My thanks to Webinar vet for asking me to present this webinar. Today we're going to discuss a question that I get asked commonly in my oncology clinic. My dog has got cancer.
What diet should I be feeding him? First, my disclosures. I've got no relevant disclosures for this session.
However, in years gone by, I have received speaker fees from Hill's Pet Nutrition, but nothing currently. And I feel I should give a second disclosure, you see, I'm an oncology specialist. I'm not a nutrition specialist.
So if you've come into this with questions like manganese content or crude fibre content of food, then I have to admit I'm probably not your guy. But what I hope I can bring is years of experience in the clinic standing in front of clients who ask questions like this, OK. What I'm going to present over this webinar is some information that I think is very useful for giving an educated response to this question.
If you want a very quick response, we could just say no, no, there isn't. But I'm sure a lot of clients will not find this very satisfactory. So we're gonna do the less flippant version today.
There's insufficient evidence to support a dietary change providing. The pet is eating a balanced and complete diet, and they're maintaining adequate body condition. And that is the message I tend to convey.
In this session then, we're going to start at the point of complete and balanced diet. What is it? Then we're going to look at the issue of weight loss.
How common is it? We're going to explore some biological features that I think are really interesting around what else I should know about diet and what cancer related processes should a diet aim to address. And finally we're going to give some practical advice on if we do think we need to change diet, how should we do it.
Let's start with the first point, then this complete and balanced diet. And my first point If a client is home cooking for their pet. This is invariably nutritionally inadequate.
And that's just not my opinion, that's the the consensus of a very thorough review from a few years ago here. There's one exception, if a client is feeding a home cooked diet that has been prepared with advice from a nutritionist due to very complex medical issues of the dog or cat, then that should be fine. But I often hear clients say they feed things like chicken and rice and sweet potato and a bit of broccoli or some leftover veg from people's plates just because that might be the only thing she eats or that's the only thing that controls her itchy skin, for example, and these diets we've got to beware of may have been just fine up to now, but now the animal's been diagnosed with cancer, there'll be extra stresses on the body.
And people like me and possibly you as well may want to give drugs or treatments that'll add even more stress to the body. So if we've got one of these clients who are doing their own thing and cooking for their pet, this is the first point where I would consider changing a diet. This begs the question, what diet would I change to, and I'll give a few pointers here.
First, I would choose a manufacturer that adheres to the AFCO or the FedDAF guidelines. If you've not heard of these organisations, they're very important. AFCO is the American Association of Food Control Officials and FEDAF, the European equivalent.
They're not policing agencies, they're institutions that offer guidelines for how a diet should be prepared. They give guidelines on specifying nutrient profiles and dictating how to analyse the ingredients to make sure that profile is met. They give guidelines on testing multiple batches to make sure that natural variation batch to batch is accounted for, and they give guidelines on how to get proof it's working from adequate feeding trials.
They talk about quality assurance to make sure the system's in place, to ensure that the ingredients are safe and the suppliers are vetted and the nutritional adequacy is maintained, and how to intervene. If that's not the case, and finally they give guidelines on safety and pathogen testing. Now I thought in years gone by that all food manufacturers would do this anyway, but actually the standard to which they do this, or whether they do this at all sometimes is extremely variable, so we want to look for a food that complies with AFO and Or FediaF guidelines fully.
Secondly, we want to feed a complete diet, and a complete diet has all the nutrients needed for a pet to be healthy. This isn't a complimentary diet. Now a complementary diet doesn't have all the nutrients needed for a pet to be healthy.
OK, a complementary diet, nothing wrong with it, but it's designed to be an addition or a treat to the main complete food. This is worth bearing in mind because some complementary diets can be premium foods that look expensive and are tasty and look really good. But no one ever said they were complete.
In this example here you can see the manufacturers very clearly put complementary on the bottom of the box. In some other manufacturers, the word complementary is actually quite hard to find. Thirdly, we need to feed a balanced diet as well, and a complete diet is not necessarily balanced.
