Good evening everybody, and welcome to tonight's webinar. My name is Bruce Stevenson, and I have the honour and pleasure of chairing tonight's webinar. I don't think we have any new members in tonight, so no long housekeeping.
You'll be pleased to hear usual story, Q and A's into the box and we will keep those over to the end. So tonight's subject is one that I'm sure we are all more than concerned about. And our presenter tonight is more than qualified to talk to us about it.
Caroline started nursing at a first opinion practise in Liverpool in 2000 and Qualified in 2002. She joined North West Veterinary Specialists, a multidisciplinary referral centre in 2007. And she became a dedicated medicine nurse in 2014, and then dedicated oncology nurse in 2016.
She passed the certificate in small animal nutrition in 2010 and became a VTS, that's a veterinary technician specialist in small animal internal medicine in 2014. In December 2020, Caroline passed the application to sit the exam to be a VTS in oncology. Excellent patient care is a real passion for Caroline, and she loves to look after patients as she would hope that someone would look after her own pets.
Caroline, welcome to the webinar vet, and it's over to you. Thank you very much, Bruce. That was very kind of you to introduce me so nicely.
So, chemotherapy complications, these are, I think, some of the, hopefully things you will never ever need to, you'll never come across. Some you may, you may come across, fairly frequently, some maybe a little bit more infrequently. And then, as I said, some hopefully that you will never ever come across and will never ever need to deal with.
So the Veterinary Cooperative Oncology Group or BCOG, have created a series of guidelines, and I think it's about a 40 page document that I've also included in the download section. And they've graded all of the adverse events. So grades 1 through 5, based on how severe any of the adverse events are.
So grade 1 is a mild symptomatic or mild symptoms, leading on to grade 5, which, is death related to that adverse event. So there's lots of ways that we can try and minimise the effects of chemotherapy on our patients. So one of the ways is by making sure that we're correctly dosing our patients.
And a lot of these chemotherapies, chemotherapy treatments are based on the metabolic basis, so as in like a 1 milligramme per metre squared and not milligramme per kilogramme. And again, we need to remember that we need to dose for lean body weight as we would normally dose for, for any other drug as well. There's lots and lots of different formulas around.
This formula is what I've taken from Withrow, and I've managed to engrave it into my brain, so I can, I can calculate this using the scientific calculator on my phone. So we can work, I can work out whatever, based on whatever weight they are. Or chemo PE very kindly provide, these wonderful charts.
So we also have these available as well. So we need to make sure that we're, we accurately convert from kilos to metres square. So by dosing on the metabolic basis, that we're hopefully going to reduce the risk of toxicity, but it does mean that some of these smaller dogs might get a larger dose compared to what larger dogs do.
So some of these treatments that we will give, if they're so example, for epiubicin, if it's a larger dog, they will get a dose of, say, 30 milligramme per metre squared. Whereas cats and dogs under, we use a cutoff of 10 kg, we'll get a dose of 1 milligramme per kilo. And it's just some of these different drugs kind of just work out slightly different, so it's, it's unders knowing the dose that you should be using.
We need to make sure that we double check the metre squared and then the the drug calculation itself, and knowing the drug and what volume should, you should actually get for that drug for that patient's size. So if you calculate 3 mL of cristine for a cat, which that is really, really wrong, and I would know that if, if I, I'd calculated it was double checking because say, actually, this is such this is way too much. Whereas 0.3 mil is more suitable for a cat.
We need to make sure that we're dosing accurately as well, so that we're using the correct size syringe. So if you are wanting to maybe draw up 0.5 mL of a solution, ideally use a 1 ml syringe so you can get a much more accurate dose.
We always double check the syringe before we administer as well, so if I've drawn up the, the, the medication, one of the other nurses or one of the, one of the vets will always double check the amount that I've drawn up. And by reformulating getting, getting some medications reformulated, it means that we can actually more accurately dose patients because we obviously we're not allowed to split, tablets or any open any capsules just for health and safety reasons. And we obviously, we're not gonna be able to carefully split to make accurate dosing.
So there's lots of companies available now who are reformulating medications. And there are some injectable medications that we could administer rather than tablets such as cyclophosphamide. So for the administration of cytotoxic drugs, these, anything that is going IV must be administered via a first or a clean stick IV catheter.
And that means you are going straight into the skin, straight into the vein. There's no, prodding and poking. Oh, I've hit the vein, I'm just gonna back out.
I'm just gonna advance. You need to go in straight in. We use Emla cream, pretty much on all of our patients, and we've also used the Epical spray.
And this means that, this, this just makes it, it's a lot nicer for our patients if we're, because they, they're coming in week in, week out. If they, if they, they, some of them get a little bit, a little bit worried about that needle stick, and if they don't feel it, it's nicer for them, and it means that we're more likely to get that first stick catheter placement. And make sure that you're secure in that catheter well, as well.
Don't leave them unsupervised once you've got that catheter placed. We always place the catheter immediately prior to us administering the chemotherapy. We won't place them, place the catheter and pop them in a kennel for half an hour and get them back out.
We do it straight away. So once that catheter has been placed, we double check it by flushing with some saline. Draw back to make sure that you've got a good flash of blood, and then flush again, and then always get someone else to double check.
And if you've got any doubt about that catheter, don't use it. If you think, actually that wasn't quite clean stick, or I'm not really getting a nice flashback or I'm not quite sure. I'm just not happy with it.
Don't use it. You, and place another catheter and continuously check, during the administration as well. I normally like to administer drawback, administer drawback, just to get just a tiny little flash of blood back and obviously keeping an eye on the leg as well to make sure that it's not the vein isn't blowing.
So saline should be the only thing that you use to flush IV catheters or in the given sets if you're using it as an infusion. Heparin and Hartman solution are reported as completely incompatible when mixed with some chemotherapy drugs and some . I, I, and well, there's a picture here with the Serena with some doxorubicin as well.
