, giving them their characteristic crunch. Sodium hydroxide is used to remove skins from tomatoes, potatoes and other fruits and vegetables for canning and also as an ingredient in food preservatives that help prevent mold and bacteria from growing in food."
"The Food and Drug Administration (FDA) allows sodium hydroxide as a food additive at levels lower than 1 percent."
As for Chlorine, if you're giving your pets tap water from a municipal water supply, then it contains chlorine. I did a little more research on this as well, and here's something I found. "The best source of chlorine is ordinary table salt, but chlorides are also naturally contained in meat, milk, and eggs. Almost all canned foods have salt added during the canning process."
As for Carrageenan, I found the following: "Carrageenan is an extract from a red seaweed commonly known as Irish Moss. This edible seaweed is native to the British Isles, where it's been used in traditional cooking for hundreds of years. It's also widely used in the food industry, mostly as a thickener and gelling agent."
As for Paraben, I found the following: "Typical food products which contain parabens for preservation, include beer, sauces, desserts, soft drinks, jams, pickles, frozen dairy products, processed vegetables and flavoring syrups. Some fruits, such as blueberries, contain parabens as a naturally occurring preservative."
My vet also explained that dogs, much like humans, are very diverse, and as with humans, some dogs are sensitive to things other dogs have no problems with. For example, my wife cannot eat fatty foods without becoming very ill, so she has to avoid as much fat in her diet as possible. I on the other hand have no problem with fatty foods, as anyone who's seen a picture of me can certainly attest. If my dogs aren't having any adverse issues, and my vet doesn't have a problem with it, then I don't have a problem treating their bad breath issues with it, as it's truly been a miracle worker, where every other products we've tried has failed. From all the information I've gathered, if your dogs tolerate it well, then I can't see anything that would cause them any underlying problems. As mentioned earlier, there are a lot of common ingredients humans and pets consume every single day that would be potentially very toxic if not properly dosed. I'll leave the rest for you to decide what's right for your furry loved ones.

We have two large dogs and four cats. I add this solution to their drinking water daily. None of them seem to notice it, and it hasn't affected their rate of drinking. I've only been using it for a few weeks, so I won't know how well it affects their tarter build-up until after their next vet appointments, but it definitely has helped with their breath, so I assume it is helping with build-up as well. My older dog's teeth seem to be cleaner and more white than they used to be also. I'm very pleased so far.