Welcome everybody to the next in the Care in the face of COVID-19 webinar series from virtual veterinary specialists. The topic of this webinar is equine respiratory distress, video triage and Management. Today our speaker is Doctor Adele Williams, our CVS and European specialist in equine internal medicine.

We are very pleased to announce that Adele will be leading a brand new specialist internal medicine equine telemedicine service, which we hope many of you will find helpful. Hello, my name's Doctor Adele Williams. I'm a European specialist in equine internal medicine.

I'm going to be talking today about equine acute respiratory distress in practise and how we can video triage and manage these cases, during the, COVID-19 coronavirus lockdown that we're currently under. So the current government advice is to only go outside for food, health reasons or work, but only if you cannot work from home. If you must go out, you must stay 2 metres or 6 ft away from other people at all times, and you must wash your hands as soon as you get home.

The RCVS have released updated guidance on veterinary work during the pandemic, and BVA and Beaver have released their advice and interpretation on this guidance. Essentially, risk assessment must be done on a case by case basis as to whether an animal should be seen, can be treated remotely or can have treatment postponed until after lockdown. There is a handy risk assessment tool available on the Beaver website to help with this decision making.

Beaver have urged vets to maintain professionalism during these fraught times. As the guidance is constantly being changed and updated, it is best to check for yourselves with the government, governing body and advisory body websites for the most up to-date information. But clearly as equine vets, there are instances when we cannot work from home.

There are, however, some circumstances when cases can be managed remotely and we can in these exceptional circumstances, prescribe remotely. We at VVS can help you with these difficult decisions and we can guide you remotely if specialist consultation is needed. Especially whilst referral centre travel is not an option.

So one common equine emergency that we get called about at this time of year is acute respiratory distress. This can be distressing for the horse and can lead to a very panicky owner. Normally, obviously you'd hop into your cart and zoom off to treat such a case straight away, but with the government lockdown and social distancing, things are no longer that straightforward.

I'm going to talk you through how we can best manage these cases during lockdown while still doing our best for animal health and welfare. It's important to remember that we aren't necessarily going to be working to gold standards during these unprecedented times and that human health must take priority over animal health. At Virtual Veterinary Specialist Eine, we can help you with these difficult cases, and we are here to support you during this crisis.

Probably the best way to go about these cases of respiratory distress initially is by remote triage, to decide if you really need to see the horse urgently or if it can be managed remotely. Video consultation is an advantage if you and the owner can achieve this, as you can then see your patient and assess their respiratory rate, etc. How they look generally, if they have a heave line, if their nostrils are flaring, etc.

And what their environment looks like. If video call isn't feasible, you could get the owner to email or WhatsApp some photos and videos of the patient for you. Remembering to ask for different angles, so from the front and sides and perhaps close up on the nostrils and on the flanks.

You can still get some useful information from a telephone call if that's all that's available to you, and then you can make some decisions and give advice from there. If you have booked a time slot with an owner for a telephone consultation, particularly if it's a phone call rather than video, you can signpost them in advance to the of the appointment to, beaver YouTube videos on how to take the horse's breathing rate and temperature. And, and you can also ask them to email you videos, so you've got this data to hand before starting the telephone consultation, so you're already getting an idea of what's going on with the patient in your head before you start.

This will provide you with valuable information and save you time during the telephone consults. With a skeleton staff, you may be being the receptionist as well as the vet nurse and admin roles. So it can be useful when answering phone calls to assume that receptionist role, requesting details and then leave the actual veterinary detail and questioning and discussion to the time of the allotted telephone consult's appointment.

The first The important thing to work out quite quickly in these cases is if the horse is actually in respiratory distress or not. It's common for more novice owners to mistake, for example, choke for a respiratory distress, and you need to figure out quickly if the horse needs attending to. And how quickly it needs to be seen.

Often horses with choke are actually more agitated than horses with dysnea. So if you can establish what the respiratory rate is and if they're showing any other signs such as nostril flare, abdominal heaving, wheezing, or other noises during breathing, swollen lymph nodes, and whether the horse is distressed and what their demeanour is, then that's really useful. Also, establishing mucous membrane colour is a very important factor early on.

