Fescue Toxicosis In Broodmares

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Much of the pasture in Virginia is tall fescue. While this hardy grass is a high quality nutrient source for most horses, it is often infected with an endophytic fungus named Acremonium coenephialum that is toxic to pregnant mares. The fungus produces damaging alkaloids such as ergovaline.

Some results of fescue toxicosis are:

  • Late term abortions (death of the fetus), usually in the last 2 months of gestation
  • Dystocia (difficult foaling)
  • Premature placental separation (red bag delivery) – This is a veterinary emergency and results in lack of oxygen during birth.
  • Prolonged gestation in mares (up to 13 months)
  • Decreased milk production
  • Failure of passive transfer (IgG) in the foal from lack of colostrum production in the mare
  • Retained placenta
  • Decreased growth rates in young horses if forage is not supplemented with grain

An ounce of prevention is worth a pound of cure! What can you do to prevent fescue toxicity?

  • Have your pasture and hay tested to determine the level of infection
  • Mow fields prior to the development of seed heads, which contain the highest levels of toxins in the plant
  • Remove broodmares from fescue pastures 30 days prior to breeding and a minimum of 60 to 90 days prior to foaling
  • Make sure hay does not contain endophyte infected fescue either
  • Keep accurate records of breeding and anticipated foaling dates
  • Monitor the mare closely during late pregnancy
  • Contact your veterinarian if impending signs of birth, including udder development, relaxation of vulva, and muscles around the tailhead fail to develop within the expected timeframe or if these signs develop prematurely
  • Attend the birth. If mare fails to show signs of normal birth progression, contact your veterinarian immediately!
  • Keep mares and foals off fescue until after weaning to prevent poor milk production

 

Reducing Your Horse’s Risk Of Gastric Ulcers

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Ulcers are a man-made disease, affecting up to 90 percent of racehorses and 60 percent of show horses. Stall confinement alone can lead to the development of ulcers. A horse’s feeding schedule also can be a factor. When horses are fed just twice a day, the stomach is subjected to a prolonged period without feed to neutralize its naturally produced acid. In addition, high-grain diets produce volatile fatty acids that can also contribute to the development of ulcers.

Stress, both environmental and physical, can increase the likelihood of ulcers, as can hauling, training and mixing groups of horses. Strenuous exercise can decrease the emptying of the stomach and the blood flow to the stomach, thus contributing to the problem.

The treatment and prevention of gastric ulcers is directed at removing these predisposing factors, thus decreasing acid production within the horse’s stomach. Follow these tips from the American Association of Equine Practitioners (AAEP) to properly treat your horse’s ulcers:

  1. Allow free-choice access to grass or hay. Horses are designed to be grazers with a regular intake of roughage.
  2. If the horse must be stalled, arrange for the horse to see the horses he socializes with. Consider offering a ball or other object that the horse can enjoy in his stall.
  3. Feed the horse more frequently to help buffer the acid in the stomach.
  4. Decrease grains that form volatile fatty acids.
  5. Medications that decrease acid production are available.
  6. Some horses need preventative doses of medications during the winter when grass is scarce or during times of stress.

The prevention of ulcers is the key. Limiting stressful situations along with frequent feeding or free-choice access to grass or hay is imperative. Neutralizing the production of stomach acid is nature’s best antacid.

Navigating Back To Normal: General Care Of Neglected Horses

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Horses that have suffered from prolonged neglect have special needs that extend beyond malnutrition. Many may have health problems need to be addressed in addition to the horse’s nutritional needs. The first step in making a plan for the long term care of horse that has suffered neglect is to have a veterinarian perform a full physical examination to determine the needs of that individual horse, and to document the condition of the horse when it arrives at its foster facility. Without previous records for healthcare, it should be assumed that the horse has not received any attention or preventative care, and the horse should be quarantined from the healthy herd initially.

Farrier care: Horses that are neglected may have significant hoof problems. Poor nutrition contributes to weak hooves, lack of good hygiene can lead to thrush, and lack of trimming leads to severe overgrowth and cracking. An early evaluation with a farrier is needed to make a plan for returning the hoof to a more normal condition. Depending on the condition of the feet, the farrier may request radiographs to evaluate the interior structures of the foot. Changing the foot is a gradual process, and may require frequent visits from the farrier for the first few months.

