A nebulizer should be found in every racing and training stable, bar none. In my view, it is just as important as any other basic form of tack that would be included in a stable. Respiratory infections are common and a good nebulizer can stop that condition in its tracks if used soon enough. Also, because I think common race track bleeding is a biofilm lung infection, a nebulizer is an important aid in preventing racehorses from developing into bleeders. If you don't own one for your horses, you should!

     There is precious little  useful information online about veterinary respiratory therapy particularly as it applies to racehorses. Maybe this page will help fill in some gaps? I will mostly delve into nebulizers, but the practice of medicinal inhalation or vapors have been around for hundreds, if not thousands of years.  Let me first say that even though I am recounting past history in human terms, that human medicine has always been applied to our animal partners sooner than later. So in this light, we need to understand how humans used medicated vapors before we touch on veterinary use.

             I am sure our primitive ancestors learned fairly early in their life that inhaling certain burning dried plants seemed to help breathing and sickness. For instance, tobacco was viewed as such a medicinal plant and smoked as such until it was found that it could generate other more interesting and addictive effects in more modern times with such effects being enhanced on how it is processed. From bowls to pipes to cigarettes, inhalation of smoke to affect our physiology is a very old practice. It is probably little known that the really carcinogenic properties of burning tobacco are more a product on how it is processed than the plant itself. We humans in our debatable wisdom can often make things very much worse just to achieve immediate gratification! If tobacco is flue cured, it has a tendency to contain aflatoxins from fungi in this curing procedure. If tobacco was processed (simply dried) as in years past without the possibility of fungal contamination, tobacco may still be considered a rather benign product. Not so. Aflatoxin is one of the most deadly toxins we know of and a powerful carcinogen.

        Studying the written histories of medicated vapors, one can go all the way back to the Greeks and Romans for interesting accounts, then further into the future with the famous Arab physicians who also used similar procedures with vinegar, camphor and other substances. In the mid 19th century, medicated inhalations were also much in vogue. Vapors from hot water containing camphor, conium, belladonna, hyocyamus, lobelia, stramonium and may other plants were commonly employed to reported good results.  They also found that various balsams and gum resins possessed expectorant properties when inhaled, i.e. balsam of tolu, balsam of Peru, benzoin, and storax. It was also very well appreciated that inhalation of moist warm steam had very valuable impact on many respiratory complaints of that time and was often employed with conjunction to medicated vapors from the above mentioned plants.

        In one 19th century medical text it was written: "Several forms of apparatus have also been devised for this purpose. The most efficient apparatus for inhalation either of simple steam or of medicated vapors is that which is known by the name of Nelson's Inhaler; it is constructed of earthenware and in addition to its complete adaptation to the purpose, for which it is intended, possesses the triple recommendation of cleanliness, portability and cheapness."

Nelson Inhaler
     Probably the first inhaler that is the forerunner of our modern nebulizer was invented in 1858 by Dr. Sales-Girons. This inhaler was the first to force medicated fluid by compressed air through a tube with a small opening against a metal plate which produces a fine spray (atomized). The first atomizer was born! Later, a modification was added that involved the use of two tubes.   It is described as such:  ". . . two glass tubes having capillary openings at one end, these two ends being placed almost at a right angle with each other.  The more open end of the perpendicular tube is immersed in the medicated fluid and as the compressed air is forced through the horizontal tube, the air in the perpendicular one becomes exhausted and the medicated solution then r3ises in it and whit it arrives a the capillary opening, is dispersed in very fine spray by the force of the compressed air passing along the other tube."  And let's face it,  our common nebulizer is simply an atomizer.

        Aerosol particle size is important! "Larger particles (> 10 μm (microns) are filtered in the nose and/or the oropharynx, largely by inertial impaction;  particles of 5-10 μm generally reach the lower respiratory tract, and particles of 1-5 μm reach to the lung periphery.  As particle size increases above 3 μm, aerosol deposition shifts from the periphery of the lung to the conducting airways. Exhaled loss is high with very small particles of 1 μm or less. Consequently, particle sizes of 1-5 μm are best for reaching the lung periphery, whereas 5-10 μm particles deposit mostly in the conducting airways, and 10-100 μm particles deposit mostly in the nose." One of the major disadvantages of nebulizes is that drug dosage loss is common by the time it reaches the inner lungs. The obstacles of preventing the full dose getting into the lungs are that much of it will be stopped at the head-nostril regions or be lost in the actual nebulizer tubing or be exhaled by the patient. Note this dispite drug dosage loss, it has been repeatedly shown that the use of nebulizers can still achieve therapeutic results. So don't be discouraged! 