It should be relatively easy to instruct the owner to show you this and tell you what the gum colour is. If there is frothy or food discharge at the nostrils or repeated stretching of the neck and wretching, then it may well be choke rather than true dysnea. It's very unlikely that you will have a case of a cyanotic horse with blue mucous membranes, but if they are, then this is an emergency with indication for a tracheotomy and or bronchodilation and possible oxygen therapy.

In this very unlikely event, we can talk you through how to carry out a tracheotomy and other emergency treatments. The differential diagnosis for acute respiratory distress can include a variety of inflammatory and infectious conditions that need to be ruled in or out. This is not a complete list, and it can be a daunting task to consider how to tackle this at the best of times, let alone when we are facing coronavirus lockdown.

Asthma previously referred to as COPD, RAO, IAD, heaves, etc. Should always be considered as a possibility in acute respiratory distress, even in cases that have had no previous history of respiratory disease. As mentioned previously, choke can be mistaken by owners to be acute respiratory distress.

Strangles is so named for a reason, so it's important to establish if there is a fever, enlarged lymph nodes, or nasal discharge, and if any other horses have been affected. Tracheal foreign body can be an occasional cause of sudden onset relentless coughing, and I once removed a 1 metre length of bramble from a horse's trachea so they can get themselves into all sorts of tricky situations. Other causes of upper respiratory tract obstruction include bilateral laryngeal paralysis, neoplasia, swelling due to trauma, foreign bodies, etc.

And then normally accompanied by an audible noise on breathing through the narrowed upper respiratory tract lumen. Smoke inhalation and aspiration pneumonia should be obvious from the history, but it's always worth checking if the owners have recently given any medication. I usually ask what medication have you given recently rather than asking if they've given any, as it usually leads to a more honest answer.

Lung worm and other endoparasite larval migration through the lungs can be a cause of coughing, though it would be unusual to present with respiratory distress. It would still be worth checking parasite control and what was last used for deworming and when it was used. Pneumonia, pleural pneumonia, and lung abscesses can all potentially present in respiratory distress, though usually accompanied by other clinical signs such as weight loss and intermittent or persistent fever.

Of course horses shouldn't be being transported at the moment, but it is probably best to check if there have been any recent travel history if you're suspicious of pleuro pneumonia. Viral respiratory infections are normally associated with a fever which is sometimes transient, and nasal discharge can start serous and then progress to mucopurulent. It's important to inquire about the status of all in contacts and again any recent mixing of horses, though again, of course, this shouldn't be happening at the moment, but that doesn't mean that it's not happening.

I've put AHS, which is African horse sickness, in brackets, since although we don't have it in Europe yet, bluetongue is carried by the same vector, and we have had bluetongue outbreaks in recent years in Europe. So it's always something to keep at the back of your mind. If, if you do come across a horse with African horse sickness, the respiratory signs are usually related to pulmonary edoema, and it tends to be highly fatal at that stage of presentation.

Rhodococcus is always a concern with folds of respiratory distress. This talk is really focusing on adult horses, but if you do need help and advice with foal medicine, we're here to support you, so please do get in touch. And then fungal lung infections and neoplasia are more rare causes of respiratory distress.

And exercise induced pulmonary haemorrhage normally has a history of epistaxis or nosebleed after exercise, so it's important to, to establish that from the history as well. To try to figure out what's going on with your patient from the long list of differentials I've just been through, we would normally do a thorough workup including a history, a clinical examination, including a rebreathing examination and diagnostic tests. Obviously things are a little bit different at the moment and we're limited in some of those things, so I'll talk about that now.

We would normally do endoscopy to visually inspect the airways, depending on the level of respiratory distress. Obviously, if something's in severe respiratory distress, then we're not going to compromise it further at that stage by putting an endoscope down its airways. We in doing endoscopy, we look for upper respiratory tract obstructions.

We look for lymphoid hyperplasia in the pharynx, we look for inflammation and mucus in the airways. You can see these airways here have got a bit of mucus, . On them, the the top left is obviously the the the pharyngeal area.

The, the bottom left is is in the mid trachea. You've got a few spots of mucus and the top right images is that the carina, the bifurcation of the trachea into each lung lobe. The, we would normally perform a tracheal lavage and broncho alveolar lavage and do cytology and culture analysis of airway samples.

The bottom right image shows typical airway neutrophilia, on cytology associated with equine asthma. But we're not going to do these procedures at the minute because endoscopy requires close personal contact and also multiple people being involved in the procedure. So something to be avoided where possible under the current circumstances.

