Rabies is a rare disease in horses, but there is always a risk of exposure in regions where rabies is present in wildlife. The fact that equine rabies is rare is a good thing, but it can also breed complacency and lead to decreased vaccination rates.

Decreasing vaccination is a bad thing. Vaccination is cheap insurance for a very serious disease. Rabies is invariably fatal in horses. It's also a risk to anyone around the horse. Transmission of rabies from horses to people is theoretically possible through bites or other contacts that result in introduction of saliva into wounds, cuts or possibly the mouth, nose or eyes. I'm not aware of any documented cases of equine-to-human transmission of rabies, but given the severity of rabies, we need to be careful. Additionally, rabid horses have killed people because they can be unpredictable and aggressive. Based on all these factors, it's important that we not become complacent about rabies in horses, and a key component of rabies control is vaccination. However, vaccination is not the only aspect of rabies control. Using various management practices to reduce the risk of wildlife exposure and controlling rabies in wildlife in the area are other important measures, but individual horse owners can have the greatest impact on their horses' health by ensuring they are properly vaccinated against rabies.

If you own a horse, make sure it's vaccinated against rabies unless you live in a rabies-free region.  More information about rabies in horses is available on the equIDblog Resources page.

Image source: www.bbc.co.uk

1. Stop focusing on the wrong things

It's easy for people to get hung up on a few concepts or topics and not see the big picture or the real problems. We need to think in terms of the horse(s), not the parasites. We're trying to optimize horse health. That doesn't necessarily mean killing all parasites, nor does it mean relying soley on drugs to control them. Conceptually, we need to think about parasite control, not just deworming.

2. Plan parasite control around parasite biology, not a calendar

There is no "standard" deworming program. Every program needs to be tailored to the geographic region, farm and horse. What happens here is Ontario is very different from what happens in Florida in terms of parasites.  For example, the risk of transmission in horses turned out on pasture in Florida in February is certainly different from those turned out in snowy fields in Ontario at the same time of year. Even in the same region, what happens on one farm may be very different than what happens on another. When designing a parasite control program, you need to consider what is going on with worms in the horses and in the environment to determine the optimal approach.

3. Don't encourage resistant parasites

Most people know antibiotic-resistant bacteria are a bad thing, but often concerns about anti-parasitic resistance are ignored. We only have a limited number of antiparasitic drugs, and there aren't many more coming in the near future. Heavy use or misuse creates an environment where resistance may emerge. It's being seen with certain bugs and certain drugs, and needs to be taken seriously - now.

4. Don't treat all horses the same

As I mentioned above, you need to tailor parasite control to something that is relevant for the region, farm and horse. Different horses are at different risks of exposure. Some horses are naturally more resistant to parasites, so these animals don't need to be (and indeed shouldn't be) treated the same as more susceptible horses. Deworming should be tailored to the needs of the individual horse. Yes, it takes more effort and some thought, but it's worth it.

5. Practice evidence-based parasite control

That means use all available information to make decisions. It includes knowing what parasites are a concern on the farm (which requires testing), what antiparasitic drugs have been effective on the farm (which requires testing to determine treatment success), an understanding of farm management practices, and information from research about deworming strategies and drugs. Performing fecal egg counts is a critical component of this, and something that is not done nearly enough.

6. Be prepared to change

Something that works today may not work in the future. You can't get stuck in your ways and assume that since something worked in the past, it will always work.

Image source: www.ponytalesblog.com

Alcohol is a disinfectant and can kill many (but not all) bacteria and viruses. Therefore, wiping an injection site with alcohol could theoretically reduce bacterial counts and maybe reduce the risk of an injection site infection. However, alcohol does not work well in the presence of organic debris (i.e. dirt), and may not (and likely won't in most cases) penetrate through a horse's haircoat down to the skin. The best aspect of alcohol is some situations is wetting down the hair to help see the area you're injecting (for example, when visualizing the vein for an intravenous injection).