This, the combination of these drugs can cause a precipitation and then potentially a drug embolism. So we need to think about how are we going to give these medications to make sure that we are doing this safely for us and for that patient. We are, big feeders in our, in our little oncology room.
We use biscuits and treats and something tasty. And most of the time patients don't really give, two hoots about what I'm actually doing, about giving the medication. They're more interested in, the bowl of food that they've got in front of them.
We may need to sedate them. If they're a little bit worried or a little bit less compliant. And we found that gabapentin and or trazodone has worked absolute wonders, especially the gabapentin for cats.
They're 20 mg per kilogramme, the night before and the morning of about 2 hours before the consultation works absolutely, absolute wonders, and it has stopped us having to completely sedate most of our cat patients. They just come in, they kind of feel so much more chilled out. We can do what.
We need to do. Their, their, their anxiety has been taken away. So, yeah, we, we're big fans of that.
And also using like stuff like Fayway and pet remedy, and making sure that you're not getting disturbed as well. If you've got someone who's, if you, if you're in, in a little room and people are coming and going all the time and the phone's ringing, and, this is more likely to disturb the patients and more, more risk of these catheters being dislodged. So this is one of the, situations that I hope you guys never, ever have to come across.
And for myself as well, and our little team. So extrophization is the accidental administration of medication outside of the blood vessel. And with some of these IV medications, this can cause absolutely awful, tissue damage.
I've got some pictures, and they just, they just, they make me so, so sad and so scared when, for all of these medications. These are medical emergency and we need to action them immediately just to try and hopefully minimise the effects. So some medications are classed as visicants, and these will cause a significant tissue damage, and this, these drugs that are in this group are doxorubicin, epiubicin, actinomycin D, Vincristin, vimblastin, and zacarbazin.
Some medications may just cause a bit of an irritation, we just need some symptomatic treatment if that happens, such as carboplatin, cyclophosphamide, 5FU and cisplatin. And there's a couple of medications that if they, if they do go, subcut, L asparaginase, we give subcut anyway, so there should be no problems there. And cytarabine can be given subcut anyway, but we can give it, we do give it as an IV infusion.
And hopefully there shouldn't, there shouldn't really be any issues, but we may just need some symptomatic treatment if, they are affected. We have an extrarovisation first aid kit with the doses and protocols in there, and we've also got this up on the wall, hopefully to ward off evil spirits. So if this ever does happen, we need to stop treatment immediately, disconnect, the, either the infusion or the syringe that you're using, and then withdraw any drug through the catheter possible.
So I, this has happened to me one time. And I had, someone else was opening syringes and literally handing me 5 mL Lulock syringes, and I would attach it to the tea connector, draw back, literally getting little tiny droplets, discard that syringe, and I got a new syringe, and I think I used maybe 5 or 6 syringes just to get back as much as I could do. You then need to remove the catheter and then depending on what the drug, what the which drug it was depends on what treatment you actually need to use and then we I said we have a kit ready just in case.
So for Vristen or Vinblastin, we need to use a warm compress for 15 minutes every 6 hours for 24 hours. And then we use some saline in that area as well, we're just infiltrating that area. And then hyaluronidase injectable into the area.
So there's, there's 2, there's two doses that I've, I've found that we have available. So either the total volume of the extra visage drug, or 150 units per 1 mL of extra visage drug. And when we are injecting that into the, the area, we would use a new needle each time, cause we would hope, we would want to be doing it maybe in 5 or 6 sites, over where you could see the drug that has extra disease.
And then we need to make sure that we're, Monitoring that wound and supplying analgesia as needed. So this is just some pictures of an extrovisation form, I think it was from Vin Christine. So they, these wounds tend to look awful and they will eventually heal, but they can take quite a long time.
So doxorubicin and epiruicin, is, as, from one of the textbooks that I read on the, it's a canine of feline geriatric oncology. It was described by Alice Villalobos the, that the doxorubicin extrovisation, the results may turn into one of your worst nightmares. And having seen some of the pictures and some of the stories, it's, yeah, it's the stuff that makes, it makes everyone certainly, definitely double, triple check before we administer these medications.
So. If this ever happens, we need to apply cold packs as much as the patient will tolerate this 48 to 72 hours. Then we have the Dexrozaxane injection.
And this is something that we do keep in stock, probably, and we, we knowing that we have chemo pet very, very close by to us and then been absolutely awesome if we do need more medications, we do, we can, we can source that easily and often and. If God forbid if it happens with you guys, contact your local, referral hospital or chemo and they can get some medications out to you. We could then need to use topical DMSO solution every 8 hours, and we can be using this for weeks and weeks.
We needed to consider immediate surgical debridement or an intervention, which potentially may end up leading to amputation. And then wound management for these guys. This is, these wounds can end up awful, and we're gonna need some analgesia, and probably antibiotics too.
So this is a 10, this is 1 mil eirubbus and that was extra dea and then led I think this dog did actually end up having to have its limb amputated. And then this is another dog, this was a doxorubicin extrarovisation, . That they eventually did end up having to go for amputation as well.
It was presented a couple a day or two after the primary vet had administered Do Rubison. I don't, I'm not sure if they hadn't realised that there had been an extraversation. And that he had this absolutely horrible necrotic wound.
So in the meantime, while this dog is driving all of this wound management, they obviously, then you can't administer any more medication, and if this dog's on treatment for lymphoma, then the, the risk of disease progression is, obviously very high as well. So moving on to acute tumolysis syndrome, this can happen when there's been a, if there's a large tumour burden, such as with a high grade lymphoma, or acute lymphoblastic leukaemia, and commonly seen within about 48 hours of initial treatment of, large volume, highly, high chemo sensitive tumours that do have a high proliferation rate. So, either from chemotherapy or radiation.
So what happens here is that there's a massive tumour cell death. This causes a release of intracellular substances, so make the phosphorus, potassium and these purines. And if this release is extensive, it can overwhelm the renal excretory mechanisms.
