Unit G Herd Health Management Equine Science II

Objective Explain major equine diseases and their treatment.

A. Equine Infectious Anemia (EIA) 1.A viral diseases that affects the equine’s immune system resulting in recurrent fever, weight loss and anemia. 2.Once an equine is infects, it remains infected for the rest of its life.

3.Chronically infected equine may go for years without showing signs of anemia only to have the sign recur when stress, environmental conditions or other disease affects the equine.

4.Horseflies and deerflies are the major natural transmitters of the virus from one equine to another. 5.Detection- A blood test called the “Coggins test” is used to detect the presence of EIA. Equine must have a negative Coggins test before they can compete or be placed in events in North Carolina

6.Prevention involves isolation from equine that are not infected and protection from biting, flying insects.

7.Treatment a.There is no effective treatment or vaccination for the disease b.In some cases, equine with EIA are required to be euthanized.

B. Equine Influenza 1.There are two common features of this viral infection a.Extremely rapid spread of infection b.Frequent, dry cough

2.Equine with influenza have an elevated temperature of degrees F which persist up to 5 days 3.The death rate from influenza is very low

4.The virus is spread to other equine when the equine exhales or coughs and may be carried by handlers on equipment that have been in contact with an infected equine.

5.Prevention a.Use two intramuscular injections of influenza vaccine scheduled 2-4 weeks apart followed by a booster shot at 3-4 month intervals for horses at risk. b.Isolation of infected equine and screening animals prior to transportation will reduce the spread of the disease.

6.Treatment a.One week of stall rest is recommended for each day the equine has an elevated temperature due to influenza b.Maintain a dust free environment during the illness and recovery by wetting hay and providing clean bedding.

C. Equine Rhinopneumonitis 1.This is a respiratory disease caused by EHV virus. 2.The infection is accompanied by a gold colored nasal discharge among foals.

3.The virus associated with this disease also may cause abortions in pregnant mares and occasional paralysis. 4.Equine may develop a temperature of degrees F which lasts for hours.

5.Equine become infected when they inhale the virus exhaled by sick or even apparently healthy equine that are infected.

6.Prevention requires a combination of: a.Sensible management practices i.Mares should be isolated and separated from other equine ii.Thorough cleaning and sanitation in the event of dead or aborted fetus

b.Vaccination i.Vaccinate pregnant mares in the 5 th 7 th and 9 th month of pregnancy. ii.Young equine should receive two injections followed by a booster according to manufacturer’s recommendations

7.Treatment is limited as there is not specific anti-viral therapy available.

D. Strangles 1.A highly contagious bacterial infection most commonly found in young equine from one to five years of age. 2.Early signs of strangles include fever, depression and loss of appetite due to difficulty with swallowing.

3.As strangles progresses, the lower jaw and throatlatch region may become hot, swollen and painful with abscesses forming and rupturing onto the skin. 4.Pus from ruptured abscesses may contaminate water buckets and communal feeders for months.

5.When strangles develop and abscesses from on internal organs, mortality may be as high as 10%.

6.Prevention and treatment are used in conjunction. a.Treat ruptured abscesses with a mild antiseptic solution to hasten healing

b.Administer Procaine penicillin G as an antibiotic treatment until clinical signs no longer exist for five days. c.Isolate affected animals from all other equine d.Vaccinate with 2 or 3 injections one month apart and apply a booster annually.

E. Equine Viral Arteritis (EVA) 1.EVA is a viral infection that causes respiratory illness with nasal and ocular discharges, swelling (stocking up) of the hind limbs and other areas of the body and sometimes abortion. 2.EVA may be passed by respiratory transmission when equine come in close contact.

3.Equine invariable make uneventful clinical recoveries even without treatment 4.Perhaps EVA is most pronounced as a breeding disease through the venereal spread of the disease by acutely affected stallions. a.Viral persistence in the stallion can range from several weeks to the entire lifetime of the equine b.Mares can be infected either at time of natural breeding or artificial breeding.

5.Prevention a.Immunize the breeding stallion population with MLV vaccine. b.Immunize all mares if they are inseminated with EVA positive semen.

6.Treatment a.There is no specific anti-viral treatment for equine with EVA b.Infected stallions should receive forced rest if they show symptoms of the disease.

F. Eastern, Western and Venzuelan Equine Encephalomyelitis (EEE, WEE, and VEE) 1.EEE, WEE, and VEE are viral infections that result in the inflammation of the brain. 2.The viral infections are spread by insect contact. a.The virus may live in reservoir hosts such as birds and rodents for long periods of time without harming the host. b.The virus is transmitted and spread by mosquitoes (vectors) to equine and humans. c.The viral infection is not transmitted between equine and humans.

3.The disease has high mortality rates:  EEE is %  WEE is 20-50%  VEE is 40-80%

4.Complete recovery is rare with equine frequently continuing to exhibit clumsiness, depression and abnormal behavior. 5.Signs of EEE, WEE, and VEE include aggression, propulsive walking, excitability, and a number of things that indicate the equine is confused.

