Colic prevention is built on consistent management practices that support healthy gut motility and function. The most impactful are: continuous or near-continuous access to quality forage; fresh water available at all times (especially in cold weather when horses voluntarily reduce intake); gradual dietary transitions (minimum 7–14 days); regular exercise and turnout; strategic deworming based on fecal egg counts; routine dental care; and feeding off the ground on mats or feeders in sandy regions.
No management program eliminates colic risk entirely, but horses managed with consistent forage access and adequate hydration have consistently lower colic rates in research studies.
Early signs include: decreased appetite or refusing feed; mild restlessness or pawing; occasional glancing at the flank; reduced or absent manure output; lying down more than usual; and a mild increase in resting heart rate. A horse that is off feed, quieter than normal, or spending more time lying down than usual may be in the early stages of abdominal discomfort.
More obvious signs include: repeated pawing, rolling attempts, looking at or biting the flank, elevated heart rate, sweating, and distension of the abdomen. Any signs of abdominal pain in a horse warrant calling your veterinarian — early treatment consistently improves outcomes.
Call your veterinarian first. While waiting, remove access to feed. Allow access to fresh water unless your vet instructs otherwise. Keep the horse as calm as possible. Do not administer medications including Banamine without specific guidance from your vet — masking pain can complicate the veterinary assessment. Monitor and record heart rate, gum color, gut sounds, and behavior so you can give your vet an accurate update.
Walking is appropriate for mild cases in some situations — ask your vet specifically, because walking is contraindicated in certain colic types. Be prepared to transport to an equine hospital if your vet advises it.
Sand colic occurs when sand and dirt accumulate in the large colon over time, forming impactions that obstruct normal motility. It is particularly relevant in the American Southwest — Arizona, New Mexico, California — where horses are commonly kept on sandy or rocky desert ground.
Prevention includes feeding hay off the ground on rubber mats or in elevated feeders to prevent sand ingestion; ensuring adequate water intake; and discussing psyllium supplementation protocols with your veterinarian — psyllium may help clear accumulated sand from the colon. Ask your vet about the most evidence-supported approach for your management situation.
The AAEP (American Association of Equine Practitioners) divides equine vaccines into core and risk-based categories.
Core vaccines (recommended for all horses regardless of use or location): Eastern and Western Equine Encephalomyelitis (EEE/WEE); Tetanus; West Nile Virus; Rabies.
Risk-based vaccines (recommended based on geographic location, use, and exposure risk): Equine Influenza; Equine Herpesvirus (EHV-1 and EHV-4); Strangles; Potomac Horse Fever; Botulism; Anthrax; Venezuelan Equine Encephalomyelitis (in endemic regions).
Core vaccines are generally administered annually, though boosters for Tetanus and EEE/WEE are sometimes recommended every 6 months in endemic regions. Rabies is typically annual. West Nile is often administered in spring before mosquito season, sometimes semi-annually in high-risk areas.
Risk-based vaccines may require more frequent administration — Influenza and EHV vaccines may be given more often than annually in horses with high exposure risk from shows, events, and travel. Strangles vaccination frequency depends on the product used.
Many core vaccines are available for owner administration. However, there are important considerations: vaccine efficacy depends on proper storage, handling, and administration technique; some vaccines (particularly modified live intranasal strangles) carry handling risks if accidentally self-inoculated; and systemic reactions to vaccines — while uncommon — require veterinary management.
More importantly, the annual vet visit that accompanies vaccination provides an opportunity for physical examination, dental assessment, body condition scoring, and health discussion that has significant value beyond the vaccine itself. Many equine veterinarians strongly recommend annual wellness exams even if vaccination is performed by the owner.
Signs that may indicate dental issues include: dropping feed (quidding) while eating; excessive salivation; difficulty chewing or eating; weight loss or poor body condition despite adequate feed; undigested grain or long hay stems in the manure; foul odor from the mouth or nostrils; head tilting or resistance to the bit; and behavioral changes under saddle that may relate to mouth discomfort.
Many horses with significant dental problems show no obvious signs — which is why regular professional dental examinations by a veterinarian are recommended regardless of whether problems are apparent.
Wolf teeth are small, vestigial premolars (first premolars, also called PM1) that typically erupt in front of the second premolars at about 6–18 months of age. They are present in the majority of horses — both sexes — though variable in size, shape, and location.
Wolf teeth can interfere with bit contact and cause discomfort when pressure is applied to the bit. For this reason, they are commonly removed before training begins. Removal is a routine veterinary procedure performed under sedation.
Sharp points on the cheek teeth (molars and premolars) develop as horses chew — because horses chew in a circular motion, the outer edges of the upper cheeks and inner edges of the lower cheeks develop sharp points that can lacerate the cheek tissue against bit pressure. This produces pain that horses express through head tossing, resistance, tongue over the bit, fighting the contact, and other behaviors that are often incorrectly attributed to training issues.