Here's an example. If you increase the dietary calcium, you will reduce the absorption of phosphorus. And you will bind the zinc in the gut, so a food may have ostensibly normal acceptable levels of phosphorus and zinc, but if the calcium is particularly high, then you'll need to add more of these things to get over the line in what's absorbed.
If you increase the fat content, you're going to burn through more fat soluble vitamins and the requirement increases. And if you increase dietary protein, you'll also need to increase vitamin E for the same kind of reasons. So a balanced diet doesn't just have all the nutrients that are required by FedDiaf or AFCO, it has to have them in the correct proportions for the right life stage.
Four life stages are usually defined a growing puppy or a kitten, an adult, pregnant animal, or a senior animal. When you discuss changing diet, something that frequently comes up is the idea of raw feeding, and my advice is not to raw feed at all, and I have 7 points which can address this. For a start, commercial raw diets are not properly quality checked.
There's very few manufacturers of raw diets that conduct Afco or Fediaf digestibility or feeding trials on the finished product. Actually, the manufacturers of the raw diets vary considerably in their quality control procedures. They're often imbalanced as well.
In some studies you find that vitamin D is commonly deficient, and that's quite a common thing we find. But in other studies we also find excessive vitamin D in some cases. Often there's undetectable levels of vitamin A&E as well as and inappropriate calcium phosphorus ratios.
Raw diets usually involve a great deal of intimacy with pathogens, for example, salmonella. In one story, one study of home cooked diets, the prevalence of salmonella was 80%. And bear in mind that the freezing and pressure washing does not kill all bacteria.
In some commercial foods, the prevalence of salmonella was almost 50%. And very worryingly, a number of salmonella islets from raw food have been found to be resistant to 12 to 16 antibiotics. While we're on the subject of resistance, 30% of raw fed dogs have bacteria which are resistant to multiple antibiotics in their mouths.
And I don't want to show any delicacy to salmonella here. Lots of other pathogens are available, and these can all be found in raw foods, for example, Campylobacter, E. Coli, Clostridium, Listeria, toxoplasma, Mycobacteria.
And here's a question What happens when we give chemo? If we immunosuppress the animal with steroids or cytotoxic drugs, what do you think's going to happen? I'll leave that to you.
Many proponents of raw feeding say it's natural. I, I think particularly in dogs it's very much not natural. Dogs are scavengers rather than top carnivores.
These are 4 dogs who I photographed during my period volunteering in India, and this is the kind of things they'd eat like contents of bins. Remains of dead animals licked off the road, faeces or waste that people throw out, which is nearly always vegan. So dogs tend to have a very varied diet, it's often poor quality and very, very low in meat.
You can take this natural argument much further in terms of genetics. The dog genome differs from the wolf in 36 areas, and 10 of these, 10 of them concern carbohydrate metabolism. If you look at the graph on the right here, you will see an important enzyme, amylase, that digests starch, and it's very, very low in the wolf and several times higher in the dog.
So there's an interesting evolutionary theory that the ability for the Canis familiaris to digest starch was a crucial step in allowing Canis familiaris to live with people and the dog to become domesticated. And finally, the problems with raw feeding don't stop here. We see mechanical damage to the GI tract if bones are fed, and you can see things like hyperthyroidism if lots of raw thyroid is fed too.
So that's not an exhaustive list, but I think it's some important points that we need to communicate to owners who are interested in this. Moving on to the 2nd issue. There's insufficient evidence to support a dietary change in a pet with cancer, providing they're maintaining an adequate body condition.
Let's start with the adequate body condition then and a question. What proportion of dogs diagnosed with cancer do you think are in inadequate body condition? According to this study, it's about 4%.
Let's look at a different study. Can you see the sample number in the bottom right? This is over 14,500 dogs with cancer.
And it's still around 5% ish that are inadequate body condition. So on first glance it does look pretty low. When you read the details, perhaps it's a bit higher though, because we're not just interested in a poor body condition.