It means a little picture kind of like it breaks it all down, what happens. So it causes several life threatening metabolic metabolic derangements such as hyperkalemia, hypophosphatemia, secondary hypocalcemia and azotemia. So the acute kidney injury will come from hypovolemia, and then this uric acid precipitates into the ureters and the distal renal tubules.
Metabolic acidosis, disseminated intravascular coagulation can also occur either there's a combination of the neoplasia or systemic inflammation, and then death potentially from these cardiac complications and multi-organ failure. So the clinical signs you'd be looking for are weakness and lethargy, any GI signs, bradycardia, other cardiac arrhythmias, and syncope. Shock, technique or seizures, petechia and ecchymosis, and then death as well.
So to treat this, we would be looking at aggressive fluid therapy, the correction of any hypovolemia and maintaining and hydration. And then we'd ideally be using, saline 0.9% at 2 potentially over 2 to 3 times maintenance.
We needed to correct this electro electrolyte abnormalities, and we can do that by, with the hyperkalemia by using neutral insulin alongside glucose. IV calcium can also be used to reduce the the effects of the hyperkalemia on the heart and any other cell membranes as well, and then that can also help to correct the hypocalcemia as well. We need to correct metabolic abnormalities as well, and then any symptomatic symptomatic treatment as well, so any any vomiting or diarrhoea.
We need to identify patients that are at high risk, so these these highly treatment responsive tumour. Any patients that do have a high tumour burden or if they've got a pre-existing dehydration, renal insufficiency, hepatic dysfunction, or hypercalcemia. So prophylactic measures, we could start by place of having them on fluid therapy at the from the time of the first treatment and making sure that we correct dehydration and electrolyte and acid base status before we actually administer any chemotherapy.
So it might be that if they're coming into you quite poorly, that we have to delay treatment by 24 hours or so before we can actually administer administer. We monitor closely the electrolytes, the renal values, hydration and the demeanour, once we have started chemotherapy. So most of our patients, we will keep in for overnight and we'll monitor this overnight.
So, so probably one of the more common, side effects that you guys will, come across is GI toxicity and diarrhoea. So these causes can be either the chemotherapy or diet changes. A lot of our patients, they get fed a lot of treats, and, and we're, we're very guilty in oncology as well.
We, we use a lot of treats. We use a lot of, tasty little snacks for them because we want it to be nice for them. And I'm sure the owners are doing the same as well, that they are starting to spoil the patients so that their pet's a little bit more, which is, absolutely fine.
It's usually self-limiting, and it does normally resolve quickly. We either we'll give them some of the other probiotics, such as like the Protex and procolo, or we'll supply with the with metronidazole for 5 to 7 days if needed. We normally get them to start, if they have maybe one bout of diarrhoea, we say, OK, we'll monitor that.
If it's ongoing over, say, 1224 hours, then we will tell them to start that straight away. And we give our owners a supplier of this to have sitting on the shelf, so should anything happen overnight or over a weekend when it's difficult for to them, for them to get hold of us or to get hold of you guys, . We just can they and they know then they can start that straight away.
If it's starting to interfere with their daily life, we can normally have to hospitalise them for some fluid therapy, and we need to make sure obviously we're using barrier creams and keeping them nice and clean. If this diarrhoea becomes hemorrhagic, we might need to use a broad spectrum antibiotic alongside the metronidazole or in place of, just because of the risk of bacterial translocation, and this can lead to sepsis, especially if the patient is already neutropenic. So Paladia has, been associated with diarrhoea or GI bleeding, which is severe and requires prompt treatment.
So if any of your patients are on Paladia and they ever ring up and say, my dog has diarrhoea, or there's a bit of blood in it, they need to stop that immediately and the patient needs to be assessed. And the risk of risk of perforation is quite high, in these patients. So sometimes we need to just kind of, we, we may give the patient a holiday from the, from the treatment and may maybe we start on a reduced dose.
It just kind of depends on how the patient responds. So Beresin may cause ileus and constipation in cats. So we need, to start with a prokinetic treatments, such as metoclopramide.
Some, some people will use this prophylactically, starting on the on the day of the Vincristin treatment, but we don't, we would just, we will just monitor the patient and then if they have issues, we would potentially then swap to a different medication. Some patients may need further intervention such as fluid therapy and tube feeding, and then along the lines of stool softeners, dietary changes, enemas, etc. Vomiting is also another common side effect.
We pre-treat all of our patients with Mirropotin before each chemotherapy. We try and get some of the owners to do this at home on the morning or even the night before. Or we'll we'll, we'll administer it, just before the chemotherapy.
Some of the medications we will treat with, for a couple of days at home, regardless of how they actually are, such as epiruicin or doxorubicin, and sometimes carboplatin as well. We always make need to, we always make sure that the owners have got sufficient, neuroppotin at home. So if their patient, if their pet isn't quite right, they can just restart that.
We may need to hospitalise if we're not able to control the clinical signs, so we'd then start, we'd be wanting them to start IV medications with with the Mirropotent, then potentially adding in metoclopramide, and we do tend to like a CRI rather than bolusing this medication. And then if we need to, then we can add in on Dansetron as well, but normally the combination of Meropotin and metoclopramide tends to be enough. So again for nausea, we it's pretty much exactly the same for nausea for the vomiting, just making sure that we are treating with Mirroetin before each chemotherapy, and then making sure that they have got sufficient at home.
Patients that become hyperorexic or anorexic, and we need to make sure that we are making sure that everything else is under control. Any vomiting and nausea, any illness or pain. Some patients just require a bit of coaxing or a bit of dietary change, or we may need to use, appetite stimulants and mirtazapine is available as tablets, and it was available as a transdermal gel via Bova.
I'm not sure if that's still available. I keep looking, but it, they can work pretty well for some patients as well. There is also Entice, which is a new appetite stimulant that is available in America, but you can import it, we haven't tried that, so I'm I'm aware it's there just in case we ever need it.