Floating — filing down these sharp points during a dental procedure — is a routine part of equine dental care. Hooks, ramps, wave mouth, and other dental irregularities can also affect bitting and performance. A thorough dental examination before attributing ridden resistance to training problems is always worthwhile.
The modern evidence-based approach to equine parasite management is targeted selective treatment (TST) rather than calendar-based deworming. TST uses fecal egg counts (FECs) — laboratory analysis of a fresh manure sample — to identify which horses are shedding significant parasite burdens and treat only those horses.
Research shows that in most herds, a minority of horses (20–30%) shed the majority of parasites. Treating all horses on a fixed calendar schedule promotes resistance development in parasites and is largely unnecessary for low-shedding horses.
Regardless of FEC status, all horses should receive a fall treatment with ivermectin or moxidectin after the first frost (or end of bot fly season) to target bot larvae, which are not detected on FECs.
The most reliable way to assess dewormer efficacy is the fecal egg count reduction test (FECRT): perform a FEC before treatment, administer the dewormer, and repeat the FEC 14 days later. AAEP's general guideline is a reduction above 95%; thresholds differ by drug class, so ask your veterinarian to interpret the result. A low reduction can indicate resistance to that product in your horse's parasite population.
Anthelmintic resistance — particularly to ivermectin and benzimidazoles — is increasingly prevalent in equine parasites. FECRT is the only way to detect resistance at the farm level.
Always call your vet immediately for: any colic signs; neurological signs (incoordination, weakness, inability to stand); eye injuries; suspected choke; lacerations near joint structures; profuse or arterial bleeding; difficulty breathing at rest; inability to bear weight; a mare showing difficulty foaling; and any situation where you are genuinely uncertain.
Signs that warrant a same-day call: lameness that is moderate or does not improve with 24 hours of rest; fever above 101.5°F; a wound that may need suturing; signs of possible infection; a horse that hasn't passed manure in over 8 hours; and any significant change in normal behavior, appetite, or water consumption.
The governing rule: the cost of a phone call is always less than the cost of delayed treatment. When in doubt, call.
A well-stocked equine first aid kit includes: veterinary thermometer; stethoscope; hoof pick; bandage scissors; non-stick wound pads; rolled gauze; self-adhesive bandage (Vetrap); standing wraps and quilts; clean towels; saline solution for wound flushing; dilute betadine or chlorhexidine; wound spray or ointment approved by your vet; latex gloves; a flashlight; and your veterinarian's phone number prominently displayed.
Discuss with your veterinarian whether keeping banamine (flunixin meglumine) on hand is appropriate for your situation and get specific instructions on its use before you need it.
Arizona summer heat — regularly exceeding 110°F in the desert regions — creates significant health risks for horses. Key management strategies include: providing access to shade at all times; ensuring multiple clean, cool water sources and checking them frequently; scheduling exercise in the early morning or evening when temperatures are lower; monitoring for signs of heat stress (elevated respiratory rate and heart rate that do not return to normal within 20–30 minutes after exercise); and allowing horses adequate time to acclimatize to heat if they have been moved from a cooler climate.
Electrolyte supplementation is often appropriate for horses in heavy work during extreme heat — discuss appropriate products and timing with your veterinarian. Heat stroke in horses is a veterinary emergency.
Water needs rise in hot weather and with exercise. Signs that may be associated with inadequate hydration include dark or concentrated urine, a slow return of gum color after pressing (capillary refill time; the University of Florida lists under 2 seconds as normal), and lethargy. These signs have many possible causes, and only a veterinarian can tell what is behind them.
Monitoring water tank levels daily during summer provides a useful baseline — a significant change in consumption is worth reporting to your veterinarian. Providing multiple water sources and ensuring adequate salt intake (loose salt or salt block) encourages drinking.
In horses, choke is a blockage of the esophagus, the tube that carries food and water to the stomach. It is not a blockage of the windpipe, so an affected horse can breathe normally.
It is still a reason to call your veterinarian right away. While the esophagus is blocked, saliva, feed, or water can be inhaled into the lungs and cause aspiration pneumonia, and the longer an obstruction lasts, the higher that risk becomes.
Sources: UF/IFAS Extension VM275; UC Davis Center for Equine Health, Esophageal Obstruction (Choke) in Horses
Reported signs include feed or saliva coming from the nostrils (often green and frothy), heavy drooling, coughing, gulping or trouble swallowing, retching, and stretching out the head and neck. Some horses have a visible or palpable bulge in the neck, and many seem anxious, restless, or sweaty.
These signs overlap with other problems, so call your veterinarian rather than trying to work out the cause yourself.
Sources: UF/IFAS Extension VM275; UC Davis Center for Equine Health, Esophageal Obstruction (Choke) in Horses; Merck Veterinary Manual, Esophageal Obstruction in Large Animals
Call your veterinarian right away and describe what you see. Keep the horse as calm as possible and make sure it cannot eat or drink, even if it seems interested: remove all feed and water, and use an empty stall or pen without bedding to eat, or a muzzle if that is not possible.