Weight loss through disease is always bad, I think most vets would agree with that one. And for those animals that might have been overconditioned but still lost weight during treatment, it's getting towards 1/3. In cats, as always in cats, there's not as much data as we like.
But in this study here again at 1st 1st glance, it looks like the body condition score of cats diagnosed with cancer is reasonable. And there was no difference in body weight between starting treatment and follow-up 10 days later. But you might argue that 10 days isn't enough follow up for meaningful conclusions.
And then when you look at the initial baseline data, you find that 91% of cats had low muscle condition score at baseline. So to sum up these studies, it could be between 5% and 37% of dogs with cancer where we might need to address diet and possibly a higher proportion in cats. Diet in cancer is quite a fascinating topic.
These are the hallmarks of cancer, the 10 features a cell must adopt, to become a cancer. And nutrition has a profound effect on two of these here, and this is very eloquently described in the hallmarks of Cancer paper, which is an open access paper. It's beautifully written, and if you're interested in cancer, I'd encourage you to read it.
But in recognition of the potentially profound effects that nutrition can have on the development of a tumour, there is a whole section of science devoted to it, and these are just some of the journals available. People are well aware of that, and people with cancer speak to their health providers about what they should be eating. Let's look at some of the advice they get.
This is from Macmillan Cancer Support, a big UK based charity supporting people who've developed cancer and their families. They talk about eating a balanced diet. They talk about maintaining healthy weight.
And they say underlined in red there is still not enough clear information to make exact recommendations about what someone with cancer should eat. In general, follow a healthy, balanced diet. Eat a wide range of foods which have the vitamins and minerals your body needs.
It's very, very moderate. So there's some cancer diet cookbooks here. And you see some of them are probably really good and really helpful to people who have poor appetites and nausea and weird tastes in their mouths like the Royal Marsden Cancer Cookbook in the bottom left.
But there are some more extreme examples that might be straying away from the science a little like some of the ones in the middle. And as we might expect, these things are now trickling down into dogs. If you Google cancer diet dogs, you get lots and lots of hits like this.
So even if it is 37% of dogs and even if it is more cats that need dietary adjustment when they develop cancer, we're gonna have to discuss it to do a good service to our client in a higher proportion of cases. In these studies here We found that over 50% of owners of a dog or cat with cancer. And distrust conventional diets, and 30 to 40% are feeding weird homemade diets which include raw meat or a combination, and these, as we've discussed, can be imbalanced and potentially dangerous.
So that's quite troubling, I think. However, one saving grace that came out of both these papers is that vets were valued as the most important source of nutritional advice. Based on that, then We're gonna go into the science a bit more and look at a couple of very interesting biological processes that can happen in cancer.
Remember at school we learnt about the Kreb cycle and release of energy. Here's a very quick summary. First, glucose is broken down to pyrivate, and this releases a little bit of energy in the form of ATP.
Pyrivate goes into the citric acid cycle and that releases a little bit of energy. You also get some byproducts of the citric acid cycle like the protons which go into oxidative phosphorylation in the mitochondria and that releases lots and lots and lots of energy. Crucially, the step between glucose and pyrivate is not dependent on oxygen being available, but the steps after pyriva need plentiful oxygen.
So if you have insufficient oxygen, you just get this. It just goes to pyrivate and we call this anaerobic glycolysis. It's very, very inefficient but it's designed for a situation where the animal hasn't got oxygen and it's just trying its best to survive.
So this process keeps turning over and turning over and turning over as rapidly as possible. And it's an equilibrium reaction, so it would cease and it would slow down due to pyrivate building up. And to combat this, the body converts pyrivate to lactate, which diffuses out of the cells, and it allows this reaction to go like the clappers.
As I say, it's extremely inefficient, but it's the best the body can do to save the cells where oxygen is not available. Does that all make sense? I hope that was revision from the stuff we learnt at school.