The risk of injection site infection is very low in the average horse, and the true benefit of wiping the site with alcohol is unknown. There is no clear evidence that this practice reduces infections. The most serious injection-associated infection, clostridial myonecrosis, is caused by either inoculation of clostridial spores (which are resistant to alcohol) or by spores that are dormant in the muscle tissue. In either case, wiping the skin with alcohol won't help prevent it.

Bottom line: There's no evidence that alcohol wiping is needed, or useful. There's also no reason not to do it, so it's really a matter of personal preference. Not using alcohol wipes is not an indication of poor practice, but a lot of people will use them on the chance that they are effective, knowing that at worst they will do no harm.

More information about clostridial myonecrosis can be found on the equIDblog Resources page.

Don't waste your money on Helicobacter testing if your horse has ulcers. Spend it on treatment and management changes to reduce the risks of ulcers recurring.

(click image for source)

There are basically two answers that I give:

1) Streptococcus equi, the cause of strangles, is susceptible to most disinfectants, provided they are used properly. That means using them at the proper concentration, providing the recommended contact time (5-30 minutes, depending on the disinfectant) and ensuring that there is minimal organic debris (e.g. dirt, manure, pus) present on the surface to be disinfected. The latter is a key point, as disinfectants do not work well in the presence of debris, so it's therefore understandably very difficult to really disinfect a stable. Some stable surfaces (e.g. sealed solid walls and floors, buckets) are able to be disinfected if it is done properly, while other surfaces (e.g. dirt floors, unsealed wood walls, leather) are essentially impossible to disinfect.

2) Disinfection is a very minor component of strangles control. It is something to pay attention to and it should be done properly, but too often people to focus on disinfection as the key infection control measure. Just disinfecting surfaces, but ignoring aspects like cohorting exposed and unexposed horses, restricting horse movement, testing for carriers, regular temperature checks of all horses to detect early cases, using good personal hygiene and using protective outerwear, is bound to fail in terms of controlling an outbreak.

So, don't ignore cleaning and disinfection, but don't' rely on it as the main component of strangles control.

More information about strangles can be found on the equIDblog Resources page.

In this outbreak, there were five horses infected and two humans infected. The horses predominantly had signs of neurological disease, not respiratory disease like some other reports describing this disease. Four horses died. One recovered but was euthanized for public health reasons.

Two people became infected after working with the sick horses, which represents 10% of the total veterinary staff that were exposed to the infected horses.  Both people started off with influenza-like illness, which seemed to improve initially, but then signs of severe neurological disease developed. They were treated with ribavirin, an antiviral drug, as part of an experimental treatment. One of them died after 40 days of illness, the other person survived.

The authors stressed that the effectiveness of ribavirin could not be determined, but they recommend it nonetheless because of the severity of Hendra virus infection and lack of other options. Ribavirin was also used in the 2009 outbreak, but it is clearly not 100% effective since one person died there also.

A number of concerning activities occurred that put people at risk of infection, including a "percutaneous blood exposure while euthanizing an infected horses" (they didn't explain exactly what this was, but it could have been a needlestick), low use of personal protective equipment, and contact with potentially infectious body fluids. This is unfortunately not surprising since the approach to infection control (particularly in terms of zoonotic infections) is often lax in equine medicine. That certainly has to change, particularly in areas where Hendra virus may be present.

Much more information about how to control this potentially devastating virus is needed. Fortunately, infections are uncommon and it is restricted to a fairly small geographic range in Queensland, Australia.

Image source: http://animalphotos.info/

Chief veterinary officer Nigel Gibbens stated that these are the first imported cases of EIA identified since 1976. This is a good example of why we need to continue routine infection control measures such as import testing, even when nothing is found for years. Some people try to argue that since certain problems don't seem to be present, or at least are not identified, that infection control testing or activities should be decreased. This situation illustrates why that's bad thinking. Despite only picking up one incident in the past 34 years, this is a very important finding - failure to detect the positive horses could have lead to widespread infection in the country, which would ultimately make it very difficult and expensive to try to control. You never know when the next outbreak is lurking around the corner, and complacency is a big enemy of infection control.