Do not pass a stomach tube or garden hose, and do not give water or oil by mouth. Passing a tube is a job for a veterinarian. Do not try to clear the blockage yourself, and ask your veterinarian before trying anything else, such as massaging the neck. Your veterinarian’s instructions take priority over any general guidance.
Sources: UF/IFAS Extension VM275; UC Davis Center for Equine Health, Esophageal Obstruction (Choke) in Horses; Merck Veterinary Manual, Esophageal Obstruction in Large Animals
Aspiration pneumonia is the main concern. Prolonged obstruction can also damage the lining of the esophagus, from mild ulceration to tears, and severe ulceration can leave scarring or narrowing (stricture) that makes repeat episodes more likely.
Even after the blockage clears, University of Florida extension advises watching for several days for coughing, changes in breathing, nasal discharge, a temperature above 101.5°F, depression, or loss of appetite, and reporting these to your veterinarian. Refeeding should be slow and gradual, and only after talking with your veterinarian.
Sources: UF/IFAS Extension VM275; UC Davis Center for Equine Health, Esophageal Obstruction (Choke) in Horses; Merck Veterinary Manual, Esophageal Obstruction in Large Animals
Risk factors listed by University of Florida extension include poor teeth or chewing, reduced saliva in older horses, improper feed such as large pellets or dried beet pulp, bolting food, excitement in a new environment, exhaustion, being allowed to eat while still sedated, and swallowing foreign material such as shavings.
UC Davis lists these management points: soak dry feeds properly; cut treats such as carrots and apples into portions; keep clean, fresh water available at all times; slow eating with haynets, feed spread over a larger area, or slow-feed toys; provide multiple feed piles or buckets in groups so lower-ranking horses do not rush; and have your veterinarian examine the mouth regularly to catch dental problems.
Sources: UF/IFAS Extension VM275; UC Davis Center for Equine Health, Esophageal Obstruction (Choke) in Horses
The Merck Veterinary Manual lists acute swelling around the eye, eyelid lacerations, corneal ulcers and abscesses, trauma to the eyeball, uveitis, and glaucoma as vision-threatening emergencies. Some corneal problems can perforate quickly, and uveitis or glaucoma can cause permanent damage if untreated.
The University of Tennessee notes that many equine eye diseases worsen quickly, and that waiting can make a condition much harder to treat and may cost the horse vision in that eye. Eye signs are not specific, so any concern warrants a veterinary exam.
Sources: Merck Veterinary Manual, Ophthalmic Emergencies in Horses; University of Tennessee CVM, Common Equine Eye Problems
Squinting or holding the eye shut (a sign of pain), excessive tearing sometimes with mucus or pus, cloudiness or a white or yellow patch on the surface, a small irregular spot on the surface, redness, and swelling of the eyelids or surrounding tissue. University of Florida also advises calling for any abnormal eye appearance in a foal.
Any eye concern is worth a call. Your veterinarian can tell what is behind these signs.
Sources: UF Large Animal Hospital, When It’s Time to Call the Vet; Merck Veterinary Manual, Ophthalmic Emergencies in Horses; University of Tennessee CVM, Common Equine Eye Problems
No. The University of Tennessee advises against putting any medication in the eye without first consulting your veterinarian, because the wrong medication can make the problem worse. The Merck Veterinary Manual adds that steroid eye preparations should not be used until a veterinarian has checked the cornea for ulcers or abscesses.
Keep watching the eye and report any improvement or decline to your veterinarian.
Sources: University of Tennessee CVM, Common Equine Eye Problems; Merck Veterinary Manual, Ophthalmic Emergencies in Horses
According to the University of Tennessee, the veterinarian may sedate the horse and use numbing medication so the eye can be examined thoroughly. A dye called fluorescein is commonly used to check for corneal ulcers. Depending on the condition, the veterinarian may also measure pressure inside the eye or dilate the pupil to examine the retina.
The Merck Veterinary Manual notes that many complicated eye cases are best handled by referral to a board-certified veterinary ophthalmologist.
Sources: University of Tennessee CVM, Common Equine Eye Problems; Merck Veterinary Manual, Ophthalmic Emergencies in Horses
The University of Kentucky lists a normal resting temperature for an adult horse of 99.5–101.5°F, with younger horses tending toward the higher end. University of Florida gives roughly 99–101.5°F.
A reading above 101.5°F is called a fever if disease is the cause and hyperthermia if exercise or heat is the cause. A thermometer alone cannot tell which, so discuss a high reading with your veterinarian.
Sources: University of Kentucky, Horse vital signs (ID-179); UF Large Animal Hospital, When It’s Time to Call the Vet
University of Florida advises calling for an adult horse with a temperature above 101.5°F, and for a foal above 102°F. It describes a reading above 103°F as a sign of a serious problem.
