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A vet of 35 years explains the real reason your cat can eat all day and still lose weight...

It is almost never how much she eats. After all these years, I finally learned what it really comes down to. And it is something no cat food label will ever tell you.

Tue. May 5th, 2026 | 11:11 am EST - 238,392 👁

Written by Dr. Sam Calloway

If you have a cat who eats well and still keeps losing weight, please read this.

 

My name is Dr. Sam Calloway. 

 

I am a vet. I have been one for more than thirty five years.

 

And for most of those years, I gave owners the wrong advice about this exact problem.

 

I did not know it was wrong. It was what they taught me in school. It was what every vet is taught.

 

So I passed it along, the same way it was handed to me. It made sense. It just did not work.

 

Then I discovered something that changed the way I look at every bag of cat food on every shelf.

 

I am not going to promise you a miracle. I do not do that.

 

I am only going to tell you the truth, in plain words, so you can decide for yourself.

 

The day I finally understood this, it was already too late for the cat I loved most.

The cat I could not save...

For years, cats came into my clinic with the same story.

 

A worried owner. A cat that ate just fine. And a cat that kept getting thinner anyway.

 

And for years I gave those owners the same advice.

 

Feed her more. Try a richer food. Add some calories. She will come back up.

 

Then one day it stopped being a story I heard at work.

 

It was my own cat.

 

She started dropping weight, slow at first. And I did exactly what I had told a hundred owners to do.

 

I fed her more. I bought the richer food. 

 

I followed the whole routine I had trusted my entire career.

 

The first few weeks, she seemed alright. I told myself it was working.

 

Then she went downhill fast.

 

She got weak. She stopped jumping up next to me. And not long after, I lost her.

 

Thirty five years of training. All those letters after my name. And I could not save the one cat that lived in my own house.

 

That broke something in me.

 

I could not accept that I had done everything right and still watched her fade.

 

So I did the thing I should have done years before. I stopped treating the symptom, and I tore the whole problem apart.

 

And when I finally dug into what had happened to her, I discovered something I had missed my entire career.

 

There was a hole in her food. A missing piece. A nutrient that had quietly starved her from the inside while her bowl was full.

 

It had killed my cat, and I never once saw it coming.

 

What I found next changed the way I look at every bag of cat food on every shelf. 

 

And it starts with one thing I had spent my whole career underestimating.

Why a full bowl was not enough

There is one nutrient your cat needs just to stay alive.

 

One her own body cannot make. Not a single molecule of it.

 

Without enough of it, the heart begins to weaken. The eyes start to fail. And the food she eats goes only half used, the fats never fully broken down.

 

It has to come in through her food. There is no other door.

 

It is called taurine.

 

Dogs make their own. People make their own. Cats cannot.

 

So every bit of it your cat has, she got from what she ate. There is no backup supply inside her.

 

And taurine is a huge part of how she breaks her food down and pulls the goodness out of it. How she absorbs it.

 

So when she runs low, the food still goes in just fine.

 

But her body cannot take up what is inside it.

 

The food more or less passes through her without doing its job.

 

Which means she can clean a full bowl, three times a day, and only keep a small piece of what she ate.

 

It was never about how much was going in.

 

It was about how little was staying  with her.

 

It is like pouring water into a glass with a hole in the bottom.

 

You can keep pouring all day. It still will not fill.

 

For years I had been telling owners to pour more water. Not one of us was fixing the hole.

 

But that left one obvious question. The bag says taurine right on it. So why was my cat starving for it.

 

The answer is the part that still makes me angry.

The part the label will not tell you

That number on the bag is very often worked out on paper.

 

From the raw recipe. Before the food is ever cooked.

 

It counts the taurine in the ingredients as they go into the mix.

 

But taurine does not survive heat well.

 

And pet food gets cooked hot.

 

By the time the bag is sealed, a big part of it is gone. In many cases only about a quarter is left.

 

And nobody goes back to measure the finished food. The number was already printed.

 

So sit with what that meant for me.

 

Every single day, with the best food money could buy, I was setting down a bowl that had already been robbed of the one thing keeping my cat alive.

 

I was doing everything right. And I was starving her without knowing it.

 

That is a hard thing to carry.

 

And then I found the second half of the problem. The part hiding in the very supplements I was about to start recommending.

The thing hiding in most supplements

At first I thought the fix was easy. Just add a taurine supplement.

 

Taurine is taurine. Right.

 

Then I asked one question I had never thought to ask.

 

Where does the taurine in most of these products even come from.

 

I would have guessed meat. Something an animal would eat.

 

It is mostly not.

 

Most of the taurine added to cat food and sold in supplements is made in a factory.

 

It is made from petrochemicals.

 

The same petroleum that gets refined into fuel and into plastic.

 

That is where it starts.

 

It becomes taurine on paper, so the makers can hit the small amount they need to earn the complete and balanced label.

 

It is the cheap way. It is the normal way. And it is added in the smallest amount they can get away with.

 

So I went looking for a better one.

And what I did not find is the whole reason this exists.

What I decided to make instead

I searched and searched.

 

I read the labels. I read the reviews. I went through brand after brand after brand.

 

And I realized there was not one. Not a single one. NONE.

 

There was not one company making this from natural sources, the way a cat is actually built to take it in.

 

That was the moment it hit me that if I wanted it to exist, I was going to have to make it myself.

 

So I did. After a long stretch of searching and testing and getting it wrong, I finally landed on the formula.

 

Taurine from natural sources. Real animal material. 

 

Around ninety nine percent natural. The exact form a cat's body knows how to use.

 

And I wanted to know if that even mattered once it was inside the cat, or if I was just telling myself a nicer story.

