Flood Injury in Horses

By Courtnee Morton, Quynchi Tran (LSU SVM, Year IV veterinary students); Britta Leise, DVM, PhD, Dipl ACVS (Assistant Professor, Equine Surgery); Rebecca S. McConnico, DVM, PhD, Dipl ACVIM (Professor, Equine Medicine)

Disease Prevention

During disaster response, animals will be stressed and are likely to have contact with other horses and livestock after rescue which can lead to transfer of disease.
Prior to the storm season, horses should be vaccinated with current strains for Equine Herpes I & IV, Equine Influenza I & II, encephalitides (EEE, WEE, WNV), rabies, and tetanus.
Providing food and fresh water to animals that are sheltered is a priority. Adult horses need 5-15 gallons of water per head per day; enough emergency hay should be available for at least 7 days.

Do your part to evacuate ahead of a flooding situation and make sure your horses can be haltered and are amenable to being led. This helps prevent injury during restraint and transportation.
Make sure your horse can be identified during an emergency in case evacuation is necessary. This can be done by painting contact information on the horse. Microchip and or brand identification can also be helpful for the rescue team when trying locate owners.
Equine emergency field response, during an event, should be carried out by an experienced team (including veterinarians, first responders, and trained handlers) due to safety concerns for both humans and horses.

For horses stranded in a flood, stress is a major contributor to flood related equine medical problems and commonly include those discussed below.
Injured horses should be examined by a veterinarian in the field and stabilized prior to transport. It is important to move the patient to an area for initial triage and assessment as soon as possible.
Equine flood victims should be decontaminated by bathing with detergent soaps (such as Dawn dish soap, etc.) and require thorough cleansing to clean toxins, debris, or microorganisms from skin and to identify additional sites of trauma.
Debris and mud should be picked out of all 4 hooves and cleaned.

Chemical restraint (injectable medication) is often indicated to calm the horse and safely manage the rescue and medical evaluation and treatment of flood-stranded horses. This restraint can minimize further injury to the horse and prevent human injury as well. Medication administration should be under direct veterinary supervision as some medications are contraindicated with certain conditions.

Limb, head, neck, and trunk lacerations and abrasions are commonly seen in equine flood victims. If a horse is exhibiting lameness, a detailed exam to localize and prevent further exacerbation will be necessary.
If a fracture is suspected, stabilization prior to transport will likely be necessary. This requires padded bandages and splinting material (PVC pipe cut in half, 2×4 boards, broom stick handles). Veterinarians should be contacted for directions on how to appropriately splint fractures.
Flood affected horses may develop dermatitis (skin infection) and cellulitis (limb swelling) due to breeches in the skin’s barrier capabilities from standing in contaminated water for long periods of time. This can lead to more serious complications such as septic arthritis and lameness if not treated appropriately. Horses with cellulitis will have swelling and heat in affected areas, and show signs of pain and lameness. Fungal infections can also occur after being exposed to flood water; this may present as ulcerative and oozing lesions with a potentially foul odor.
Horses that are recumbent (down) for long periods of time can develop myositis (severe muscle inflammation/cramping) that can be life-threatening. This condition should be treated by a veterinarian.

After standing in mud or water for extended periods of time, horses may suffer from thrush, soft soles, and sloughing of the frog which may predispose them to other hoof problems such as laminitis.

Traumatic corneal ulceration and uveitis (inflammation within in the eye) are common medical emergencies seen in equine flood victims due to flying storm debris and damaged stable and pasture environment. After rescue and transport, equine eyes should be irrigated with sterile eyewash solution followed by a close detailed eye exam by the veterinarian. Squinting and excessive tearing and swelling around the eye is suggestive of these conditions.

Horses that are stressed from being stranded, injured, or unattended during a flood situation or have ingested contaminated water may develop colitis (severe diarrhea) or other forms of colic or systemic toxemia (sepsis).
Common signs include lethargy, inappetance, colic, fever, and some may develop mild to severe diarrhea.

Equine flood victims are at increased risk of developing head and neck injuries and are more susceptible to infectious diseases such as viral encephalitides or clostridial infections (tetanus and botulism).
During patient triage, immediate action including prevention of further progression of neurological abnormalities and emergency treatment should be implemented. If vaccination status is unknown, tetanus toxoid booster is indicated in addition to tetanus antitoxin may be beneficial.

Aspiration of water into the lungs of horses exposed to floodwaters may cause acute pulmonary edema and pneumonia which is usually life-threatening.
Horses that have been stuck in deep mud or flood waters and struggle for long periods of time can develop upper respiratory tract inflammation resulting in swelling and obstruction of airflow.
After evacuation and rescue, horses may commingle and become infected with respiratory diseases from other horses. The best way to prevent this is providing herd immunity optimization prior to storm season.