The same guide also lists abnormal gum color (red, purple, white, or yellow), yellow or green nasal discharge, breathing difficulty, and depression among reasons to call.
Sources: UF Large Animal Hospital, When It’s Time to Call the Vet
Not necessarily. The University of Kentucky explains that a reading above 101.5°F is hyperthermia when exercise or heat causes it and a fever when disease causes it. Respiratory rate also rises in hot, humid weather.
University of Florida lists heat stress as a reason to call your veterinarian. If you are unsure which applies, call.
Sources: University of Kentucky, Horse vital signs (ID-179); UF Large Animal Hospital, When It’s Time to Call the Vet
The University of Kentucky gives these ranges for an adult horse at rest: temperature 99.5–101.5°F; heart rate 25–45 beats per minute (higher in younger horses); respiratory rate 14–20 breaths per minute, which rises with distress, pain, or hot, humid weather; and capillary refill time of 2 seconds or less. Longer refill times can indicate dehydration, infection, fever, or blood loss.
Gut sounds, a normal gurgling heard anywhere on the abdomen, are also checked. Absent gut sounds are a concern in colic and warrant a call to your veterinarian, though they can be absent right after exercise. The same source advises calling your veterinarian if a horse showing discomfort has a pulse above 60, or has an abnormal breathing pattern.
University of Florida advises calling for heavy bleeding, deep wounds, any injury over a joint or tendon or on the bottom of the foot, unusual swelling, and suspected bites such as from a snake or spider.
Texas A&M adds that a veterinarian should see a wound that is over a joint, involves bone or ligaments, or pulls apart when the horse moves, and wounds on the leg, especially near a moving joint or below the knee, where there is little tissue and dirt contamination is more likely. Neither list is exhaustive. When in doubt, call.
Sources: UF Large Animal Hospital, When It’s Time to Call the Vet; Texas A&M Vet Med, Topical Wound Care for Horses
Not simply. Texas A&M explains that drying a wound out may seem natural, but the white blood cells that clean the wound need moisture to work. Too much moisture can cause excess granulation tissue (“proud flesh”), which can stall healing and may need veterinary care.
Ask your veterinarian how to manage the moisture balance for your horse’s particular wound.
It depends. Texas A&M notes that some cuts and abrasions do not need one. Leg wounds may, to limit dirt contamination and skin movement. A bandage also holds topical medication on the wound, and its light pressure can reduce excess skin outgrowth and scarring.
Ask your veterinarian whether and how to bandage a given wound.
Texas A&M states that tetanus is always a threat and that horse owners should keep tetanus vaccinations current. Small wounds can go unnoticed and become contaminated or infected before they are found.
See the vaccination questions above for how your veterinarian sets a schedule for your horse.
Per the AAEP, lameness is generally any change in a horse’s gait. It can also show up as a change in attitude or performance. Pain in the neck, withers, shoulders, back, loin, hips, legs, or feet can cause it, which is why finding the source matters.
Owners can watch for a shorter stride, irregular foot placement, head bobbing, stiffness, or shifting weight from one leg to another. Riders may notice subtle changes before observers do.
The AAEP advises contacting your veterinarian promptly if lameness occurs, because early exams can keep small problems from becoming serious, and says to stop riding and seek advice if you suspect a problem.
University of Florida also lists head-bobbing, reluctance to walk or trot, and lying down more than usual as reasons to call, and says to call if a horse cannot get up or move. In older horses and foals it advises calling for any lameness, and for a swollen joint in a foal.
Sources: AAEP, Lameness Exams: Evaluating the Lame Horse; UF Large Animal Hospital, When It’s Time to Call the Vet
The AAEP describes a sequence: a history of past and current problems and the horse’s workload; a resting exam of conformation, balance, and weight-bearing; a hands-on exam of muscles, joints, bones, and tendons for pain, heat, or swelling; hoof testers on the soles; and watching the horse walk and trot on hard and soft surfaces, on a lunge line, and sometimes under saddle. Flexion tests can reveal hidden problems.
If needed, nerve and joint blocks help pinpoint the painful area, and imaging such as radiographs or ultrasound may follow. Radiographs mainly show bone, not soft tissue.
The AAEP scale runs from 0 to 5. Grade 0: no perceptible lameness. Grade 1: difficult to observe and not consistently present. Grade 2: difficult to see at a walk or on a straight trot, but consistent under certain conditions such as carrying weight or circling. Grade 3: consistently visible at a trot in all circumstances. Grade 4: obvious at a walk. Grade 5: minimal weight-bearing in motion or at rest, or complete inability to move.
A grade describes how visible the lameness is. It does not by itself tell what is causing it, so any lameness is worth discussing with your veterinarian.
University of Florida advises calling your veterinarian for reduced appetite or trouble eating. The same guide lists fever, abnormal gum color, depression, diarrhea, and colic signs among other reasons to call, so tell your veterinarian about any of these that occur at the same time.
Your veterinarian can work out why the appetite has dropped.
