Ch. 11: Common Equine Diseases

anthrax

A reportable bacterial disease caused by Bacillus anthracis

Gram + bacillus

Causes sudden death and septicemia

Can affect all warm-blooded animals (including humans)

Vaccine in presence of an outbreak

botulism

"Shaker foal syndrome"; Bacterial disease caused by Clostridium botulinum

Gram + rod, anaerobic, spore-forming

Ingestion through contaminated feed

Survives in soils and marine/freshwater sediments

Causes sudden death and muscle necrosis (prevents release of acetylcholine --> paralysis)

Types B, C, and D most common

High mortality from resp. paralysis

Vax: Series of 3, then consult vet

canker

Chronic hypertrophic, moist pododermatitis of the epidermal tissues of the foot

Caused by Fusobacterium necrophorum or Bacteroides spp.

Seen in South and Midwest

HX of housing in wet areas year round

Characteristic odor and lameness

TX: Superficial debridement and topical ABX

Lyme disease

Bacterial disease caused by B. burgdorferi

Gram - unicellular spirochete

Follows 2 yr enzootic life cycle

Primary vector= Deer tick (female) attaches for > 24 hrs

Common in humid areas w dense veg., May-

August

Signs: Low grade pyrexia, depression, stiffness, lameness, anorexia, joint swelling, eye problems

DX: ELISA

TX: Tetracycline, ORAL doxycycline

Potomac horse fever

Bacterial disease caused by Neorickettsia risticii

Gram - cocci, obligate intercellular bacterium attracted to monocytes

Live inside flukes that infect snails --> larvae eaten by caddis/mayfly --> eaten by horse --> infection

Signs: Depression, D+, fever, toxemia, abortion, laminitis

DX: Feces/blood, PCR

TX: Oxytetracycline, fluids, NSAIDs

Vax: Series of 2, then semiannually

rain rot

Dermatophilus congolensis

Gram + actinomycete, facultative anaerobic

Also infects cattle, sheep, goats, pigs, cats, dogs

Found in high temp/humidity areas

Signs: Crusty scabs, matted hair tufts, yellow/green pus

DX: Culture

TX: ABX, soak/remove lesions, lime sulfur

Salmonella

Bacterial infection caused by Salmonella spp (esp. S. typhimurium)

Gram - rod

DX: Based on signs, neutropenia, and cultures; PCR

TX: IV fluids, electrolytes, plasma, NSAIDS

Zoonotic risk to staff --> quarantine!

carrier Salmonella

Subclinical carriers of Salmonella that intermittently shed the organism

May develop clinical signs if stressed

mild clinical Salmonella

Form of Salmonella infection involving pyrexia, anorexia, depression, and soft watery D+

Clinical signs for 4-5 days but shed organism for days to months after infection

acute clinical Salmonella

Form of Salmonella infection involving watery foul D+, abdominal pain, severe depression, anorexia, and pronounced neutropenia

Dehydrat equickly --> electrolyte imbalances

strangles

Caused by Streptococcus equi

Gram + cocci transmitted through nasal discharge (direct or indirect contact)

Signs: Sudden fever, mucopurulent discharge, abscess of submandibular/retropharyngeal lymph nodes, listlessness, anorexia

May be difficult for horse to swallow

DX: Culture (nasal swab, abscess pus, nasal wash), PCR, serology

TX: Penicillin, rest, palatable food, warm compress, flush (povidone-iodine), isolation, temp taken 2X daily

Prevention: Vax, quarantine new horses

Vax: Series of 4 (inj) or 2 (IN); booster semiannually

bastard strangles

Strangles that has metastasized throughout the body

Found in spleen, kidney, liver, mesentery, lung, brain

Tetanus

Clostridium tetani

Gram + bacillus, motile, anaerobic

Cause: Contaminated wounds (puncture involving rusty metal or manure) or surgical incisions

Incubation: 1-60 days (usually 7-10)

Signs: Generalized stiffness, dyspnea, "sawhorse appearance"

TX: Place horse in quiet dark area, raise food/water, body support, tetanus antitoxin, sedatives, muscle relaxants

