WHAT YOU NEED TO KNOW ABOUT


CONTAGIOUS DISEASES


YOU CAN GET FROM YOUR HORSE

BY  NICOLE  KITCHENER


There are indeed some diseases that can be transmitted from horses to humans. Diseases that are communicable between animals and humans are called zoonotic. Luckily, most of those we can catch from horses are avoidable with good sanitation and biosecurity, although some can be quite dangerous.


ZOONOTIC DISEASES


People who work with or spend time around horses should be aware of the zoonotic diseases that exist and be ready to deal with them if necessary.



LEPTOSPIROSIS


What is it?


A bacterial infection linked to abortion in pregnant mares and the chronic eye condition equine recurrent uveitis (ERU or moon blindness). The spiral-shaped bacteria, Leptospira, are highly capable of movement, allowing them to spread through the bloodstream and affect various organs. 


Symptoms

Mild illness: fever, lethargy, loss of appetite

Rarely kidney and/or liver failure

Respiratory distress

Mid- to late-term abortion

Birth of weak foals

Eye swelling, light sensitivity, excessive tearing, discharge, cloudiness, redness, muscle spasms, blindness


Transmission

Shed in urine, blood and other discharges of infected animals, leptospirosis is transmitted by direct contact with mucous membranes and broken skin, but most often by eating or drinking food or water contaminated by wild animals. Foals can be infected in-utero. 


Carrier Status

Infected animals may shed bacteria for at

least a year.


Diagnosis

Blood or urine tests.


Treatment

Antibiotics


Eye symptoms: topical steroids to reduce inflammation, atropine to dilate the iris and relieve muscle spasms, photosensitivity and other symptoms


Incubation

One to three weeks.


Illness Duration

Ranging from mild illness lasting a few days, to chronic effects. 


Disease-specific Prevention

Control wildlife population around barns and pastures, especially at feed and water sources.

Eliminate standing water.

Vaccine: Lepto EQ Innovator, released late 2015.


Effects on Humans

Flu-like symptoms, vomiting, diarrhea

More seriously: jaundice, kidney or liver failure, meningitis and rarely death


Most Common Route of Contagion

Direct contact with urine from infected animal via open skin or mucous membranes.


Treatment for Humans

Antibiotics



Busy barns, with lots of horse and human

traffic on and off property, are particularly

at risk of picking up and passing around

contagious illnesses. Be sure to institute

biosecurity rules, such as having those visiting

from other farms disinfect their hands and feet

before entering your barn.



SALMONELLOSIS

What is it?


An intestinal infection caused mainly by the bacteria strain Salmonella typbimurium in horses.


Symptoms

Moderate to severe watery diarrhea; may be foul-smelling or contain blood

Loss of appetite

Lethargy

Dehydration

Weakness

Colic

Organ failure and death, particularly in foals



[Clean and disinfect stalls regularly, especially after a sick horse has used the space]


[If illness is suspected, take precautions to protect yourself while treating your horse. Wear gloves and/or wash and disinfect your hands thoroughly]


Transmission

Excreted through feces, salmonella is usually transmitted orally when horses consume contaminated water or food, but it's also spread indirectly via contaminated items such as grooming and stable supplies, tack and clothing. The bacteria can live for months to years in warm, moist environments.


Carrier Status

Many horses shed salmonella for many months post-illness. Others carry it without falling ill. Sickness and stress can fuel shedding. 


Diagnosis

Fecal sample cultures


Treatment

Fluid, electrolyte therapy

Ami-inflammatories to reduce shock, prevent laminitis

Antibiotics (although controversial as some experts believe they aren't effective, may reduce helpful intestinal microflora and promote drug resistance)


Incubation

About seven to 10 days.


illness Duration

Five to seven days.


