“I want to thank California’s horse owners and veterinarians for their prompt and thorough actions to isolate and monitor exposed animals and contain this outbreak of EHV-1,” said State Veterinarian Dr. Annette Whiteford. “We also owe the success of this project in part to the outstanding isolation biosecurity measures implemented by horse facility managers, show/event managers and other professionals who work with and care for horses.”

It is important that the California horse owners remain vigilant as there is always risk of disease when horses of unknown health status are commingled at one location. Consistent, basic biosecurity practices play an important role in reducing risk of exposure to diseases such as influenza, strangles, pigeon fever, or equine herpes virus.

By implementing the biosecurity measures below, you can minimize disease risk:

• Minimize horse nose-to-nose contact with horses of unknown disease status.
• Don’t share equipment including buckets, tack and grooming equipment.
• Avoid using communal water troughs.
• Fill water buckets directly from the faucet to eliminate potential hose contamination.
• Limit human contact between horses or wash hands or use hand sanitizer between horse contacts.
• Prior to returning home from an event, clean and disinfect all equipment, including trailer, clothing, tack grooming supplies.
• Isolate all new horses or horses returning home for a minimum of three weeks. Isolation means no direct  contact with other horses or humans and no indirect contact via shared equipment.
• Consult your veterinarian to establish appropriate vaccination for your horse(s).

Horse owners are strongly encouraged to consult their veterinarian regarding these steps and others to determine how best to reduce the risk of your horse acquiring an infectious disease.

(Following this Fact Sheet are several links for up to date information about the EHV-1 virus outbreak in California and general facts about the disease.)

A recent disease outbreak of Equine Herpes Myeloencephalopathy (EHV-1) has been traced to horses who attended the National Cutting Horse Associations’ Western National Championships in Odgen, Utah on April 30 – May 8, 2011. California horses who participated in this event may have been exposed to this EHV-1 virus.

The California Department of Food and Agriculture encourages owners of horses who participated in the Odgen, Utah event to isolate and monitor their horses for clinical signs of disease. A rectal temperature in excess of 102F commonly precedes other clinical signs. Therefore, we are urging owners to take temperatures on each individual horse(s) twice a day. If a temperature above 102F is detected contact your private practitioner immediately. Laboratory submission of nasal swabs and blood samples collected from the exposed horse can be utilized for virus detection and isolation.

The EHV-1 organism spreads quickly from horse to horse and the neurologic form of the virus can reach high morbidity (illness) and mortality (death) rates. The incubation period of EHV-1 is typically 2-10 days. In horses infected with the neurologic strain of EHV-1, clinical signs may include: fever, nasal discharge, incoordination, hind end weakness, recumbency, lethargy, urine dribbling and diminished tail tone. Prognosis depends on severity of signs and the period of recumbency. There is no specific treatment for EHV-1. Treatment may include intravenous fluids, anti-inflammatory drugs and other appropriate supportive treatment.

Currently, there is no equine vaccine that has a label claim for protection against the neurological strain of the virus.

The strain of EHV-1 causing neurological symptoms is a mutation of the EHV-1 virus most often associated with abortion in pregnant mares. There is NO vaccine for this strain. The commonly used 5-way or Flu/Rhino vaccine has EHV-1 antigens (the sensors that alert the body to produce antibodies to a specific disease) in the vaccine but the “load” of antigens is too low for protection in horses challenged by the virus. However, the Pneumobort-K vaccine and Rhinomune vaccine have a high antigen “load” against EHV-1, but still does not protect against the mutated strain of EHV-1. There is some thought that giving the Pneumobort-K vaccine or Rhinomune vaccine with a high “load” of EHV-1 antigen may be of benefit, but this is purely antidotal, and there is no research to support this protocol. Information suggest that both vaccines create similar immune response to EHV-1, however neither vaccine create direct protection to the mutated strain of EHV-1.

The disease is a virus and requires direct contact from horse to horse, or perhaps more commonly owners are contaminating their hands, and then contaminating others horses. Also, the virus can be airborne and transmitted as an aerosol to other horses. Common sense regarding direct contact with other horses should be used.