But to discuss something new I'd like to introduce this gentleman. This is Otto Wohlberg. A very, very clever man.
And later became a Nobel laureate. And about 100 years ago he had some interesting findings on cancer tissue. He found that cancer tissue used 10 times more glucose than normal tissue.
And produced 100 times more lactate. But without using any more oxygen So we find The Wahlberg's theory is explained as this. Cancer tissue chooses to do aerobic glycolysis.
Plenty of oxygen is available, but that doesn't matter. The cancer doesn't bother with the citric acid cycle. It doesn't bother with oxidative phosphorylation.
It just uses this hugely wasteful, inefficient process of aerobic glycolysis, and it's termed the Warburg effect. For many years people have debated why this is, and I'm not sure anyone has given a full proof yet. Initially people thought the cancer is genuinely hypoxic, but now it's been shown the cancer tissue consumes normal amounts of oxygen.
People thought it could be damage to respiratory machinery of the cells, but actually we've shown that the cells do a normal amount of oxidative phosphorylation. So a theory that's now widely adopted is focusing on the byproducts of the breakdown of glucose to pyrivate, you see. In highly active cells These byproducts, these that form cellular macromolecules like nucleic acids, lipids, etc.
Are in very, very short supply. They're often in far shorter supply than energy is, so it kind of makes sense to use this just to get the macromolecules rather than focusing on the energy. Initially, the lactate has been shown to be a harmful signalling molecule.
It's not just a waste product. It has been shown to fan the flames of the nascent cancer. It can fuel the stroma, have effects on the immune system to allow and the cancer to escape it, and promote angiogenesis and to promote invasive behaviour of the tumour.
So all this biology is very interesting, but knowledge of the Wahlberg effect is quite common. It's quite common for owners to find on the internet and it begs the question, can we treat cancer with a low carbohydrate, high fat diet? Let's have a look at this study here about 30 years ago now.
When they tried, so here are 22 dogs with lymphoma, and they were fed either a high fat or high carbohydrate diet. The diets were, exactly the same in terms of energy overall and were controlled for all other factors. It's just one was high carb and one was high fat.
Between the diets there was no difference in remission time, overall survival, or tumour burden. And curiously, the resting energy requirements didn't change when the dog went into remission. You'd kind of think it would But it didn't That's backed up by this study in solid tumours which said the resting energy requirement of the dog didn't change after the tumour was excised and you kind of think it would.
And there could be a few explanations. One of them could be that the metabolism of the cancer tissue is just very small compared to the metabolism of the whole body. So the body copes with this extra demand for glucose, and it doesn't seem particularly significant overall.
Additionally and possibly more importantly, Any effect of a low carbohydrate diet is blunted somewhat by the actions of the liver. You see, there's parts of the body like the brain that have an obligate requirement for glucose. Your neurons can't metabolise, can't oxidise fats to produce energy.
They have to have glucose all the time. And in recognition of this, if you're not eating enough glucose, your liver will produce glucose to satisfy your requirements and will catabolize your tissues to do so if necessary. But again, to quote from this and this review, currently the authors are aware of no evidence to suggest that cancer patients have nutrient needs that differ dramatically from the maintenance requirements.
A variation on the low carbohydrate, high fat diet that we sometimes have to address is the ketogenic diet. Now we've said that low carbohydrate diets on their own have no beneficial effect in treating cancer, and I don't think that's a particularly contentious thing to say. People have been trying to actually treat their cancer with a low carbohydrate, high fat diet for over 100 years now, and cancer, as we know, is sadly, a game that not everyone wins.
But there is an increasing number of medical doctors who feel that ketogenic diets can be beneficial. That is that the ketones produced also act as signalling molecules a bit like lactate to have anti-cancer effects. If you look in this human review here, they conclude that the ketogenic diet probably creates an unfavourable metabolic environment for cancer cells and can be regarded as a promising adjuvant to therapy.
So let's briefly look at this. Here's the cross talk between the three food groups here of notes. You can see that amino acids can be converted to glucose, but amino acids can't produce energy directly.