So prednisolone, as you all know, can cause a whole wide range of ster complications and side effects, the polyuria, the polydipsia as a consequence of that polyuria, polyphagia and scavenging, and papatomegaly. So if they're on, . You know, so we need to monitor, we do monitor their some of their liver values.
There's a risk of GI ulceration because of this increased gastric acid secretion, so we, if they're on a higher dose of prednisolone, such as at the beginning of a lymphoma CO protocol, we will always give them some gastro protection alongside as well. So a GI ulceration, this could be caused by the primary GI tumour, or it could be a secondary from, chemotherapy, such as paraoplastic syndrome, secondary to mast cell tumours like degranulation, such as maybe once they have started on chemotherapy. These can lead to GI perforation and we say yeah we do, we would then want to be using a H2 blocker such as famotidine or a proton pump inhibitor as well.
So, speaking of degranulation and mast cell tumours, malignant mast cell tumours do secrete heparin, histamine, and these proteolytic enzymes. And this can happen as a sometimes just by looking at them, I feel they, it will just, they'll just get angry. Usually by tumour manipulation, so taking FNAs, handling them, poking them, having a little bit of a feel, just measuring them.
Or even when we started giving them the chemotherapy, or if they've had radiation treatment. So the local effects, so we have a little lump or we have a mass, what can happen here, we will see some swelling or inflammation and irritation. And if they've had surgery, wound healing can be poor in some of these patients.
So the systemic effects, hyper histaminemia is regarded as one of the main factors that contribute to GI ulceration and perforation. So we do want to use, this is why we do use a lot of antihistamines, such as chlorophenamine, alongside, some gut protectants as well. So yeah, as, as I've just said, yeah, we aim to minimise the side effects of the histamine release.
So, we do use the antihistamines alongside the H2 blockers or a proton pump inhibitor. And we, we always do pre-treat if we're going to take some FNAs or, the patient is in for ultrasound and we want to take some, and it's got a confirmed mast cell tumour, and we wanted to take further samples from the liver and spleen, we will always then pre-treat with, chlorophenamine as well. So some of these necrotic lymph nodes that I think that large lymph nodes or masses can potentially sometimes become necrotic once we have started treatment of just the the massive cell death that can occur, and we've seen a few patients that have A lot with lymphoma, when they've had massive lymph nodes and then they've, we've started treatment, and then they've come back with, these abscessed lymph nodes.
So we, we need to do some cultural and sensitivity, wound management, and then potentially surgical intervention if needed. So this little chap, he, had a scrotal mast cell tumour and was, had a recurrence, and he had a massive inguinal mesenteric lymph node. And then all the skin, all around his scrotum was all thickened, and this then became infected, and then this all kind of opened up and was, once we started the treatment, became a, became so all open and, needed quite a lot of, wound management.
So sterile hemorrhagic cystitis is a side effect of, potentially a side effect of cyclophosphamide. So this is metabolised by the liver and excreted in the urine. The metabolite, which is called acrolin, can have a, have an effect on the bladder mucosa causing cystitis.
So if they're having, if they're following the protocol for lymphoma and they're having quite a high dose of cyclophosphamide administered, ideally we'd want it to be administered in the morning. And we do give ruzamide alongside, 1 to 2 mg per, orally, with the cycloprostamide to encourage drinking and urinating. And we use 3 doses over 24 hours, so a dose at the time of the treatment, one later that evening, and then one the following morning.
And we need to make sure that these guys have got plenty of opportunity to drink and urinate. We always do a urine sample prior and following administration, and we're just observing for any signs of UTI or blood. If there's any evidence, we won't use this and we'll use something else.
And if these patients do present with cystitis, it is supportive care for these guys, some fluid therapy and analgesia, and if they have, if they do come up with this, we would then discontinue this from their protocol. Some patients are on metronomic cyclophosphamide at home, so they are having this daily, a low, a much, much, much lower dose than what we would use for the protocol, the lymphoma protocols. So we get the owners to check a urine sample weekly at home.
So we teach them how to use a urine dipstick and how to read that. And if there's any sign of the, blood on the dipstick, we'll get them to contact us. And it might be that we need to, we probably will be discontinuing that medication and finding something else for them.
So a couple of drugs can cause some urine colour changes, which shouldn't cause any problems. So epiruicin might cause urine to be coloured orange to red for a couple of days after dosing, uncommon in veterinary patients, I don't think I've seen or seen this happen or had any owners mention it to me. And Nitoxantro can change the urine to a bluey green colour.
And then maybe change the blue, change the whites of the eyes to a blue colour, and again it's not something I've actually seen. So lamastine or CCNU can cause hepatic toxicity. It's extensively hepatically metabolised, and chronic administration can cause, can lead to hepatic enzyme elevations and possible dysfunction as well.
But this can occur after a single dose as well. It doesn't need to be multiple doses. So this, if something, if they're, you're noticing these liver enzymes, the ALT and ALKP are starting to, they've, if they've jumped up maybe after a single dose, we may be able just give them a bit of a delay.
If we, if we were aiming to treat them that day, we'd probably say, actually, you know, go, go away, come back in a week's time, let's reassess and go from there. We use Denemain alongside for a week at the time from the time of administration of Lamaine, for all of our patients. Some patients, we will keep them on it, completely, continuously, but most of our patients will just have this, for 7 days, and we do monitor the ALT and ALKP before we actually administer it.
It's back to prednisolone, so this can cause some hepatic changes as well. And a lot of these cha, a lot of some of these changes can then be improved once we've actually started to dose reduce them as well. So epiruicin and doxorubicin both have the potential to cause cardiac toxicity.
