Ticks:  A Health Risk for Livestock and their Owners

Ticks: A Health Risk for Livestock and their Owners


Historical photo of ranchers spraying cattle for ticks in Florida. Photos from the Smathers Archives.

The bacteria that cause Lyme disease is transmitted by the black-legged tick, Ixodes scapularis. Credit:  James M. Newman, UF/IFAS FMEL

Most people can probably tell you that ticks carry Lyme disease. This bacterial disease can cause long-term health problems for humans if left untreated, but it is thankfully relatively rare to find in Florida (132 confirmed cases in 2016). Though Lyme disease may be the best known tick-borne disease, there are others, such as Ehrlichia and Anaplasma, that are potentially harmful to both humans and animals, including livestock.

Ticks are not insects. They are arachnids, closely related to spiders, but with the bad habit of feeding on blood. Humans are not the preferred source of blood for ticks, but most species are perfectly happy settling for human blood. Of the ticks found in our area, the brown dog tick and American dog tick cause the most trouble. That being said, you might also find other species such as the Gulf Coast tick or lone star tick, but these are less likely to be problematic.

The cattle tick may be of interest to livestock owners, as it may transmit disease to not only cattle but also horses, sheep, and goats. Introduced to the United States along with the cattle that accompanied early explorers, this tick was originally native to the Mediterranean region and the Near East. It stays on one host, feeding for 18-20 days before females drop off to lay their eggs. They may produce up to four generations every year, meaning that a small population, once established, has the potential to grow very large very quickly. This makes them dangerous, coupled with the fact that they can carry diseases such as anaplasmosis, caused by the bacteria Anaplasma marginale, and Texas cattle fever, caused by the haemoprotozoan parasites Babesia bigmina and Babesia bovis.

Texas cattle fever devastated herds in the late 1800s, spread by the cattle tick. Eradication programs in place since 1906 have limited this species of tick to a few counties in south Texas, but the danger exists that deer or other wildlife could carry these pests to other areas. Part of what helps keep this danger to a minimum are ongoing eradication and surveillance efforts, including surveillance by the Florida Department of Agriculture and Consumer Services (FDACS). You can help these efforts, whether or not you own livestock, by turning ticks you find in for testing to FDACS. Their Division of Animal Industry can be reached at (850) 573-0299.

To help control ticks of any sort, try maintaining the landscape to deter them. Keep wildlife out with fences or deterrents, and ensure the edge of lawns, fields, and pastures are free of leaf litter and debris. Keep lawns mowed and don’t let pets out into the woods where they can pick up ticks to bring home. Use insecticides if needed; repellents may work for personal use. Livestock may be treated with pyrethroid sprays or wipe-on products. Ticks may attach to any part of an animal, but in livestock tend to prefer the tail, head, neck, chest, and belly, particularly near the legs. Heavy infestations may require an application of insecticides to the area, indoors or out, to reduce major infestations.

The lone star tick feeds on the blood of various animals including humans. This tick does not transmit Lyme disease, but can transmit various other pathogens such as ehrlichiosis, rickettsiosis, tularemia, and theileriosis. Adult lone star ticks: male (left) and female (right).  Source:  EDIS Lone Star Tick Photo credit: Lyle Buss, UF/IFAS


For more information on this subject, use the following links:

Texas A&M’s TickApp

Ticks (Family Ixoididae)

Gulf Coast Tick, Amblyomma maculatum Koch (Acari: Ixodidae: Amblyomminae)

Lone Star Tick Amblyomma americanum (Linnaeus) (Acari: Ixodidae)

American Dog Tick, Dermacentor variabilis (Say) (Arachnida: Ixodida: Ixodidae)

Brown Dog Tick, Rhipicephalus sanguineus Latreille (Arachnida: Acari: Ixodidae)

Lyme Disease

Lyme Disease in Florida Horses

Ehrlichia and Anaplasma in Florida

External Parasites on Beef Cattle


Future Livestock Producers are Developed through Local Livestock Shows

Future Livestock Producers are Developed through Local Livestock Shows


Christian Rodriguez of Live Oak, with his Brahman Heifer, Welu. Credit: Tyler Jones

Audrey Bodiford, of Jay, FL, winner of the 2017 SRC Fair & Youth Livestock Show Spirit Award.

Santa Rosa County Extension Agents have worked closely with the Santa Rosa County Fair over the last five years to grow the livestock show. The Santa Rosa County Fair (SRC Fair) is held in April each year, but requires considerable planning throughout the year. The board has many sub-committees that focus on the various events of the fair. These committees meet numerous times throughout the year planning their specific activities.  Their efforts come together on opening day to make the SRC Fair and Youth Livestock Show an enjoyable time for our area residents. With the support and efforts of the Gulf Coast Agriculture & Natural Resource Youth Organization (GCANRYO) and the Santa Rosa County Fair Board, the livestock show has grown from a handful to over 300 youth participants this year.