Sources: UF Large Animal Hospital, When It’s Time to Call the Vet
University of Florida notes that in older horses, weight loss, poor eating, dropping feed, or difficulty chewing may point to dental disease, and advises calling your veterinarian.
See the dental care questions above for the signs of dental problems and how often veterinarians recommend examinations.
Sources: UF Large Animal Hospital, When It’s Time to Call the Vet
The AAEP describes laminitis as a painful foot disease. It occurs when blood flow to the laminae, the tissue that attaches the coffin bone to the hoof wall, is disrupted. The exact way the feet become damaged is not fully understood, and the cause often lies elsewhere in the horse’s body.
Because the root problem is often elsewhere in the body, your veterinarian looks beyond the feet for the underlying cause.
Acute signs listed by the AAEP include lameness that is worse when turning in circles; warm feet with a stronger digital pulse; pain at the toe when hoof testers are applied; a hesitant gait often described as “walking on eggshells”; and a “sawhorse” stance, with the front feet stretched forward and the hind feet set farther back. The University of Georgia adds constant weight shifting and reluctance to move or rise, most often involving the front feet.
Signs of long-standing (chronic) laminitis include growth rings on the hoof wall that widen from toe to heel, bruised soles, a widened white line, dropped or flat soles, dished hooves, and a thick, crested neck.
Sources: AAEP, Learn to Recognize the Signs of Laminitis; University of Georgia Extension and Equine Science, Laminitis in Horses
Yes. The AAEP says to treat suspected laminitis as a medical emergency and contact your veterinarian immediately, because earlier treatment gives the best chance of recovery. The University of Georgia likewise says prompt veterinary care can limit hoof damage and improve outcomes.
The AAEP page gives no home-care steps beyond recognizing the signs and calling promptly, so ask your veterinarian what to do while you wait.
Sources: AAEP, Learn to Recognize the Signs of Laminitis; University of Georgia Extension and Equine Science, Laminitis in Horses
The University of Georgia groups causes into several categories. Endocrine or insulin-related causes: it states that most cases involve insulin dysregulation, with some reports as high as 90%, and that obese or insulin-resistant horses are especially prone to pasture-associated laminitis. Diet and pasture: excess grain, toxic plants, and lush pasture. Mechanical overload: working on hard surfaces, or carrying extra weight on one leg when the opposite leg is injured. Systemic inflammation, such as systemic inflammatory response syndrome (SIRS).
The AAEP notes that the triggering problem is often a disturbance elsewhere in the body, which is why a veterinarian looks for the underlying cause.
Sources: University of Georgia Extension and Equine Science, Laminitis in Horses; AAEP, Learn to Recognize the Signs of Laminitis
Yes. Michigan State University and the Royal Veterinary College both list laminitis among the signs of pituitary pars intermedia dysfunction (PPID, or equine Cushing’s disease). The University of Georgia links laminitis to insulin dysregulation and obesity, and recommends keeping horses at an optimal body condition and having a veterinarian check for underlying conditions that may cause insulin dysregulation.
See the Cushing’s (PPID) questions below for the other signs to watch for.
Sources: Michigan State University CVM, Equine Cushing’s: Clinical Signs; Royal Veterinary College, Cushing’s Disease fact file; University of Georgia Extension and Equine Science, Laminitis in Horses
The University of Georgia lists these points: inspect hooves daily and schedule regular farrier visits for balance and proper toe angles; store grain securely; support the opposite limb when a horse has a limb injury (ask your veterinarian how); and, for high-risk horses such as those with previous episodes or insulin resistance, limit sugar and starch in the diet and limit pasture access, especially in spring and fall, possibly with a grazing muzzle.
Work with your veterinarian on body condition scoring and on a feeding plan for a horse at higher risk.
Sources: University of Georgia Extension and Equine Science, Laminitis in Horses
The Royal Veterinary College describes equine Cushing’s disease, also called pituitary pars intermedia dysfunction (PPID), as a disorder of the pituitary gland at the base of the brain. Loss of normal control causes the gland to overproduce hormones, which circulate and affect the whole body.
It mainly affects horses over 10, with an average age at diagnosis of 19. Ponies are more prone than horses, and sex does not appear to matter. The RVC describes the disease as incurable, though medication can control it.
Sources: Royal Veterinary College, Cushing’s Disease fact file
Michigan State University lists the classic sign as a curly coat that does not shed normally. Other signs it lists are heavy sweating, bulging eyes caused by fat above the eye sockets, increased thirst and urination, infertility, insulin resistance, laminitis, tiredness, muscle loss, repeated infections, sinus problems, and tooth decay. The Royal Veterinary College also lists weight loss and a long coat that is not shed in warmer months.
Many of these signs have other causes, so only a veterinarian can say whether PPID is behind them.