So acute cardiac toxicity, and this manifests as a transient, transient problem, and can cause some arrhythmias associated with, circular circulating histamine and catecholamines. This is caused because the, usually because the drug has been administered too quickly, so we should be administering this over 15 to 30 minutes and it's usually of little little significance, so once you've slowed down or stop the administration, everything should settle down. It's mainly a cumulative effect, and this can be shows us a decrease in the myocardial contractility, with or without arrhythmias, and it does often, it can lead to congestive heart failure.
The damage is irreversible and it does carry a grave prognosis. So both of these drugs have a maximum lifetime dose. So we, if we're using this, longer term, or if it's a patient with lymphoma that has relapsed, and we're needing to go back to, we're restarting the protocol, we need to be careful about calculating how much medication they have actually used.
And once we start to get up, up to this, this maximum dose, we would need to switch it out for something else. But complications can be seen with much, much lower doses as well. So we, we, we pretty much always pre-treat, use a pre-treatment echocardiogram to assess the systolic function as well, just to make sure that there's, hopefully there's nothing going on there already that we're going to exacerbate by administering epirubin or doxone.
So dogs that do have an impaired function, or the dose has been reached, you can use that same medication that we would use for extra extravisation administered prior to, the doxorubicin being administered and hopefully that that can . Hopefully help prevent any further problems. This isn't something that we've done though.
So epi and doxorubicin can also cause nephrotoxicity in cats. So we need to be careful, when we are using it in patients that have an underlying renal disease. So we need to be closely monitoring their renal function.
And some of these guys, we might get them in and have them on fluids for an hour or so before we start the treatment, and then keep them on for a couple of hours after they've had the treatment as well, if we, if, they do have some renal impairment. Cisplatin in dogs can also cause renal toxicity, as if, it contains a heavy metal and can result in a decreasing, filtration rate as well as damage to the tubules. It's less toxic in a saline environment, so we should administer it alongside saline.
And there's various protocols that we've, I, I saw, varying from 2 to 24 hour saline administration. But this is one of the protocols I saw, via the BSAVA. So back to Tubicin and doxorubicin, these can cause some problems.
So hypersensitivity reactions, both have the potential to cause reactions if they're administered too quickly. And again, this is just due to the transient increase in circulating histamine. So this is why we should administer over 15 to 30 minutes.
Some people will pre-treat with an antihistamine, but we don't because we, we, ours, we do administer over between, say, 25 to 30 minutes. Eospirogenase, which is the rescue therapy for lymphoma, can also cause hypersensitivity reactions. It can happen after the first dose or after repeated doses, but the, the risk increases with the repeated doses.
Usually within 60 minutes, but can be 4 to 24 hours, so we normally keep these guys in for a little while, just so we can, we can monitor them and monitor their heart rate respiration and temperature and look out for any clinical signs. We normally pre-treat these patients with antihistamines such as chlorophenamine and dexamethasone as well, and I I like to administer them and then leave it for about half an hour or so before I administer the LSA, just to, hopefully minimise the reactions. We should always make sure that we're administering this sub or or potentially IM IV administration of this can increase the risk of reaction, so it, it must never be given IV.
So spa can also have effects on the protein syn synthesis, causing, a pancreatitis. So we need to be careful when using it in patients that are, have either had pancreatitis before or in the breed category, such as a cocker spaniel or the schnauzers who are at increased risk. So with bone marrow suppression, it I can be quite common with chemotherapy, and it's very, very sensitive to the effects of chemotherapy due to its high, the rapid turnover and the high growth action and the mitotic rate of these bone marrow cells.
It's because the normal bone marrow transit times and the circulating half lives of each cell are different. Neutropenia will occur first and then followed by thrombocytopenia, so the white cells first, then the platelets, and then potentially the red cells, but that's less common. So neutropenia, or the reduced numbers of neutrophils.
This is a dose, this is the main dose limiting toxicity of many of these chemotherapy agents. Mild neutropenia is common. We see quite a lot, but it's not often a clinical problem, and patients are probably absolutely fine, not showing any, any clinical signs.
Severe neutropenia, especially when these guys are pyorexic, can be complicated by sepsis and maybe life threatening. These guys are really can be quite poorly. So patients that that have a severe neutropenia, they will have clinic, most likely will have clinical signs.
And if they're pyorexic, they must be treated as an emergency. So we need to, so if you have an owner who rings up and says, my, my dog had chemotherapy on such and such a day, and today he's not eating, he's not drinking, he's, I've taken his temperature and he's really warm. These, we need to treat these in emergency.
So signs we're likely to see pyrexia, most of them will be pyrexic, anorexia, lethargy, dehydration, GI signs, just generally feeling pretty rubbish really. So for Neutropenic, we, we do a haematology before each chemotherapy treatment and at set points following some of the medications. So with, single agent epiubicin, after they have that every 3 weeks.
So after the first treatment, 7 to 10 days later, we will do a haematology just to check the Nadia, and this is the lowest possible point. This is the lowest point, hopefully, that the neutrophils will get to. Some medications are a little tricky.
Carboplatin likes to, to toy with us a little bit, and we get them patients back at 3, maybe 10 days. Everything's fine. We get them back at 3 weeks for the next dose of chemotherapy, and their, their, their white cells are really, really low.
And this is sometimes these, some of these drugs can have a double in day. So, by having, by having this Nadia, it helps us plan for the next dose of treatment. So as I said, with this, if they were having single dose epiubicin, and after their first treatment, the Neutrophils were within normal limits, it means we can either increase that dose or we stay the same, cause everything was absolutely fine.
If they were neutropenic, we would probably need to do we decrease for the next time. And the level of neutropenia depends on the action that needs to be taken, so that's whether or not the patient is due chemotherapy now or is due, or it's just we're here having this done as a nadir. So if the neutrophil count is above 3, that's no neutropenia.
Everything should be absolutely fine. There's no action to be taken. If the patient is due chemotherapy, we'll continue as normal and we carry on with the protocol.
If this is the Nadia, blood test, the dose can either be kept the same or we can increase it for the next time. So if the neutrophils are between 2 and 3, this is a mild neutropenia. If they do chemotherapy, we'll double check that on a blood smear, and we'll do a manual neutrophil count.