Horse-to-horse contact, aerosol transmission, and contaminated hands, equipment, tack, and feed all play a role in disease spread. However, horses with severe clinical signs of neurological EHV-1 illness are thought to have large viral loads in their blood and nasal secretions and therefore, present the greatest danger for spreading the disease. Immediate separation and isolation of identified suspect cases and implementation of appropriate management measures (contact your veterinarian for proper management, if you suspect you have a neurological EHV-1 horse) are key elements for disease control.

CONCLUSION: Monitor your horses for illness and/or neurological symptoms. Avoid contact with horses that you may suspect have had contact with the disease, and wash your hands between horses that you are not familiar with. Common sense and contacting your veterinarian if you have symptoms or concerns is the best approach. We encourage you to contact your veterinarian with specific questions.

California Department of Food and Agriculture Daily Update

UCDavis Center for Equine Health White Paper on EHM

EHM Owner Update

EHV-1/EHM FAQ’s

USDA Resources

USDA Equine Herpes Myeloencephalopathy Brochure

American Association of Equine Practitioners Fact Sheet

TheHorse.com Equine Herpesvirus-1 Myeloencephalitis (EHV-1/EHM) Resources

CDFA Equine Herpes Myeloencephalopathy Fact Sheet

USDA Biosecurity Brochure

Link to United States Veterinarian’s Directory

National Cutting Horse Association Website

These biosecurity guidelines have been developed by CDFA veterinarians and the faculty at the School of Veterinary Medicine, University of California, Davis, CA, to minimize the risk of transmission of infectious diseases at public equestrian events.
Based on what is known today, June 8, 2011, regarding the current neuropathogenic EHV-1 outbreak, we are suggesting that managers of horse shows or events occurring in California during the month of June 2011 incorporate the following biosecurity measures to minimize the risk for all participants:

1. Non- exposed horses: Event managers should create a short document for participants to sign upon arrival at the show grounds to confirm that their horses, mules, and burros attending the show/event have not been exposed to a clinical case of the neuropathogenic strain of EHV-1 and have not been on premises with a confirmed positive case within the prior 28 days.
* Clinical case is defined as a horse testing positive on a laboratory test for the neuropathogenic strain of EHV-1 and having exhibited compatible clinical signs for EHV-1 which may include fever, abnormal nasal discharge and/or neurologic signs.

2. For exposed horses: Event managers should create a short document for participants to sign upon arrival at the show grounds to confirm that their horses, mules, and burros attending the show/event have not demonstrated clinical signs compatible with EHV-1 for the preceding 28 days and no other horses on the premises where they reside have shown clinical signs (fever, abnormal nasal discharge and/or neurologic signs) for the preceding 28 days. Additionally, it is recommended that the owner/trainer of an exposed horse showing residual neurological deficits provide evidence of two negative tests for the neuropathogenic strain of EHV-1 within the prior 14 days.
* Exposed horse is defined as a horse which has resided on a premises with a confirmed positive EHV-1 horse or on a property which has had horses that have displayed clinical signs compatible with EHV-1 in the prior 28 days.

3. Establish a “No Fever” policy for horses attending the event. Give the participants prior notice of the new “No Fever” policy before they arrive at the show grounds. Provide instructions for obtaining the horse’s temperature and an index card on which to record temperature readings for each horse.
* All horses will have temperatures taken twice daily and results will be posted on front of the stall/pen for inspection.
* Any horse will be subject to random temperature check by the show veterinarian or designated member of the veterinary staff during the event.
* Any horse with a fever of 102°F or greater will be removed from the event and premises immediately (i.e. within 2 hours of detection of fever).
* If the owner cannot move the horse off the premises, a professional horse hauler contracted by the
event will remove the horse to a designated isolation area at the owner’s expense.

4. It is understood that some (most) horses with a fever will not have EHV-1; however, in the interest of conducting a safe event under the current circumstances, we recommend event managers use the non-fever policy. Participants who choose not to comply with these safety measures should be advised to not attend the event.

Large Animal Veterinary Associates is now offering permanent identification for your horse with AVID microchips. Avid is the leader in personal identification chips for animals. It is even used by many wildlife agencies for marking and tracking wild animals such as bears and lions. Each chip contains a unique number that is readable with a scanner. The chips are placed in the nuchal ligament of the neck, half way between the poll and the withers and the injection is as easy as a vaccination. Once a horse receives a microchip he or she has their own unique number much like a social security number or the VIN# of a car.