Jenny is just one example of how these type programs can nurture the development of life skills and passion for the livestock industry. Jenny was a very shy youth who had a passion for raising livestock. However, she struggled with communicating with adults outside her family who were prospective buyers and sponsors. She attended a buyer communication workshop that was presented at the local Extension Office. After attending the workshop, she was more comfortable pursuing financial support for her steer project. At the livestock show and sale, she informed the extension agents that she had secured a buyer for $3.00 a pound and had received over $2,500 in sponsorship’s for her project in 2016.  This year, her steer project was even more successful building on what she had learned the previous year.  At a nutrition workshop held at the beginning stages of the project year, Jenny shared that she had already secured $3,150 in sponsorship and had a buyer for her steer!  While securing auction buyers, and project sponsors is not a true commercial business model, the communication skills and self-confidence gained from this experience will aid these youth for the rest of their lives.

Livestock committees are tasked with ensuring all the infrastructure is in place for our 4-H and FFA youth to show and exhibit their livestock projects consisting of: beef cattle, swine, goats, poultry, rabbits and horses.  The 2018 SRC Fair and Youth Livestock show is just around the corner. It is open to youth across the Panhandle. If your kids, grandkids or neighbors have in interest in livestock, please share this information with them and their parents.  Offer them facilities and equipment to use for livestock projects, or just assistance getting started in the livestock industry.  Give generously of your time, talent and experience to volunteer and support your local livestock show.   Through organized shows, farmers and ranchers can make a difference in the lives of youth that  will impact them for the rest of their lives.  These are the future leaders of our communities, and in some cases of the agricultural industry in this region.  Find a way to get involved, even if only through financial contributions.

Key Upcoming Dates for the Santa Rosa County Fair:

  • Saturday, November 4, 2017 – Market Steer Weigh-in and registration – 3 pm- 5 pm
  • Saturday, January 6, 2018 – Market Hog Weigh-in and registration –  , 10 am – 12 noon
  • Livestock Show dates are:
    • March 29th – Youth Rabbit Show
    • April 1st  –  Youth Poultry Showmanship
    • April 6th – Youth Goat Shows
    • April 7th  – Youth Beef Cattle and Hog Shows

For rules and further information please visit the SRC Fair website.

Friday Feature:  Preventing Needlestick Injuries to Ranch Hands

Friday Feature: Preventing Needlestick Injuries to Ranch Hands

More than 80% of workers on livestock farms have accidentally stuck themselves with needles used for vaccine and drug administration.  Accidental needlestick injuries are usually minor, but can be serious with skin infections, allergic reactions, and deep tissue wounds that require surgery.   This week’s featured video was developed by the Upper Midwest Agricultural Safety and Health Center (UMASH) to be used to provide employee training for dairy farm workers.  These same principles apply to workers on any type of livestock operation who are using disposable hypodermic needles for vaccine and drug administration.

Key Points to Emphasize with employees or family members regarding needle safety:

Don’t Get Stuck (Prevention)

  • Slow down and don’t rush injections

  • Restrain animals properly

  • Get help from coworkers to properly restrain animals before injection

  • Use good techniques and the correct equipment with every animal

  • Don’t remove needle caps with your mouth

  • Don’t recap used needles (Never try to reinsert used needles into the cap held in your mouth or hand)

  • Dispose of used needles in a rigid sharps disposal container

  • Discard bent, dull, or dirty needles that contact mud and manure

  • Don’t carry around syringes with needles in shirt or pants pockets while working with animals

  • Don’t dispose used needles into normal trash containers

Been Stuck (Care after accidental injection)

  • Stop working to provide care for the wound

  • Immediately wash skin thoroughly with soap and water

  • Apply topical disinfectant

  • Bandage puncture wound to prevent further contamination

  • Report injury to supervisor

  • Contact your health care provider to ensure tetnus vaccinations are current and to seek advice for wound care

To share this information with employees, print out the needlestick safety poster to display near chutes, handling facilities, and drug storage areas:

Don’t Get Stuck Needlestick Prevention Safety Poster


If you enjoyed this video, you might want to check out the featured videos from previous weeks:  Friday Features

If you come across a humorous video or interesting story related to agriculture, please send in a link, so we can share it with our readers. Send video links to:  Doug Mayo



Quarantine Lifted, Screwworms Eradicated from Florida Keys

Quarantine Lifted, Screwworms Eradicated from Florida Keys

Screwworm larvae. Source: Foreign Animal Diseases “The Grey Book” USAHA

In the fall of 2016, USDA’s Animal Health Inspection Service (APHIS) confirmed the presence of screwworms in the Florida Keys.  The Florida Department of Agriculture and Consumer Services (FDACS) announced on March 18, 2017 that they were winding down their response to the screwworm infestation in Monroe County.  After months of surveillance, trapping, sterile fly release and an animal checkpoint leaving the keys, no new screwworm infestations have been found since January 10, 2017.  FDACS lifted the animal quarantine for Monroe County, and closed the Animal Health Check Point in Key Largo on Saturday, March 18, 2017.  On Thursday, March 23, 2017 USDA’s Animal and Plant Health Inspection Service announced the successful eradication of the New World screwworm (NWS) from Florida.

