Recognizing and Managing
Common Health Problems
of Horses
F.C. Faries, Jr., DVM, MS
Texas AgriLife Extension Service
Texas A&M System
College Station, Texas
Cutaneous (Skin) Problems
 Rain Gall
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Fungus (Dermatophilus)
 Summer Itch
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Face-neck allergy
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Gnats (Culicoides, Simulium)
Skin Worms (Onchocerca)
Mane-tail allergy
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Gnats (Culicoides)
 Summer Sores
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Stomach worms (Habronema)
Skin wounds
Mucous membranes
 Proud Flesh
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Wounds (irritation)
Rain Gall, Dew Poisoning (Cutaneous
Dermatophilosis, Streptotrichosis)
 Agent – fungus (Dermatophilus)
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Actinomycete
 Transmission – mechanical

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Vector – stablefly
Vehicles – instruments
 Season – April – October (Summer)
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(rain, hot, high humidity, sweat, dew)
 Effects – Serum Dermatitis
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Inflammation – crusts (paint brushes)
Lower legs, thighs, croup, poll
(areas sweat, areas wet + fly bite)
 Recovery – suppression November – March
(Winter)
(activates annually)
 Diagnosis – paint brush lesions
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Culture
 Management
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Dry conditions
Bathe (remove lesions)
Drying solution
Summer Itch (Gnat Allergy)
 Agent – gnats (Culicoides, Simulium) (Eggs,
larvae, pupae – water, mud, decayed
vegetation)
 Season – April – October (Summer)
 Effects – allergic dermatitis
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Hair loss
Inflammation – papules, vesicles, pustules,
scabs
Pruritus – self trauma
Face, neck, chest, armpits, ventral midline,
flanks

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Ears
Mane, tail
Reaction to saliva (hypersensitive horses)
 Recovery – November – March (Winter)
(recurs annually)
 Diagnosis

Skin biopsy
 Management
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Reduce gnat exposure

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Stall – Daylight to 10am
– 4pm to dark
Fans, smoke, screens
Skin oil – prevents biting, promotes healing
(petroleum jelly, glycerin)

Insecticides, repellents
Summer Itch (Cutaneous
Onchocercosis)
 Agent – Onchocerca microfilariae
(Adults – ligamentous tissues – withers, legs,
spleens – nonpathogenic)
 Vector – common gnat (Culicoides)
 Season – April – October (Summer)
 Effects – allergic dermatitis
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Hair loss
Inflammation – papules, vesicles, pustules,
scabs
Pruritus – self trauma
Bilateral symmetrical – face, neck, chest,
armpits, ventral midline, flanks
Reaction to dead microfilariae in only
hypersensitive horses (universal infections)
 Recovery – November – March (Winter)
(recurs annually)
 Diagnosis

Skin biopsy
 Management

Reduce gnat exposure
Summer Sores (Cutaneous
Habronemiasis)
 Agent – stomach worm larvae (Draschia,
Habronema)

Adults – stomach
 Vector – common housefly, stablefly
(Eggs, larvae, pupae manure, stall bedding, hay
waste, decayed vegetation)
 Season – April – October (Summer)
 Effects – granulomatous lesions
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Skin wounds
Wet tender irritated skin
Conjunctiva, prepuce, penis, vagina
Proud flesh – hypergranulation of tissue
Aberrant larvae – irritates tissue
Worsens


rubbing (pruritus)
irritation (flies, gnats, grass, tail)
 Recovery – noncomplete healing in winter,
reinfection in summer
 Diagnosis

Biopsy
 Management

Control flies
Digestive Problems
 Foot founder (Bahia grass)
 Colic (cold front)
 Tying-up (oats feed)
 Chronic diarrhea (low roughage)
 Foal diarrhea (Strongyloides)
 Stumpsucker (boredom) (low roughage)
 Cribber (boredom) (low roughage)
 Bark chewing (hypervitaminosis)
 Ankle swelling (sodium imbalance)
Infectious Disease Problems
 Sleeping sickness – Encephalomyelitis
 EIA – Equine Infectious Anemia
 Rhinopneumonitis
 Influenza
 Lockjaw – Tetanus
 Strangles (Streptococcus)
 Salmonellosis (Salmonella)
 PHF – Potomac Horse Fever (Ehrlichia)
 EPM – Equine Protozoal Myeloencephalitis
West Nile Encephalitis
 In U. S.