Once your horse is chipped, he or she can be identified if lost or stolen. A perfect example of this were the fires in 2003 and 2007, as many horses were displaced without the owner’s knowledge. Microchipping would help owners reunite with their companions and is also helpful in ownership verification. Many breeding facilities utilize these chips to assure accuracy when breeding. A horse that has an AVID microchip will be registered with our practice and the owner will have copies of the ID# for their records. In addition the horse can be enrolled in “HORSEtrac”. This is AVID’s 24/7 disaster and recovery program. If a horse is found and scanned, HORSEtrac will contact the owner with the location of their horse.

This is truly a wonderful opportunity to have peace of mind knowing that your horse is permanently identified. The chips are guaranteed for the life of the horse. Microchips have been used for years by several of the breed registries and are now available to the general horse owner as well. If you have any questions or would like to see how the chips work, please contact our office at 619-590-1991. Microchipping is $75.00*, including the life time registration with HORSEtrac.

*Cost does not include sedation. Sedation may or may not be necessary for all horses to be microchipped. Please consult your veterinarian if you think your horse may need sedation.

Thinking of becoming a veterinarian?  Check out these stats from MSU’s Vet School Class:

• foals from mares which have a history of abortion.
• foals from mares which have a history of producing weak or sick foals.
• foals from mares which have a history of illness of any type during their pregnancy, especially if they have been exposed to infectious diseases or have required and anesthetic procedure.
• foals from mares with a history of chronic uterine infections despite the fact that they are presently in foal.
• foals from mares that have a history of no milk production, especially if this has occurred more than once.
• foals from mares which have poor quality colostrum or no colostrum.
• foals from mares which have premature lactation (dripping milk for several days prior to foaling).
• foals from mares which are malnouished during their pregnancy.
• foals which survive a difficult birth (dystocia).
• foals born by cesarean section.
• foals which are unable to nurse and do not receive colostrum for any reason.
• foals housed in an unsanitary environment regardless of the mare’s health and the fact that the foal received colostrum.

This is a partial list of some of the situations that may place a foal in a high-risk category. There are many specific causes of the above situation; for instance, allowing the mare to graze infected fescue pastures after 300 days of gestation is a common cause of failure to produce colostrum and milk (agalactia).

Foals fitting into one or more of these categories should be thoroughly examined by a veterinarian soon after birth and closely observed and monitored by the owner or farm manager for at least 10-14 days. Be on the alert for any of these early signs that a foal may be developing a problem:

• Decrease in the frequency of nursing, as noted by frequent observation of the foal or evidence by a continuously full udder on the mare.
• Decreased activity of the foal. The normal routine of a healthy foal is to nurse frequently, play actively for a short period, investigate its surroundings and sleep. A foal which doesn’t become increasingly interested in its surroundings, doesn’t actively seek out the mare when hungry, acts lethargic, sleeps most of the time, has problems getting up after 24 hours of age or in any other way doesn’t follow the typical pattern of the normal foal may be developing a problem and should be examined further.
• Gradual loss of the suck reflex (ability to nurse).
• Increased periods of recumbency.
• Any lameness with or without joint swelling. Do not dismiss lameness or a hot, swollen joint as due to “trauma” (mare stepped on the leg or something similar). Every lameness or swollen joint in the equine foal should be treated as infected until proven otherwise.
• Persistent loose stools with depression and/or appetite loss.
• Labored breathing, nasal discharge, coughing. When foals are sleeping, their breathing pattern may look irregular. This is normal in most foals. A very rapid respiratory rate, however, may indicate respiratory disease.
• Intermittent or continuous dripping of urine from the umbilicus or navel.
• A swollen umbilicus, discharge from the navel.

Equine Neonatal Diseases

Numerous diseases can affect the foal during the neonatal period. These range from congenital abnormalities (birth defects) to serious systemic infections (septicemia). However, in the early stages of many neonatal diseases, the clinical signs are subtle and similar. In order to achieve early detection it is important to know what is normal and to observe the foal frequently enough to be able to detect a deviation from normal. The highest rate of successful treatment of sick foals occurs when therapy is initiated early. Here are some things that can be done to achieve early detection of impending illness:

• Identify high-risk foals before birth if possible.
• Attend all foalings.
• Perform routine post-partum veterinary examinations on all apparently normal foals at 24 hours of age. This examination should include testing for immunoglobulin (IgG) levels. Any foal that is in a high-risk category or that is not normal after birth should be examined by a veterinarian shortly after parturition.
• Observe all foals closely at least two to three times per day for the first 10-14 days. This means that the mare and foal should be housed in an area that has easy access and that they should not be immediately turned out in a large pasture where they may not be seen frequently and where catching the mare is difficult. If you do not observe the foal, then you cannot detect a problem early.
• Make an effort to learn how normal foals act if you do not already have experience in this area.
• Horse owners invest a considerable amount of time, effort and money in breeding and maintaining mares in hope of obtaining and raising a foal which can be used for its intended purpose. To lose this foal after 11 months of effort because of poor planning represents a considerable loss. While not every sick foal can be saved, prevention and early detection increase the chance of a favorable outcome and decrease the cost of therapy.

After the birth it is important to allow the mare and foal time to rest and bond with minimal interference. If the foal has not broken the membranes soon after being born the owner may tear them and check to make sure the foal is breathing. It is generally not recommended for the owner to cut or break the umbilical cord as it will usually break on its own about one inch from the foal’s abdomen. In the rare occurrence that the cord does not break you can break it by twisting and pulling which will decrease the possibility of excessive bleeding. The umbilicus should be dipped in a dilute (50%) nolvasan or betadine solution soon after birth and every 6 hours thereafter for the first 24 hours. This will help prevent any infection of the umbilicus.

The foal should appear bright and alert soon after birth. It should make attempts to stand within 30 minutes, is usually on its feet by one hour, and nursing by 2 hours after being born. If the foal has not nursed by 4 hours after birth it may need assistance and a call should be made to the veterinarian.

The meconium (the first dark sticky stool) should be passed within a few hours after birth. Occasionally an enema may be given to assist with passage of the meconium, but it is important to be very gentle when administering so as not to damage the tissues. After the meconium is passed, the foal’s manure will become light brown and pasty, this is called milk feces. If the foal does not pass the meconium it may be stuck and form an impaction. The foal may show signs of mild discomfort such as restlessness, straining, holding the tail elevated, or of colic, such as rolling and getting up and down. If a meconium impaction is suspected a call should be made to the veterinarian.

The foal should urinate around 8-10 hours after birth. It is important for the owner to witness the foal urinating to make sure there are no problems such as a patent urachus (where the foal urinates out of its umbilicus), or uncommonly a ruptured bladder, in which the foal may not be able to urinate at all.

The foal’s first nursings are the most important of its life. The mare’s initial milk is called colostrum. It is rich in antibodies that give the foal immunity until its own immune system can kick in. The foal can only absorb these antibodies for the first 18 hours after birth, after that the intestinal tract will no longer absorb the antibodies to become a part of the immune system. If a foal is weak or unable to nurse it may be necessary to milk the mare and feed the foal either with a bottle or through a stomach tube. Blood can be drawn from the foal and tested by 12 hours of age to measure the IgG antibody levels in the blood. If the IgG levels are too low the foal may need to be given extra colostrum or intravenous plasma.

In summary here is a checklist of things to do for your new foal:

1. Dip the umbilicus in a dilute nolvasan or betadine solution after birth and then every 6 hours for the first day
2. Monitor the time it takes for the foal to stand and nurse, it should have had its first drink of milk by 4 hours after birth
3. Make sure the foal has passed the meconium
4. Make sure the foal is urinating normally
5. Have blood drawn to check the IgG antibody levels

In general it is advisable to have a veterinarian do a post partum exam on both the mare and foal. The veterinarian can check for any abnormalities, draw blood on the foal, and answer any questions you may have about your new arrival.

1. Deworming every two months, rotating dewormers to prevent parasite resistance.
2. Immunization Program
   1. Rhinopneumonitis vaccine at 5-7-9 months to prevent viral abortion.
   2. Tetanus, Influenza, Encephalitis vaccine at 10 months to boost immune status and maximize colostrum levels of protection.

II. Normal Parturition:

1. Mammary gland begins filling 30-45 days prior to foaling.
2. Maximum gland filling with “waxing” 24-48 hours before foaling.
3. Relaxation and lengthening of the vulva 24-48 hours before foaling, no vaginal discharge will be seen normally before foaling as in other species.