It's also possible without an endoscope to perform bronchoalveolar lavage with a bronchoalveolollivage or bowel tube and also tracheal wash percutaneously through the skin if no endoscope's available. But again, those procedures will infringe on social distancing rules because you need to have someone close to you holding the horse, and passing you, . Syringes of fluid for instilling and collecting out.

So, with the social distancing rules as they are, it's best to avoid these procedures for now unless there's an urgent need to perform them. If you need advice on decision making or whether to do these procedures, or actually technical help with carrying out the procedures or interpreting cytology, please do get in touch. We would normally also do thoracic ultrasound and radiography.

To help identify problems in the lungs, the image at the top shows some typical acoustic shadow artefacts named comet tails, which usually occur when there are irregularities or inflammation on the plural surface, and we can't see below that into the deeper tissues. We are going to be really limited on the diagnostics we can do at the moment, unfortunately, because of lockdown. The radiographs on the bottom of this slide are from a horse with acute onset dysia, and they show an interstitial pattern, particularly in the caudal dorsal and ventral lung fields.

Chest radiographs, of course, require a large X-ray exposure to get through the whole thickness of the horse's chest, and so it's not appropriate to do them in the field or with someone holding the plate. So it's not really possible to do X-rays without moving the horse to a facilities with the gantry for taking chess films. And therefore, this probably isn't justified in most cases at this time.

Having said that, if you do have cytology, ultrasound or radiographs you need help interpreting or advice on, we are available to help with that at VVS. So what can you do and what should you do, is the real question. Given the limitations of the current lockdown, what What you can do and what you should do er depends on the patient in front of you.

So you need to decide quite quickly if the horse is in real distress and needs immediate veterinary attention, or if you can first do a remote consultation with the, the owner by video or telephone. It's important to remember that you can get a good idea of which differential is most likely from that long list I gave earlier based on the history and the clinical examination, even if that's a remote and basic clinical examination with you at a distance and the owner giving you the information. You can then decide if a visit is needed.

So it's, there are some important things that you need to get from the history, such as the vaccination status and any mixing with other animals, and if there's any signs in any intact animals which might indicate some sort of infectious or toxic cause. If there's been any recent travel or or any other previous episodes of choke, it's important to establish as well. The deworming history will point to potential lung worm problem, and if they've had previous respiratory disease and suffered with similar symptoms before, that's really important information.

You want to know, of course, how long it's been going on, and questions about the environment, so bedding, obviously take note of what time of year it is, the type of food that they're on, what the quality is like, . And what the animal's appetite is like and if there's been any recent dietary changes, you want to know about other symptoms, so if there's any signs of cough or nasal discharge or exercise intolerance. And sometimes I find that owners don't notice nasal discharge if it only happens when the horse's head is down on the ground when they're eating.

You'll want to know about recent activity. So if they've been, riding, then perhaps there'll be, there'll be a foreign body that they've inhaled. Also, you know, if there's been any nose bleeds post exercise, exposure to noxious substances such as smoke, and, if there's been any weight loss or any other signs of systemic disease.

So the idea of a virtual examination can make some of us feel uncomfortable and it can take a bit of getting used to. But it's similar to the information you would normally automatically gather whilst chatting with the owner, and observing the horse in its environment when you first get there. So if you look at the horse from a distance, you know, you can do that via video, you can gain information about the vital parameters, so you can certainly look at respiratory rate and effort.

You can do a sort of whole body gauge, look at their body condition score, is there a heave line, what sort of condition they seem to be in, if they're with lots of others or if they're on their own. And you can get an idea of what the environment looks like as well if if you're on a video chat, which is great. If not, you'll have to quiz the owner on these and get them to tell you what the environment is like, how, how many of the horses there are there, neighbouring stables, .

Who they're turned out with, etc. Etc. So the things that you can observe via a video are the housing situation.

So if they're in a stable, a barn or a field, if they've got nose to nose contact with other horses, what do you think the air quality looks like, you know, whether they. Got nice open doors or is it kind of all all inside? What bedding they're on, the feed type and the quality.

