equine asthma | Horse Racing Free Tips

Owner Diligence Key To Equine Asthma Management, But Many Won’t Implement Management Changes

Scientists in Portugal have discovered that many horses suffering from equine asthma aren't given a fair shake at disease management for one reason: their owners are reluctant to follow vet advice to reduce the horse's exposure to environmental irritants, reports EQUUS magazine.

Dr. Joana Simões and a team of scientists examined 39 horses that were diagnosed with severe equine asthma (SEA), also known as heaves. Heaves is triggered by environmental factors like dust and mold, and is characterized by coughing, labored breathing, and airway inflammation. Reduction of exposure to triggers normally allows the symptoms to subside.

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The horses' owners were given a questionnaire asking how the horse was housed and fed, and what respiratory issues he showed. A veterinarian then offered six management recommendations, which included things like soaking hay before feeding and turning horses out as much as possible. Each strategy was directly correlated with equine asthma improvement.

One year later, the researchers contacted the horse owners again to see if they had followed through on the veterinary recommendations. They discovered that only three of the 38 owners had implemented all six recommended strategies for keeping their horse healthy, and only six owners were utilizing five of the recommended measures. About half of the owners had adopted one or two control strategies. Horses that did not have management changes remained symptomatic and required medical treatment.

Simões notes that it may be difficult to implement every suggested control strategy, like increased barn ventilation, but some of the strategies required only that a horse owner change their daily routine. Some horse owners responded that implementing things like soaking the affected horse's hay was too time consuming or that they could not get the horse's caretaker to comply.

The scientists believe that some lack of compliance may be because the disease can only be managed and not cured – there is no quick fix or pill to solve severe equine asthma. The research team suggests that horse owners may be more inclined to better manage the condition if they understood the disease and its progression more completely.

Seeing Reduced Performance In Your Racehorse? Study Suggests Switching Steamed Hay Or Haylage Could Help

Pinpointing the cause of poor performance in athletic horse is often a challenge. If it turns out there could be a respiratory cause, then mild equine asthma (EA) could be to blame. Luckily, the common saying that “prior preparation prevents poor performance” can be taken to heart in such situations. While hay steamers have been marketed to horse owners for several years, new research demonstrates that steamed hay and haylage can make measurable differences in a horse's

Mild EA, the preferred term that replaces inflammatory disease, describes horses with a chronic low-grade cough (defined as having gone on for longer than three weeks), decreased/poor performance, and the presence of tracheal mucous when the horse is scoped. Many underlying conditions can be confused with EA. Those include infectious causes (viral or bacterial), upper airway obstruction (dorsal displacement of the soft palate, for example), and exercise-induced pulmonary hemorrhage. Some veterinarians have even speculated that those conditions may even predispose horses to mild EA.

“The most important factor contributing to mild EA in Thoroughbreds is the small dust particles horses breathe in primarily as a consequence of feeding dry hay,” explained Dr. Laurent Couëtil, section head of Large Animal Internal Medicine at Purdue University, in West Lafayette, Ind.

Dry hay contains fungi, molds, mite debris, inorganic particles, endotoxins, and other inflammatory molecules. This microscopic particulate matter contaminates the horse's breathing zone, causing inflammation in the lower airways.

“Particulate matter measuring less than 4 microns in diameter results in a sharp and significant increase in the number of neutrophils in mucus collected from the lungs,” said Couëtil.

Particles this small cannot be seen to the naked eye but can be measured with specific, wearable equipment fastened to a horse's halter.

Mucus — a hallmark of EA — can easily be collected from horse's lungs via bronchoalveolar lavage (BAL) and microscopically analyzed. The presence of neutrophils in this BAL fluid indicates inflammation. Other inflammatory cells may also be appreciated, such as mast cells and eosinophils.

The amount of tracheal mucous, which can be scored on a scale ranging from 0 (no excess mucous) to 5 (defined as a profuse amount pooling throughout the trachea) can also be used to gauge the severity of mild EA.

According to Couëtil, studies in both Standardbred and Thoroughbred racehorses have demonstrated an association between severity of mucus score and poor performance. As mucous scores increase, speed of the horse decreases.

“A 2006 study performed by Sue Holcomb showed that horses with tracheal mucous scores of 2 or greater were significantly behind in finishing place than horses with a score of 0 or 1,” Couëtil relayed.

Because forage is the most important source of dust that triggers EA, various tactics designed to minimize dust have been explored. Recently, Couëtil and colleagues conducted a study at an Indiana Thoroughbred racetrack. They demonstrated that racehorses actively involved in training and competition that were fed steamed hay or haylage had reduced exposure to dust by approximately 30% when compared to horses fed dry hay.

In that study, Couëtil's team recruited 69 Thoroughbreds and divided them into three groups based on type of forage fed: haylage, steamed hay, and dry hay. All horses were fed this diet for a total of 6 weeks. On weeks 0 (baseline), 3 and 6 of the study, endoscopy was performed after coming back from the track to assess respiratory function and to grade mucous. In addition, all horses were equipped with sensors to measure respirable particles (less than 4 microns in diameter) for 3 hours after returning from training and being fed.