6.Prevention focuses on mosquito control. a.Use insecticides and repellants when possible and practical b.Eliminate standing water c.Screen stalls, use fans to move air, and limit the use of incandescent lights in stall areas d.Brings equine inside prior to dusk e.Vaccinate with 3 injections at 3, 4, and 6 months of age and give a booster at the beginning of insect season

7.Treatment a.There is not specific treatment available

G. Equine Colic 1.Colic is the behavioral signs of abdominal pain in equine characterized by various activities including, but not limited to: tail twitching; head tossing; kicking toward the belly with one of the hind limbs; pawing the ground; grinding the cheek teeth and frequent attempts to lie down and roll on the back, etc. 2.True colic is due to intestinal obstruction or disease which causes pain

3.95% of all colic cases are from two causes a.Spasmodic causes where their is intestinal spasm caused by numerous things such as stress, anxiety, diet change, parasite damage, dewormers, etc. b.Large intestinal impaction (constipation) caused most often by improper diet and exercise (Human management is often culprit)

4.Prevention a.Use a parasite management program to avoid problems b.Careful rotation of pasture helps reduce levels of parasites c.Avoid overstocking pastures d.Use “Ivermectin” as a deworming compound e.Pay attention to the equine’s diet

5.Treatment a.Place the equine in a safe environment b.Treat with analgesia for pain relief c.Treat with mineral oil as a laxative

d.Remove feed until the equine has improved and then reintroduce feed gradually e.Do not allow the equine to eat too much hay or roughage (lightly grazing the pasture is recommended)

H. Founder 1.Characterized by the hoof collapsing as a result of laminitis (inflammation of the supporting tissue between the hoof wall and pedal bone) 2.Causes lameness in the horse and if left unchecked can cause permanent lameness or even require euthanization.

3.The leading cause of founder is gastrointestinal disturbance from any number of factors such as colic, grain overload, lush grass, excessive cold water, etc. 4.Other factors that cause founder are exhaustion, excessive concussion (road founder) contact with black walnut shavings, etc.

5.Prevention a.Control diet b.Avoid overworking the equine

6.Treatment a.Identify cause and direct treatment toward alleviating the problem b.Increase blood flow to the laminae through the use of drugs and IV fluids c.Use aspirin or heparin to thin blood

d.Use anti-inflammatory non-steroidal drugs (Ketaproten) to reduce laminar swelling e.Pack the frog and sole to increase support f.Use specialized shoes to relieve pressure to the hoof area.

I. Tetanus (Lockjaw) 1.Caused by a neurotoxin that allows uncontrolled muscle contraction and muscle spasms 2.Affected horses most often have sustained a wound from 2 days to a month prior to the onset of tetanus; however, tetanus bacteria also live in the equine’s digestive tract

3.Tetanus has become less common due to vaccination, but is still highly fatal 4.Equine usually die from suffocation, cardiac arrest or starvation since their muscular system does not function

5.Prevention a.Vaccination with two doses of toxoid vaccine given one month apart followed by a booster shot annually b.Equine that are injured should receive the toxoid booster if there is no record of prior shots

6.Treatment a.Administer penicilln b.Aggressively clean the wound c.Administer tetanus anitoxin d.Use tranquilizers and muscle relaxes to relieve spasms and muscle pain e.Provide IV fluids and nutritional support

J. Potamac Horse Fever (PHF) 1.PHF is a disease which in its extreme form results in profuse, watery diarrhea, fever, shock and laminitis 2.The occurrence of PHF disease is consistently within 5 miles of a river

3.PHF is caused by an organism that can survive within living cells and must be transmitted through blood cells by insects such as ticks 4.Equine with PHF are not considered contagious to other equine

5.Prevention a.Vaccinate with two injections one month apart b.Give a booster injection annually in May or June

6.Treatment a.A veterinarian should use tetracycline (anti-microbial drug) for 4-5 days b.IV fluids, frog pads, sole support, and anti-inflammatory drugs also help

K. Borreliosis (Lyme Disease) 1.Lyme disease is a bacterial infection transmitted primarily by certain ticks 2.Rare among equine and only a problem where Lyme disease is found among human populations 3.Arthritis is the most commonly reported sign of Lyme disease in equine

4.Prevention a.Careful grooming to remove ticks b.Avoiding tick-infested areas

5.Treatment a.Use antibiotics such as tetracycline and ampicillin b.Prolonged treatment of days usual

L. West Nile Virus (WNV) 1.Viral infection that can cause inflammation of the brain and often mimics EEE in equine a.First introduced in western hemisphere in 1999 b.Equine are more often affected by WNV than any other domesticated animal

2.WNV is spread by mosquitoes when they bite an infected bird and then bite a human or an equine a.Equine are not contagious and do not pose a health risk to other animals or humans b.About 30% of horses who show clinical signs either die or have to be euthanized

3.Clinical sign of WNV may include circling, aimless wandering, head pressing, impaired vision, hyper excitability, etc.

4.Prevention a.See mosquito and control techniques listed for EEE, WEE and VEE b.A veterinarian should vaccinate with “protocol” and follow with a booster injection three weeks later 5.Treatment is still developing

Student Activity- Class Bubble Map Divide into groups. Each group will create one bubble for the assigned disease. BE CREATIVE- you have to use the designated bubble, but you can add images or add to it to help us remember the information. Once complete we will create a class bubble map highlighting the equine diseases.

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