Disease-specific Prevention

Minimize stress and illness; institute day-to-day biosecurity protocols

Vaccine: Aren't widely commercially available


Effects on Humans

Diarrhea

Vomiting

Stomach cramps

Fever


Most Common Route of Contagion

Oral transmission of fecal matter from

affected horse or contaminated objects

(mainly due to poor hand washing

practices).


Treatment for Humans

Re-hydration



Some diseases can be transmitted from horses to humans through contact with urine and feces.



……………………………………………………………………………………

PREVENTING CONTAGION: 

EVERYDAY BIOSECURITY 

PRACTICES


Incorporating biosecurity protocols into everyday barn life can help prevent and minimize the risk of transferring diseases. Your veterinarian can help develop a plan that's appropriate for you. In the meantime, here are some basics to consider.


AT HOME


Vaccinate to increase resistance to many contagious diseases.

Each horse should have its own bucket, feed tubs, grooming tools and equipment.

Routinely clean and disinfect stalls, stable equipment, grooming tools.

Ask visitors to wash hands or use a liquid hand disinfectant before handling horses.

Minimize rodent, wildlife, bird and insect populations and keep them away from feeding areas and water sources.

Maintain pastures, manage manure and avoid overcrowding.

Group like-used horses (i.e. separate broodmares from competition animals).

Isolate new horses, those returning from off-farm events or hospital for a minimum of two weeks to monitor for disease.

Disinfect your shoes, equipment after shows, visiting other barns.


OFF-PROPERTY


Don't allow horses to co-mingle with other animals.

Only use your own equipment cleaning tools, buckets and equipment during that time.

Don't let horses eat off the ground or use community water troughs, buckets.

Wash your hands after touching other horses.

Clean and disinfect your trailer after every trip.

HELP! HORSE MAY BE CONTAGIOUS


If any of the contagious diseases mentioned here are suspected, execute the following sick horse biosecurity protocols.

Quarantine sick horse(s).

Call veterinarian immediately.

Post signs warning of illness and quarantine.

Assign care of sick horses to specific individuals.

Wear protective clothing when dealing with infected animals. Remove immediately and dispose or launder.

Install footbaths and alcohol-based hand sanitizers at the quarantine area exit.

Wash hands thoroughly with pump-dispensed soap.

Handle healthy horses and muck out their stalls first.

Use separate stable equipment to muck out infected horses.

Contain stall waste to a separate bin and don't spread or put it on manure piles.

Don't allow dogs, cats or other farm animals near isolated horses. 

…………………………………………………………

…………………………………………………………

RINGWORM

What is it?


A skin infection, scientifically known as dermatophytosis, that's caused by Trichophyton and Microsporum fungi that feed on keratin, the primary protein that makes up hair and skin. Young horses are particularly susceptible, as they have yet to develop immunity, while adults generally are affected to a lesser degree and see quicker resolution. 



Symptoms

Small, circular tufts of hair, which then fall out, leaving scaly skin patches.

Rarely itchy or bothersome, ringworm can appear anywhere on the body, but usually affects areas in contact with tack or other items such a rider's boots.


Transmission

Horses pick up the fungal spores by direct contact with other infected animals, contaminated tack, equipment, grooming tools and blankets. Ringworm can also survive dormant for many years on surfaces such as stall walls or fences.


Carrier Status

Horses can carry ringworm without showing symptoms.


Diagnosis

Fungal culture of hair or skin. 


Treatment

Clip hair away from lesions, gently removing scabs. Spot treat with an anti-fungal medication or bathe horse with an anti-fungal shampoo, then treat with medication. Stop treatment when no new lesions appear and the skin looks healthy.


Incubation

Between one and six weeks. 


illness Duration

With treatment, usually about three weeks.


Disease-specific Prevention


Isolate and treat horses new to a premises with anti-fungal.

During treatment, carefully dispose of loose hair and skin, which will still contain spores.


Effects on Humans

Itchy, circular red skin lesions, with

hair loss if on scalp.


Most Common Route of Contagion

Skin contact with infected horse or items containing spores.