You can take note of whether they're fed from the floor or from a hay net or a manger because that's quite important with the respiratory disease. You can take note of the horse's demeanour and appetite, their respiratory rate and their effort, and if there's a heave line. If there's any nostril flare and if they're coughing while you're talking to the owner as well and if there's any nasal discharge, you might want to ask the owner to zoom in on the nearies so you can get a good look for that as well.

If we watch these video clips from a stallion with respiratory distress, you can see that he's kept outside in his own paddock, but he has got other horses nearby. He's got an increased respiratory rate with nostril flare, and he's got an an increased obvious abdominal effort and a heave line. But left in the field on his own, he's still eating and wandering round and interested in his environment and other horses.

The video we'll get to that in a minute, just so it's very obvious heave I see he's he's mooching around in the field, he's still happily . Looking over the fence at other horses, so although he's got dyspnea, he's having difficulty breathing, he is not in distress in the terms that we would think of distress, even though an owner might find this a very distressing for them. The horse.

Is not so bothered about it that he's not eating or going about his normal daily things that he would do. So that's an important thing to to think about and observe when you're deciding whether you need to rush out there or it's something that you could perhaps initially remotely manage. So you have to make a decision on whether you should visit based on the history and the appearance of the horse and the information that you've got from telephone consultation.

If the horse is genuinely distressed, then they may well need a bronchodilator and other urgent medical therapy. If it's pyrexic, are you perhaps able to prescribe an oral anti-inflammatory drug, or do you feel that the horse would benefit from a faster onset of action in injectable medication? If the breathing or the coughing is so bad or there's signs of choke, then a visit is definitely warranted.

If you're suspicious of infectious disease, you could get the owner to do perhaps some nasal swabs, and if there's obvious nasal discharge, and you can give them instructions on biosecurity, and you could provide symptomatic treatment with oral non-steroidals to help the horse feel feel better in itself, and advise on monitoring and testing of other in contacts as well. So it's important to weigh up the welfare of the horse versus the current restrictions and your own and the owner's safety. If you need help making decisions on these cases, we are here to support you and talk you through your clinical decision making.

So the horse in the video was a 6 month pregnant mare that had been bitten on the muzzle by an adder. You can see there's a very severe degree of facial swelling, and it's so severe. That she has audible noise with breathing through that very restricted upper airways, and this sort of case is an indication for an urgent tracheostomy, because we need to give her an airway that she can breathe through, basically, we don't know if that swelling's going to get any worse, so that would be an urgent, you need to visit this case.

This is an Appaloosa, and this little pony has got a chronic severe asthma and she's in respiratory distress. The breathing is laboured with an increased respiratory rate and nostril flare at rest, and the pony is inappetent and quiet, alert and responsive. Bronchodilation and anti-inflammatory medication is urgently needed, as well as management changes to maximise the pony's air quality.

So these medications could potentially be administered by the owner, depending on the medication and the route of administration. And it's important to know, you know, we shouldn't be expecting owners to administer intravenous medication, even in these lockdown situation. So gauge your patient and risk assess, you know, each individual patient and how bad their their breathing is and how, how urgent it is that the medication needs to get into them.

Because injectable medication is needed, you've still got to get out there with inhaled or oral medication. Could the owner perhaps come and pick it up from you that day and it still be administered within a similar sort of time frame, so you've got to sort of make those decisions and rationalise those and think of not only the horse's welfare, but your health and safety and the owner's health and safety as well. OK, the owner will undoubtedly be panicking if their horse is in respiratory distress.

So it's really important to try to get them to keep calm and to keep the horse calm. Instruct them to keep the horse quiet and rested, and to improve the air quality as much as possible in any case of respiratory difficulty. For longer term respiratory health, feeding a supplement rich in omega 3 will be beneficial to help reduce airway inflammation, and most owners relish the opportunity to add a supplement to their diet.

So that's a little project that you can give them to do. If you do decide a visit is essential, remember to try and maintain social distancing and remind the owner in advance of the requirements and what you're going to, to be able to do and not be able to do. If possible, the owner should stay 2 metres away from you, and there shouldn't need to be other people present.

Often find that on a yard there's a myriad of people that want to watch what you're doing. Well, you must expressly forbid this from the outset before you get there, you know, minimum number of people please involved. Also remember to wear your PPE and to remove it safely without contaminating yourself when you remove it, and wash your hands and disinfect any equipment, including, importantly, your stethoscope, because they're they're always good vectors for harbouring disease at the end of the visit.

