Grain that becomes moldy either during cultivation or storage can produce mycotoxins that pose health threats for horses, including corn, oats and barley.

Fescue poisoning is a risk for mares who graze mold-infected tall fescue pasture in late pregnancy. Exposure to mycotoxin-laden tall fescue can result in difficulty foaling, thickened placentas, reduced milk production and even death of their foal.

Grass Staggers

Grass staggers (also referred to as grass tetany or hypomagnesaemia) is a metabolic disease caused by magnesium deficiency, with magnesium playing an integral part in nerve and muscle function as well as essential functions in the heart and other body systems. Magnesium levels typically decline during autumn and winter when pasture consumption declines significantly and during pregnancy or lactation mares. Pregnant or lactating mares also can become susceptible.

grass staggers refers to the distinctive symptoms associated with feeding contaminated fescue forage to horses, including tremors and staggering. Horses affected by grass staggers usually appear normal at rest with only minimal head or neck tremor. When moved, their movements become stiff and uncoordinated with spastic movements of forelegs or hind legs becoming spastic and sometimes spastic movement seen between forelegs and hind legs becoming spastic or spastic at times; in severe cases severe symptoms result in seizure-like seizures known as tretanic seizures which often leads to horsing or weaving; grass staggers can be caused by both perennial ryegrass (P. ryanum), as well as toxic Fusarium toxin trichothecenes containing deoxynivalenol (DON), and zearalenone.

Other sources of grass tetany include wheat, oats and barley; as well as some less-than-appetizing field plants like hoary alysum or wild sesame (Sesamum indicum) that are easily consumed when dried into grain or hay products for consumption in food stores or processed into grain products that then end up being consumed as dry hay or grain products.

Long-term prevention strategies for grass tetany include developing nutrient management practices to lower potassium or ammonia levels in soil, and employing diverse grazing rotations.

Short-term prevention measures involve limiting exposure to moldy feed or hay and regularly evaluating its quality. Consumption of moldy hay may cause digestive upset; so it’s essential that horse owners monitor for signs such as abdominal pain (colic) or loss of appetite within 24 hours after consumption of moldy hay.

At this time of year when many horse owners are feeding out hay to their horses, it is especially essential that owners make sure it does not contain harmful molds and steer clear from feed that has been treated with propionic acid or molasses as these chemicals may be detrimental.

Colic

Horses tend to be more sensitive than cattle to certain kinds of mold, as some mycotoxins produced by such mold can be toxic for horses even at relatively low concentrations. Colic has also been known to occur if horses ingest contaminated feed (grain or hay) that produces mycotoxins; in such instances it’s vital that an affected horse see a veterinarian immediately in order to address their situation and get treatment as quickly as possible.

Spasms of the digestive tract and entrapment colic are the two primary forms of colic a horse may experience, respectively. Entrapment colic occurs when part of an intestinal tract becomes dislodged from its normal position within an abdominal cavity and displaces itself outwards causing severe pain and potentially blockage of an intestine. A more serious complication known as intussusception arises when one or both large or small intestine sections telescope into an adjacent bowel restricting blood supply reducing blood supply to its intended organ and eventually killing it off swiftly.

Displacement colic may be caused by various factors, including sudden increases in feed, eating difficult to digest foods, feeding an extremely hot horse, dental issues and parasites; or by buildups of sand or other materials in the digestive tract which interfere with digestion, leading to blockages.

Foals may also be susceptible to colic, which can be fatal. Premature placental separation may occur leading to fetal suffocation; eating infected hay during gestation could limit her ability to carry her foal effectively resulting in weak and unhealthy foals born at birth.

Mycotoxin poisoning in horses can be fatal. Moldy hay should be stored in dry, cool areas that will not expose it to moisture; extra caution must be exercised if your area experiences wet summers followed by dry winters as this provides ideal conditions for mold growth in hay.

Heaves

Horses suffering from heaves cannot expel air from their lungs as efficiently, leading to intermittent asthmatic disease (IAD). While this condition typically starts off mildly, over time its severity may worsen over time; often due to certain types of moldy feed or dust and pollen entering through open doors; symptoms often worsening in late spring and summer when evergreen trees bloom with intense heat and humidity conditions.

Horses who suffer from heaves are at greater risk for developing bacterial infections and may lose weight, as well as having difficulty exhaling air from their lungs. A physical exam and understanding their history can help your veterinarian diagnose heaves; additional tests such as bronchoalveolar lavage may be performed to confirm this diagnosis; another common one being endoscopy which involves passing a camera down their trachea while looking for inflammation or mucus build-up may also be performed to confirm diagnosis.

Once a horse with respiratory conditions is identified, the initial step of treatment should be to limit their exposure to allergens. This could involve changing their environment by swapping out their food sources – for instance switching hay out for pelleted feed or keeping horses at pasture – thereby decreasing dust and mold spore exposure on an ongoing basis.

Many horses with heaves will benefit immediately from treatment with immediate improvements in both health and performance, though long-term management practices should still be adhered to in order to minimize exposure to allergens. Some horses may require medication in addition to environmental management in order to treat their disease, including corticosteroids and bronchodilators which reduce inflammatory responses while relaxing airways to make breathing easier – these should always be taken as prescribed by your veterinarian.

Mycotoxins

Mycotoxins, produced by specific types of mold, can build up to dangerous levels in forage such as hay and grain and contribute to various immune, respiratory, gastrointestinal and reproductive problems in horses.

Molds produce mycotoxins through fermentation processes that take place under various environmental conditions, including warm and moist conditions. Mycotoxins produced through this process then travel on fungal spores that can be inhaled, eaten or absorbed through the skin – with ingestion leading to various symptoms or even death.

Trichothecene is one of the most frequently found mycotoxins in hay and grains, typically caused by Fusarium fungi, and typically appears during harvest seasons with cold and wet weather. Studies have demonstrated its harmful effects, including reduced feed intake and absorption for horses as well as decreased fertility in mares as well as weak or stillborn foals due to premature placental separation during gestation.

Vomitoxin is another prevalent mycotoxin found in cereal grains exposed to high humidity levels such as during harvest season or wet hay storage, such as harvest. This mycotoxin has been linked with reduced feed intake among horses, gastrointestinal tract lesions and immunosuppression; additionally it may contribute to abortion in mares as well as premature separation of their placenta leading to foal suffocation.

Recent advances include binding agents designed to mitigate mycotoxin ingestion by horses. These supplements work by blocking absorption by the gut and excreting it through urine instead. While such binding products have yet to become widely available here in the US, they could play an essential role in lessening moldy hay’s negative impacts; until that day comes, horses should only consume dry forage without moisture contamination from mycotoxins.