Image source: www.collectgbstamps.co.uk

An article in the International Journal of Infectious Diseases (Friederichs et al) describes infectious arthritis of the shoulder of a horse owner that was caused by Streptococcus zooepidemicus, a bacterium commonly found in horses but rarely associated with disease in people. The person didn't have a wound in the shoulder area or any other obvious route for the bacterium to get to the shoulder joint. They searched for a source of the infection and all they found was a chronic lesion on the person's foot. This, combined with the patient's history of taking care of his horses in "bare feet in boots", led them to implicate the foot as the source of infection.

The idea, I guess, is that socks would be a barrier to help prevent contamination of the foot wound. That makes sense to a degree - the person could contaminate his foot with S. zooepidemicus from his hands (probably acquired from touching the horse's nose) while removing the boots, or manure could work its way into boots and directly contaminate the wound. Both are possible, but we have to be a little cautious in interpreting these conclusions. However, this is a bacterium that is associated with horses and the foot lesion is certainly a possible route of entry.

Overall, this should be considered an interesting report of a very rare problem, not something that indicates a major concern. However, there are a few good points to take away from this story:

• If you have a wound or chronic lesion of any sort, make sure you take measures to reduce the risk of bacterial contamination when working around horses. This might be as simple as making sure it's covered by clothing, or something more involved like using an impermeable bandage.
• Hands are probably the major source of infection transmission, and good hand hygiene is important after horse or stall contact, particularly if you have an underlying disease.

This equIDblog entry was originally posted on our sister site, Worms & Germs Blog, on 20-Jan-10.

The article asks, "If your client suspects that a horse has been bitten by a rabies-infected animal, what should be done?"

Answer: "Contacting you as the veterinarian is always the first step."

Great first step.  A second step that wasn't mentioned should be, "Try to identify and (safely) capture the animal that bit the horse." This is often impossible but certainly worthwhile if it can be done.  However, if you're trying to catch the offending animal, make sure you don't put yourself at risk of exposure to rabies in the process.  If the animal can be caught, it's rabies status at the time of the bite can be determined (either through testing or quarantine). If it can be shown that the animal wasn't rabid, a lot of stress, hassle and expense can be saved.

"If the horse was previously vaccinated... Then isolate and observe the animal for 45 to 90 days (your clinical evaluation will involve gait analysis, radiography and a spinal tap)."

Boosting the rabies vaccine is also a good idea. The next step, however, needs to be contacting local regulatory officials to find out what you have to do. They determine if, how and how long an animal needs to be quarantined - this is NOT the decision of the local veterinarian nor the animal's owner. Most likely, they will recommend a 45 day quarantine for a vaccinated horse, since this is what is recommended in the NASPHV Compendium on Rabies. The discussion of diagnostic testing makes no sense. There is absolutely no indication to perform diagnostic tests on a horse that has been bitten by a rabies suspect. None. There are no tests that can be used to diagnose rabies in live horses (also exposed horses don't instantly develop signs of rabies). Horses should be monitored closely for signs of rabies during the quarantine period, but that's it.

"...and have the client make a list of all people who had contact with the horse."

This is often done when horses have or are suspected of having rabies, but not horses that are potentially exposed. It is done to help public health personnel contact people that may have been exposed to rabies. A horse that was just bitten by an animal is not a risk for transmission of rabies.  (However, keeping a list of people who have contact with the horse after it's been bitten (i.e. durng the quarantine period) - which should be as short a list as possible - is a reasonable precaution in the unlikely event that the horse does develop rabies.)

"If the animal was not vaccinated, your options are to euthanize and perform a postmortem examination of the brain (the only way to definitely confirm rabies)..."

