Florida Equine Piroplasmosis Investigation Continues

The Florida Department of Agriculture and Consumer Services continues to keep the horse industry informed about the discovery of horses with the rare and contagious disease of Equine Piroplasmosis (EP).

A total of 18 premises are currently under state quarantine due to exposure to EP. Since the investigation began, 25 premises have been quarantined, with approximately 200 horses being tested for the disease. Seven of the 25 premises have been released from quarantine as a result of negative testing and an extended time since exposure to the disease.

During the investigation this week no additional premises have had horses test positive, leaving the current number of positive premises at 6. Only 3 of the quarantined premises have positive horses still residing on the farm.

The investigation is continuing and animals are still being traced and tested. Tick surveillance is continuing as well. There have been no exotic ticks found and all testing on ticks collected has been negative for EP.

There are no state restrictions placed on Florida horses at this time and the only country that has placed restrictions on Florida horses is Canada, which will not accept any horse that has been in Florida within the past 21 days. The State Veterinarian’s Office is continuing to work with the United States Department of Agriculture in an effort to have the Canadian restrictions reduced or lifted but for now, they remain in effect.

Florida Authorities Continue to Quarantine Farms withe EP-Positive Horses

Last weekend two additional horse facilities in Florida were identified as being exposed to Equine Piroplasmosis (EP), according to the Florida Department of Agriculture and Consumer Services. The disease is believed to be spreading via horse movement in the Manatee County area. The latest premises, located in Dade and Lake Counties, were quarantined after finding that one horse at each location tested positive for EP.

These cases bring the total number of quarantined premises to 19 and the number of horses testing positive to 20, on 6 of the quarantined premises. All of the horses testing positive are closely linked via movement and common premises.

Because there is a close association between all 20 positive horses, the spread of the disease is believed to be due to management practices, such as the improper use of hypodermic needles, that result in the transfer of whole blood between horses.

State health authorities report that tick trapping and surveillance is ongoing but no foreign ticks have been found and no domestic ticks have tested positive for the organism that causes EP.

Canada has issued an order banning entry from any horse shipments originating in Manatee County.

EP was believed to have been in control in the USA for the past 20 years or so. It is a disease carefully monitored by health officials. The USDA has strict import rules about horses coming from countries where EP is found. Finding it here was a big surprise for everyone, and a health concern that complicates the big picture of equine disease in this country.

Florida Disease Update: Four Additional Horses Infected with EP

(This information is provided by the State of Florida. Please see the previous post on this blog about Equine Piraplasmosis (EP) in Florida for much more in-depth information. This post is simply an update.)

Further testing on samples from horses on the index premises in Manatee County, have
indicated that four additional horses on the premises are infected with the organism that
causes Equine Piroplasmosis (EP). The four positive horses were stabled in the barn with the
initial clinical horse. All other horses on the premises, which are managed separately from the
horses in the barn, were negative on testing. In addition, 20 ticks found at the premises were
identified as the Gulf Coast tick (Amblyomma maculatum), which has not been shown to
transmit the disease between horses.

The preliminary investigation indicates that the transmission on the index premises may have
been caused by use of common needles between horses and not spread naturally by a tick
vector. The Department is continuing its investigation including additional horse and tick
surveillance of the area. As a precaution, 3 adjacent premises and 1 contact premises have
been placed under quarantine pending further sample collection and testing.

Today the State of Florida issued an additional update:

While Tropical Storm Fay delayed investigation efforts earlier in the week, additional samples were collected and tick inspections performed yesterday. Further horse testing and tick surveillance will continue over the weekend.

Currently the only premises with evidence of EP is the one index premise in Manatee County. There have been no additional clinical cases reported at this time.

While no states have restricted movement of Florida horses, Canada has advised the United States Department of Agriculture they will not accept horses originating from Manatee County, effective immediately. This ban will stay in effect until further notice.

Equine Piroplasmosis Case in Florida: First US Case Since 1988

Equine piroplasmosis is spread by ticks. It can be carried by several types of ticks, including the American dog tick, according to the AVMA.

Many horses are not allowed to be imported into the US because they come from countries where the disease of Equine Piroplasmosis (EP) is found. The US has not had a case since 1988, and the import restrictions have always been credited with eradicating the tick-borne disease.

So, today's news from Florida is a shock. We will print here the entire health warning from the Florida Department of Agriculture and warn Florida horse owners to keep an eye out for strange behavior and disease symptoms. The web site of the Florida authorities will be at the end of this post.

The infected horse is a seven-year-old Quarter horse gelding in Manatee County.

According to the American Veterinary Medical Association (AVMA), an outbreak of EP in Florida in the 1960s was traced to a horse imported from Cuba. At the 1996 Olympics in Georgia, horses from EP-infected countries--which make up about 90% of the world--were not allowed to compete in the eventing, because of the risk of infecting countryside tick populations in the state. On the US and Canada, Australia, Japan and the British Isles are technically free of this disease.

Here's the official warning from the State of Florida:

Florida Agriculture and Consumer Services Commissioner Charles H. Bronson announced today that a Manatee County horse has been diagnosed with Equine Piroplasmosis (EP) - an animal disease that the U.S. has been considered free of since 1988.

Blood and tissue testing of a seven-year-old gelding that had been euthanized after a three-week illness confirmed the presence of the disease in the animal.

State officials immediately quarantined the premises in which the horse resided, as well as two adjacent properties containing horses pending a determination of their status.

An ongoing investigation is being conducted by the State Veterinarian’s Office to determine the source of the disease and whether it has spread beyond the immediate area where the infected animal was housed.

EP

Equine Piroplasmosis (EP) is a blood-borne parasitic disease primarily transmitted to horses by ticks or contaminated needles. The disease was eradicated from Florida in the 1980’s, and the tick species believed to transmit EP in other countries have not been identified in Florida in many years. This disease is not directly contagious from one horse to another but requires direct blood transfer. Human infection with equine piroplasmosis is extremely rare.

Acutely affected horses can have depression, fever, anemia (decreased red blood cells) jaundiced (yellow) mucous membranes and low platelet counts. EP can also cause horses to have roughened hair coats, constipation, and colic. In its milder form, the disease causes horses to appear weak and show lack of appetite. Some horses become chronic carriers of the disease.

ADVICE TO VETS AND HORSEOWNERS

Veterinarians, horse owners, and others in the equine industry in Florida are asked to monitor their horses carefully and contact their veterinarian if they suspect this disease. Because it is a disease that the U.S. has been free of for two decades, suspected cases must be reported to the Office of the State Veterinarian by law.

With the exception of the quarantined premises, there are no EP movement restrictions on horses within Florida or between Florida and other states. Horses entering Florida from other countries with Equine Piroplasmosis will continue to be tested prior to and following entry according to the current rule.

WHAT HORSEOWNERS SHOULD DO

1. Monitor your horse for the presence of ticks. Use commercially available topical products labeled for ticks if your horse is in an area where tick infestation is a problem. Most of these products are synthetic pyrethrins. Include an avermectin product in your deworming program to provide systemic treatment for ticks. Ask your veterinarian if you are unsure.
2. If you find large numbers of ticks or suspect piroplasmosis, please contact your veterinarian.
3. Do not share needles between animals during the administration of any medication or vaccinations. EP and other diseases can be spread by the introduction of blood cells from an infected animal into an uninfected animal during routine administration of injectable medications.
4. Continue your normal equine activities.

Additional updates and information will be posted to the Florida Department of Agriculture and Consumer Services, Division of Animal Industry web site at: http://www.doacs.state.fl.us/ai/.

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