If it's normal, we'll go ahead because a manual count is fine. If the chemo, if it's low on a blood smear, we'll probably then delay the treatment, if it, they were due treatment and then recheck in a few days. And usually within 48 hours, they're back to where they should be.
If this is the Naira blood test, we may need to do to dose reduce for next time. So if they're neutrophils are then between 1 and 2, this is a moderate neutropenia, and if they do chemotherapy, we'll check a blood smear again, but most likely the machine's reading pretty true, and we'll delay treatment and recheck in a couple of days. We'll probably give them a broad spectrum covering antibiotics, just, just in case, because, because they are kind of running a little bit low, and we'll get these patients home as quick as possible, so that they're hopefully they're not going to pick up anything in the hospital.
If they're not pyorhexic, yeah, we will get these guys home. If they are pyrexic or starting to show any clin clinical signs, we will need to hospitalise and barrier nurses. So anything less than one, if that patient is, it's classed as a severe neutropenia.
But if that patient isn't febrile, there's blood, we probably, again, give them a broad spectrum antibiotic, and then send them home, get them out of the hospital as quickly as possible. There'll be no chemotherapy going on today. If they are febrile, the patient needs to be admitted for treatment, and we need to bury and nurse these guys because we're, they're, they're at serious risk of becoming septic.
We need to offer supportive care, so fluid therapy, electrolyte supplementation, IV medications, and then potentially thinking about feeding tubes as well. So we need to make sure owners are well aware of the signs of neutropenia, just to make sure that there's they can pick up signs pretty quickly. Neutropenia associated with chemotherapy just tend to .
Tend tends to rectify pretty quickly, as I said, normally within about 48 hours, they're back to where they're not, where they were. I can, I can remember one of our patients, he came in on one day. He felt absolutely dreadful.
And then the following day, you could see he, he was starting to get his little spark back, and then like, by 48 hours later, it was like nothing was, nothing was wrong with him, and he was back to his normal, cheeky Labrador self. But for some of these patients that are persistically neutropenic and that we're struggling to, yeah, that that they're not coming back to the normal levels as quickly as poss as quickly as they we would expect. There is medication, the granulocyte colony stimulating factor that can be administered.
And this is used to increase the neutrophil precursor cells, the neutrophil production rate, and it also shortens the maturation time as well. It's pretty expensive. So we tend to only, use this, when absolutely necessary, rather than just, oh, that he's really low today, we need to increase it.
We'd normally just let them, right, they'll normally be back to normal within 48 hours anyway. So it's not something that we, we use commonly. I think that maybe I've seen it used maybe once or twice if that.
So thrombocytopenia is commonly seen with platinum medications such as carboplatin and cisplatin, Lamistine and then long-term metronomic chlorambil. It's generally safe to continue as long as the platelet count doesn't go below 50. And if it starts to, we should be starting to either delay or discontinue these medications.
And this is, yeah, as I said, this is common with some of the, the longer term, metronomic treatments. Anaemia, associated with chemotherapy does, is, is rare, really, but it can still occur. It tends to normally be, due to the disease, either a GI bleed or, a concurrent disease as well.
It doesn't tend to be as a side effect of the, the chemotherapy, really, could potentially happen with, some of the metronomic, chemotherapies. So if we are starting to see some lots of bone marrow changes, we do need to think actually is this because of the is this either, is this chemotherapy induced or is it actually due to disease progression? Some medications are fatal to cats, so we absolutely mustn't use them.
So 5FU and cisplatin, must not be used in cats. 5FU can cause a severe fatal toxicity in cats, and absolutely mustn't be used. Cisplatin causes a fatal pulmonary edoema and pleural effusion in cats, so again, should not be used.
So lots and lots of people will be asking, oh they are my patient is my dog gonna lose his hair? Is his hair is it all gonna fall out? Is he gonna be completely bald, .
Sometimes we do see, maybe see a bit of a delayed growth and this is, especially with like some of the longer term chemotherapies like the, the, the lymphoma protocols, maybe there'll be a little bit of a a little bit of coat changes, they tend not to lose all of their coat. We have some patients who've lost part of their coat. If they've been like black and white dogs, they've lost, some of the coat, and I've got some pictures of this dog for you.
And this does usually resolve after the discontinuation of treatments as well. Potentially may see alopecia and poodles, some old English sheepdogs and terriers, and we tend to see kind of the the the coat tends to go just really, really thin and kind of, all wispy. I've got again, I've got some pictures of, a poodle for you as well.
So cats can develop a bit of a velvety coat after some of the long-term chemos, and it tends to be mainly that the whiskers, maybe start to fall out, maybe with no replacement after the long term chemo. And we've seen some coat colour changes with poodles. And we've had two poodles, who have had a beautiful white coat.
And once we've, started on chemotherapy, they've actually turned into an apricot colour. So, this is the beautiful Bella. She's a dinkiesest little poodle in the entire world, and she was a beautiful white colour, and now you can see, she's an apricot colour.
And this is beautiful Barney, and you can see, he has lovely black and white, luscious locks in the top picture here. And then once we got our hands on him and started administering the chemotherapy, it was the most bizarre thing for him. It was all of his white coat that became really, really thin.
And he ended up, so his black coat was absolutely fine, but all of the white coat on his head and all over his body actually started to thin out there. And it all did grow back once we had just once we'd finished his chemotherapy protocol. So, a lot of those are some of these patients, you see these herding breeds like the border collies, the Shelties, Australian shepherds and long haired whippets could potentially have this MDR1 gene mutation.
And any signs associated with this following treatment would include tremors, hypersalivation, blindness, coma and death. So dogs that are positive for this gene mutation, . Would potentially be more sensitive to such medications such as Doorubicin, napiruicin, think alkaloids such as Vincristin and vilastin.