        There are basically four types of nebulizers on the market:

     The common and low cost compressed air (jet) type. Ranging in new price from $50-up). This is the common nebulizer seen almost everywhere that incorporates a small air compressor with the system and is likely the system configuration of equine nebulizer units found and sold at the tack shops.  If you already own an air compressor, it is a simple matter of just buying low cost components and making your own unit.  The higher the air pressure, generally the smaller the particle produced so models can vary in efficiency. "Increasing the fill volume is another factor that increases the efficiency of jet nebulizers. These nebulizers do not function well with small fill volumes like 2 mL or less because this is close to dead volume (also termed residual volume). Jet nebulizers do not aerosolize below dead volume; therefore, it is recommended to use a fill volume of 4-5 mL unless the nebulizer is specifically designed for a smaller fill volume."

    The ultrasonic type of nebulizer is the second type most commonly found and a bit more expensive than the jet nebulizer.  ($100 and up). It uses a ultrasonic transducer to vaporize the solution.  It is generally thought that this type of nebulizer will produce a more consistent, smaller particle size, but it will also heat up the nebulizer solution and for some heat sensitive compounds, this action may show some degradation.  The ultrasonic nebulizer creates particle sizes of about 1-6 microns.  An ultrasonic nebulizer has 3 components: the power unit, the transducer, and a fan. The power unit also controls the amplitude of the ultrasonic waves. This is user adjustable, with an increase in amplitude resulting in an increase in output from the ultrasonic nebulizer. In some ultrasonic nebulizers, the solution to be nebulized is placed directly over the transducer. In others, the solution to be nebulized is placed into a nebulization chamber and a water couplant chamber is placed between the transducer and the medication chamber. A fan is used to deliver the aerosol produced by the ultrasonic nebulizer to the patient, or the aerosol is evacuated from the nebulization chamber by the inspiratory flow of the patient.

     The other two types: (3) vibrating mesh/horn nebulizer and the (4) microprocessor controlled breath actuated nebulizer will not concern us here due to cost and other factors.

This is the simple jet nebulizer configuration consisting of :

1)  air compressor,
2)  tube from air compressor to nebulizer  chamber,
3)  nebulizer chamber,
4)  tubing from chamber to mask,
5) bucket type of mask that is easily made.
This is the common nebulizer mask that can be easily made from a light weight plastic bucket. One needs to remove the metal bail handle and either fix strap snaps into it to fasten to the patient's halter (as pictured above) or a  construct a strap that goes from one side of the bucket over the horse's poll and downward buckling into the opposite side of the bucket. At the bottom of this bucket you would drill a hole that can be adapted to plastic hose fittings (found at most hardware stores) to allow the nebulizer tubing coming from the nebulizer chamber to connect.  You may also want to glue foam rubber around the top inner edge of this bucket to make it a bit more air tight.
     I generally prefer an ultrasonic nebulizer and have been lucky enough to find some nice hospital grade used units which I bought for pennies on the dollar. Currently, I am using a Devilbiss 65 ultrasonic unit pictured below which I bought off of ebay for under $50. It is built like a tank and I am very happy with it for a barn setting. One can make a glass nebulizing chamber for it out of a commonly availabe pyrex 125ml vaccuum flask which I will demonstrate how to configure as most of these used Devilbiss 65 units can only be found on the used market without the chambers and other accessories.
Parts needed to make a new nebulizer chamber:
1)  125ml vacuum flask
2)  rubber stopper that will fit the nebulizer hose with one hole drilled in it,
3) simple plexi-glas lid that is shaped on a common table saw with L-hooks added to support flask.
This is how you will commonly find these used Devilbiss 65 units. Sold without nebulizer chamber. You put distilled water in this well then you need to place a glass flask over top of it to allow for vaporization of nebulizer fluid.
This is an example to show how one can re-configure obsolete nebulizers found on auctions cheap. Also, making a homemade glass nebulizer chamber will allow one to use essential oils which need to be vaporized in glass and not the commonly sold plastics. Many essential oils will melt or damage most plastics! Another reason to make one's own.
     So one has several options to obtain a nebulizer for your stable. If you have plenty of money to spend, you simply go out and buy an expensive unit which can cost you up over $1000. That is certainly not necessary and one can put together a unit for under $100 which will be just as useful, if you already own a small mobile air compressor. The air compressor is the most expensive part of this system and if you own one already, great! You can by components at many tack supply companies and I find Big-Dees to be reasonable. They sell tubes, nebulizer chambers, etc. or you can buy an already assembled air jet nebulizer for under $300 new.  For under $50, you can buy a nebulizer chamber, tubing and mask from them to add to your own air compressor and build a unit just as good as their $300 one.