Deworming: Horses that have not been well cared for are at risk for significant parasitism. The best way to document the parasite burden in a horse is to have a fecal flotation performed. While it is true that parasites contribute to malnutrition in a horse, it is also true that severely debilitated horses lack the internal resources to withstand the damage to the intestinal tract that can occur when parasites die off and are eliminated from the body. Also, it is very difficult without a scale to determine the weight of an emaciated horse to determine proper dosing of anthelminthic drugs. There is no clear consensus in the veterinary community about the exact method that is best for deworming debilitated horses, but there is agreement that the gravest danger to these horses is the emergence of encysted cyathostomes (small strongyles) from the gut wall. When the adult forms of these parasites are killed by drugs like ivermectin, the larvae emerge from the gut wall, causing bleeding, inflammation, and loss of protein. Thus, recommendations most commonly include using a larvacidal medication (a single dose of moxidectin (Quest®) or 5 double doses of fenbendazole (Panacur®) to prevent this rapid emergence. Because there is still damage done to the gut lining, however, it is prudent to wait until the horse is acclimated to a normal plane of nutrition and gaining strength and condition prior to administering any anthelminthic. A veterinarian can help to determine when and how often to address parasite issues in recovering horses.

Vaccination: Horses suffering the effects of chronic malnutrition do not have the ability to respond normally to vaccination. The immune system depends on the body’s ability to produce proteins and build tissues, which is crippled during starvation. Vaccination should not be initiated until the horse is beginning to improve in condition after acclimating to a normal diet; vaccination is an important defense against infectious agents, but is secondary to rebuilding the body from strict survival mode. An initial series of each vaccination will be required, unless there are records to prove previous vaccination. During recovery, a staggered vaccination schedule is preferred, as debilitated horses are not able to withstand the challenges of vaccination that healthy horses are. The American Association of Equine Practitioners deems rabies, tetanus, Eastern Equine Encephalitis, Western Equine Encephalitis, and West Nile Virus to the core vaccines that all horses should receive. Additional recommended vaccinations for different geographical areas should be determined through consultation with the attending veterinarian.

General considerations: Very thin horses lack the intrinsic resources to withstand changes in weather. Providing shelter and blankets helps to avoid further depleting the horse’s energy stores in cold weather. Fresh, clean water and minerals should be available at all times. Meticulous wound care and general hygiene are important, as the immune system is damaged in starvation, and unable to fight against infection. When possible, stress should be minimized; horses should not have to compete for food or shelter, but should have other horses within sight to reduce anxiety. Dental care, which is important, should be delayed until the horse is stronger and gaining weight, as sedation and dental work are often poorly tolerated by debilitated horses. Many horses are rescued from neglectful situations with diseases that are a consequence of their poor care. Frequent veterinary evaluation, including blood work if a problem is suspected, can help to guide treatment and improve outcomes.

How To Safely Refeed Malnourished Horses

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Recent events in Orange, VA have had a powerful emotional impact on many people in and out of the equestrian community. Images of severely thin horses have inspired many good hearted people to offer help and care to the affected horses, either through donations, fostering, or both. It is important to realize, though, that it is actually possible to kill a starving animal with kindness.

During prolonged periods of inadequate nutrition, several changes occur in the body. First, there are changes in the gut. Digestive enzymes are reduced when there is less to digest. The population of organisms that live in the gastrointestinal tract also changes in response to diet. If the feed is poor quality, the types of bugs change. If there isn’t much of anything coming in, the populations die out. Thus, chronically malnourished horses have different, and smaller populations of, GI bugs than well fed ones do.

Secondly, when the incoming calories are too few to support the needs of the animal, the body consumes its own stores. First, it uses up stored carbohydrates and fat. Once these supplies run low, the body starts to consume its muscle tissue as a source of protein. The body breaks down the skeletal muscles first, but the heart muscle and other organ tissue may also be consumed. This can make the heart weak and reduce kidney and liver function.

Once these changes are in place, any rapid changes in diet can cause catastrophic events. Increasing the blood glucose through feeding carbohydrates causes insulin to be released, which moves not only blood glucose, but also essential (and depleted) ions into cells. This leads to neurologic abnormalities, deterioration of red blood cells, liver failure, heart failure, and death. Rapidly increasing the amount of feed in an unaccustomed gut can result in diarrhea, colic, and founder.