Mortality: 50%

Vax: Series of 2 or 3 (depending on vax status of mare); annual boosters

sawhorse appearance

Characteristic stance seen with Tetanus infection caused by stiffness

Head, back, neck, and legs are stiff and tail head is elevated

thrush

Fusobacterium necrophorum

Gram - bacillus

Degenerative condition of the frog (central/lateral sulci)

Caused by unsanitary conditions

Signs: Odor, black discharge, lameness

DX: Clinical signs

TX: Cleaning affected area, antiseptic

EPM

Equine Protozoal Myeloencephalitis

Caused by Sarcocystis neuroma or Neospora hughesi

Carried by opposums; transmitted through consumed feces

Reportable

Signs: Muscle atrophy (quads/glutes), cranial nerve abnormalities (self-mutilation of tongue), recumbency

DX: ID of characteristic lesions, parasites on necropsy

Antemortem tests of serum/CS fluid

TX: Antiprotozoal drugs, NSAIDS, vitamin E, limit access to opossums

piroplasmosis

Babesia equi and B. caballi

Protozoans transmitted by ixodid ticks (Dermacentor nitens), esp. in tropical/subtropical and temperate regions

Protozoans invade RBCs

Signs: Pyrexia, depression, anemia, thirst, eye problems, yellow/red urine

Prevention: Tick control, sterilization of needles/instruments

Mortality: 10-15%

DX: Blood smears, complement fixation tests, ELISA, PCR

TX: Imidocarb dipropionate, tetracyclines, etc

Dermatophytosis

Ringworm

Trichophyton and Microsporum spp. of fungi

Superficial cutaneous fungal infection (invasion of stratum corneum)

Highly contagious, direct/indirect contact

Can survive on equipment for 12 months

Signs: Small round lesions covered w small scales

DX: Wood lamp, culture, histologic exam

TX: Povidone-iodine, sulfur dip, antifungals, captan, thiabendazole ointment

Treat environment w dilute bleach

white line disease

Caused by bacterial, fungal, or yeast infection in the inner horn

Fungal = Onychomycosis

Signs: Hoof fills with cheesy material, lameness, warm soles, black foul-smelling substance

TX: Resection of underlying hoof wall, topical antiseptic

encephalomyelitis

Caused by equine alphaviruses

3 types: Eastern, Western, Venezuelan

Transmitted by mosquitoes

Neurologic disease

Signs: Fever, ataxia, anorexia, paralysis, circling, head pressing, hyperexcitability

No known TX; supportive therapy

Vax: Series of 3, 1 mo. apart; annual boosters in Spring

equine viral arteritis

Caused by equine arteritis virus (EAV)

Signs: Flulike symptoms, abortion, pneumonia in foals

Transmitted through resp. particles or venereally

Infected semen primary source

Stallion= natural reservoir

Incubation= 2-14 days

DX: Virus isolation, paired serum samples, viral antigen, viral nucleic acid detection

TX: NSAIDs, antipyretics, diuretics, rest

Castrate infected stallions

Vax: 1 dose after 6 mo. in intact breeding stallions; annually if still breeding

EIA

Equine infectious anemia (aka swamp fever)

Caused by equine infectious anemia virus (EIAV), a lentivirus

Transmitted through blood-sucking insects

Signs: Fever, lethargy, anorexic, pale MMs, petechiae, icterus, neurologic signs, thrombocytopenia, anemia

No specific therapy

REPORTABLE

Quarantine or euthanasia

Coggins Test

Coggins testing

Serologic testing performed for the diagnosis of Equine infectious anemia

equine influenza

Orthomyxoviridae

Often spread at rodeos and horse shows

High morbidity, low mortality

Incubation: 48 hrs

Targets lower resp. tract

Signs: Fever >106 F, anorexia, weight loss, mucopurulent nasal discharge, increased RR, retropharyngeal lymphadenopathy

DX: Virus isolation, immunoassay, PCR, antibody detection

TX: Supportive; rest, hydration, NSAIDs

Vax: Inactivated inj= series of 3, then every 3-4 months

MLV Intranasal= 1st at 11 mo, then q 6 months

Rabies

Infection caused by rhabdovirus (enveloped RNA virus)

