immune system | Horse Racing Free Tips

Horses, Humans Have Similar Reactions To Allergic Dermatitis

The intense itchiness caused by allergic dermatitis can make horses scratch to the point where they harm themselves, breaking the skin as they scratch in an attempt to relieve the itching. This inflammatory disease often affects a horse's ears, face, and other hair-free areas, and it can be caused by insect or environmental allergies. Humans also experience atopic dermatitis, often called eczema.

Dr. Rosanna Marsella reviewed literature on the current understanding of atopic dermatitis in dogs, cats, horses, and people to try to improve understanding of the disease and develop new treatments. In people and horses, allergy-related disease often first shows itself as dermatitis, but respiratory disease can occur later. Some atopic horses develop heaves and some affected humans can develop food allergies, rhinitis and asthma.

Atopic dermatitis is often diagnosed by analyzing the patient's history and clinical signs, though serology testing can be done to create a definitive diagnosis. Affected horses are often given glucocorticoids and antihistamines, but controlling triggers for itchiness is crucial to the success of therapy, Marsella says.

Allergen specific immunotherapy is recommended for horses that suffer from the disease and has a success rate of between 64 and 84 percent. Most improvement is seen after the first year of treatment. Some horses require other medical interventions while receiving immunotherapy, but the amounts of these medications may decrease the longer immunotherapy is administered. Interleukin-31, which causes intense itchiness, may be a target for therapy.

Though understanding of atopic dermatitis is limited, affected horses seem to suffer similarly to humans affected by the disease. Treatment has evolved from suppressing the immune system to a more holistic restoration of the immune system, often through allergen-specific immunotherapy.

Read the review here.

Horses May Need Up To Three Weeks Of Recovery After A Virus

It's not just humans that should take it easy if they're ill: experts say horses that have had the flu or other respiratory issues should rest for at least three weeks to allow their bodies to heal. Though lower-level exercise isn't necessarily harmful, high-intensity exercise can suppress immune system response and increase the horse's susceptibility to disease.

Intensely exercising a recovering horse can also cause him to lose weight and tire more quickly, as well as have a harder time recovering. Exercising does not affect virus duration or the duration of virus shedding.

It takes a minimum of three weeks for the respiratory epithelium and the mucociliary apparatus to heal, so allowing horses to rest or complete only low-level exercise is imperative. If exercise is begun and the horse seems distressed, it should be stopped immediately. Open communication with the treating veterinarian is key to creating a return-to-work plan tailored to the horse and his specific health issue.

High-Tech Tool To Diagnose Rainrot

Rainrot is a common, painful skin condition affecting horses that are exposed to rainfall for an extended period of time. Caused by an opportunistic bacterium, a horse exposed to wet, humid conditions can rapidly develop a crusting infection that causes tight scabs in a drip pattern down his back, rump and flanks. Rainrot can also show up on areas of the horse that are in contact with wet grass, like on the lower legs and muzzle.

Though many horses can be treated for rainrot with over-the-counter products, older horses and those with comprised immune systems tend to get more-severe infections that may require veterinary intervention. When dealing with a severe case, a vet will generally sample the crusts and examine it under a microscope, looking for the specific bacteria that causes rainrot.

A New option available to veterinarians is the use of polymerase chain reaction (PCR) technology. This DNA-amplification technique is commonly used in gene sequencing and forensic analysis, as well as for diagnosing infectious diseases. Extremely sensitive, PCR is a routine diagnostic test for most labs and it's affordable: The test isn't as expensive as most cytology tests.

Once run, it can differentiate between rainrot and other skin conditions, which will assist in determining a course of treatment, shortening the trial-and-error efforts sometimes needed to assist with healing.

Antibiotics And Equine Gut Health

Antibiotics can be hard on the digestive and immune systems of horses, but there are some natural approaches that can assist in restoring the equine body back to a normal state after a course of antibiotics has been finished.

Horses, just like humans, have bacteria and microbes that live in their intestinal tract; antibiotics damage the microbiota and inflame the gut wall, creating a “leaky gut” that allows compounds that are normally blocked to pass into the body. Damage to the microbiome also damages the immune system. In the case of chronic infections like Lyme disease, for which a horse may be on repeated rounds of antibiotics, the immune system and gut may never fully recover.

Helping a horse repair his gut is essential after the course of antibiotics is completed. Quality feed, prebiotics and probiotics can assist in repairing the gut wall and the immune system. Horses that eat mainly hay and forage are generally healthier than horses fed lots of grain.

Prebiotics are short-chain fibers that microbiota grown on; common forms are inulin and beta-glucans, among others. Horses can get additional amounts of prebiotics by including items in their diets that contain them (like chicory, oats and barley) or by using a commercially available supplement. Herbs like marshmallow, aloe, dandelion and ginger can all help heal the gut wall and can be planted in pastures or gardens to be fed to horses.

Probiotics fed to the horse while he is taking antibiotics can help do some damage control, but they will assist even more once the course of antibiotics has finished. Other nutrients like glutamine and colostrum can help heal the gut wall and repair the immune system. It will take a minimum of three months for the horse's gut to heal after a short course of antibiotics and much longer for repeated antibiotic use for chronic disease.