Euthanasia is one of the options that needs to be considered in an unvaccinated horse that has been exposed, which is one of the reasons that identifying the biting animal and testing it is critical, if it can be done. The last part of the above sentence (from the atricle) is complete nonsense. Why would you test the brain of a normal horse that has been euthanized because it's just been bitten by a potentially rabid animal? The horse isn't being euthanized because it has rabies, it's being euthanized because of the likelihood  of it developing rabies weeks to months later. Testing of the brain will tell you absolutely nothing if the animal was only bitten recently.

"...or isolate and observe the horse for six months and develop the human contact list."

Again, this needs to be decided based on discussions with regulatory personnel who are responsible for dictating what is to be done. A six-month quarantine is a pretty standard recommendation for an unvaccinated animal. Creating a human contact list should not be necessary, since quarantine involves severely restricting contact of people with the horse and only a few (ideally one) person would have any type of contact.

The article wraps up with the very true emphasis on vaccinating horses. It's a cheap measure to prevent a relatively rare but invariably fatal disease.

Click image for source.

The latest incident involves the diagnosis of piroplasmosis in three race horses in New Mexico, which were picked up as part of routine screening. There were only three positives out of about 1200 horses tested, so the disease is still rare, but the fact that it was there and none of the positive horses had any link with previous outbreaks is definitely a concern. The OIE report states that transmission is suspected to have been from "artificial" means like sharing needles between horses, not natural tick transmission. This could account for the multiple horses affected but doesn't explain where the disease came from it the first place, and it's unclear how solid that hypothesis really is.

It's quite interesting (surprising, frustrating...) that few comments are put forth in any of these outbreaks indicating where the infections may have originated and why we are seeing recurrent, unrelated infections. Is increased testing in different areas helping to pick up cases that would otherwise have been missed (i.e. were already there), or is piroplasmosis in the US an emerging problem? How confident are they that there are no ticks capable of transmitting T. equi in some of these areas? Is wider screening of horses required to determine the extent of the problem and to determine whether it can be controlled? Is broader screening of ticks in the affected areas needed to see if there are ticks known to be able to transmit T. equi? Are studies needed of other tick species in areas where unexplained cases have occurred to determine if some tick species that are not currently known to be able to spread the parasite can actually do so? Lots of questions... hopefully someone's trying to find some answers.

Click image for source.

Equine infectious anemia is a viral disease of horses and other equids that is characterized by recurrent fever, lethargy, decreased appetite and decreased red blood cell numbers (anemia). Sometimes, the first episode of disease (acute EIA) can be fatal, but most horses recover. Most survivors experience recurrent episodes of illness. In some horses, these episodes become frequent and severe.

A major problem with EIA is that horses are infected (and are infectious) for life. Even if they recover from the acute disease and rarely or never get noticeable recurrent disease, they are still carrying the virus in their blood. Biting flies are the main means of transmission from horse-to-horse, although human-associated transmission through reuse of needles or other procedures that cross-contaminate blood between horses can also be involved.

The combination of life-long infection and an insect vector is BAD. That's why, in areas where EIA is not endemic, infected horses are usually immediately euthanized. In some regions, affected horses can be branded or tattooed to permanently indicate their EIA status and housed at least 200 yards from any other horse (and often with strict insect control measures).

Control of EIA focuses on identification of carriers. Most jurisdictions require regular EIA testing (formerly the "Coggins test") for horses that are traveling or competing, as well as imported horses. While this disease is extremely rare and the vast majority of routine tests are negative, it's a disease that can silently spread in a population if people are not looking for it - routine testing is critical for keeping this disease at bay.

Do all foal's need specific umbilical care? Not really. Most foals, especially those born normally in a clean environment to a healthy mare and who received adequate colostrum, don't need anything done. However, it's not always easy to differentiate these low-risk foals from others, and it is possible for the healthiest foal born in the cleanest environment with ingestion of an adequate volume of good quality colostrum to develop complications, so most people perform some form of post-birth umbilical care (and that's a good thing). The key is making sure that it's the right umbilical care.