Thus, it is essential to change the diet of malnourished horses very slowly. For the first several days, the horse should not receive any concentrate (pellets or grain) feed at all, and should only be fed very small meals (1/4-1/2 flake of hay) every 4-6 hours. This allows the gut to start to gear back up, and avoids big spikes in glucose (and therefore insulin). Horses can graze for 2-3 hours, increasing pasture time by an hour every 3 days. During this time, the horse should have access to minerals and unlimited access to fresh water.

After the first 2-3 days of eating just small meals frequently, the amount of hay can be increased to just meet caloric needs of the horse in its thin body condition for 3 more days. Then, feed can be increased over a 7-10 day period to start supplying enough energy for the horse at its ideal body weight. During the period of weight gain, carbohydrates should still be less than 20% of the ration. Senior feeds are typically alfalfa based, easily digestible, and an excellent source of protein and calories for recovering horses. Introduction of these feeds should also be done slowly, starting at ½ a pound twice daily and increased every 2-3 days as needed. If the horse is not gaining weight as expected, fats can be slowly introduced into the diet, but not until after 10-14 days after the horse is adapted to its new diet.

Once the horse has adapted to a more normal diet, it should have free choice access to good quality grass hay and/or pasture. Supplemental feeding should be provided to meet the needs of the horse’s target weight. The process of weight gain should proceed slowly; very thin horses will take 6-10 months to return to a normal body condition when fed back properly.

Unfortunately, some horses will not recover from chronic malnutrition, even with meticulous attention to nutrition. Horses that have lost half of their body weight, or are too weak to stand have a very poor chance of recovering. The best chance any horse has of recovering from starvation is providing a gradual transition back to eating to allow its body to adapt to a more normal state.

Author:

Tracy Norman, VMD, ACVIM

Rescue Horse Success Story!

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Thank goodness there are horse “angels” in our midst, like our client Becky Moore.  Becky shares her journey with her rescue horse, Raven, in her own words:

“Raven is a 12 year old Tennessee Walker gelding that arrived at our farm on 6/14/14. I picked him up only knowing that he was underweight but looked better than he did over the winter. He is an owner surrender- the former owner not having a good place to keep him and not able to afford the proper feed. A couple of weeks prior to picking him up I sent sweet feed home with the owner and directions on how to start feeding it. When I picked him up, I was unsure if he had the energy to withstand the trailer ride back to my farm as he was severely malnourished. Upon arrival at my farm he weighed 848 lbs, we dewormed him and introduced him to our herd. Dr. Hecking came out after he had been with us for about two weeks and floated his teeth and checked him over and agreed that it seemed to be a malnourishment issue only and his ideal weight should be somewhere between 1000-1100 lbs. Once his weight increased, Ray received all of his shots and proper deworming medications. Ray’s feeding schedule was quite intense. He was fed a combination of two different sweet feeds, beet pulp, alfalfa, cocoa soya, a weight supplement and free range hay. Ray was extremely nervous and during feeding times I had to stand with him so that he would not leave his food- for the first 2 ½ months I spent a total of 3 hours per day feeing him. I do not know exactly how many pounds of food he was consuming per day but he received 4 – 8 qt buckets of the beet pulp/alfalfa mixture and one 8qt bucket twice a day.

Raven is now 1020lbs and the leader of herd. He has a great personality and is super friendly with most people. He still has some weight left to gain but he is eating an almost normal diet and feeding time is down to a total of 45 minutes per day. Raven seems to be very happy in his forever home, he has lots of energy and likes the attention from my children. Over the next few weeks I do hope to take him for a test drive as I am told he was an excellent trail horse.

Thank you to Blue Ridge Equine for promptly visiting Raven and examining him so quickly and providing me with information on ways to achieve his ideal weight. Floating his teeth and shots have been a key part in his recovery.”

Dealing With Foxtail In Your Hay

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Foxtail is very commonly found in horse hay. Foxtail is a common meadow grass that has soft brush like flowering spikes. Unfortunately, it is hard to bale hay without getting foxtail mixed in as well. If you have a load of hay delivered to your farm that contains foxtail, it doesn’t mean the hay is bad, and your horse may never be bothered by it at all. However, many horses are irritated by the small spikes that come from the foxtail.

If you notice your horse not wanting to eat his hay or grain, check his gums and in between his teeth for ulcers or irritation. Sometimes their mouths will even bleed from the irritation or you may see the small foxtail spikes lodged in the gums. If you notice this, you may need to find another source of hay that does not contain the foxtail, and you should also consult with your veterinarian on how to treat the ulcers and inflammation.