On the other hand, fatty acids and glycerol can be used to make energy through the beta oxidation of fats, and that doesn't involve going through glucose. When fatty acids are oxidised, you get production of ketones. So it's a very logical thought, if we cut out the carbohydrates, the ketones may have a beneficial effect on the cancer.
But this schematic there is not realistic. Remember that parts of the body like the brain have an obligate requirement for glucose all the time. You can't make glucose from anything in the fats, column.
So where there's zero glucose coming in through the food, the body has to cattabolize amino acids to do that, and thus it produces glucose to provide energy and in doing so, the ketones will go away. So to feed a truly ketogenic diet, it needs to be very extreme. You need to feed pretty much just fat.
And then you will genuinely get production of ketones and most of the body running from fat. So this is something I wouldn't want to do to one of my patients, and I hope that you guys wouldn't want to do that either. But there are some people that are advertising this very extreme treatment on the internet.
This link was only 2 clicks away from Google. This place would be offering a diet that's 80 to 90% fats like coconut oil with only a small amount of protein and carbohydrates. And what do you think's gonna happen if we do that?
Well, first, who's not thinking that the dog is going to get pancreatitis, OK, because a high fat diet is a huge risk. It's going to be very poorly tolerated by the dog, and it may cause a lot of other comorbidities. A diet that's almost 100% fat is going to be very, very imbalanced as well.
The animals are going to be breaking down their own tissue. To satisfy the glucose requirement that they need. And finally, people who've had a lot of ketones in their body either deliberately through a diet or through diabetes say they feel a kind of malaise, a keto flu.
When we're treating an animal for their quality of life, do we really want to do any of these things? Bear in mind it's also a minority of human doctors who propose the ketogenic diet as an adjuvant to cancer treatment in people. It's not a mainstay of treatment by any means, and you can kind of understand why when you see just how extreme a truly ketogenic diet should be.
So we've talked about the Wahlberg effect and I'm gonna take this huge demand for glucose a little bit further. On the left is a cancer cell and on the right is a healthy cell, and we know that the cancer cell needs lots and lots of glucose, it pulls it in from the tissue fluid. And in response, the levels of glucose in the tissue fluid are elevated.
So there's lots of glucose floating around, but the healthy cell, needs less glucose and it shouldn't really let lots of glucose into the cytoplasm because this would cause a lot of oxidative damage to the cell. So what happens is the healthy cell takes down those glucose transporters, so it gets the glucose it needs and no more, fair enough. But then we get a disparity.
You see, glucose passes freely into the cancer cell, but you need much, much, much more insulin to get the glu same amount of glucose into the healthy cell, and thus we start to see the development of insulin resistance. We can take this further. The cancer cell produces lots of lactate, and what does lactate do to healthy cells?
Produces insulin resistance. You can understand the reason why as a stress response. OK, in a very stressful anaerobic situation like being stuck under water.
You want to minimise uptake of glucose in a lot of the peripheral cells so that you're saving the little glucose available for the tissues like the brain that have an obligate requirement for it. Cancer produces lots of inflammation, and we haven't got time to go into that now, but this inflammation fans the flames of the cancer in many ways. And one of the things that inflammation also does is produce lots of insulin resistance in healthy cells.
And again you can view that as a stress response, say fighting a severe disease. Now at the same time as this massive amount of insulin resistance, the inflammation will often put the animal off his or her food. And then you may get clinical signs of the cancer, for example, nausea, lethargy.
People like me may give drugs that affect appetite. Some of my colleagues may anaesthetize the animal or perform surgery on the animal, and this all suppresses the appetite further. So you can easily get a situation where the energy requirement far exceeds the energy intake.
If this happens in a normal healthy animal, you'd get glycogen stores used and fat stores used. The muscle mass would be maintained, and we call this simple starvation. But in the case where there's massive insulin resistance.