Transmitted through bites for infected skunks, raccoons, foxes, bats (saliva)

Signs: Ataxia, lameness, loss of bladder control (GI/neuro signs)

No TX

DX postmortem (spinal cord and brain)

Vax: Series of 2 or 3; booster annually

rhinopneumonitis

Caused by equine herpesvirus type 1 and 4 (EHV-1 and EHV-4)

Signs: Mucopurulent nasal discharge, lymphadenopathy, coughing, abortion, scrotal edema, loss of libido in stallions, reduced sperm quality, ataxia, fever, loss of anal tone, tail paralysis, urinary incontinence, recumbency

DX: Postmortem PCR

TX: Isolation of horses w resp. form; all other cases treat w supportive care

Vax: Series of 3 (1 mo. apart), then q3-4 months or annually

vascular stomatitis

Rhabdoviridae familiy

Transmitted through insects (black fly, sand fly, mosquito, housefly)

Incubation= 3-7 days

Signs: Initially fever and excessive salivation --> white fluid-filled areas on oral mucosa --> ulceration

Vesicles and lesions form on other areas (coronary band, belly, muzzle, prepuce, udder)

DX: Antibody detection, viral isolation

TX: Limited b/c horses recover usually within 7-14 days; supportive care in severe cases

West Nile virus

Caused by virus in Flaviviridae family

Spread by mosquitoes after biting infected birds

Signs: Low grade fever, inappetence, depression, colic, personality changes, unresponsiveness, coma

Many show signs of recovery in 3-7 days and fully recover in 1-6 months

DX: IgM ELISA of CS fluid, plaque reduction neutralization test (PRNT) of serum, PCR of brain tissue

TX: Supportive

Reportable disease if neurologic

Remove stagnant water to keep mosquito pop. low

Vax: 1st at 3-4 mo, 2nd 1 mo. later, 3rd dose at 6 mo; annual booster

cutaneous papillomas

Equus caballus papillomavirus type 1

Warts that appear around the lips and muzzle, but also the eyelids, prepuce, inner thighs, and distal limbs

Spread by direct contact (horse shows, sales, breeding) or fomites

Usually harmless until irritated by tack

Usually resolve in 3-4 months

If not gone in 6-9 months, indicates autoimmune deficiency

Can be removed by cautery or cryosurgery

choke

Noninfectious

Occurs when feedstuffs become lodged in the esophagus

Causes: Inadequate water intake, large particles, quick eating, dry food

COPD

Chronic Obstructive Pulmonary Disease, or "heaves"

Noninfectious resp. disease

Cause: Air pollutants (dust, mold), diet, genetic linkage, HX of resp. tract infection

Mor common in horses >6 y.o.

Signs: Dyspnea, abd. breathing, nasal discharge, cough, lack of stamina, hyperpnea at rest

Some have summer-pasture associated

DX: HX, clinical signs, endoscopy, trach wash (neutrophils), culture

TX: Remove resp. irritants from environment

heave line

A ridge along the costal arch that may develop in horses with COPD due to chronic abdominal breathing

colic

Abdominal pain

4 Causes:

1) Gut distention (fluid, sand, gas, ingesta)

2) Pulling at root of mesenteric artery (torsion, hernia, tumor)

3) Ischemia/infarction (torsion, thrombus)

4) Enteritis/ulcers (inflammation of GI tract from stress, disease, parasites)

Signs: Repeating standing/lying down, rolling, kicking @ abd., pawing, looking at abd., grunting, sweating, distention, positioning to urinate, tenesmus, decreased BMs, tachypnea, flared nostrils, abnormal behavior, inappetence

DX: Exam, HX

TX: Place NG tube to administer mineral oil/pain meds, hand walking, continued monitoring, IV fludis, abd SX

Prevention: Establish and adhere to set routine, high quality forage, small freq. meals, deworming, daily exercise, avoid meds, inspect feeds, reduce stress, elevate feed