And wipes for your steering wheel in your car and and that sort of thing and some hand gel are also, you know, really handy just to have with you and do as much as possible. . I think it's really, really important to manage the owner's expectations over what's possible or what's not possible in advance of your arrival, so they're not expecting you to be scoping an ultrasounding when when perhaps you're not going to be able to do that at this time.

If you're suspicious of an upper respiratory tract obstruction. Remember to have your tracheostomy kit ready. The video shows a tracheostomy being performed and a tracheotomy tube being inserted that's in the mare that had the snake bite and the swollen upper airways.

It's a relatively quick procedure to do and it does, it provides this mare with instant relief for her respiratory distress and her respiratory rate instantly reduces, and you can hear. A big gush of air going in when, when that track tube goes in. If you suspect esophageal obstruction or choke, which is being shown in the picture of the horse on the bottom right, then make sure that in your car you've got sedation and a nasogastric tube ready and instruct the owner to get ready some buckets of water and some empty buckets for you to, to do the lavage to try and clear that choke.

I would also recommend heavily sedating a horse with choke, as it will make your job a lot easier. It will mean that hopefully you don't have to have such close contact with other people while you're doing the . Lavage of the oesophagus, and, and sometimes a nice relaxed source, the choke clears on its own as well, so sedation is your friend, when with cases of esophageal obstruction.

For acute bronchoconstriction, the parasimatholytic drug atropine, so that's why I've got a picture of Belladonna up there, at a dose of 0.01 to 0.02 mg per kg IV, that's 0.01 to 0.02 Migs per kg IV will give instant bronchodilation.

And it's also a crude diagnostic test for the presence of bronchoconstriction. If the horse's breathing does not improve after administration of atropine, then something other than bronchoconstriction is going on. It's important to remember though that we don't want to give repeated doses of atropine as this will cause gut stasis, and we don't want to cause an impaction colic on top of everything else.

The effects of atropine last anywhere between 8 hours and 3 to 4 days in a horse. If you didn't have any atropine, but you had some hyacine or buscopan in the car, you could use that to relieve bronchoconstriction. But remember the effects are really quite short-lived, so it would only be a very temporary measure to sort of perhaps calm the horse down while you sort out some other stuff.

So if you decide that no visit is needed at this stage, you have probably reached a presumptive diagnosis of asthma, if there's no other in contact horses affected and if they're not pyrexic and. It's OK to sort of come to this presumptive diagnosis in these times because you're not gonna be working to the gold standard of practise. Explain to the owner that it's not ideal to not have diagnostics, you can still work together to improve their horse's breathing and well-being.

A few years ago, the ACVIM, so the American College of Veterinary Internal Medicine. Released an updated consensus statement on inflammatory airway disease in horses and have adapted the term asthma to encompass inflammatory airway disease and REO and and all those sorts of inflammatory airway diseases. So heaves or OREO as you, you might know it, an inflammatory airway disease, have many similarities with human asthma in terms of aetiology, clinical presentation, lung histology, and response to therapy.

And it's also a term that's much easier for horse owners to understand and get on board with, so that's why we've adopted this term asthma. And it will help you communicate with your clients because they will understand the term asthma. And also they might then better understand some of the treatment therapies as well.

Asthma is a broad term covering all allergic and inflammatory airway conditions and can be thought of as more a clinical sign continuum than one specific disease. Based on severity, acute respiratory distress caused by asthma, we use the term severe equine asthma to describe the phenotype of what would previously have been known as heaves or REO or COPD. That is horses with laboured breathing at rest and abnormal lung sounds on clinical examination.

Typical signs can range from poor performance and exercise intolerance to cough and nasal discharge to increased respiratory effort and even respiratory distress. Inflammation is present in the airways and the gold standard diagnosis is based on demonstration of inflammatory cells, most usually neutrophils, in airway inflammation. Airway inflammation in asthma is underpinned by allergy to inhalational allergens, but sufferers often have a lower threshold to other inhaled particles such as endotoxin indust, etc.

Which can sometimes actually play a more pivotal role in the disease than the actual allergens themselves once a horse has been sort of set in a cycle of of being triggered and having respiratory distress. And that means that improving air hygiene is critical in these severe asthma cases. These diagrams demonstrate the pathophysiological changes that occur in the small airways in severe equine asthma with normal airway on the left and affected airway on the right.

