Written by Ty Wallis, DVM, MS, DACVS

The summer show season is upon us!  While it brings longer days and time for more shows, it also brings warmer weather and its own set of challenges for you and your horses. Before everyone gets bogged down by the heat, let's take some time to revisit some common problems show horses encounter during the hotter months of the year and, more importantly, what you can do to prevent them.
 
As with any show environment, proper sports medicine preparation is paramount.  We recommend having your horse regularly evaluated by a veterinarian during show season. This will allow you to stay ahead of any impending lameness issues which could become problematic under the different training and footing conditions at a show. Hot weather can present additional risks to the horse which you can help prevent with your trainer and veterinarian ahead of time.  The two most common clinical problems we see at summer horse shows are colic and shipping fever. Though this article will be discussing how you can prevent and treat them during your summer show season, we encourage you to employ these strategies year round. 
 
Colic, which is described as the outward clinical symptoms due to abdominal pain, can be caused by many different factors including the following three common culprits: dehydration, a change in diet and stress. Since the show environment often exacerbates these factors, particularly in the summer, it is common to see colic at horse shows.  Even in a perfect management scheme, horses can still experience colic; unfortunately, the design of their GI tract lends itself to colic far too easily. There are several specific diagnoses related to colic in horses.  The most common are gastritis/equine gastric ulcer syndrome, gas or spasmodic colic, impaction colic, mechanical obstruction, functional obstruction and displacement. Although these are quite variable, many episodes of colic are started by the three factors listed above and then progress to something more severe. There are several key steps you can take to mitigate these factors and decrease the odds of your horse experiencing colic this summer.
 
Dehydration was mentioned as one of the key factors that lead to colic. Making sure your horse is well hydrated before hauling and during the trip so that there is less "catching up" to do upon arrival is one way you can stay ahead of dehydration. This can be easier said than done as some horses don't drink very well while traveling. You can encourage a horse to drink by adding a daily electrolyte powder supplement in their feed 3-5 days before leaving and continuing through the show and trip home.  Alternatively, you can administer an electrolyte paste starting 2-3 days before leaving and continuing daily. A commonly used brand that we find effective is Summer Games, but there are many great choices. A salt lick in the stall or feed trough also helps keep the horse drinking well year-round. On longer trips, some horses seem to do better if they are administered water, electrolytes and a small amount of mineral oil via a nasogastric tube by your veterinarian prior to hauling. Be sure to offer water at each stop along the way and when the horse arrives. Some horses do not like the taste of new water at different venues, and you might choose to offer water mixed with apple juice or Gatorade to help encourage them to drink better. If you do this, always make sure to hang a second bucket of plain water as not all horses like flavored water.
 
Another common way horses colic is an abrupt change in diet. Most horses travel with enough of their own concentrate to last throughout the show or purchase more of the same concentrate at the show as it is often commercially available everywhere. But since many shows are quite long, it is often impractical to haul enough hay for your horse, especially if you're in a large group. Thus, sometimes you will have to change the hay portion of your horse's diet at shows. Something as common as a slight change in hay can stress a horse's delicate GI tract which can lead to colic. However, if the transition to the new hay is done slowly, the GI tract usually has time to adjust to the new hay and colic can be prevented. In order to ease the transition, start folding the new hay in slowly with the hay brought along on the trip so the change is less abrupt. Coastal Bermuda hay is very common in the southern United States and is actually a good nutritional hay, but it can be difficult for horses to get used to it. Bermuda can be fine-stemmed which can have a tendency to bunch together and cause impactions, particularly in horses that are not already used to eating it. Grass hays such as timothy, oats, or alfalfa mixes are easier to digest. A small amount of alfalfa has a lubricating effect on the GI tract and can be useful at shows as well, but it is a richer hay and your horse may have other medical conditions precluding its use in their diet, so check with your veterinarian and trainer.
 