The goals of umbilical care are pretty basic:

• Prevent bacteria from entering the umbilicus.
• Avoid damaging the umbilicus and other body tissues, and avoid delaying normal drying of the umbilicus.

What to use?

• Research has indicated that a 0.5% chlorhexidine solution is the optimal umbilical dip. Other disinfectants can also kill local bacteria on the umbilicus but may not be as effective, may not work as well in the presence of debris (dirt, manure...), or may be irritating to body tissues.

Read the label:

• Make sure you are actually using 0.5% chlorhexidine and that it's a solution (diluted in water), not a tincture (diluted in alcohol). If you don't have 0.5% chlorhexidine solution and are unsure about how to dilute it properly, ask your veterinarian.

More is not better!

• Don't think that since 0.5% is good, 5% must be 10 times better. The stronger the concentration, the greater the chance of damage to local tissues, which can increase the risk of complications. Stick with 0.5%.

More is not better! Part 2

• The umbilicus should be dipped in disinfectant, not marinaded in it! The goal is to cover the umbilicus and not other tissues (e.g. the abdominal wall). You don't need to soak the umbilicus or hold the disinfectant in place over it. Short term contact (dip) is adequate. Dip it and walk away. The umbilicus needs to dry up - repeated soaking isn't helpful.

More is not better! Part 3

• The umbilicus should be disinfected shortly after birth, then every 6-8 hours for the first 24 hours of life. That's usually enough. If the umbilicus still appears wet at that time, it can be dipped again. Continued dipping "just is case" is not needed.
  

Don't tie off the umbilicus:

• Tying off the umbilicus can actually increase the risk of complications such as infection and patent urachus (urination through the umbilicus).

Hands off!

• Don't touch, poke or otherwise make contact with the umbilicus with your hands. It's not needed and it's a great way of transferring bacteria to the umbilicus.

If in doubt, call your veterinarian:

• A proactive call to your veterinarian is much better and cheaper than an umbilical infection, umbilical abscess, septic foal or patent urachus. These are all expensive complications and  often difficult to treat successfully. Foals can change very quickly, and waiting to "see what happens" for a day or two can be the difference between a minor complication and a life-threatening problem.

The following general criteria need to be in place to eradicate a disease:

• It must have a clearly defined host range and that range is ideally only one species. A disease that can affect multiple species is very hard to control.
• It must predictably cause disease in individuals that are infected.
• There must be no long-term carriage state. Once a person/animal gets over the illness, he/she/it must get rid of the infection completely in a defined and predictable period of time.
• A highly effective vaccine should be available.
• There must be a commitment to put in lots of time, money and effort everywhere the disease exists.
  

This isn't the case with most diseases, and equine herpesvirus (EHV) has many characteristics that make eradication impossible:

• Unpredictable disease: EHV infection doesn't always cause signs of disease. When it does cause disease the signs can be quite variable and difficult to easily differentiate from other infections.
• Longterm carriage: This is the biggest problem with herpesviruses. EHV is able to survive in a latent (dormant) state in the body after infection. It can lie dormant for a long period of time, but infected animals can always start shedding the virus again. A large percentage of horses are carrying EHV in their bodies and there's no way to get rid of it.
• Vaccine: Vaccines are available but they are by no means 100% effective at preventing infection.
• Time, effort, money and cooperation are terms that are not commonly associated with disease control in horses. Getting everyone to follow a standard recommendation (if one were able to control disease) would be difficult to impossible. The entire horse-owning population would not be willing to spend the money for broad control measures, and there's no real impetus for governments to do so. Even getting people to agree to follow basic vaccination and infection control recommendations is difficult.  If there is any negative impact on use of horses, ease of management or any other minor inconvenience, 100% compliance with any recommendation becomes impossible to obtain.