Cushings syndrome

Hyperadrenocorticism

Usually secondary to adenoma or hyperplasia

Signs: PU/PD, long/thick/curly coats, failure to shed in spring, dull coats, sway back, pot belly, laminitis, fat deposition in supraorbital fossae, weight loss, polyphagia, depresison, increased sweating, loss of back muscle tone

May be diabetic

DX: ACTH test, insulin/BG test

TX: Cyproheptadine, pergolide mesylate

EIPH

Exercise induced pulmonary hemorrhage ("bleeders")

Hemorrhage that originates from small pulmonary vessels associated with strenuous exercise

DX: Endoscopy

TX: Rest to allow lesions to heal, furosemide, nasal strips, nitric oxide, bronchodilators, procoagulants, antiinflammatories, omega 3 FAs

exertional rhabdomyolysis

Necrosis of the striated skeletal muscle associated with exercise

"Cording up/Tying up"

Can be sporadic or chronic

sporadic exertional rhabdomyolysis

"Cording up" that occurs when a horse is asked to perform for long periods or perform heavy exercise when not in condition to do so

Other causes: Deficiencies of vit. E, selenium, Na or Ca

Signs: Muscle cramps, refusal to move, increased RR/HR, excessive sweating

DX: Increased serum creatine kinase and aspartase aminotransferase (AST)

TX: Stall rest, fresh water, hay diet, correct fluid balance + diuretics

Prevention: Proper conditioning and balanced diet

EPSM

Equine polysaccharide storage myopathy

Form of chronic exertional rhabdomyolysis

Seen in draft horses, Quarter Horses, warm bloods

INHERITED

Signs: Camped-out stance, sweating, hindlimb stiffness, abnormal gait, reluctance to move, loss of muscle mass, weakness

DX: Increase CK and AST, signs, muscle biopsy, CBC, UA, exercise testing

TX: Forage diet at 1.5-2% of BW, limit starch to <10%, increased fat (horse is more sensitive to insulin)

Gradually introduce exercise

recurrent exertional rhabdomyolysis

Form of exertional rhabdomyolysis seen in Thoroughbreds, Arabians, and Standardbreds

Caused by autosomal dominant trait (TBs) or improper reg. of intracellular Ca in skeletal muscle

Signs: Muscle stiffness, sweating, refusal to move

DX: CBC/chem, UA, exercise testing, blood vit. C/selenium levels, muscle biopsy

TX: Reduce anxiety, high caloric intake, dantrolene, phenytoin

HYPP

Hyperkalemic periodic paralysis

Form of recurrent exertional rhabdomyolysis

Autosomal dominant trait associated with Quarter horses + their crosses, Appaloosas, and American Paints

Diagnosed between birth and 3 y.o.

Signs: Not always shown; may include muscle weakness, twitching, dog sitting, staggering, periodic URI obstruction, recumbency

TX: Light exercise, corn syrup, grain, calcium gluconate, sodium bicarbonate, trach tube (if URI obstruction)

Prevention: Decrease dietary K (avoid beets/molasses, alfalfa, brome hay, soybean oil/meal, canola oil); feed beet pulp, corn, oats, barley, late cut Timothy hay/Bermuda grass

Feed several small meals

Meds: Acetazolamide, hydrochlorothiazide

habronemiasis

Summer sores; characterized by granulomatous lesions caused by larvae of Habronema spp or Draschia megastoma

Seasonal with fly pops.

Common with high heat/humidity areas, or poor sanitation

DX: Location and characteristics of lesions (found on glans penis or urethral process), time of yr, histopathology

TX: Kill parasites (ivermectin, others), decrease inflammation, ABX

hernia

Protrusion of internal organ through the wall of its containing cavity

Intestines, umbilical, scrotal, inguinal

Usually self-correcting, but may perform surgery after foal is weaned

hypothyroidism

underactivity of the thyroid gland

Causes: Low T3/T4

Signs: Slow shed or absence, long rough hair coat, cold intolerance, depression, weakness, lack of muscle tone, tying up, laminitis, infertility, irregular heat cycles, lack of milk production, goiter