Treatment for Humans

Topical antifungals


Ringworm in horses looks like a circular raised welt, which is similar to how it appears in humans (bottom left).




RARE BUT DEADLY ZOONOTIC DISEASES


Following are zoonotic diseases that are extremely fatal to both humans and horses but are, thankfully, uncommon in both. All cases must be reported to the Canadian Food Inspection Agency under Canada's Health of Animals Act.


RABIES

What is it?


A central nervous system disease caused

by Lyssavirus.



Symptoms

Highly variable, rabies can mimic many

other diseases as the virus travels from

nerves at the infection site to the brain.

Subtle signs can include colic and

lameness. More extreme symptoms

include aggression and neurologic

issues.


Transmission

Horses usually contract rabies from the

saliva of infected raccoons, skunk and

foxes via bites or less often, open cuts

or mucous membranes.


Diagnosis

Post-mortem brain examination.


Treatment

None


Incubation

Usually two to six weeks.


illness Duration

Death within a week.

Disease-specific Prevention

Rabies vaccine is highly effective. Also

vaccinate farm cats and dogs.


Effects on Humans

Without prompt post-exposure

vaccinations, 100 per cent fatal.


Most Common Route of Contagion

Saliva of infected animal enters open skin or mucous membranes.


Treatment for Humans

Fourteen-day post-exposure course of rabies vaccine and/or rabies immunoglobulin (blood antibodies). If symptoms are present, supportive care until death.


ANTHRAX


What is it?


An infection caused by the bacterium

Bacillus anthracis.


Symptoms

Difficulty breathing

Loss of appetite

Chills

Fever

Depression

Severe colic

Bloody diarrhea

Shock

Swellings in the neck, sternum, abdomen 


Transmission

Extremely hardy, anthrax spores can live in soil for many years. Horses are usually infected by ingesting spores from contaminated pasture. It can also be contracted through inhalation, a break in the skin or mucous membranes when dead animals shed the disease. Insect bites can also transmit anthrax. 


Diagnosis 

Blood samples 


Treatment

Antibiotics

Anti-inflammatories

Fluid therapy


Incubation

Three to seven days. 


illness Duration

Called "the quick killer," without treatment, death occurs within three days. 


Disease-specific Prevention

Horses in endemic areas can be given a livestock vaccine. 


effects on Humans

Humans rarely contract the disease, but symptoms can include skin infections, gastrointestinal issues and potentially deadly respiratory problems. 


Most Common Route of Contagion 

Spores enter the body through open skin or by inhalation. 


Treatment for Humans

Two months antibiotic treatment

Antitoxins in some cases



BRUCELLOSIS


What is it?


An infection caused by the bacterium

Brucella abortus.


Symptoms

Painful inflammation and pus-filled wounds of the bursa (fluid sacs) along the spine (also called fistulous withers and poll evil)

Abortion


Transmission

Usually contracted from infected cattle

by ingesting contaminated pasture or

via direct contact through open skin or

mucous membranes. Also shed in equine

manure and tissues from aborted

fetuses.


Diagnosis

Blood tests


Treatment

Antibiotics

Anti-inflammatories

Surgical drainage and removal of diseased tissue


Incubation

Up to two years.


illness Duration

Can take many months to heal post-   

treatment, with a high re-occurrence

rate.


Disease-specific Prevention

Avoid horse-cattle contact in endemic
areas. (Although Canada eradicated
brucellosis in livestock with the last
confirmed case reported in 1989.)

Vaccine isn't available.


effects on Humans

Rarely humans contract brucellosis via direct contact with discharges and aerosol exposure. The disease, called undulant fever, is quite serious.


Most Common Route of Contagion

Direct contact with infected tissues or fluids of an infected animal. 


Treatment for Humans

Antibiotics 


Antibiotics are necessary

to combat some zoonotic

diseases, so it's important

to see your doctor if signs of

illness are present.


…………………………