     If you would prefer an ultrasonic nebulizer like I do, then the best bet is to buy a used hospital grade model that has been discarded by those health institutions in upgrades. These can be found on ebay and Craigs List. Often times, they can be had quite reasonably with still plenty of hours of use left in them. However, they do have the disadvantage of often  being sold without nebulizer bottles and you may have to improvise to make a substitute like I did above.
     I think a nebulizer can be invaluable in treating many lung problems and that goes for general race track bleeding as well. However, I am not sure how useful this might be for allergies or palate flipping. For general allergies, you should look into MSM. Actually, I think most forms of observed race track bleeding is a product of biofilm infection. It is really the only thing that makes sense to me in why racehorses bleed!

     In all likelihood, equine pulmonary bleeding is a symptom of a biofilm infection in the horse's lungs. Biofilms are colonies of bacteria and possibly other microorganism types that have found that living together, protected by a self-secreted polymeric matrix can evade normal immune responses and foster a viable community on a living or non living surface. Dental plaque is probably our best known and studied biofilm, but it is becoming increasingly appreciated that biofilms can be found anywhere in the body. Biofilms are microorganisms characteristically encased by slimy, gluey films that help these pathogenic microorganisms adhere to moist lung tissue and evade the horse's immune cells and commonly administered antibiotics. Biofilms cannot easily be cultured or detected. A study done by Cross, Ramadan, & Thomas, The impact of Furosemide on Pseudomonas Aeruginsoa Biofilms, found that furosemide (lasix) at 10mg/ml reduced some biofilms by 50% at a pH of 8-9. Furosemide seemed to destabilize biofilms at pH-dependent concentrations. Perhaps this is why lasix, generally, but not always, seems to help race track bleeders? It is not so much its diuretic action but rather its biofilm destabilization characteristics that produces efficacy in the bleeding racehorse. Fusomide seems to be only effective at proper pH and specific concentrations which in real life could be quite variable in individual racehorses and racing conditions and may be one reason why we see so much variation in Lasix's efficacy on track.

     It seems quite likely to me that if indeed a biofilm infection is at the heart of our racetrack bleeding problem-that it is in all probability not a simple bacterial biofilm. It could quite likely be made up of a combination of bacteria and fungal components all working in a synergistic environment to further each's goal of survival to the detriment of our racehorse's health. Not only are biofilms off the radar screen of our racetrack vets but a hybrid biofilm consisting of bacteria and fungi would be totally unheard of by this group! Many times, fungi will be secondary colonizers of a biofilm. It has been written that bacteria in these hybrid biofilms can be up to 4000x more resistant to our common antibiotics and the quencher is that most common antibiotics have very little effect on fungi. A recent study found fungi to be a consistent component in biofilms in sinus mucosal samples from patients with eosinophilic mucin chronic rhinosinusitis (EMCRS) and allergic fungal rhinosinusitis (AFRS). Why should the equine be much different? Certainly, one of the protocols to treating bleeding horses is to be very careful about the hay which is fed, guarding against moldy (fungi infested) hay! Maybe this should be a tip-off of sorts?

     Now the question is how to combat these lung biofilms and I think nebulizer solutions are one way to go. One has to vaporize an adequate anti-microbial for infusion into the lungs PLUS some thing that will dismantle the protective biofilm to allow penetration of any vaporized antimicrobial. I think DMSO lazed solutions may be very helpful in penetrating the polymeric matrix . I would certainly use a DMSO based solution. One may also want to experiment with other known compounds that will dissolve the biofilm such as certain specific Fibrinolytic Enzymes: nattokinase and lumbrokinase. Also using the chelating compound, EDTA to remove minerals from the biofilm will further help with its destruction.