III. Gestation Length:

1. Variable, normal being 335-360 days.

IV. Stages of Labor:

1. Stage 1
   1. Restlessness.
   2. Colic symptoms.
   3. Tail switching.
   4. Stretching to urinate, looking at their flank.
   5. Frequent small bowel movements.
   6. Stage 1 ends and Stage 2 begins when the “water” breaks (amniotic fluid).
2. Stage 2
   1. Rapid phase of labor usually lasting an average of 20-30 minutes.
   2. Feet present first, usually on foot, then the head and second foot together.
   3. Forceful contractions will occur as the head and shoulders come through the birth canal.
   4. 20-30 minutes is average but can take up to 60 minutes, longer than 30 minutes after the water breaks should warrant a call to your veterinarian.
   5. Celebrations and flash photographs should be delayed until after the umbilical cord breaks.
   6. Allow the mare and foal to lie comfortably so that maximal placenta blood reaches the foal without premature rupture of the cord. Clamping of the cord is beneficial.

NORMAL PROGRESSION

Stages	Time
Water bag breaks	Time 0
2 front feet and head appears	Time 10 minutes
Feet, head, chest and hips	Time 25-35 minutes
Foal standing	Time 1-2 hours
Fetal membranes passed	Time 2-3 hours
Foal nursing	Time 2-4 hours

3. C. Stage 3
   1. Passing of the placenta.
   2. Normal passage of the placenta is less than 3 hours after foaling.
   3. Retention of the placenta longer than 3-4 hours would warrant veterinary attention.
4. D. Stage 4
   1. After care checklist:
      1. Care of the Umbilical Cord
      2. Enema for the foal if necessary.
      3. Be sure the foal nurses, this can occur as soon as 1-3 hours, longer than 2-4 hours without nursing should warrant veterinary attention.
      4. Save the placenta for examination to be sure that it is present in its entirety.
      5. 18-36 hour test for Immunoglobulins. This test determines the amount of immunity that the foal has received from the mare’s colostrum.
   2. Problems:
      1. Improper presentation.
      2. Failure of the placenta to rupture and the foal unable to pass out of the membranes.
      3. Premature rupture of the umbilical cord.
      4. Failure to nurse.
      5. Failure of progression during Stage 2 of labor.
      6. Rectal and Vaginal tears to the mare.
      7. Uterine artery ruptures of the mare.
      8. Prolapsed uterus of the mare.

To begin, owners can ensure proper care and nutrition of the mare during her pregnancy. This includes not only adequate food and exercise, but keeping current on vaccinations and deworming. Mares should be current on all vaccinations before breeding. During their pregnancy, mares should receive a Rhinopneumonitis vaccine (Pneumobort-K) at 5, 7, and 9 months, as well as boosters for EEE/WEE/tetanus/ influenza and west nile one month before their due date. Mares should also remain on a regular deworming schedule, receiving a deworming dose one month before their due date.

The mare should be familiar with and comfortable in the area where she is going to give birth. This foaling area should be clean and dry with plenty of room for the mare to lie down. Straw is the preferable to shavings for bedding but either is better than plain dirt.

Typically a mare will show certain signs that she is getting ready to give birth, but be prepared for surprises. The mare’s udder usually begins filling about 2-4 weeks prior to foaling, and some mares may develop swelling/edema along the midline. The teats will begin to become distended about 4-6 days before foaling. At around 1-4 days prior to foaling, the muscles of the croup and vulva relax and the teats will wax (small droplets of milk appear on the ends of the teats). Some mare may also drip milk. Special test strips are available that measure the electrolyte concentrations in the milk, typically the calcium levels will increase 24 hours before parturition.

There are some things that owners can do to prepare the mare when they think she is getting ready to give birth:

1. keep the birthing area clean
2. wash the mare’s vulva and teats with a mild soap and rinse thoroughly
3. wrap the mare’s tail with a clean wrap when you witness the first stage of delivery.