Can be congenital in foals (caused by low iodine diet by mare during pregnancy)

DX: CBC, serum chem, TSH stim test

TX: Supplemental T3/T4 through feed additives

lameness

incapable of normal locomotion; failure to travel in regular and sound manner

Causes: Structural or functional disorder of one or more limbs or of the trunk

Can be associated w pain

Weight-bearing, non weight-bearing, mixed, compensatory/complementary

DX: HX and exam, local anesthesia, rads, ultrasound, scintigraphy, MRI, arthroscopy, synovial fluid analysis, electromyography, muscle biopsy

Watch head (will rise when lame forelimb is bearing weight) or croup (raise on lame hindlimb side)

weight bearing lameness

Animal tries to decease weight placed on affected leg by taking shorter steps, leaving leg on ground for shorter time, and elevating body

Often associated w injuries to motor nerves, ligaments, tendons, bones, and feet

non weight bearing lamenss

Swinging leg disorder

Seen as animal brings leg forward

Associated w joints, muscles, extensor tendons, bursasa, and tendon sheaths

mixed lameness

Lameness that affects both weight-bearing phase of gait and the swinging phase

complementary lameness

Aka compensatory lameness

Develops as compensation for originally affected limb

predisposing lameness

Lameness that results from a factor that predisposed the horse to lameness

Includes poor shoeing, systemic disease, faulty conformation, poor condition, immaturity, and poor hoof care

inciting lameness

Lameness as a result of trauma

Trailer accidents, kicked by another horse, incoordination

laminitis

Inflammation of the sensitive laminae of the foot

Causes: Endotoxin-induced microthrombosis, altered vascular flow, vasoconstriction, enzyme destruction, grazing during certain months, grain overload, GI inflammation, metritis, retained placenta, endotoxemia, sepsis, pleuropneumonia, Cushing's, prolonged weight bearing, black walnut exposure

subacute laminitis

Mild form of laminitis

Causes: Riding on hard surfaces, hooves trimmed too short, black walnut

Signs resolve quickly without permanent damage

Usually no coffin bone rotation

acute laminitis

More severe laminitis

Disease does not respond rapidly to TX

Likely coffin bone rotation

TX: To prevent chronic form of disease; includes antiendotoxin therapy, vasodilators, anticoagulants, corrective trimming, SX

refractory laminitis

Form of acute laminitis that doesn't respond within 7-10 days of TX

Signs: Increased digital pulse, lifting feet every few sec, lameness, camped-out stance, pain

chronic laminitis

Continuation of acute stage of laminitis

First signs of coffin rotation

Early= begins with rotation of coffin (days to months)

Chronic active= Coffin is rotated but unstable and could penetrate sole

corns

Bruises of the soft tissue underlying the sole that cause development of reddish discoloration

Causes: Work on hard surfaces, flat soles, stepping on small objects

TX: Rest, drying of abscess, soaking in Epsom salts, prevent infection

navicular syndrome

Syndrome that causes signs associated w navicular region

Predisposing conditions= Hard work, small feet, heels trimmed too low, upright pasterns

Signs: Intermittent lameness in horses between 4-15 y.o., shor choppy stride, pointing of affected toe

TX: Special shoeing, cutting of navicular nerve

nerved

A horse that has had its navicular nerve cut to treat navicular syndrome

These horses can't be used for hard work and can be dangerous to ride (can't feel ground)

1/2-1 inch scars above bulbs of front feet

quittor

A deep-seated sore that drains at the coronet

Causes: Corns, puncture wounds, chronic inflammation of collateral cartilage of distal phalanx

sand cracks

Toe cracks/quarter cracks/heel cracks

Vertical cracks in the hoof wall

Causes: Dryness/brittleness of the hoof, injury to coronet, long hoof walls

TX: Burning crescent at tip of crack, filing groove across the tip, corrective shoeing, commercial sealants

Prevention: Keep hooves moist with hoof dressing and regular trimming

grease heel

Dermatitis verrucosa

Chronic seborrheic dermatitis of the plantar surface of the fetlock or pastern

Usually found on hindlimbs; can also affect palmar surface of fetlock on forelimb