Sources: Michigan State University CVM, Equine Cushing’s: Clinical Signs; Royal Veterinary College, Cushing’s Disease fact file
According to the Royal Veterinary College, veterinarians base the diagnosis on history, clinical signs, and hormone tests, either measuring ACTH levels or running a TRH stimulation test. Diagnosis is difficult early in the disease because tests can give false negatives, hormone output varies by season, and there is no true gold-standard test.
Michigan State University likewise says no test is completely accurate and that the time of year affects how results should be read. Ask your veterinarian when to test and how to interpret the result.
Sources: Royal Veterinary College, Cushing’s Disease fact file; Michigan State University CVM, Equine Cushing’s: Clinical Signs
The Royal Veterinary College states that the disease is incurable but that medication can control it. Treatment options include medication, and owners decide whether to treat based on the signs and how severe they are, so discuss the options with your veterinarian. Some animals are managed by addressing problems such as laminitis and infections and by adjusting the diet.
Medication choices and dosing are decisions for your veterinarian.
Sources: Royal Veterinary College, Cushing’s Disease fact file
Strangles is a highly contagious bacterial disease of horses, donkeys, and ponies caused by Streptococcus equi. The AAEP lists early signs as mild lethargy, eating less, a slight cough, nasal discharge, and fever. A few days later, lymph nodes in the throat (and sometimes near the base of the ear) swell and form abscesses, and the nasal discharge changes from clear to cloudy to thick and yellowish. Some horses hold the head low and extended because of throat pain.
Some cases never develop the classic abscesses and show only fever and reduced appetite. Texas A&M adds that signs appear within a few days to two weeks of exposure, that the disease most often affects horses two years old or younger, and that enlarged lymph nodes can interfere with breathing or swallowing.
Sources: AAEP, Strangles: A Contagious Equine Disease; Texas A&M Vet Med, Strangles: Understanding Equine Distemper and Purpura Haemorrhagica
Horses spread it through nasal secretions (snorting, coughing, nose-to-nose contact) and through pus from draining abscesses. People can carry the bacteria on contaminated clothing, hands, and equipment, and the bacteria can contaminate water and feed.
Texas A&M adds that the germ can survive in contaminated soil, water troughs, feed buckets, and tack, and can travel on vehicle tires.
Sources: AAEP, Strangles: A Contagious Equine Disease; Texas A&M Vet Med, Strangles: Understanding Equine Distemper and Purpura Haemorrhagica
The AAEP advises isolating the horse right away, calling your veterinarian, and stopping horse movement until the outbreak is resolved. Texas A&M advises seeking veterinary care immediately, and notes that veterinarians may prefer to examine the horse away from their clinic to avoid contaminating it.
Your veterinarian directs testing and care. The AAEP says to seek veterinary help promptly for complications such as purpura, internal abscesses, or muscle problems.
Sources: AAEP, Strangles: A Contagious Equine Disease; Texas A&M Vet Med, Strangles: Understanding Equine Distemper and Purpura Haemorrhagica
Yes. The AAEP says some horses that look healthy keep shedding the bacteria in nasal discharge for a long time and can infect others, and that testing can determine whether a horse is shedding. Texas A&M says infected horses can shed the germ for about two to three weeks starting after clinical signs appear.
This is why new horses and horses with unknown exposure are isolated before joining a herd.
Sources: AAEP, Strangles: A Contagious Equine Disease; Texas A&M Vet Med, Strangles: Understanding Equine Distemper and Purpura Haemorrhagica
The AAEP says most horses recover within two to four weeks, immunity afterward varies, and some horses die from suffocation or other complications. Texas A&M puts mortality generally under 10 percent.
Texas A&M also describes purpura haemorrhagica, in which vasculitis in the legs causes painful swelling. It can follow strangles or exposure to the germ without infection, and horses with it are typically sicker. Complications can include lasting musculoskeletal damage and laminitis.
Sources: AAEP, Strangles: A Contagious Equine Disease; Texas A&M Vet Med, Strangles: Understanding Equine Distemper and Purpura Haemorrhagica
The AAEP recommends biosecurity for people and horses entering a facility: avoid sick or unknown-status horses; do not overstock; ask for a veterinarian’s health statement for new horses and isolate them for a few weeks; take precautions when staff move between isolated and other horses; do not share tack, feed tubs, water containers, trailers, pens, or stalls with horses of unknown health status; and clean nonporous surfaces with soap and water, rinse, then disinfect. Texas A&M advises isolating horses with unknown exposure history for at least two weeks.
Vaccines exist, but the AAEP notes they do not fully protect every horse, and Texas A&M notes the recommendation is debated and that strep vaccines have historically had more potential for reactions than other equine vaccines. Discuss vaccination with your veterinarian.
Sources: AAEP, Strangles: A Contagious Equine Disease; Texas A&M Vet Med, Strangles: Understanding Equine Distemper and Purpura Haemorrhagica
The University of Arizona Extension describes EHV-1 (equine rhinopneumonitis) as affecting all equids, including horses, donkeys, and mules. It can cause a respiratory form, a neurologic form called equine herpesvirus myeloencephalopathy (EHM), and abortion in mares. EHM is comparatively rare. Texas A&M AgriLife describes the same three forms.