The patients get bronchoconstriction, smooth muscle hyperplasia, mucous cell in the epithelium and goblet cell, in the epithelium hyperplasia, and mucous hypersecretion. So a, a, a large increase in, in mucus in the airways, all accompanied by a neutrophilic inflammation in the airways, and all of these things together lead to a significantly reduced airway lumen and a physical barrier to air exchange. Chronically exposed asthma sufferers also lose their airway elasticity and get fibrosis, which contributes to chronic exercise intolerance, and these remodelling changes may be the reason for disease progression, as, as the disease goes on.

To demonstrate the point in severe asthma, such as those cases presenting with respiratory distress, there is airway smooth muscle hyperplasia. Bronchoconstriction, inflammation, and increased mucus secretion. All of these factors work together to lead to small airway luminal obstruction.

You can see these comparative histology images from, from real life horses, obviously that are dead, the, the left being a normal healthy horse and the right being a severe asthma horse airway. The L, points to the airway lumen, so you can see on the, the left hand image it's a, it's a large lumen on the right hand image, there's a very small amount of white lumen that's actually available in the airway because all of the, the dark blue is is mucus within the, the airway, and then there's a mix of inflammatory cells in there with it. .

So, You can see just, just how narrowed that lumen is and and that sort of explains the respiratory distress that we see. So treatment is therefore aimed at removing the inciting causes of the inflammation, reversing the bronchoconstriction, reducing the inflammation as much as as we can, reducing the mucus production and, and aiding getting mucus out of the airways, as would happen in a normal healthy horse airway. Although drug therapy may be needed in the severely affected case initially to ease clinical signs, clear air management remains the key to control of asthma.

But is also important in in any airway disease. You will already have gauged an idea of the horse's environment if you're having a video consultation. There are some basic principles it is worth reinforcing to the owner.

Ideally, the horse should be turned out 24/7 unless it's allergic airway disease that's pasture related. Then medication will definitely be needed alongside management changes. They must stop bedding the animal on straw and change it to an inert low dust bedding if stabling is unavoidable.

If the field is dusty, they can dampen it down. We've recently had quite warm, dry spell in recent weeks, so you may well have dry paddocks, like the dusty paddock, the equine in the top right picture is demonstrating. On a side note, I've never diagnosed asthma in a zebra, but then again, I, I've never been presented with a zebra in respiratory distress.

So, so your owners can, can dampen down the paddocks, . Owners can also dampen down, soak, or steam hay before feeding to reduce the dust in it, or they can switch to haulage, but it is important that they, they make the switch over about a week, slowly removing one and introducing the other bit by bit. So they don't just make a sudden change and then we get a colic.

And it's important to emphasise to the owners that the hay doesn't need to be soaked for long because that will leach nutrients from it, unless of course you've got an overweight animal, but that's a side issue. So they can just literally wet the hay to reduce the dust, and that's all that's necessary. There are those commercial steaming chambers which are very nice and good at removing dust as well for these cases.

What, what is even more critical, I think, in terms of the feeding is getting the owners to feed the animal from the floor. And this is such an easy, obvious thing to us, but something that is overlooked very frequently and can really help the horse. Because like the horses in the bottom right picture that are I see in the paddock and they've got the heads down, that will allow the natural drainage of mucus from the respiratory system as nature intended.

I like to. Remind owners that horses are grazers and should spend 90% of their day with their heads on the ground grazing like those those horses in that lovely paddock in that sunset picture and feeding horses with their heads up like the horse in the bottom left photo . And probably about 75% of UK stabled horses, it's very unnatural and it doesn't permit mucus drainage from the airways.

It keeps the mucus in the airways, which is what we don't want in these cases, . And feeding from the ground also has the added advantage of reducing the airborne dust exposure, as some studies have shown very nicely that there's less particulate matter at the lower ground level compared to hay net level in stables. So, so it's a double whammy, so you must reinforce feeding anything with respiratory problems from the floor.

In fact, all horses in my view, should be fed from the floor, but anyway, . That's it, that's my 2 cents on that one. So, it's also important to ensure good airflow in the stable and low dust and in a barn situation.

