First-Aid, Diseases & Parasites

Risk Assessment

• Boarding & training facilities have a high volume of horses with a rapid turnover rate.

• Breeding farms have a high number of horses with a high turnover rate.

• Farm & ranch settings have working horses that remain in the same facility until sold or deceased.

• High performance horses have a high workload and are exposed to many other horses from different backgrounds

General Farm PracticesBreeding Farms

• Foaling represents a significantly higher disease risk period for both the mare and the foal.

• During late gestation the mare’s immune system is reduced.

• The neonatal foal has limited immune capabilities for many months.

General Farm PracticesBreeding Farms

• Provide a clean, hygienic foaling environment.• Disinfect the navel soon after birth.• Ensure every foal ingests an adequate amount of

quality colostrum.• Test the foal for adequate blood IgG levels.• Limit contact between very young foals and older

animals.

General Farm PracticesWeaning

• One of the greatest periods of stress & disease.• Stall or small paddock results in increased

stocking density, enhancing the transmissibility of disease.

• Ideally, the mare is removed and the foal is left in familiar surroundings.– Limits the exposure of the foal to new pathogens.

General Farm PracticesGeriatric Horses

• Increased disease susceptibility.• Four main factors: decreased nutrient absorption, poor

teeth, decreased immune response and age-related disease.– Decreased absorption of phosphorus, vitamins, and

protein.• Antibody response to vaccination is decreased and T

cell function is lowered.• Prone to develop age-related disorders such as liver

failure, kidney disease, tumors, and anemia.

Health Protocols

• The greatest impact on disease management is determined by the measures directly taken to prevent and treat disease.

• Develop a standard (and preferably written) health protocol.

• Define goals and outline specific means of ensuring the objectives are achieved.

• Include SOP for: identifying, examining, separating and treating sick animals; administration of routine health procedures and schedules (vaccinations, deworming, castration, etc.); and general husbandry procedures.

Vaccination

• All horses should be vaccinated for diseases that are prevalent in the area.

• Not all diseases can be vaccinated against.

• Vaccines are not 100% effective for disease prevention.

• Vaccination protocols should be reviewed annually.

Currently there are equine vaccines available for:

• Tetanus : injection of modified toxin (toxoid)

• Eastern, Western, Venezuelan Viral Encephalomyelitis : injection of killed virus

• West Nile Viral Encephalomyelitis : killed virus (Fort Dodge) / modified live canarypox vectored (Merial)

• Influenza, many different strains : injection / intranasal

• Herpesvirus-1 : abortion, respiratory, and neurological disease

• Herpesvirus-4 : respiratory disease and abortion

Currently there are equine vaccines available for:

• Strangles : injection of killed bacterin / intranasal vaccine (Fort Dodge)

• Rabies : injection of killed virusUncommon Vaccines Given• Potomac Horse Fever : killed rickettsia• Equine protozoal Myelitis (EPM): killed protozoan• Botulism : injection of modified toxin (toxoid)• Equine Viral Arteritis• Anthrax• Endotoxemia• Rotavirus

Should You Vaccinate?

• How serious is this disease?• How well does the vaccine work?• What is the frequency and seriousness of the side effects of

the vaccine?• Does protecting the horse also protect other horses or the

horse owner from contracting the disease?• Does vaccination result in persistence of the disease in the

population?• Does the vaccine create a diagnostic enigma or cause

export restrictions?• Does the vaccine create export or transport restrictions

EQUINE VIRAL ARTERITIS

– Fever

– Edema (or swelling especially in the legs, genitals and around the eyes),

– Abortion

– Nasal discharge,

– Skin rash (localized or generalized)

– Loss of appetite.

• BECAUSE EVA IS A VIRUS, ONCE CONTRACTED, THERE IS NO direct treatment for it. Treatment is focused on alleviating symptoms to ease the horse’s recovery.

Equine Viral Arteritis

• Equine viral arteritis is an infection by the equine arteritis virus (EAV). Testosterone-dependent virus

• EVA is not usually lethal to adult horses.• The greatest danger of EVA is abortion in mares.• EVA is transmittable via respiratory and venereal paths.• Once infected, mares, geldings and sexually immature

stallions recover within a few weeks. They shed the virus and become immune, but will test seropositive the rest of their lives.

• Sexually mature stallions can become carriers the rest of their lives and might shed the virus in their semen. The virus can survive being cooled and frozen.

Equine Viral Arteritis

• There is a vaccine available for EVA. It is safe for almost all horses.

• Horses exposed to EVA, including mares bred to EVA-positive stallions, must be properly quarantined to prevent the spread of the virus.

• Horses and semen testing positive for EVA may not be allowed to be exported to other countries. Before vaccinating, discuss the risks with your veterinarian.

AQHA to Store Equine Viral Arteritis Vaccination

Documentation• EARLY JULY: NEW MEXICO SIRE DASH TA

Fame, along with numerous other horses at MJ Farms in Veguita, New Mexico, was infected with equine viral arteritis– By mid-July, the farm has lost about 50 percent of its

pregnancies– Stallion shed the virus - During this year’s (2005)

breeding season, the farm has bred nearly 200 mares and shipped semen to 16 states.

– “There was an outbreak last year in New Mexico on a nearby breeding farm that was not reported,”

Vesicular Stomatitis

• Caused by a virus

• Transmitted by insect vectors

• Once introduced to herd, can be transmitted by animal to animal contact

Vesicular Stomatitis

• Excessive salivation• Blanched raised or broken vesicles of various sizes in the mouth:• Horses: upper surface of the tongue, surface of the lips and around

nostrils, corners of the mouth and the gums.• Cattle: tongue, lips, gums, hard palate, and sometimes muzzle and

around the nostrils• Pigs: snout.• Lesions involving feet of horses and cattle are not exceptional.• Teat lesions occur in dairy herds.• Foot lesions and lameness are frequent in pigs.• Recovery in around 2 weeks.• Complication: loss of production and mastitis in dairy herds due to

secondary infections, lameness in horses.

PARASITES

• Strongyles (bloodworms)

• Ascarids (roundworms)

• Bots• Pinworms• Strongyloides

(threadworms

Signs of Parasitism

• Dull, rough hair coat

• Lethargy• Wt. Loss• Coughing &/or

nasal discharge• Tail rubbing• Colic• Summer sores

• Depression• Anorexic• Unthriftiness• Diarrhea• Resistance to

bit

MANAGEMENT FOR CONTROL OF INTERNAL

PARASITES• Proper manure disposal

• Pastures

• Feed

• Water

• Drug control

Lameness

• Grade 1 – Difficult to observe; not consistently apparent

• Grade 2 – Difficult to observe at walk or trot on straight line; consistently apparent under certain circumstances

• Grade 3 – Slight to moderate & consistently observable at a trot under all circumstances

• Grade 4 – Obvious lameness; marked nodding, hitching or shortening stride

• Grade 5 – Minimal weight-bearing in motion and/or at rest, inability to move