Respiratory illness usually resolves in one to two weeks, while horses with EHM may take longer and neurologic signs may never fully resolve. The Arizona bulletin gives EHM mortality as 15% to 30%.
Sources: University of Arizona Extension, Equine Herpesvirus-1 (AZ2176); Texas A&M AgriLife Extension, Equine Herpesvirus (ANSC-PU-462)
Early signs include a fever above 101.5°F, often the first sign, along with lethargy and reduced appetite, and respiratory signs such as nasal discharge and cough. Neurologic signs (EHM) are an emergency and include swollen legs, wobbliness, a weak hind end, toe dragging, difficulty rising or sitting like a dog, urine dribbling, loss of tail tone, leaning against walls, behavior changes, head tilt, and seizures.
Texas A&M notes that fever often comes before neurologic signs and that a horse without fever may still be infected.
Sources: University of Arizona Extension, Equine Herpesvirus-1 (AZ2176); Texas A&M AgriLife Extension, Equine Herpesvirus (ANSC-PU-462)
The University of Arizona says to call your veterinarian immediately if any neurologic sign appears, and Texas A&M says to contact your veterinarian immediately if a horse shows symptoms. Horses with clinical signs such as nasal discharge, abortion, or neurologic signs should be considered contagious until cleared by a veterinarian through testing, quarantine, or both. Diagnosis is by PCR testing of nasal swabs and whole blood.
The Arizona bulletin notes that EHV-1 is reportable in Arizona, and that horses with neurologic signs should be reported to the Arizona State Veterinarian’s office. Never haul a horse with fever or clinical signs.
Sources: University of Arizona Extension, Equine Herpesvirus-1 (AZ2176); Texas A&M AgriLife Extension, Equine Herpesvirus (ANSC-PU-462)
Horses spread the virus through nasal discharge and airborne droplets in shared spaces such as aisles, arenas, and trailers, and through contaminated stalls, water, feed, tack, and transport vehicles. People can carry it on hands, clothing, and equipment. The virus survives minutes to hours in sunlight and up to 21 days in cool, damp, shaded areas and water sources.
Incubation is 2 to 10 days, and horses can shed the virus before they show signs. Infected horses become lifelong carriers that can intermittently shed without signs, and reactivation can occur during stress such as travel or illness.
Sources: University of Arizona Extension, Equine Herpesvirus-1 (AZ2176); Texas A&M AgriLife Extension, Equine Herpesvirus (ANSC-PU-462)
The University of Arizona recommends taking temperatures twice daily for exposed horses and for all horses returning from travel; isolating new arrivals and horses returning from travel for 14 days (Texas A&M says 14 to 21 days); not sharing tack, buckets, rags, or grooming tools; disinfecting tack and grooming tools daily; limiting visitors; caring for healthy horses before sick ones; and changing clothes or disinfecting after handling sick animals.
When traveling: haul only healthy horses without fever, bring your own labeled buckets, avoid communal water troughs, do not submerge hoses, and keep horses separated in alleys, arenas, and tie areas. Texas A&M also advises removing manure, bedding, and water residue from trailers, stalls, and buckets before disinfecting.
Sources: University of Arizona Extension, Equine Herpesvirus-1 (AZ2176); Texas A&M AgriLife Extension, Equine Herpesvirus (ANSC-PU-462)
Not as labeled. The University of Arizona states that a vaccine is available to help prevent the respiratory form, and that no vaccine is labeled for preventing EHM. It says the AAEP recommends the vaccine for horses that travel or have high movement, with boosters every six months, and that the vaccine can decrease viremia and nasal shedding, which helps reduce spread. Texas A&M does not say the vaccine prevents EHM.
Ask your veterinarian which vaccines and schedule fit your horse.
Sources: University of Arizona Extension, Equine Herpesvirus-1 (AZ2176); Texas A&M AgriLife Extension, Equine Herpesvirus (ANSC-PU-462)
UF/IFAS Extension explains that heaves, recurrent airway obstruction (RAO), and other older terms are now grouped under equine asthma. It most likely results from the lungs overreacting to inhaled allergens, mainly mold, organic dust, and endotoxin in hay, straw, bedding, and pasture. The Merck Veterinary Manual describes it as an allergic lung disease similar to asthma in people.
Onset is usually around ages 9 to 12 according to UF/IFAS, and the disease has a hereditary component.
Sources: UF/IFAS Extension VM142, Understanding Equine Asthma (Heaves); Merck Veterinary Manual, Heaves in Horses (owner version)
Signs include faster breathing, labored breathing out, flared nostrils, coughing (often during feeding or exercise), nasal discharge, and reduced exercise tolerance. Overworked abdominal muscles can form a visible “heave line” along the lower ribs. Mildly or moderately affected horses may look normal at rest but cough and tire during exercise, and young horses may show only exercise intolerance and occasional coughing. Severe cases may involve weight loss, poor appetite, or respiratory distress.