The loose box closest to the exit would seem like the obvious choice because it's next to the big open doors, but the box next to the exit is actually likely to have more particle movement from traffic of horses and people moving in and out through the doors all day. So that's just something to bear in mind as well is how much traffic is going past the stable, because any traffic creates dust which then it makes the air quality worse. It's also really important that the horse is not in the stable when it's being mucked out or when nearby stables are being mucked out, or when sweeping or brushing is being done in, in the corridor or whatever or outside.

And so the horse needs to be taken away from that situation. And also the horse shouldn't be present at feeding time if any hay nets are being hung or hay is being carted around because again the dust associated with that will not be good for this horse's airways. The, top left image highlights how close a horse's neighbours can be in a stable block, which I know we all know.

But it's something that owners often overlook the importance of a shared airspace. So it's a good idea to ensure that neighbouring stables do not have straw beds or are fed dry or dusty hay as well. And it would seem really obvious to us, but it's better to state that the horse needs resting completely from exercise until the clinical signs have resolved.

If a horse has respiratory distress, they are probably going to need therapeutic medication, at least in the short term, to improve airway function by reducing inflammation and bronchoconstriction. The best way to achieve this is directly into the lungs with an inhaled bronchodilator and inhaled steroids, allowing drug deposition directly where it's needed and minimising side effects. You can prescribe these for the owner to give and explain remotely how these can be used and therefore you don't need to break social distancing rules to to do this.

So I'll just talk about some of the medications now and go through each of those. So Clenbuterol, which is a symphomimetic beta 2 agonist, you can get it in the, the entoppomin granules. I believe there is an oral syrup available now as well.

. That increases mucociliary clearance and has anti-inflammatory properties. However, what I would guard against using this is that only 24% of horses respond well at the recommended dose of 0.8 mcg per kilogramme peros twice daily.

More horses do respond to higher doses, but then you get more side effects such as sweating and tachycardia with higher doses and persistent use of ventilmin can of of clambuterol, sorry, can lead to down regulation of beta 2 receptors. So . Really, it should only be used as a rescue drug and it's, it's inferior to an inhaled bronchodilator.

So just bear that in mind, particularly for cases in, in real respiratory distress with, with asthma. In terms of inhaled bronchodilators, you're looking at a human meta dose inhalers. There are two commonly used ones on the market.

There's salbutamol, which is a beta 2 agonist, and, that's an inhaled medication at 1 to 2 mcg per kilogramme. But it's got a very short duration of action, so it needs giving about every 3 hours. OK, so that's not ideal for use in our horses.

The one I prefer is salmeterol, which again is a beta 2 agonist, and it's a longer lasting one, but it's also more expensive. And that's also anti-inflammatory, and that, is a dose of 0.2 to 1 mcg per kilogramme every 6 to 8 hours inhaled.

So, corticosteroids, corticosteroids are indicated in severe equine asthma alongside management changes to help improve airway obstruction. It should be noted that unlike equine blood neutrophils, equine airway neutrophils in severe asthma are insensitive to corticosteroids. So airway fluid neutrophil counts will not decrease with corticosteroids despite improvements in clinical signs.

So the, the corticosteroids will help . Reduce the airway inflammation and and the mucus overproduction, etc. They will not affect the neutrophils.

The only thing that will improve neutrophil counts in bowel and track wash fluid is improved air hygiene. So this can actually be a good way to monitor if owners are managing to achieve good air quality or not by looking at the bowel, repeated bowel counts when we're in a situation when we can do these sorts of diagnostics again. It's also worth noting rather interestingly that intra-articular and intramuscular trimacinolone will improve lung function in asthmatic horses for 28 days.

So it might be worth considering an IM dose in the interim if obtaining or use of a metre dose inhaler and spacer are an issue for the owner and the horse. So that's just something that I found quite interesting. I will give, you know, sort of a month's worth of, of improved lung function.

So that could be quite a useful thing to do. For the inhaled corticosteroids, belamethasone, fluticasone, and more recently budesonide and cyclazinide have all been shown to improve lung function in asthmatic courses. Inhaled fluticasone used for more than 6 months, does not result in immunosuppression.