Haylage is grass that is cut and baled at a higher moisture content (about 30%) than regular hay (about 15%) and is package in sealed plastic films similar to shavings bales. This packing prevents molding of the moist forage and allows preservation of the nutritional value of fresh grass similarly to what is achieved with silage for cows. This moist forage results in a marked decrease in dust exposure when horses eat haylage. For the purposes of this study, trainers were each given a hay steamer provided by Haygain.

Key findings of the study were:

Respirable dust particles (less than 4 microns in diameter) were significantly higher in the breathing zones of horses fed hay. Both the steamed hay and haylage generated the same, significantly lower level of dust particles;
By the end of the study, mucous scores were significantly higher in the hay group. Both the steamed hay and haylage groups had the same, significantly lower mucous scores;
BALF analysis showed that the number of neutrophils, an indicator of airway inflammation, increased significantly as the respirable dust concentration in the horse's breathing zone increased; and
Over time, the number of neutrophils in BALF decreased in horses fed steamed hay and haylage but only reached statistical significance for horses fed haylage.

“In sum, our results clearly demonstrated the benefits of feeding low-dust forages on airway health in just 6 weeks,” Couëtil concluded.

Another conclusion that Couëtil highlighted was that BAL can be performed safely in Thoroughbred racehorses without interruption in racing or training.

“For some veterinarians, owners, or trainers, the idea of a BAL can be off-putting,” Couëtil said. “Many veterinarians are not familiar with the procedure, and others think that a BAL will require resting their horses for an extended period of time after infusing fluid in the lungs.”

The reality is that even if only 50 percent of the sterile saline solution administered is recovered, the rest is rapidly absorbed. Couëtil's study proved that a BAL can be performed without interfering with the training and racing schedules.

“Owners and trainers shouldn't hesitate to perform a BAL in any case of chronic cough, poor performance or when excess mucus is seen by endoscopy after the race,” Couëtil said. “This test can be highly beneficial especially when used in conjunction with the mucous score. The BAL rules in mild EA while endoscopy can help rule out other causes of cough and poor performance.”

One caveat worth noting is that medications are sometimes used for sedating the horse and to decrease coughing during BAL, and it is important to respect drug elimination times prior to racing.

In sum, identifying realistic ways of decreasing airway inflammation, such as a small change in hay preparation, is important because an estimated 80% of Thoroughbred racehorses have mild EA and are not living up to their potential.

Dr. Stacey Oke is a seasoned freelance writer, veterinarian, and life-long horse lover. When not researching ways for horses to live longer, healthier lives as athletes and human companions, she practices small animal medicine in New York. A busy mom of three, Stacey also finds time for running, hiking, tap dancing, and dog agility training.

The post Seeing Reduced Performance In Your Racehorse? Study Suggests Switching Steamed Hay Or Haylage Could Help appeared first on Horse Racing News | Paulick Report.

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Inhaled Human Medication Helpful For Asthmatic Horses

The British Equine Veterinary Association (BEVA) has reported that inhaled ciclesonide can assist in controlling severe asthma in horses. Horses with severe asthma often cough, have a runny nose and have difficulty forcing air into their lungs.

Corticosteroids have been shown to calm inflammation in the respiratory tract. These medications can be administered multiple ways, but inhaled therapy is considered ideal as it gets the drug directly into the lungs. Ciclesonide is used in human medicine and has been shown to be effective in horses that become asthmatic when exposed to certain conditions like moldy hay. The drug had not been studied in the field.

Researchers used 220 severely asthmatic horses from 24 clinics in Germany, France and Switzerland for a study to test inhaled ciclesonide efficacy. The horses either received an inhalation solution containing ciclesonide or a placebo inhalation.

To test their hypothesis, the horses were given ciclesonide through an equine inhaler at eight actuations twice daily and then 12 actuations once daily for five days. The horses receiving the placebo received the same number of treatments, but they did not contain ciclesonide.

The study team found that 73 percent of the horses receiving ciclesonide showed improvement in their asthma after the 10-day study. Horses with more severe asthma showed the most improvement. Horse owners reported an improved quality of life in nearly 70 percent of the ciclesonide-treated horses.

Read the full article here.

Just Breathe: Analyzing Horse Breath May Help ID Equine Asthma

Equine airway disease can be tricky to diagnose; analyzing the horse's breath may help identify horses affected by the disease. A study out of Italy collected equine breath condensate and studied its metabolic byproducts to see if there was a difference between healthy horses and those suffering from the disease.

Drs. Marilena Bazzano, Luca Laghi, Chenglin Zhu, Gian Enrico Magi, Beniamino Tesei and Fulvio Laus studied six healthy horses and six horses with equine asthma. Equine asthma affects about 14 percent of adult horses; affected equine can be used as animal models for human asthma research and treatment.

The team then studied the metabolic byproducts in bronchoalveolar lavage fluid and the exhaled condensate of each horse. The team found 12 metabolites in the lavage fluid and seven in the breath condensate. There were notable differences between the healthy and asthmatic horses, including higher levels of methanol and ethanol in the asthmatic group. The higher methanol level indicates the horse's lungs were actively inflamed. The scientists believe the higher ethanol concentrations may be related to pulmonary disease.

The researchers noted that there is a lack of standardized collection methods for equine breath condensate, as well devices to collect it, which limits the ability for horses to be used as animal models for human research. Though the study used a small number of horses, the scientists are confident that analyzing metabolites has potential to assist in diagnosing horses that suffer from equine asthma. Further research is needed.