You get use of amino acids. You know the body can't generate enough glucose from glycogen and it can't generate any glucose from fats, so to meet this huge requirement of glucose, most of which is wasted because the cells are so resistant to it. Then, the body has to break down amino acids and cattabolize muscle, and we call this cachexia or stress starvation.
Cachexia then is the loss of lean body mass due to disease. You can think of it as the loss of muscle rather than the loss of fat. It's not the preserve of oncologic conditions in veterinary medicine, in fact, it's very commonly found in cardiologic conditions, as well as renal disease.
But lots and lots of chronic serious diseases can cause it. And as clinicians we need to be aware of it. Just weighing an animal is insensitive.
We need to look at the muscle condition. And the places where you find the muscle condition most effectively are either side of the dorsal spinous processes as in the top pictures or in the temporal muscle as well. So I would encourage you to look at this WSAVA muscle condition scoring chart, to download it, have it in your clinic, and where you put the body condition score of the patient on clinical notes, always put the muscle condition score of the patient on clinical notes too.
And I'll do this for all your cancer patients and also all those with other chronic diseases like heart failure, like renal disease. You could take it a step further. Because just feeling the bony prominences is quite insensitive, you can use ultrasound and you can measure them quantitatively.
Now this is a dog who's quite obviously cachexic. You can see the muscle loss either side of his dorsal spinous processes, and in the picture on the left you can see his temporal muscles have lost as well. This dog, it's harder because this dog was obese.
He was body condition score 8 out of 9, but you can see we're starting to develop cachexia over the temporal muscles. Can you see that? So he remains obese, but he's also cachexic.
Now the fundamentals of a diet to control a cachexia would involve high protein because the protein keeps being broken down to produce glucose. High fat and low carbs. So we've kind of gone full circle here.
I started by saying high fat, low carbs is not an effective way of treating the cancer. It isn't. But it can be often the best thing we can do to try to manage cachexia, and that's not because of any cancer property, but it's to avoid promoting more inflammation or exacerbating the insulin resistance.
A high simple sugar diet is very inflammatory in the body, so let's avoid it, let's not add to that. And lots of simple sugars will of course ratchet the negative spiral of more production of insulin to meet more insulin resistance ongoing. So I think if we're feeding a diet for an animal with cancer who's losing weight, these would be three key components.
They're not the only components, I'm gonna come back to this a couple of times and I'm going to expand on this. So if I can give you some practical advice to approach a cancer patient who's losing weight, I wouldn't jump to cachexia first until you're certain it's happening. I would also not wait until cachexia develops.
I would first look out for the patients who may be the most vulnerable. Those could be the ones where the cancer is not in complete remission or the treatment is ongoing. For example, a dog with multicentric lymphoma where the lymph nodes still remain quite big, although not as big as they were, or one of these metastatic mast cell tumour cases where the tumor's shrunk a bit, but it's still in situ, and it's only on medical treatment to try to keep it stable.
For those patients that have lost 5.5% body weight unintentionally in recent months or the patients who've had a dip in the appetite, be prepared for it in these because it's easier to intervene when it's much more mild. Prevention is always better than cure.
When you've found your candidate, please read the WSAVA guidelines. Here they are, they're really helpful. And based on information from these guidelines, plan time for a weight loss consult.
You're going to need to take a thorough dietary history, and I'm afraid I haven't got a very quick way of doing that. Really, you should be looking at 20 to 30 minutes with a client to do this and preferably face to face because we want to look at their body language as well as the answers that they give. Remember.
I know it's maladaptive, but sometimes the clients give us information that they think we want to hear but may not actually be the case. So this is the dietary history from the WSAVA form. The first thing we want to look at is, is there things that we can treat like nausea or pain.
Is that stopping the animal eating? Very, very easy to treat these. Are there behavioural issues at home?
For example, is the animal not eating because she's been bullied off food by another pet they have? Is the cat not wanting to eat because a worried owner is just watching them all the time and the cat is very freaked out with that and doesn't want to eat when they're watched? Are they being fed supplements which could change their taste and change the way they want to eat like turmeric, circumin can be really, really bitter.
