Chronic kidney disease (CKD) is one of the most common and serious conditions affecting cats in the UK. Large-scale studies suggest that between 1% and 3% of the general cat population is affected, but that figure climbs steeply with age to as many as 80% of cats over fifteen. Given that the median age at diagnosis in UK primary care practice is around fifteen years, this is a condition that most cat owners will face at some point, and one that vets spend a significant portion of their clinical lives managing. The arrival of what is being described as the world’s first prescription-only medicated diet for companion animals could change how we manage CKD for our cats, and perhaps it could also change the way we manage other chronic illnesses in the future.
What does managing feline CKD actually involve?
Unfortunately, there is no cure for CKD. Instead, vets must manage the condition to delay progression of the disease. There is no single treatment for managing CKD in cats. Current evidence-based guidelines from the International Renal Interest Society (IRIS) recommend a layered approach. This includes placing cats on a specialist diet low in phosphorus and protein to help support the kidneys, phosphate binders if needed, blood pressure management for cats with high blood pressure, and where the kidneys are leaking protein into the urine, a drug called an angiotensin-converting enzyme inhibitor (ACE inhibitor) can help. Proteinuria, the leakage of protein into the urine, is increasingly understood to actively worsen kidney damage, driving progressive fibrosis and loss of nephrons over time. Controlling this protein leakage is therefore an important part of the treatment plan.
Benazepril is the ACE inhibitor most commonly used in cats for this purpose. In medical terms, it works by blocking the renin–angiotensin system, reducing intraglomerular pressure and lessening the amount of protein that spills into the urine. In other words, it works by calming down a set of chemical signals in the body that control blood pressure. This takes some of the strain off the tiny filters inside the kidneys, so less protein leaks out into the urine.
Several well-designed studies, where some cats received the medicine and others received a dummy tablet, have clearly shown that a daily dose of benazepril reduces the amount of protein leaking into the urine. In one large study of 192 cats, this was true even for cats that only had a small amount of protein in their urine to begin with (King et al., 2006). The research also revealed that cats taking benazepril often had a better appetite, a huge benefit when kidney disease frequently causes cats to go off their food and start losing weight.
The compliance problem we don’t talk about enough
It’s great to have an effective treatment option to delay the progression of kidney disease. But as every cat owner probably knows, cats aren’t always willing to take their medicine!
Sadly, many cats with kidney disease never receive the medicines that could help them. One UK survey found that only about one in four owners was giving their cat the kind of medicine that reduces protein leaking into the urine (Elliott et al., 2025). It is not hard to understand why. Giving tablets to cats is notoriously difficult. Almost half of owners report being scratched or bitten when they try, and many cats will simply spit the tablet straight back out, no matter how carefully it is given (Taylor et al., 2022). To make things worse, cats that have been through the ordeal of being medicated will often start to avoid the very owner who was trying to help them, and this can put a strain on the close bond that makes caring for a poorly cat possible. Even owners who do manage to give medication successfully face the pressure of doing this every single day, which can be stressful for the cat, the owner, and the vet team involved in their care
Compliance is the silent enemy of evidence-based medicine. A treatment with excellent trial data achieves nothing if the owner cannot administer it at home. This is not a criticism of owners. It is a problem with how we deliver medication when the animals themselves do not know that we’re trying to help them.
A concept borrowed from farm animal medicine
This is where the new prescription kidney diet comes in. Instead of being given as a separate tablet, the medicine (benazepril) is added directly into the kidney food itself. Every time your cat eats her dinner, she will automatically get her daily dose of treatment.
Vets who work with farm animals will recognise this idea. For decades, medicines have been added to the feed given to cattle, pigs, and poultry. It is far easier and less stressful than giving injections to large numbers of animals one by one. In the UK, this kind of medicated feed is tightly controlled by law, and a vet’s prescription is always required before it can be used.
What is new here is using this same idea for a pet cat, and not just for a short course of treatment but as a long-term part of managing a lifelong illness. The diet is officially classed as a ‘Medicated Complete Food’ and can only be obtained with a vet’s prescription. The amount of medicine a cat gets is linked to their bodyweight and how much they eat each day. Safety testing has shown that the medicine is well tolerated even at doses twenty times higher than the treatment dose, and the manufacturer claims that in taste trials, 88% of cats happily ate at least their full recommended daily amount. It’s worth noting though, that this is not independent, peer-reviewed evidence, but an internal study conducted by the manufacturer of the product.
What does this mean for cats and their owners?
The most important thing is the wellbeing of the cat. If a cat with kidney disease can get her medicine simply by eating her food, not needing to be held still, no tablet forced into her mouth and no stress, that is a big improvement. It also takes a real weight off the owner’s shoulders. Studies have found that almost all owners of cats with kidney disease feel significant anxiety about their pet’s condition, so anything that makes daily care simpler and less distressing is going to help a lot.
The second thing to think about is what this might mean in the future. If hiding medicine in food works well for kidney disease, could the same approach work for other long-term conditions in cats? For example, conditions like an overactive thyroid, high blood pressure, or heart disease? In theory, yes, though each medicine would bring its own set of challenges around safety, dosing and getting the right approvals.
There are some real practical challenges to think through. In homes with more than one cat, how do you make sure the right cat eats the right amount and that any other cats do not eat it instead?
Also, the manufacturer says the diet should be the cat’s main or only food. If it is given alongside wet food, the medicated biscuits need to be eaten first. Cats with very poor appetites (which is common in more advanced kidney disease) may not eat enough to get a reliable daily dose, which means owners and vets need to keep a close eye on things.
Finally, there is an important point about responsibility. Prescription kidney diets have been around for a long time, and everyone understands what they are. But a food that is also a licensed medicine, regulated in the same way as medicated farm animal feed, is something different. It deserves the same careful prescribing, monitoring, and follow-up as any other prescription-only medicine. The fact that the medicine is in the food rather than a tablet does not reduce the vet’s professional responsibility one bit.
A step forward
Looking at all the evidence, this new medicated diet is a good development, on balance. The science behind using benazepril in cats with kidney disease and protein in their urine is well established. The problem of cats not getting their medication is real, and its impact on their health is significant. Building medicine into food is a concept that has been used safely and sensibly in farm animal medicine for many years.
What this should not do is make anyone less careful about monitoring. Cats eating this diet still need their urine checked regularly for protein, their blood pressure measured, and their weight kept an eye on. A prescription food is not something you can just set up and forget about, any more than a prescription tablet is. But if it means that more cats actually receive the treatment that the evidence says they need, then this closes a gap that has been affecting the quality of cats’ lives for a very long time.
It is also important to note that the decision to prescribe this diet should always be made by a registered vet, based on a proper assessment of the individual cat.
Whether this turns out to be the first of many medicines delivered through food for pets remains to be seen.
References:
Elliott, J. et al. (2025) ‘Owners’ experiences of caring for cats with chronic kidney disease in the UK’, Journal of Feline Medicine and Surgery, 27(4), p. 1098612X251314769.
King, J.N. et al. (2006) ‘Tolerability and Efficacy of Benazepril in Cats with Chronic Kidney Disease’, Journal of Veterinary Internal Medicine, 20(5), pp. 1054–1064.
Taylor, S. et al. (2022) ‘Online survey of owners’ experiences of medicating their cats at home’, Journal of Feline Medicine and Surgery, 24(12), pp. 1283–1293.
Discussion