Actinamycin D, methotrexate, and nitoxantrom. And we, if we have a colleague come in, we will normally start them on a low dose of, medication until we know otherwise. And testing is, pretty readily available.
It's linked as labokin and I said, I think it's an EDTA blood test that we need to send off or the owners can, most, a lot of owners will maybe have already looked into this themselves, and you can use, I think it's the oral swabs to the same place. So Selfonta is this new medication that is out for non-metastatic, cutaneous and subcutaneous mast cell tumours and that are located to er or distal to the elbow or the hock. .
There's a very, website for, with lots of pictures and lots of information, with Verbach. And if you search on the webinar vet, if you search for mast cell tumours, there's been a couple of talks over the last couple of months all about Stephonte and about any updates, what's going on with mast cell tumours. So these are really definitely well worth watching.
So the stealphonta is designed to be injected into these non-surgical tumours, to help, treat these. And we need to be super careful when we're dosing and administering these. It, I think it was a, it needs to be less than 10 centimetres cubes.
So we need to be very, very careful when you're measuring the size and the depth. And then for when you're administering it as well, ideally these patients should be sedated so that you know you're only injecting into that mass. I follow quite a few, mast cell tumour pages, led mainly by owners, and a lot of these owners that are sharing their stories are saying how that their dogs have been a little bit painful that first night that they've come home after the injection.
So we should maybe, maybe consider hospitalising for that first night, just to make sure that they, they're comfortable before we, we send them home. Vomiting and diarrhoea is also common, and there will be a wound. Once this, medication starts working, there will be a wound.
It will be open. It will be there. We need to keep that clean.
We need to avoid, ideally avoid dressings, but they do say just some loose dry gauze can help just to prevent any self trauma. And we should be avoiding, soaps and shampoos and all that sort of stuff and just kind of let it, let, let it heal. Antibiotics can be used at the discretion of the treating vet as well.
So, a lady on one of these Facebook pages actually was very kind enough to let me use some of her pictures, just to, just to document that the, the journey that her and her dog went on. As you can see, this, this wound developed and developed, and then eventually, this big massive scab fell off and left this open wound. And then 21 days later, he's left with this little wound and then 3 months later he's left with a left with a scar.
Again, this is something that we've not, not used as yet, exciting to try, exciting that we've got more options available now. So there are side effects from other medi other potential treatments as well. So radiotherapy could cause impairment to any wound healing, so we need to make sure that we're timing any radiotherapy treatments following the surgery at a suitable time.
There's potentially damage to normal tissue cells, that may inadvertently be in, be in the way as we're trying to treat. So, sometimes if we're trying to treat, tumours on the face, eyes, and, Tissue and everything can all start to be damaged, the skin can be damaged, the oral mucosa could be damaged, and a lot of it is just symptomatic treatment as well and making sure wounds and everything are managed. It does require multi radiotherapy does require multiple GA's within a short period of time as well, which then obviously comes with their own risks.
Electric chemotherapy is also a form of local cancer therapy that is, we either use bleomycin or lit cisplatin for dogs, combined with this electric pulses, to help the chemotherapy get into the cells. Again, this does require anaesthesia or sedation, and there's risks associated with that. There may be some discomfort at the site and some scabs may form.
This Rottweiler had the most enormous mixosarcoma. So she had a massive area to be treated. And you can see, so this is a, like a, two little plates next to each other.
They're about 1 centimetre so long, they're about 1 centimetre, wide. It's two little plates. And you can see just, she just had some, it wasn't quite scabbing, it was just kind of a little bit of, dry skin all over the patch that we had treated.
She wasn't particularly, bothered by that. So the bleomycin that we use as part of the electro chemotherapy protocol can . Cause pulmonary fibrosis, and the combining oxygen with the bleomycin, to administering oxygen to the patient at the time of the bleomycin being administered, can increase the risk of this pulmonary injury as well.
So, once we have our patients sedated, . And we're giving the obli ice and we we turn off the oxygen. We've also started using and we mainly we do use a sedation just because we can't really administer the oxygen.
We've also started using a total intravenous anaesthesia, so we've had a CRI of propofol, and then we've been able to intubate and then ventilate with room air as well, and then using local box as well. So, quality of life is the most important thing to consider during all of these treatments. There's absolutely no point.
And we, I say, we say this to all of our own is that when they're, we know that they're worried about starting chemotherapy, because they see all of the side effects that they've seen friends or friends of friends and family that have gone through chemotherapy and they've been so unwell. There's no point for us if we've got a cancer that is completely under control and we've cured it, and it's amazing. That would be amazing if that patient has then had to spend most of his life on a on fluids in the hospital because he's been having vomiting and diarrhoea, and he's been neutropenic, and he's been miserable the whole time.
Quality of life is so so important. So we need to consider all the joys of life for these guys, if they're on treatment. We want to make sure that they're eating and drinking OK.
Are they able to get up and around and, do what they should be doing? Are they able to interact as they normally would? Are they, do they have a healthy mental state?
Do they seem happy? Are they able to play either with you or with any of the, if they are any other dogs or any other pets in the household? And the but this, this dog's cancer survival guide suggests that when maybe 2 or 3 of these are affected, that quality of life may be starting to drop.
So we need to then start to consider what we should actually be doing for these patients. And we've had some patients that have just not tolerated any medications, and we think, actually, you know what, we just need to maybe, maybe palliate these cat guys and just have them comfortable for as long as possible because we're making them poorly by actually trying to help them, and that's absolutely not our aim. So if with these side effects, and you've got an owner on the phone, so the main thing we need to do is think about, ask them, what the clinical signs, when did they start?
What have they already done? I said, if they've come from us, they will have had the metronidazole and Serena already provided, so they will normally have started to use this. And how is the petting himself?
Are they, are they, are they actually bouncing off the walls really happy, but they've vomited once, or are they really poorly? And then find out what the pet, what treatment the pet had had it, what, what, when the patient had the treatment and what it was as well. So we can kind of think actually we're, we're looking at so many days post treatment, this patient could potentially be neutropenic.