Are we giving them medications that could do a similar thing like metronidazole sometimes gives people a bitter taste in their mouth. So I would cover all these thoroughly before I'm asking what are they actually eating and then how much and then what else are they getting, what kind of treats are they getting? Because you could get to 0.7 and you think well this all sounds really good.
But you might have a situation where the animal is refusing a complete and balanced food in correct proportions because they're full up with lots of high fat treats, so we do need to explore lots of angles to this, and we need to make sure that we have the right amount of information from the person who actually deals with the feeding. And sometimes we need to ask if anyone else is involved with the feeding or giving the animal treats. Remember weaker sick animals may be eating less, they may get full easier if you give them some treats.
So the diet to look for, we have high level good quality protein. Remember that if you if you're dealing with a cat they will require most protein from animal source. OK?
A rat carcass, for example, is 98% protein, and we want animal protein rather than vegetable protein for feeding the cats. We want the high fat, as I said, and relatively low carbohydrate or carbs with a high glycemic index. A good starting point would be some of the commercial diet.
This is Hill's on-care diet. I think it's a good diet, it's certainly very tasty, it's very, very energy dense, low in carbohydrates, high in fat, high in protein, but other diets can be quite similar like the diets for kidneys or the diets for heart disease for example. And you've got to remember that the onca diet being so high in fat may not be appropriate for all animals.
If the animal has a history of chronic pancreatitis or some other intolerance of fat, for example, it may not be your best one. You may want to start with one of the other diets, and if you think the protein is too low, you could add cooked eggs, for example, or cottage cheese. If you have serious gastrointestinal issues, for example, a gastrointestinal lymphoma that's not in remission, you might want to consider using a a hydrolysed diet.
And the reasoning is not for an immunologic purpose, it's just that most of the digestion of a hydrolysed diet has been done, so it's much easier to absorb and therefore it's less likely to spark reflex release of acid and gastrin and things in the stomach which could aggravate clinical signs and exacerbate anorexia. So that's where we are now. Supplement with protein if needed.
Keep high fat, low carbs, or high glycemic index carbs, high, high level, good quality protein, and you might want to start with one of the commercial diets and add to it if needed. If you're doing things like that, help is at hand. There are lots of veterinary nutrition specialists available.
They may not work anywhere near you, but then that's OK. There's a diplomat directory of the American College of Veterinary Nutrition. You could look up British nutrition specialists on the RCVS website.
Even if they work hundreds or thousands of miles away, they can still give really good advice when you describe the case based on a very thorough dietary history and the clinical information that's relevant. So whether you're thinking, do I go with a hydrolyzed diet and add things? Do I go with a cardiac diet, these people may be very helpful to give you confidence in that regard.
Finally, in the last part of this webinar. I'm gonna mention one more thing that could be very useful and we're gonna discuss this story with the help of Sasha here who's profoundly cachexic. You see, the story on cachexia is a very long one.
In humans Huge amounts of research and huge amounts of money are invested to try to get a better treatment for cakesic patients, and it's really hard. Cachexia involves 5 broad processes. Put simply, it involves the decreased energy intake, inflammatory cytokines from the tumour like TNF and others.
Production of myostatin, which causes, atrophy of muscles, neurohormonal activation, and reduced anabolic signals. And in humans they try to treat each of these 5 separately. You can address the energy intake with alteration of food or symptomatic therapy.
You can use anti-TNF antibodies to address the inflammation. Myostatin antagonist to address the myostatin beta blockade for neurohormonal activation. And supplemental IGF one or selective androgen receptor modulators to reduce the anabolic to address the anabolic signals.
Now a lot of these are humanised antibodies and very specific to people and we just haven't got the option of those. However, in veterinary medicine we can focus on the 1st 3 things here. We've talked about how we can address the energy intake.
