LAT II: Common Equine Diseases

List the equine core vaccines:

• Rabies

• EEE/WEE

• West Nile Virus

• Tetanus Toxoid

The the equine risk-based vaccines:

• Strangles

• EVA

• Potomac Horse Fever

• Influenza

• Rhinonumenitis

List the c/s of botulism?

• Creeping flaccid paralysis

  • starts in the head and moves caudally

  • can cause respiratory paralysis

• Sudden death

• Muscle necrosis

How can we treat botulism?

• Supportive care

• Gastric lavage— if recently ingested

• Antitoxins

How does botulism typically infect patients?

Contaminated feed.

What kind of areas of theh country is Canker usually seen in?

Wet year-round places— south and midwest.

What are the c/s of Canker?

• Odor or friable

• White cottage cheese frog

• Lameness

How can we treat Canker?

• Superficial debridement- a good trim

• Topical antimicrobial agents

How is Lyme disease spread?

Via ticks.

What are common c/s of lyme disease?

• Low-grade pyrexia (fever)

• Depression

• Stiffness

• Lameness— shifting leg lameness

• Loss of appetite

• Joint swelling

• Eye problems

How can we dx lyme disease?

ELISA or IFA.

How can we treat and prevent lyme disease?

Antibiotics

• tetracycline or doxycycline (PO)

Prevention:

• insecticide and vaccination

What is the endemic region for Potomac Horse Fever?

Northern California.

How can we treat potomac horse fever?

Supportive care.

How can we prevent potomac horse fever?

Vaccinate every 6 months and reduce snail numbers.

What is a way that horses can get potomac horse fever?

• Snails.

Potomac horse fever is a concern when what is involved in pastures or trails?

Running water (rivers or streams).

What are some GI c/s you can see with potomac horse fever?

• Anorexia

• Colic

• Colitis

• Decreased GI sounds

• Abortion in mares

• Moderate to severe diarrhea with in 24-48 hours

Clinically ill horses with potomac horse fever are ____ contagious.

Not.

Horses with rain rot are typically seen in areas that are high in what?

High heat and humidity.

What are the c/s of rain rot?

Crusty scabs and matted tufts of hair.

What are the c/s of salmonella?

Carrier, mild clinical, and acute clinical”

• Very profuse diarrhea

How do we treat salmonella?

• Supportive care

• Quarentine!

Why is salmonella a risk?

It is zoonotic.

What is the causative agent for strangles?

Streptococcus equi.

Strangles is most common in:

Horses under 5, foals, and yearlings.

How is strangles transmitted?

• Sharing water buckets

• nose to nose contact through nasal discharge

• contact with people handling an infected horse

How long can Strangles survive in ideal conditions outside the host?

7-9 weeks.

How long are barns considered contaminated after an outbreak of strangles?

2 months.

What are the clinical signs of strangles?

• Lymphadenopathy- submandibular and retropharyngeal

• Cough and thick, mucopurulent nasal discharge

• LN abscesses + rupture

Abscesses or lymph nodes in other areas of the body caused by strangles is called?

Bastard strangles.

What is the causative agent of tetanus?

Clostridium tetani.

How can horses become infected with tetanus?

Contamination of wounds.

What are some c/s of tetanus?

• Sawhorse appearance

• Recumbent

• CNS

• Photophobia- sensitive to light

• Rigid paralysis

• Lock jaw

How can we treat tetanus? What is the prognosis?

• vaccinate- tetanus toxoid

• 50% mortality rate

If a horse has a wound or surgery 3-6 months or more after the tetanus vaccine, should it be boostered?

Yes; immediately.

What are clinical signs of thrush?

• Odor

• Black discharge

• Lameness

How is EPM, Equine Protozoal Myeloencaphalitis, spread?

Sporocysts in opossum’s feces.

What are some c/s for EPM?

• Asymmetric muscle atrophy in glutes and quads

• Cranial nerve abnormalities- variable

Is EPM a reportable disease?

Yes.

How is piroplasmosis spread?

Transmitted by ticks.

What are some c/s or piroplasmosis?

• Pyrexia (fever)

• Depression

• Anemia

• Thirst

• Eye problems

What is the causative agent for piroplasmosis? How does this play into dx?

• Babesia equi.

• It can be seen on RBCs.

What is the most common form of dermatophytosis in horses?

Ringworm.

What are the c/s of dermatophytosis?

Round, small lesions covered with scales.

How can dermatophytosis be dx?

• Wood’s lamp

• Culture

• Histology

What are common c/s of White Line disease?

• Cheesy material

• Air pockets that pack with debris

• Laminitis

• Black, foul-smelling material

How is encephalomyelitis transmitted?

Through mosquitoes.

What are the 2 main types of encephalomyelitis we deal with in the US?

• Eastern— most damaging to horses (50-90% mortality)

• Western

Will horses that recover from encephalomyelitis have lasting neurological signs?

Yes.

What are some c/s of encephalomyelitis?

• Hyper-excitability

• Head pressing

• Circling

How effective is the vaccine against encephalomyelitis?

Very effective.

What season should the encephalomyelitis vaccine be given? Why?

Spring.

Before mosquito season.

How is EVA, Equine Arteritis Virus, spread?

• Contaminated semen

• Venereal transmission

• Artificial breeding

What kind of operations should vaccinate for EVA?

Breeding farm facilities.

What is EIA also known as?

Swamp fever.

How is EIA transmitted?

Bloodsucking insects.

• horseflies and deer flies

What tests look for EIA? How often should this be done? How many states require this?

• Serologic tests

  • Agar gel immunodiffusion

  • ELISA tests

• Coggin’s test

• All 50 states

What are some c/s of EIA?

• Pale MM

• Petechiae

• Icterus

• Neuro signs

• Thrombocytopenia

• Anemia

Is EIA a reportable disease?

Yes.

What type of nasal discharge do you see with equine influenza?

Mucopurrulent

How is equine influenza treated?

Supportive care

• Rest

• NSAIDs

How long is the recovery period for equine influenza?

2-3 weeks

Severe— 6 months.

Why is rabies so important?

• It is zoonotic

• Fatal

• No tx—> euthenasia

How is rabies spread?

Saliva.

Is the rabies vaccination required by law in horses?

Yes—> core vaccine.

Is rabies a reportable disease?

Yes.

What is the causative agent for rhinopneumenitis?

• Equine herpesvirus I

• Equine herpesvirus 4

What are the clinical signs for rhinopneumenitis?

• Mucopurrulent nasal dc

• Abortion

• Paralysis of the tail

How contagious is rhinopneumenitis?

Very contagious.

Where do you commonly see ulcerations with Vesicular stomatitis?

• Oral mucosa

• Coronary band

• Belly

• Muzzle

• Prepuce

• Udder

Is vesicular stomatitis a reportable disease?

Yes.

How is vesicular stomatitis spread?

Via biting flies.

How is west nile virus transmitted?

From avian reservoir host by mosquitoes

What are some c/s of west nile virus?

• Low-grade fever

• Lack of appetite

• Colic

• Personality changes

• Neuro signs

  • Hyperesthesia

  • Cranial nerve deficits

Horses with west nile virus are hypersensitive to what being touched?

Head and neck.

What kind of cranial nerve deficits will you see with West Nile virus?

• Facial paralysis

• Drooping eyelids

• Drooping face

Will horses show residual effects for up to 6 months after surviving west nile virus?

Yes; about 40%.

What is a common sign of Cutaneous Papillomas?

Warts.

How long will the warts resolve after treating cutaneous papillomas?

3-4 months.