Greasy, foul-smelling lesions

May have lameness

Prevention: Good housing conditions

TX: Clipping hair and cleaning with soap/water, topical antiseptic

TBX, tetanus prophylaxis (if cellulitis develops)

seedy toe

"Hollow wall" or dystrophia ungulae

Condition that occurs secondary to laminitis

Palmar hoof surface contains hollow space that varies in size

Mealy substance found inside hollow space

TX: Clean area and pack with juniper tar and oakum

side bone

Ossified lateral cartilages located proximal to the rear quarter of the hoof head

Often on forelimbs, on one or both legs, and on either or both sides of the hoof

Unknown cause

Horse may become lame

TX: Rest, NSAIDs

bucked shins

Found in horses 2-3 y.o. that are involved in intense training

Temporary unsoundness originating at dorsal surface of the cannon bone --> inflamed periosteum

Pain and lameness

TX: Rest for 30-60 days

Prevention: Gradual increase in exercise

splints

Abnormal or new bone growth that occurs on the splint bones or cannon

Causes: Strain/trauma to the interosseus ligament between splint bones and cannon, conformation faults

Influs of blood supply

Signs: Subtle lameness, pain, heat at palmar cannon surface, lump on cannon

Sweeney

Any group of atrophied muscles

No known TX

In shoulder muscles, associated with nerve over the shoulder crossing the spinal cord

shoe boil

"Capped elbow"

Soft swelling at the elbow caused by irritation

Causes: Injury from long heel on a front shoe, or from contact with surface horse is laying on

TX: Tincture of iodine, shoe boil boot/roll

Prevention: Don't leave long heels on front shoes

bone spavin

Distal tarsal osteoarthritis

New bone growth on the medial/proximal end of the 3rd metatarsal/tarsal and central tarsal bones

Causes: Faulty conformation

Signs: Pain on hock flexion, rolled hip during mvmt, toe dragging

TX: SX; full recovery not always possible

curb

Fullness of the plantar surface distal to the hock

Causes: Enlarged plantar ligament due to poor conformation, hard stops, or long sliding stops

stringhalt

Involuntary flexion of the hock during forward mvmt

May affect one or both hindlimbs

Cause: Nerve degeneration

Signs: Jerking of leg toward abdomen w mvmt

TX: SX to remove part of lat. digital extensor tendon

ringbone

New bone growth that occurs on the proximal, middle, or distal phalanx

Most commonly on forelimbs, but can occur on hindlimbs

Causes: Poor conformation, heavy work for years, excessive pulling on ligaments --> disruption of periosteum

Classified by location on bone or by joints involved (high, low, periarticular, or articular)

Articular always causes lameness (involves joint surface)

sesamoiditis

Inflammation of proximal sesamoid bones

Horse doesn't extend fetlock to normal level

Inflammation and pain of fetlock

May involve periosteum damage and new bone growth

osselets

Inflammation around fetlock joint

Causes: Strain or concussion on immature bones

Upright pasterns can predispose

Inflamed area feels like putty (hemorrhage/fluid)

Short, choppy stride

Arthritic condition

windpuffs

"Wind galls"

Enlargement of the fluid sacs around the pastern or fetlock

Can occur on any limb

Causes: Hard work or work on hard surfaces

TX: Cold packs over "puff", topical liniment

Reappears when horse is exercised

Not serious

bog spavin

Filling of the natural depression of the dorsal surface of the hock; chronic distention of the jiont capsule

Causes: Faulty conformation (too straight in hock joint), trauma

carpal hygroma

"Popped knees"

Traumatic bursitis of the carpus

Sudden onset due to strain/sprain on ligaments that hold carpal bones of knee in place

Damage to joint capsule --> fluid fills area

capped hock

Traumatic bursitis of the hock --> enlargement

Caused by bruising

TX: Tincture of iodine to reduce size

bowed tendon

Hemorrhage inside tendon sheath due to severe strain (superficial or deep flexor tendon)