We need to make sure these owners have plenty of help and guidelines as well. So we have some little leaflets that we give to all of our owners so they know, what to look out for. Do they, they're looking out for, the vomiting and the diarrhoea, this patient, is he potentially neutropenic?
Are there any other side effects actually starting? Are they starting to drink more? Are they, peeing more, or is, is, is it, what changes are starting to occur?
So they, our owners are pretty, and most of them are pretty on the ball with this. So if you do need any help, contact us or your local oncologist for anything chemotherapy. We're happy to do any advice calls, or for a referral.
And chemo, I love chemo pet. They're absolutely awesome. They can sort out, so if you're trying to admit it, if you're wanting medications or advice on anything, they are awesome and they will help you out as much as they can.
So there's a little bit of further reading, . So I, I've lots of the information I've got from all of here. And there was another webinar that I did a little while ago, and that was the chemotherapy safety and practise.
So that, and the notes that are associated with that webinar, discussed kind of more, a little bit more about the, the safe administration to try and minimise the risks, risks of extrovisation and everything else in practise. So this is something else I, I've, I, I did include. I've tried to research, tried to find whatever I could about this, but I kind of kept hitting little dead ends, and I'm convinced I've been, given this information somewhere along the way.
Need to consider any rabbits or ing. Pigs that are potentially eating grass outside, that could be potentially contaminated by dogs that have been urinating on it. Just the risk of potentially, making these pets sick because they will be eating basically eating chemotherapy.
So I always suggest that these owners should either keep, make sure the dogs have a separate toileting area, or that they definitely don't go into the areas where, the rabbits and guinea pigs are eating grass. But, I tried to find out as much information as I could, as I said, I just kept eating, eating, hitting dead ends with getting any information, but it's always something I do, get owners to consider. Remember to look after yourself, in practise it's been tougher as you know, at this moment, and especially all things oncology related, with especially what we deal with all of the time, look after yourself.
And if you do have any questions, I may have to take any questions, and if you think of anything after, this evening, please do email me, I put email, my emails in the notes, and you can either contact me or contact my practise as well. Yeah, thank you very much. Caroline, thank you very much.
That was absolutely fantastic. It really was and I, I wasn't convinced you get through all your time. Thank you.
Yeah, it's, it's interesting, you know, to, to see all these side effects when they're put together like that. Because when we're studying these drugs or when we start using them, we think about them, but to put them all together, it, it's, Yeah, it's, it's quite impressive how the, the oncology teams and the veterinary teams in the practises manage all of this, with the patients and, and having to keep the owners in the loop. Yes.
Absolutely. We, we've got all, we know, we, we know what could potentially happen. And we, we make sure that we, we're trying to do as much as we can to minimise some effects.
As I said, we, we send all of our own owners home prepared with the Cerenia and the metronidazole, so they can start them straight away if they're worried. And yeah, just trying to make, keeping on top of stuff like that to make sure we're minimising any potential side effects, as well. Yeah, I think it's, it's just such a fine balance of informing them without scaring the life out of them that they don't want to go ahead.
Yeah, so there's been many a conversation that I've had with owners who have been, they've been scared to start the protocols, and, I've been like, well, actually have a look at. Go and chat with other people, and we've got some videos on our, on our, oncology Facebook page as well and say, actually go and have a look at these dogs that are running around the beaches, that have, he, she had chemotherapy two days before, and she's running around like a crazy dog, and she's really happy. And we, we, we, we educate and we counsel them so much through the whole process, especially at the beginning.
And we just kind of actually, you know what, we need to spend some time with you and Not have you absolutely terrified. If you're wanting to go down the street, we will absolutely support you all the way. And, they said, we, it's making sure that they're, they're educated and prepared.
And you can see that the first couple of weeks tend to be, they, they're very, very nervous. We'll get lots of phone calls, we get lots of emails. And then it, as they kind of go, actually, you know what, they're doing really, really well.
They, they're not poorly, they're not sick. They're doing. Absolutely great, they have the inconvenience of coming in to see us once a week or every couple of weeks, and besides that, everything in their life has pretty much stayed the same, they don't know their poorly.
Yeah, and, and I think one of the biggest shocks that I've always found with owners is that they, they kind of admit after 3 or 4 or 5 weeks that they didn't believe you, that their hair wasn't gonna fall out in the beginning. And they're quite surprised that it doesn't in most cases. Yes.
And yeah, I think the hair loss tends To be the, the main thing that most people do seem to be worried about. And, yeah, we've had a few that I can, I can, I can still remember 11, a couple of owners that had, they had the most beautiful poodle. She had the most beautiful white poodle cut.
She had the most, it, it was pristine. And they were so upset when it all started to fall out that they actually want, they considered to stop the chemotherapy even though she was doing really well. But her coat was falling out, and then all of a sudden, they kind of went, What are we doing?
She's doing amazingly. It's just her coat. And they clipped it all right down, and she, she did amazing.
She grew back apricot, clearly, from her beautiful white. But then, yeah, once we kind of got them through that and that, they were like, she's doing great. She doesn't know her coat's all falling out and going a bit funny.
And they just carried on, and she did really well, eventually. Yeah, fortunately, the apricot. No, it's been so bizarre to see patients or 3 patients actually, that that's happened to.
So yeah, it's, it's one of the things we do warn them about. Yeah, fantastic. Caroline, once again, thank you so much for spending this time with us and sharing your it really does .
Create a sense for us that, you know, we need to be careful, but we don't need to be scared and educate, educate, educate. Yes. Absolutely, absolutely, yeah, it really, really is.
Fantastic. Thank you very much. And to Kyle, my controller in the background, thank you for setting everything up.
To all of you for attending tonight. Thank you for your time. I hope you enjoyed it as much as I did.
And from myself, Bruce Stevenson, it's good night. Thank you very much. Good night.