 

So I tested it.

 

The cats took up the natural form quite a bit better than the factory kind. Close to half again as much.

 

Turn that around, and it means a cat on the factory version is keeping only about half of what she is given.

 

So picture the cats I had been seeing all those years.

 

A food with most of the taurine cooked out of it. And a supplement they could only half absorb.

 

No wonder feeding more never worked. No wonder nothing I tried saved my own girl.

What it actually is

It is called PureSource By Pet Relief

 

And honestly, it is a boring little product. I mean that as a good thing.

 

It is just a powder.

 

No smell. As far as we can tell, no taste. Cats do not notice it in their food.

 

You mix one scoop into whatever your cat already eats. You change nothing else.

 

No special diet. No syringe. No new routine.

 

After everything those owners had tried, the fix turned out to be almost nothing.

 

I want to be careful here, because I do not trust things that promise the world.

 

It is not magic. Nothing happens in the first few days.

 

It works slowly, because it is refilling something the body has been short on for a long time. 

 

Most owners start to notice a change somewhere in the first 2 weeks.

 

And some cats are just naturally lean, and stay that way. That is fine. The goal is a healthy weight, not a fat cat.

Why you can actually trust this

I have been let down by enough products to know exactly how you feel reading this.

 

So I will not ask you to just take my word.

 

I put my real name on this. My real background. A real practice behind it.

 

Not a made up brand hiding behind a photo of a happy cat.

 

And we show you what is in it.

 

Then go look at the big name brands you have been buying.

 

See if even one of them will show you the same thing.

 

They will not. Just nice words, nice packaging, and nothing you can check.

 

I would rather hand you the proof than ask for your trust. With this, you never have to take my word for anything.

About the wait, and the guarantee

Because this takes a little time to work, I back it with a sixty day money back guarantee.

 

That is longer than most, and it is on purpose.

 

I did not want anyone paying for something before they had a fair chance to see it work on their own cat.

 

Try it for two months.

 

If your cat is not holding a healthier weight, and you do not feel better at feeding time, you email us and you get your money back.

 

You do not ship anything back. You do not argue with anyone.

 

I can offer that because I know what happens when a cat finally gets taurine her body can keep.

One honest note before you decide

I will be straight with you about stock, because I hate fake pressure as much as you do.

 

The natural way we make this takes longer and gives us less. So we do not keep a huge amount on hand, and it has sold out before.

 

There is a summer sale running on it right now.

 

That is all true, and that is all I am going to say about it. No countdown. No games.

 

So here is where things stand.

 

You can keep doing what you have been doing. Feeding more. Feeding richer. Watching the scale move the wrong way.

 

Or you can look at the one thing almost nobody checks. Not how much she eats, but how much of it she can actually keep.

 

If you want to read the rest and see the testing for yourself, it is here

 

I spent a long time giving good owners the wrong answer.

 

I gave it to my own cat, and it cost me her.

 

This is me trying to give you the right one, while it still matters.

 

Because if your cat is eating and still fading, please do not wait the way I did.

 

Understanding this might just be the thing that saves her.

 

To your cat's health,

 

Dr. Sam Calloway

 

P.S. If your cat eats well and still keeps losing weight, the food and the amount were probably never the thing to fix. I learned that the hardest way there is. It is worth understanding why before it costs you what it cost me.

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Comments
Add a comment...
Karen M.

Honestly I've tried everything at this point. Slow bowl, three different foods, two vet visits that found nothing. If this is one more thing that doesn't work I give up lol. But I'm going to try it.

· ·51 min
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Denise R.

My cat refuses ANY supplement, she can smell a pill from across the house. This one she genuinely doesn't notice. I just stir it into her wet food and she cleans the bowl.

· ·1 h
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Patricia H.

Doesn't good cat food already have taurine in it though? Genuinely asking, not trying to be rude. Why would I need to add more.

· ·2 · 2 h
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Sandra K.

It does, but I learned they add it before cooking and heat destroys a lot of it. That's why the rules make them put nearly double in wet food. That was news to me too.

· ·1 h
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Michelle T.

I've seen so many of these cat supplement ads that turned out to be junk. What made me actually order was that they show the lab test and give you 60 days. Figured I had nothing to lose.

· ·1 · 3 h
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Angela P.

This looks interesting but I'd love to hear from someone who's actually used it for a while. Anyone been giving it a few months?

· ·1 · 3 h
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Robin S.

Coming up on four months here. Nothing dramatic the first couple weeks, then around week 5 her coat looked better and she just seemed more like herself. I keep it on subscription now so I don't run out.

· ·3 · 2 h
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Laura B.

Do you have to switch their food to use it? I finally found a food mine will eat and I'm not changing it for anything.

· ·8 · 3 h
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Jessica W.

Nope, that's the best part. You just add the scoop to whatever they already eat. No switching.

· ·2 · 2 h
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Nicole F.

Anyone else worried their cat will taste it? Mine notices everything.

· ·1 · 4 h
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Simone C.

Mine is the fussiest cat alive and hasn't noticed once. There's no smell to it at all.

· ·2 · 2 h
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Brenda L.

Bit more than the ones on Amazon. But I checked and the cheap ones are mostly filler, this one is just taurine and nothing else. You get what you pay for I guess.

· ·4 · 5 h
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Diane W.

Honestly too early for me to say for certain, only about 3 weeks in. No complaints though and she eats it fine. Will report back.

· ·2 · 6 h
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Carol A.

I asked my vet about adding taurine before I ordered and she said it was fine to. Nice to use one that actually tells you to check with your vet instead of talking you out of it.

· ·3 · 7 h
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