Stress manifests itself in different ways in horses, and gastric ulcers is a very common symptom of stress. Gastroprotectants are particularly useful in show horses since a large percentage of them have at least a minor amount of gastric upset during hauling and showing.    Omeprazole, found in Gastrogard and Ulcergard, is made up of proton pump blockers that reduce the production of acid in the stomach. This is doubly effective as it heals ulcers that are already present and helps prevent new ones from forming. Pump blockers must be started three days before hauling since they are absorbed in the small intestine and work through the bloodstream. H2 blockers like ranitidine and cimetidine are also effective as they block acid production at the receptor in the stomach. These work more quickly, but require more frequent dosing. Gastric coating agents like sucralfate have value in blocking the effects of the acid splashing on the upper, more sensitive portion of the stomach, but the effect is short-lived (60-90 minutes).  Gastric buffers such as Maalox or Neigh-lox, are very effective, but they should never be used in a horse that is not on a proton pump blocker because of a phenomenon called the Rebound Effect. Because they are so effective at buffering the acid and raising the pH of the stomach, the stomach reacts by pouring in massive amounts of acid to get the pH back down for digestion. If the horse isn't on a proton pump blocker, this happens after the buffer has already left the stomach, and the effect is quite painful if ulcers are present.
 
The stress of hauling can also manifest in another way, which brings us to our other most common clinical problem seen at shows: shipping fever. Shipping fever is a condition that is aptly named; horses commonly develop a fever after hauling a long distance or upon arrival in a new environment. The two main reasons for this are bacterial pneumonia from airborne debris and particulate matter and exposure to a viral pneumonia agent such as the equine herpes virus or equine influenza. Horses have a long trachea, and the ciliary process that helps them clear mucous and debris from their lungs and airway is not very efficient. They really need the ability to lower their head to help clear their airway.  Long trailer rides with their heads tied up make this difficult.  Compounding this issue is dry bedding containing urine or manure and hay that swirls around in the trailer and becomes inhaled as well as drier dustier conditions during the summer at show grounds. If some of this dust contains bacteria and settles in the lungs without being cleared out, it can set up an infection. Likewise, exposure to viral agents in new environments around new horses can lead to infection. This pneumonia leads to fever and systemic illness, loss of appetite, depression, increased respiratory rate, and sometimes coughing. Since the fever is often the first sign, this condition has been dubbed "shipping fever".
 
It is a good idea to check temperatures upon arrival and call a veterinarian to treat early if any abnormality exists. If the pneumonia is not caught and treated early, it can lead to a very serious and difficult to treat condition called pleuropneumonia which is an infection outside the lungs but inside the chest cavity. In most of those cases the horse will not get to show, they will require hospitalization and longer term treatment, and will have to stay after the show until they are healthy enough to haul home.
 
Prevention strategies for bacterial pneumonia shipping fever include decreasing exposure to dust by using larger shavings as bedding, wetting hay, allowing horses to lower their head while hauling, and feeding on the ground when possible. Immune stimulants, discussed later, can also help.  The chances of viral pneumonia can also be decreased by adequate vaccination. The USEF has a new requirement that all horses vaccinated for influenza and rhino (equine herpes virus) within the six months prior to showing. The new policy has been created in an effort to decrease exposure to these pathogens when horses are commingled at shows. In order for these to be effective, they have to be given at least twice yearly requiring an initial vaccine and then a booster to achieve adequate systemic immunity. It has been found that the intranasal product called Flu-Avert is also effective. It incites a local nasal immunity to these pathogens almost immediately and for a short-term period of several weeks after administration, even without a booster, and it can be an added layer of protection. Immune stimulants given as a series at least a week prior to hauling have been effective at decreasing illness, at least anecdotally. Your veterinarian can advise to the appropriate product based on your horse and availability. Products like Eq-Stim and Zylexis are given as a series of shots to help boost the immunity of the horse and make them more effective at fighting off infection.
 
Using a few simple strategies outlined above such as keeping your horse well-hydrated, easing the transition to new hay, modifying your hauling techniques, and administering some preventative gastroprotectant, vaccination, and immunostimulation strategies prior to hauling can help keep your horse healthier at shows, especially during the summer.  These small investments of finances and effort far outweigh the potential negative consequences including potentially compromising the horse's health, the finances involved with treating a sick horse and financial loss and disappointment of having to withdrawing from the show. Hopefully, by using the strategies provided above, you and your horses will have a healthy and successful show season. We hope you have a fun and safe summer and enjoy your Arabian and Half-Arabian show horses! 

Editor’s Note: Original article written for the Arabian Horse Association’s Flash Insider Newsletter.