We have to live with EHV. It will always be a risk to horses. Good infection control measures and vaccination of certain groups (e.g. pregnant mares) can help control the impact of the virus.

While the risk of horses contracting H1N1 is very low, it can be reduced further with common sense practices to reduce the risk of exposure. If you may have influenza, avoid contact with people and other animals, including pets and horses, and get a flu shot.

Image source: http://graphicshunt.com

Equine herpesvirus can cause a range of clinical signs, including fever and respiratory disease, severe neurological disease and abortion. The affected filly in this case had neurological disease and was euthanized. Outbreaks of abortions or neurological disease are the greatest concern, and a specific type of EHV-1 has been implicated as the main cause of neurological disease.

It's always hard to say what the most appropriate response is to a scenario like this. Equine herpesvirus is an endemic virus that is present throughout the world and lies dormant within a large percentage of healthy horses. Most infections are sporadic and only involve a single horse or small number of horses, but outbreaks can occur and that's why aggressive measures are sometimes taken. With only a single diagnosed case and no apparent evidence of transmission to other horses in this case, it's uncertain whether such an aggressive approach is required. However, it's worse to be too lax initially than too aggressive, and a logical approach is to implement aggressive measures, and then reassess them as more information becomes available. If no other horses develop signs consistent with EHV-1 infection, then loosening of the restrictions would be reasonable. If there is evidence of transmission and disease in other horses on the property, continuation with aggressive measures makes the most sense.

A great resource regarding EHV-1 is the ACVIM Consensus Statement on this subject, which is available on the equIDblog Resources page.

Image source: www.calderracecourse.com

The loss of low-risk status greatly affects how Canadian mares are handled upon arrival to breeding facilities in the UK, and will create major hassles for people moving horses to the UK for breeding. There's no indication whether this is a permanent change or whether it may be revisited with more information on the status of CEM in North America.

Image source: http://animalphotos.info/a/

Foals become infected by swallowing the virus, which they usually pick up from the feces of other horses (including their mares) in their environment. The exact source of infection is rarely identified. It is likely that some healthy adult horses are the reservoirs and shed the virus in their manure.

Like other types of diarrhea, rotaviral diarrhea in foals can range from mild diarrhea alone to severe diarrhea with weakness, loss of appetite and dehydration. Colic can occur because of intestinal cramping associated with diarrhea. You cannot differentiate diarrhea due to rotavirus from other types of diarrhea by appearance alone. The diarrhea must be tested to identify the cause.

There is no specific treatment for rotavirus infection, but "supportive care" is often provided. One of the primary components of supportive care is fluid therapy, which may be needed for foals that start to become weak and dehydrated. Aggressive intravenous fluid therapy may be needed in some cases, depending on the severity.

Rotavirus vaccines are available in some regions, although there is limited evidence that they have much of an effect. Few people recommend vaccination. Rather, good attention to foal management practices, hygiene and early diagnosis of infected foals is the key. Foaling mares outside on pasture has been an effective practice in some outbreaks, presumably because there is less rotavirus contamination on pasture.

Image: Colourized TEM of rotavirus particles (source: CDC PHIL 173)

This report is very concerning for several reasons:

• A previous report indicates that positive horses were likely on the index farm for at least a year or two, making it likely that more infected horses are out there. The longer a disease like this goes unnoticed, the farther it can be spread before it's detected and controls are put in place. It's possible that an even larger number of infected horses are in the US now.
• The widespread infection makes it more likely that the disease will establish a true foothold in the US. This bloodborne parasitic disease (caused by Theileria equi) is naturally transmitted by certain types of ticks (not all tick species are able to transmit the parasite). The more areas in which infected horses are found, the greater the chances that infected horses will be bitten by ticks that can transmit the parasite. If it gets established in the tick population, it becomes much harder to control.
• It's not known how so many horses became infected. With this number of infected horses, it seems to me that tickborne transmission is more likely, rather than human-associated transmission through re-use of needles or other means of transmitting bloodborne pathogens. If the disease is being spread through it's natural route, it's harder to control.
• It is still not clear where this outbreak (or the other recent US outbreaks) originated. If you don't know how something started, it's hard to prevent it from happening again.