Occurs in fatigued horses, usually on forelimbs

Thickened palmar surface of cannon

thoroughpin

Tenosynovitis of the tarsal sheath

Soft, puffy area of hock caused by trauma or tendon strain

Excess buildup of synovial fluid

TX: Pressure and massage of area

patellar luxation

Displacement of the stifle

Usually moves upward and to inside

Can be replaced

Recovery more likely if young

physitis

Enlargement of the growth plates of certain long bones

Affects young, rapidly growing foals (4-8 mo. old)

Unknown cause

Signs: Enlargement of distal radius, tibia, and 3rd metacarpal/tarsal

TX: Change foal's ration, limit exercise, NSAIDs

subchondral cystic lesions

Bone cysts

Articular or nonarticular

May not always produce lameness

TX: Normal bone remodeling, intraarticular meds

Usually in horses <3 y.o.

Most common sites= stifle, pastern, coffin, elbow

melanomas

Benign growths of the tail and anus, and the head of gray horses

8-% of gray horses >15 y.o.

TX: SX removal

Can become malignant and invade vital organs

recurrent uveitis

aka periodic ophthalmia, or moon blindness

Recurrent inflammation of uveal tact in one/both eyes (iris, ciliary body, choroid)

Causes: Bacterial/viral infection, parasites, trauma; LEPTOSPIROSIS

Appaloosas predisposed, Standardbreds at reduced risk

Signs: Blepharospasm, conjunctival/ciliary injection, lacrimation, vascularization, hypopyon, swollen dull iris, vitreal inflammation,

Can cause secondary conditions of eye

Common cause of cataracts

DX: Clinical signs, serum for lepto. titration, conjunctival biopsy

TX: Reduce inflammation (corticosteroids), ABX

Prognosis variable

roaring

Laryngeal hemiplegia

Whistling/wheezing when respiration is increased

Usually associated with inspiration

Causes: Broken rings in trachea, paralysis of muscles controlling vocal cord tension

Can usually be surgically corrected

wobbler syndrome

Compression of spinal cord in neck region

Identified between birth and 4 y.o

Incoordination begins in hindlimbs and becomes worse

True wobblers will not improve

May be genetic

Can be caused by equine degenerative myeloencephalopathy or deficiency of vitamin E during rapid growth phase

sarcoids

cutaneous tumors of fibroblastic origin

Linked to bovine papillomavirus type 1/2

Can develop anywhere; appearance varies with type

6 recognized types

DX: Histopathology

TX: SX excision (recurrence likely), chemo, imiquimod, irradiation

toxins

Ionophores, Yew poisoning, poison hemlock, red maple leaf, oleander toxicosis, blister beetles, Bracken fern, yellow star thistle, tansy ragwort

Signs vary, but usually include neuro, CV, MS, colic

parasites

Includes large/small stongyle, pinworm, bot flies, ascarid/roundworm, stomach worm, threadworm, tapeworm, apicomplexa, lice, flies, mites, ticks

persistent patent urachus

Urine passes through urachus after 48 hrs of age

TX: Keep umbilicus clean and dry, antiseptics, monitor rectal temp, ABX, closure of urachus

septic foal

Neonatal bacterial septicemia

Most common cause of morbidity in foals from birth to 7 d.o.

Mortality- 75%

Cause: Failure of passive transfer of antibodies

Can be acquired before or after birth

Usually gram - (E. coli) or Strep/Staph

May be multisystemic

DX: Blood culture, aerobic/anaerobic culture

TX: Systemic ABX (after C/S results), antiulcer meds

premature foals

Delivery before gestational age of 320 days

Signs; Small size/BW, weakness, delayed time to stand, poor suckling reflex, silky hair coat, floppy ears, prominent forehead, hyperextension in fetlocks

No specific therapy

dummy foals

Neonatal maladjustment syndrome, or asphyxia

Foals lose suckling reflex by 24 hrs old

Causes: Low O2 levels during birth (cerebral edema and hemorrhage)

Signs: Neuro

TX: Supportive care

Anaplasma

Tick borne bacterial disease similar to Lyme, but causes higher grade fever

Clear leg edema present