In response to the confirmation of screwworms in the keys, Florida Commissioner of Agriculture Adam Putnam declared an agricultural state of emergency in Monroe County, Florida on October 3, 2016. An Animal Health Check Zone was established at mile marker 106 to ensure that animals did not leave the area with screwworms. Inspectors checked more than 16,000 animals with no detection of screwworms.  APHIS reports having released over 150 million sterile male flies and completing 430 hours of surveillance in the keys, and 250 hours of surveillance on the Florida mainland.  APHIS and FDACS will continue passive surveillance over the coming weeks.

Florida livestock and pet owners should continue to monitor animals carefully and report any potential cases to 1-800-HELP-FLA (1-800-435-7352).

More information on the FDACS & APHIS response to the New World screwworm eradication project in the keys is available at:


Article Sources: FDACS: With No Screwworms Found in Months, Animal Health Checkpoint in Monroe County to Close, and USDA Announces Eradication of New World Screwworm in Florida


APHIS Confirms New World Screwworm in Dade County Dog

APHIS Confirms New World Screwworm in Dade County Dog


Screwworm larvae. Source: Foreign Animal Diseases “The Grey Book” USAHA

The United States Department of Agriculture’s (USDA) Animal and Plant Health Inspection Service (APHIS) confirmed the presence of New World screwworm (Cochliomyia hominivorax) in a stray dog near Homestead, Florida. The dog was isolated and his infested wounds were treated. Federal and state officials have started active surveillance in the area.

This is the first confirmed case on Florida’s mainland. Screwworm was first confirmed on October 3, 2016 in Key deer from National Key Deer Refuge on Big Pine Key, Florida. This initial presence of screwworm was the first local detection in the United States in more than 30 years and Florida’s Commissioner of Agriculture, Adam Putnam declared an agricultural state of emergency in Monroe County, Florida.

Since October, 13 Keys had known infestations mostly in the key deer population, with five confirmed infestations in domestic animals. Animal health and wildlife officials at the state and federal levels have been working aggressively to eradicate this pest. Extensive response efforts have included fly assessments to determine the extent of the infestation, release of sterile flies to prevent reproduction and disease surveillance to look for additional cases in animals. Officials have received significantly fewer reports of adult screwworm flies in the area and fewer cases of infected Key deer. To date, fly assessments have been conducted on 40 Keys. USDA has released over 80 million sterile flies from 25 ground release sites on twelve islands and the city of Marathon. The initial epidemiology report on the Florida Keys infestation may be viewed at https://www.aphis.usda.gov/stakeholders/downloads/2017/nws-epi-report.pdf.

Life cycle of New World Screwworm from Fernandez and White, 2010. Investigation into Introduction of New World Screwworm into Florida Keys

Residents who have warm-blooded animals (pets, livestock, etc.) should watch their animals carefully. Florida residents should report any potential cases to 1-800-HELP-FLA (1-800-435-7352) or non-Florida residents should call (850) 410-3800.  Visitors to the area should ensure any pets that are with them are also checked, in order to prevent the spread of this infestation.

While human cases of New World screwworm are rare, they have occurred, and public health officials are involved in the response. No human cases have been reported in Florida. For more information about this disease in humans, please contact your local public health department. Using fly repellents and keeping skin wounds clean and protected from flies can help prevent infection with screwworm in both people and animals.

New World screwworm are fly larvae (maggots) that can infest livestock and other warm-blooded animals, including people. They most often enter an animal through an open wound and feed on the animal’s living flesh. While they can fly much farther under ideal conditions, adult flies generally do not travel more than a couple of miles if there are suitable host animals in the area. New World screwworm is more likely to spread long distances when infested animals move to new areas and carry the pest there.

In the 1950s, USDA developed a new method to help eradicate screwworm using a form of biological control, called the sterile insect technique, which releases infertile flies in infested areas. When they mate with wild females, no offspring result. With fewer fertile mates available in each succeeding generation, the fly, in essence, breeds itself out of existence.  USDA used this technique to eradicate screwworm from the U.S. and worked with other countries in Central America and the Caribbean to eradicate it there as well. Today, USDA and its partners maintain a permanent sterile fly barrier at the Darien Gap between Panama and Colombia to prevent the establishment of any screwworm flies that enter from South America.