And also really importantly, antibody response to vaccines is not affected by fluticasone use, which is great, so that makes it a really strong choice. Furthermore, fluticasone combined with the long acting bronchodilator salmeterol has been shown to be more effective at improving asthmatic horse lung function than either either drug on their own, so using combination, that's a really good combination. There are various equine spacer devices on the market, including a new novel equine specific mist producing device, but a human paediatric spacer placed over the nostril of one nostril of the horse works just as well in in my experience and can be readily and affordably obtained from a human pharmacy.

The development of portable nebulizer units has increased the interest in using injectable corticosteroids for the treatment of equine asthma. However, a word of caution, dexamethasone administered using a mechanical nebulizer was proven less effective than the same dose administered orally in horses. So that really puts into question the use of this therapeutic option for severe equine asthma.

Unfortunately, there's no strong evidence to support the use of mucolytics, and feeding from the floor to encourage mucus drainage and measures to reduce airway inflammation and thereby curb the mucus overproduction are the best ways to tackle the excess airway mucus at present. There are some important points to note regarding metre dose inhaler and spacey use and training the horse, which should be reiterated very clearly to the owner. You can see in the top left image on the screen, the spacer here, which is a human one, is cloudy, and that's from buildup of drug inside the the plastic chamber due to static.

To prevent this every few days. The spacer should be disassembled and washed in a detergent such as washing up liquid and then allowed to drip dry overnight rather than towel dry to stop static building up and then it can be reassembled and reused the next morning. With the use of the metre dose inhaler, note here that each canister contains a limited number of actuations that contain the active ingredient, and that differs between the different, makes and models of metre dose inhaler.

So you can see that there's 120 in the one on the left. There's 200 in the middle one, and there's 200 in the, the blue one on the right as well. It handily, some of the newer metre dose inhalers like the white one in the middle of the lower image have a counter on the device, so you can keep track of when the drug is running low.

Otherwise you need to advise the owner to keep a record of the number of puffs they've actually used so they know when the drug is depleted or about to run out. It's worth noting that the metre dose inhaler will continue to spray even when the drug runs out, as there'll be propellant remaining after the last dose is gone. So it's really important to pay attention to the number of puffs used.

Also, when medicating the horse, the inhaler canister needs to be warm to body temperature and shaken for 30 seconds before use to mix up the drug with the propellant. The first puff should be discarded as that will contain just propellant and no drug. So you should attach the metre dose inhaler to the spacer keeping the inhaler vertical.

Then ensure the spacer has an airtight seal over the horse's nostril. I don't think there's any need to cover the other nostril. Watch the horse's breathing pattern.

Actuate the inhaler once just before or at the start of inspiration, and then you need to shake the inhaler again before the next actuation. Some horses don't mind the spacer and inhaler at all, but some of them, really do, and most of them need at least a little bit of training to get used to it and for the owner to get used to it as well. There is a really useful little video on YouTube on clicker training the horse for use of a spacer with a metre dose inhaler.

And I think it's well worth directing owners to that YouTube video, so, so that they can watch and they can practise doing this with their horse and get their horse used to it and see also that it's possible to do and the horses can be accepting of this way of medicating. It's really important to remember at the end of the remote consult to make sure that the owner feels supported during this difficult time. Arrange a recheck appointment by video so that you can see how they're getting on and how the horse is doing.

Particularly if you've prescribed some medication, find out in sort of 3 to 5 days how they're getting on and what the response is. Explain to them that you'll be able to do further diagnostics once life returns back to normal. And finally, we are here at any stage for help and advice.

If you feel you're struggling with a case or just want a second opinion, please don't hesitate to get in touch with us at VVS. You can do this by filling in the online form or by calling or emailing us. We're all in this together, so let's support each other as best we can.

So do reach out to us during this difficult time. We're here to support you. It's difficult for everyone and we know that, .

We've got lots of specialists on board and we're here to support you. If, if you've got any questions, please reach out to me via VVS and I'll do what I can to help you with your difficult cases. It's worth noting that virtual veterinary specialists are offering half price specialist telephone consultations during the COVID-19 lockdown, making a significant saving for your clients for specialist inputs into into their horses, .

And we also have some free webinars like this one on small animal medicine, and there are online some information sheets dealing with specific scenarios that you might encounter and need some help and advice on during the COVID-19 lockdown, including all of that. So that's it for now. Please stay safe and look after yourselves and your clients as as best you can.

If you have any questions, please contact us on equine@vvs. Vet. Thank you very much for listening.