With regard to the muscle atrophy, we could talk about gentle exercise or in lieu of that, some gentle physio, for example, passive extension and flexion of limbs, massage, etc. Something that is very interesting though is addressing the cancer related inflammation directly. We haven't got the humanised antibodies that are available to people, but a very simple and effective thing we can use is omega 3 fatty acids.
I think the omega 3 fatty acid content of the diet and the necessity for supplement is a question we need to be asking in all patients with cancer that are losing weight, you see, Omega 3s are proven to decrease IL-1 and TNF, decrease the muscle loss, improve the appetite, and the great thing is we have doses of these. They are doses developed for cardiac cachexia. But there's no great reason to suggest why they should be any different for cancer related cachexia.
Here I have another clinical trial. It's similar to the one I showed you earlier from around 25 years ago now. It's a double-blinded prospective randomised trial of 32 dogs with stage 3 lymphoma, and they were randomised to either have an experimental diet or a control alongside an identical course of chemo.
The experimental diet and control were identical in every way apart from the experimental one being supplemented with fish oil and arginine, whereas the control diet was supplemented with soybean oil. Let's look at some results. You can see that the disease-free interval and the survival time was significantly higher in the group that had the fish oil than in the control group.
The experimental group had higher serum levels of omega 3 fatty acids, lower lactate responses to intravenous glucose. And a positive linear association between the serum omega 3 concentration and the survival times in the dog fed the supplemented diet. So we have evidence in dogs from quite a strong, well constructed trial that supplementing with omega threes is going to be beneficial.
Now whether the effect of the omega threes was beneficial on treatment of the cancer or whether it was just maintaining quality of life and reversing cachexia of the animal, that's not really addressed, but we see the end result if we supplement with omega threes or they're on a diet that's high in omega threes, that is beneficial, and that's the bottom line. If we're supplementing with omega 3s, we need to be aware that if we try to get this through using fish liver oil, we will get toxic levels of vitamin A and vitamin D, commonly vitamin D. So we must not try to get these doses of omega 3s through using the fish liver oils.
We need a specific veterinary product that just contains omega 3s, and I've got pictures of some of those here. So my final diet then is we want a high level good quality protein and remember that for a cat it needs to be most calories from an animal protein. Needs to be high fats to supply as much energy through fat as possible.
Needs to be relatively low in carbohydrate or high glycemic index carbs. And use a supplemental omega 3 fatty acids if necessary. Many of the commercial diets I showed a few slides ago have supplementation of omega threes.
And if you're concerned whether that's enough, I would probably speak with a nutrition specialist. If you're not feeding a commercial diet and you've continuing with the animal's own diet, I think at the very least we would need to give an omega 3 supplement like I showed you. And with Sasha I want to show that it's not all doom and gloom, because this is Sasha a few months afterwards, and you can see that we have actively got on top of her muscle loss.
We have to some degree controlled her cachexia and given her a good quality of life, and she's back to biting people again. So in summary, please feed a proprietary food that conforms to AFCO or FDAF guidelines. There's no evidence to support a special cancer diet of every dog and cat.
Regularly body condition and muscle condition score the patient during treatment. If they're losing more than 5% of body weight, remember to do a thorough dietary history. Treat those clinical signs if they're present and make changes where prudent.
A diet to manage cachexia should be high in fats, high protein, supplemented with omega threes, and low in carbs or rich in complex carbs. If a diet change is needed, consider a cancer diet, a cardiac diet, or a renal or a renal diet. You could consider a hydrolysed diet in some situations, and remember that nutritional advice from a nutrition specialist may be invaluable in the management of one of these really difficult cases of a cachexic animal during cancer treatment.
I'd like to acknowledge my team at Bristol Vet Specialists where I work. I'd like to thank you for tuning in to the webinar and thank you again to Webinar Vet for asking me to do it. Finally, in my last slide, I will put the links to that I've given in the presentation to WSA VA things and the ACVIN.
Hope you found this useful. See you next time.