A reportable disease
 Viral Bird Disease – >100 Species


Blue jays, crows, hawks
Encephalitis death
 Transmissions
 Virus in bird blood
 Mosquito (>75 species) bite bird
 Virus in 1% mosquito salivary glands – 10 to 14 days
later
 Mosquito bite bird - virus in blood (carrier)
 Mosquito bite mammal – virus not in blood (dead end)
 1% horses and people – encephalitis (death or recovery)
 30% encephalitis horses – death (2 wks to 6 mos)
 6% encephalitis people – death
 Incubation Period

3 to15 Days
Horse WNE – Rabies Symptoms
 Virus in brain
 Stumbling, staggering wobbling
 Leg weakness – falling
 Difficult rising – dog sitting
 Muscle twitching
 Horse WNE Diagnosis

Blood, postmortem brain
 Horse WNE Vaccination


Innovator® WNE killed vaccine (Ft Dodge)
Recombitex® WNE recombinant vaccine
(Merial)
Attack Mosquito Breeding Sites –
Standing, Stagnant Water
 Attack mosquito breeding sites


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Standing, stagnant water
Eliminate junk (cans, jars, buckets, tubs, pots,
tires)
Treat troughs, bird baths, low areas (Bt
Mosquito Dunks®)
Swamp Fever (Equine Infectious
Anemia) (EIA)
 Agent – virus (Lentivirus)
 Transmission – mechanical


Vector – horsefly, deerfly
Vehicles – needles, instruments
 Season
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Peracute, acute – summer
Chronic – year around
Inapparent – year around
 Effects – anemia
 Peracute, acute – death
 Chronic – emaciation
 Inapparent – possible fever attacks
 Recovery
 Lifetime infections (chronic, inapparent)
 Diagnosis
 AGID (Coggins), CELISA serology
 Management
 Reportable to TAHC
 Disposal or quarantine
Hereditary Problems
 HYPP

Hyperkalemic Periodic Paralysis
(Gene Defect)
Horse Health Management Practices
 Shelter Management
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Adequate housing
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Open sheds
Stalls (12’ x 12’)
Proper ventilation
Protect against heat and cold
Adequate exercise
 Environmental Management
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Prevent overcrowdedness
Maintain cleanliness
Maintain dryness
Utilize composts
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Stall bedding disposal
Manure disposal
Hay waste disposal
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Reduce dust
Proper ventilation
Protect against heat and cold
 Nutritional Management
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Adequate forages

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Grass and/or hay
Required supplements

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Concentrates (grains)
Protein supplements
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Free choice salt
Clean water
Proper hay/grain storage

Dry and rodent free
 Insect Management (horseflies, deerflies,
stableflies, houseflies, mosquitos, gnats)
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Utilize composts
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Stall bedding disposal
Manure disposal
Hay waste disposal
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Proper drainage
Maintain dryness
Routine insecticide applications
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Premise chemicals (sprays, baits)
Animal chemicals (sprays, dusts, repellents)
 Worm Management (strongyles, roundworms,
pinworms)
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Prevent overcrowdedness
Maintain cleanliness
Utilize composts
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Stall bedding disposal
Manure disposal
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Maintain dryness
Proper drainage
Separate age groups
Routine deworming (1 to 12 times per year or
continuous)
 Infectious Disease Management
 Avoid exposures

Isolate sick
 Diagnose and treat
 Diagnose and dispose
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Quarantine exposed (2 to 8 wks.)
Adjacent premise buffer zone
Separate needles for injections
Disinfect instruments (tattoo, bits, floats, twitch)
Insect management
Rodent management
Separate feed-water utensils in travel
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Separate age groups
Provide immunizations
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WNV (1 to 2 times per yr.)
VEWT (1 time per yr.)
Flu (1 to 6 times per yr.)
Rhino – respiratory/live (1 to 6 times per yr.)
Rhino – abortion/killed (5, 7, 9 mo. pregnancy)
Strangles – high risk (1 time per yr.)
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Care for new entry

Prior to entry (3 to 6 wks.)

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Pre-purchase exam
Tests (EIA)
Immunizations
Deworm
After entry (immediately)
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Post-purchase exam
Tests (EIA)
Isolate (2 wk. minimum)

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Annual physical examinations
 Tests (EIA) (1 to 4 times per yr.)
 Dental care (1 to 2 times per yr.)
 Foot care (1 to 6 times per yr.)
Integrated management practices
 Shelter
 Environmental
 Nutritional
 Insect
 Worm
 Infectious disease

Identify sources
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Horses
Other animals
Environment
Vehicles
Vectors
Normal Vital Signs
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Respiratory Rate
Heart Rate
RR:HR Ratio
Hydration
Capillary Refill
Mucous Membrane Color
Sweating
Strength
Temperature
8 – 24
36 – 48
1:4 – 1:2
1
1
Pink
None – Slight
Strong
99 – 100
Stress Vital Signs
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Respiratory Rate
Heart Rate
RR:HR Ratio
Hydration
Capillary Refill
Mucous Membrane Color
Sweating
Strength
Temperature
>40
>72
1:1 – 2:1
>3
>3
Pale-Blue
Excess
Weak
>105