UF/IFAS notes that fever is usually absent unless a secondary bacterial pneumonia develops.
Sources: UF/IFAS Extension VM142, Understanding Equine Asthma (Heaves); Merck Veterinary Manual, Heaves in Horses (owner version)
UF/IFAS says a veterinarian can usually diagnose the condition from the horse’s history and examination. Further tests can confirm and characterize airway inflammation, including endoscopy, bronchoalveolar lavage (BAL), lung function testing, X-rays, and ultrasound. Elevated neutrophils in BAL samples confirm lower airway inflammation.
The Merck Veterinary Manual adds that X-rays may be useful if there is no response to standard treatment after several weeks, or to tell heaves apart from similar conditions.
Sources: UF/IFAS Extension VM142, Understanding Equine Asthma (Heaves); Merck Veterinary Manual, Heaves in Horses (owner version)
Both UF/IFAS and the Merck Veterinary Manual describe reducing exposure to dust and mold as the most important step. Medications can relieve signs, but signs return if the horse stays exposed. UF/IFAS describes the condition as chronic and needing lifelong management.
Environmental points listed include: more time on pasture; avoiding round bales; keeping stalls clean and well ventilated; not storing hay in the loft; limiting sweeping and blowing of dust in barn aisles; avoiding straw bedding in favor of low-dust options; and soaking hay or feed. Severely affected horses may need hay removed entirely in favor of pelleted feed, and the Merck manual advises against housing horses in the same building as an indoor arena. Your veterinarian sets medication choices and dosing.
Sources: UF/IFAS Extension VM142, Understanding Equine Asthma (Heaves); Merck Veterinary Manual, Heaves in Horses (owner version)
UF/IFAS advises calling for any suspected signs so the condition can be diagnosed. It also lists respiratory distress or moderate to severe signs, where medication may be needed; a horse that does not respond to standard therapy; and signs that suggest infection, such as fever, opaque nasal discharge, or abnormal bloodwork.
University of Florida’s general call-the-vet guide also lists chronic cough, breathing difficulty (flared nostrils, distress, or faster breathing), and yellow or green nasal discharge among reasons to call.
Sources: UF/IFAS Extension VM142, Understanding Equine Asthma (Heaves); UF Large Animal Hospital, When It’s Time to Call the Vet
Signs that may indicate gastric ulcers include poor performance, attitude changes, girthiness, sensitivity when touched on the flank or belly, mild intermittent colic, reduced appetite, rough or dull coat, and difficulty maintaining body condition. In foals, signs include grinding teeth, excessive salivation, poor nursing, lying on their back, and diarrhea.
These signs are non-specific — many conditions can produce similar presentations. Gastroscopy (passage of a camera into the stomach) is the only definitive diagnostic test for EGUS. Without a scope, you cannot know whether your horse has ulcers or what grade they are.
Teeth grinding (bruxism) in horses can indicate abdominal pain or discomfort — it is a common sign in horses with gastric ulcers, particularly in foals. It can also be associated with other sources of oral or gastrointestinal discomfort, pain elsewhere in the body, or occasionally stereotypic behavior (habit).
Bruxism combined with other signs — poor appetite, colic, performance changes, or behavioral changes — warrants veterinary evaluation to determine the underlying cause.
Weaving — rhythmic side-to-side swaying of the head, neck, and sometimes the entire front end — is a stereotypy (repetitive behavior) most commonly associated with stress, confinement, and social deprivation. It is most prevalent in stabled horses with limited turnout, social contact, and enrichment.
Weaving is considered a welfare concern — it typically indicates that the horse's behavioral needs are not being fully met. Management changes including increased turnout, social contact with other horses, forage enrichment (slow feeders, multiple small meals), and environmental complexity are commonly used to address it.
A "cold-backed" horse is one that humps up, bucks, or is stiff and resistant when first saddled or mounted, improving after a warmup period. While historically attributed to sensitivity or disposition, cold-backed behavior should be evaluated as a potential sign of physical discomfort.
Common physical causes include saddle fit issues, back pain (including kissing spine), girth sensitivity related to skin conditions or ulcers, gastric ulcers with sensitivity around the girth area, and musculoskeletal pain that resolves as the horse warms up.
Topline development requires adequate protein and energy in the diet, appropriate conditioning exercise, and — crucially — ruling out underlying health reasons for topline loss. Health reasons that can contribute to poor topline include Cushing's disease (PPID), insulin dysregulation, inadequate dietary protein (particularly lysine), dental problems limiting nutrient absorption, and chronic pain conditions that cause the horse to hold the back rigidly and not use the musculature normally.
Exercises commonly used for topline development include hill work, cavaletti and pole work, baited stretches, long and low work encouraging thoracolumbar flexion, and appropriate collection under saddle as fitness develops.