There are three stages of labor in the mare:

1. the beginning of the uterine contractions. This stage may last a variable amount of time, usually around 1-3 hours. The mare may act uncomfortable and get up, lie down or roll several times in order to position the foal properly. The fetal membranes may become visible at the vulva.
2. begins with the rupture of the fetal membranes and is the actual giving birth of the foal. This stage should last no more than 20-30 minutes. The normal presentation of the foal begins with the front feet first, soles down, followed by the nose, head, neck and shoulders. If you suspect any change from this presentation, or after 10 minutes of strenuous labor there is no sign of the foal you should call your veterinarian. Also, if instead of the normal white/clear fetal membranes present the membranes are a dark red, this is considered a “red bag delivery”. The membranes are prematurely separating, disconnecting the foal from its oxygen supply. They need to be cut and the foal delivered as quickly as possible, and you should call your veterinarian immediately.
3. expulsion of the placenta. This should take place 1-3 hours after delivery of the foal, the mare may become uncomfortable again and lie down to pass the placenta. If the mare does not pass the placenta the veterinarian should be called as a retained placenta can cause serious medical problems. After the mare has passed the placenta, it should be removed as soon as possible to prevent it being stepped on and placed in a safe place for later examination by a veterinarian. During the warmer months it is best to put it in a cool dark place, preferably in a bucket of water to decrease the “smell factor”.

After the birth monitor the mare for the next several days. She should eat, drink and pass manure normally. If she does not appear to be acting relatively normal (minus the fact she has a new baby!) or displays continued pain after passing the placenta you should contact you veterinarian as mares can occasionally become sick or colic after giving birth.
Most mares give birth with no complications, but with a little knowledge and preplanning an owner can be prepared to help their mare should any problems arise.

First, we need to get the mare into heat. Horses are seasonally polyestrous, which means that they stop cycling, usually in the late fall, and do not begin again until the early spring. However, we can alter this process by putting them under lights to artificially create springtime. We want the mare under lights 16 hours per day. This can be done with a timer and a 100 watt light bulb. Usually, having the light on from 4pm to midnight is adequate. This process should begin 4-6 weeks prior to breeding.

As veterinarians, we want to check the mare with ultrasound prior to breeding, particularly in the months of February and March to be sure that your mare is cycling and is not transitional. Mares that are not yet cycling will have small inactive ovaries and a “quiet” uterus (a uterus unresponsive to estrogen and progesterone).

Mares go through a “transition” period as they begin to cycle at normal intervals. During this transitional period, the mare may have inconsistent “heat” cycles and inconsistent “heat” behavior. Mares are not generally fertile during the transition period, but can successfully respond to hormone therapy while in transition and then be bred.

Hormone therapy for mares has become a mainstay in the industry to make breeding more efficient, reducing costs and increasing fertility rates. The hormones most routinely used are Lutalyse (prostaglandin), Regu-Mate (progesterone), HCG (human chorionic gonadotrophin), and Deslorelin (Ovuplant).

OK, your mare is ready so let’s get started. You have selected a stallion. You want to ship semen to AI (artificially inseminate) your mare. We need to synchronize your mare for breeding during the mid-week to facilitate shipping and avoid weekend inconveniences and costs.

This would be the reasonable protocol for most circumstances:

• Have your mare ultrasounded to be sure she is cycling properly and to observe for intrauterine fluid or any other abnormalities in the uterus or of the ovaries. Mares with “fluid” will need culturing and uterine therapy. Maiden mares (mares not having been bred before) generally have a “clean” uterus.
• Determine if your mare needs an intrauterine culture to rule out infection.
• Begin giving Regu-Mate orally for 15 days to take “control” of your mare’s reproductive cycle. Begin Regu-Mate on a Monday.
• Give a Lutalyse injection intramuscularly on day 16 (a Tuesday). The day of the Lutalyse shot can be adjusted based on semen shipment availability.
• Ultrasound your mare 7 days later (a Monday) to determine follicle size and appropriate day for breeding, which would usually be Wednesday or Thursday.
• Inseminate mare based on prior examination and give HCG or Deslorelin to stimulate more rapid ovulation and shorten the time interval between ovulation and insemination.
• Have an Ultrasound pregnancy exam 15-18 days post-ovulation.
• Other issues include what days the stallion owner provides semen and is the semen being transported via UPS or FedEx.
• This protocol is also very efficient for mares that are being bred with live cover as well because it minimizes the handling and labor involved with teasing and multiple breedings, which can lead to injury and infection.
• Most importantly, it is necessary to plan ahead to have the stallion owner, mare owner, and veterinarian all working together for optimal success.

Further questions can be personally addressed by calling the office at (619) 590-1991 or (760) 789-6845.