Here are two interesting websites on biofilms and therapeutics:



In one of the above sites, Cohen suggests this protocol:

"First do the enzymes along with EDTA, then thirty minutes later, add in an arsenal of antimicrobials. I use formulations containing berberine, artemisinin, citrus seed extract, black walnut hulls, artemisia herb, echinacea, goldenseal, gentian, tea tree oil, fumitory, gentian, galbanum oil, oregano oil, neem, and pharmaceuticals as well when necessary, such as Vancomycin, Diflucan, Gentamycin.

Focus: When you began to work at dissolving the biofilms, did you find the bugs?

Cohen: Oh yes! But I found something else that was just as fascinating, something nobody was thinking about … It's standard knowledge that biofilm bacteria sequester calcium, magnesium and iron to help build that matrix. Minerals give the biofilm integrity-as if you're building a wall … To address this, first you use fibrinolytics to help dissolve the fibrin, then you use EDTA to chelate out the minerals. And guess what? We started getting huge dumps of toxic metal. Now why is that? I think the answer points to something so huge, whether we're dealing with autism or lyme disease or multiple sclerosis or lupus or even cancer.

Cohen: Remember, these patients are very young; some are just a few years old. So I will recommend half a capsule of each, two times a day. That would be a 50 milligram capsule of nattokinase, and a 20 milligram capsule of lumbrokinase. First do the enzymes along with EDTA, then thirty minutes later, add in an arsenal of antimicrobials. I use formulations containing berberine, artemisinin, citrus seed extract, black walnut hulls, artemisia herb, echinacea, goldenseal, gentian, tea tree oil, fumitory, gentian, galbanum oil, oregano oil, neem, and pharmaceuticals as well when necessary, such as Vancomycin, Diflucan, Gentamycin. I use a different one every day. Then an hour later you come in with the binders to help mop up the debris. I use chitosan, citrus pectin, a special bicarbonate formula, organic germanium, chlorella and others. I also use buffering agents, such as buffered vitamin C, since when the body is destroying bacteria it becomes acidic. Minerals must be

Cohen: Yes, I think biofilms are a huge missing piece in Lupus, Lyme Disease, Multiple Sclerosis and any autoimmune-type chronic infection. You have to ask, what compels the immune system to maintain this state of dysfunction? Ask yourself, how could an organism perceived by the immune system as foreign survive its presence? Either something has corrupted the immune system, or the organism has transformed itself in a way that the immune system can't find it. That's what the biofilm does. I believe it's one of the biggest medical issues we're dealing with today."

     This seems to be bascially a good strategy to me except DO NOT use Black walnut on horses! One can run into toxic responses with that herb when used on the equine!

     As far as the actual antimicrobial needed in conjunction with DMSO, enzymes, or chelating agents like EDTA, I would experiment with Colloidal Silver, and/or a host of other anti-microbial (particularly anti-fungals) known herbs which I will discuss shortly in another post.

     Lastly, just remember, particle size matters when mixing nebulizer solutions! A Guide to Aresol Delivery Devices For Respiratory Therapists explains:

"Gravitational settling is a function of particle mass and time, with the rate of settling proportional to particle size and mass. Diffusion occurs with particles smaller than 1 μm.  These mechanisms come into play as aerosol particles are inhaled orally or through the nose. Larger particles (> 10 μm) are filtered in the nose and/or the oropharynx, largely by inertial impaction; particles of 5-10 μm generally reach the proximal generations of the lower respiratory tract, and particles of 1-5 μm reach to the lung periphery.  Particle size plays an important role in lung deposition, along with particle velocity and settling time. As particle size increases above 3 μm, aerosol deposition shifts from the periphery of the lung to the conducting airways. Oropharyngeal deposition increases as particle size increases above 6 μm. Exhaled loss is high with very small particles of 1 μm or less. Consequently, particle sizes of 1-5 μm are best for reaching the lung periphery, where as 5-10 μm particles deposit mostly in the conducting airways, and 10-100 μm particles deposit mostly in the nose."

One may need to filter the final nebulizer formulation for more efficient therapy to the lungs. Coffee filters will generally filter out 20 μm or larger practicals sizes, though they are never made in very consistent fiber widths.

     For a more indepth look at various nebulizer solution formulations, go to a nebulizer solution thread in my below Message board,
Spitbox. Click on it.