Piroplasmosis may be on its way to becoming an endemic (established) disease in the US. Broad investigation is required to see if it is present beyond the affected premeses identified so far.

Image source: http://animalphotos.info

Losing national piroplasmosis-free status could have significant repercussions on horse movement to and from the US, and a major impact on the equine industry overall. For this reason, some people might prefer to try to ignore the problem and hope it goes away. But, as I've said before, hope is not an infection control strategy.  It's much better to investigate this carefully and transparently to figure out what is going on. Without knowing the scope of the problem, it's impossible to control it.

Image source: www.australiasigns.com.au

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November 4, 2009

Equine Piroplasmosis Disease Investigation Continues

Canada and a number of U.S. states have imposed movement restrictions or additional entry requirements for horses from Texas after equine piroplasmosis, a tick-transmitted blood disease of equine animals, such as horses, donkeys, mules and zebras, was detected in South Texas in mid-October.  Equine piroplasmosis may be carried and transmitted by as many as 15 species of ticks.  Although ticks have been collected from the South Texas ranch for testing, final results are not complete, and it is not known whether any of the ticks can serve as a host for the disease.

“Before moving horses from Texas, we urge you and your veterinarian to check with animal health officials for any state of destination, to ensure the animals have met all entry requirements,” said Dr. Bob Hillman, Texas’ state veterinarian and head of the Texas Animal Health Commission (TAHC), the state’s livestock and poultry health regulatory agency.  “Regulatory requirements can be fluid as disease situations evolve, so it is essential to call each state each time you haul.”  As states provide entry restrictions and requirements, the documents are posted on the TAHC web site at http://www.tahc.state.tx.us.  Dr. Hillman urged equine owners and veterinarians to call state animal health officials directly before hauling, as many states have not yet distributed entry requirement information. Contact information for state veterinarians may be obtained from the TAHC at  800-550-8242, ext. 710, or by emailing ceverett@tahc.state.tx.us.

“We are continuing the equine piroplasmosis disease investigation initiated in October in South Texas. No horse movement is being allowed from or to the ranch where the infection was detected,” said Dr. Hillman.  “While this tick-borne disease has not been considered endemic in the U.S., cases of the disease, scientifically known as Theileria equi, and previously called Babesia equi, have been detected in the U.S.   Our epidemiologists are tracing the movement of specific equine animals. Blood tests will be conducted, and the animals will be examined for ticks. Individual equine owners will be contacted, if their horse needs to be tested by animal health officials.”

Dr. Hillman refrained from speculating on how many equine animals will be tested or how many may be exposed or infected.  “Until the epidemiological work and testing of potentially exposed horses is completed, there is no way to predict how many horses may be affected with this tick-borne illness,” he said.

Dr. Hillman said horses infected with equine piroplasmosis may appear well, while others may exhibit a host of non-specific clinical signs, such as fever or anemia. These clinical signs also could be attributed to a variety of other diseases or causes. Blood tests are needed to diagnosis the disease. 

“Equine owners should talk with their private veterinary practitioners about complying with interstate movement requirements, testing recommendations and protecting their horses from ticks.  If a horse appears to be ill, it should be evaluated by an accredited private veterinary practitioner,” said Dr. Hillman.

Texas Animal Health Commission
Bob Hillman, DVM * Executive Director
For info, contact Carla Everett, information officer, at
1-800-550-8242, ext. 710, or ceverett@tahc.state.tx.us

We thank Carla Everett, Texas Animal Health Commission for sending this report.