For more information on this subject, use the following links:

USDA Confirms Screwworms in the Florida Keys

Investigation into Introduction of New World Screwworm into Florida Keys

APHIS New World Screwworm Fact-sheet


Medicated Livestock Feeds Will Require Veterinarian Authorization in 2017

Medicated Livestock Feeds Will Require Veterinarian Authorization in 2017

As January 1, 2017 nears, beef cattle producers need to be prepared for the Veterinary Feed Directive (VFD) regulation. Photo courtesy of Troy Walz.

Livestock producers will need veterinarian authorization, similar to a prescription, to utilize feeds that include antibiotics in 2017. Photo credit: Troy Walz, Univ. of Nebraska

Source: FDA CVM Animal Feed Safety System Team

As of January 1, 2017, animal producers will not be able to purchase feeds over the counter that contain antimicrobials deemed important for human health. Instead, to buy and use feeds containing those antimicrobials, animal producers must be authorized by a licensed veterinarian who is operating under the Food and Drug Administration’s revised Veterinary Feed Directive, or VFD rule.

The VFD rule has been in effect for 20 years, but it affected only a small number of producers, and just a few antimicrobials. As of January 1, changes to the rule will mean that it will impact most animal producers and apply to many more antimicrobials.

The antimicrobials that will be covered by the VFD rule are considered “medically important,” because they are important for human health. A list of medically important antimicrobials is in Appendix A of FDA’s Guidance for Industry #152: http://www.fda.gov/downloads/AnimalVeterinary/GuidanceComplianceEnforcement/GuidanceforIndustry/UCM052519.pdf.

And, information on drugs transitioning from over-the-counter status to VFD status is available here: http://www.fda.gov/AnimalVeterinary/DevelopmentApprovalProcess/ucm482107.htm.)

Also, after January 1, animal drug sponsors will have removed the claims of “growth promotion” and “feed efficiency” from the labels of medically important antimicrobials. Animal drug sponsors, in cooperation with CVM, are currently changing the labels for their products so that production claims such as “growth promotion” or “feed efficiency” will be gone from labels, thus those uses will no longer be permitted.

These changes will have a significant effect on the animal production industry. Animal producers must have a VFD order – issued by a licensed veterinarian, operating under a veterinarian-client-patient relationship – to use a feed with a medically important antimicrobial. (To find out more about veterinary-client-patient relationships, see Guidance for Industry #120, which you can get to from the VFD page listed below.)

The feed distributor that the producer works with must receive the order before releasing the VFD feed to the animal producer. The veterinarian can, for example, give the producer a second copy of the order (one for the producer to keep, and one for the producer to give to the feed distributor), or the veterinarian could send the order directly to the feed distributor.

The animal producer must use VFD feeds only in accordance with the VFD order. In other words, the producer can feed only those animals identified by the order, and only during the time period specified in the order. Feeding animals other than those specified in the VFD order or feeding them beyond the expiration date of the VFD order is considered an “extra-label” use of feed. That’s an illegal use. Once the order expires, if continued treatment is required, the animal producer must get a new VFD order from the veterinarian.

We understand that there are some questions concerning the use of antimicrobials in feed for show animals, including animals used in FFA and 4-H shows. If you have specific questions about the VFD rule and show animals, please send those questions to this e-mail address: AskCVM@fda.hhs.gov. Your questions will be promptly answered.

The changes in the VFD rule will help FDA address the issue of antimicrobial resistance. In principle, giving antimicrobial drugs to food-producing animals at low levels for long periods of time and giving the antimicrobial drugs to large numbers of animals may contribute to the development of antibiotic resistance, which makes diseases caused by resistant bacteria more difficult to treat. Finding antimicrobials to treat a disease is far more difficult when the disease is caused by resistant bacteria.

A veterinarian’s involvement is important because veterinarians have the medical training necessary to diagnose the disease and to identify the appropriate antimicrobial for the specific situation.  The veterinarian’s involvement will help to ensure judicious use of antimicrobials.

Here’s how you can find out more about the VFD rule.

More information, including brochures in both English and Spanish for producers, veterinarians, retailers, and distributors, is available on FDA’s VFD page: http://www.fda.gov/animalveterinary/developmentapprovalprocess/ucm071807.htm.

Information about the reasons for the change is in Food and Drug Administration Guidance for Industry #213, which you can find here http://www.fda.gov/downloads/AnimalVeterinary/GuidanceComplianceEnforcement/GuidanceforIndustry/UCM299624.pdf.

Should you have additional questions, please contact AskCVM@fda.hhs.gov.  And, for other information about safe feed, please come to www.FDA.Gov/SafeFeed, a site maintained by CVM’s Animal Feed Safety System Team.