Dr. Erika M. Johnson, DVM

06/05/2026

The U.S. Department of Agriculture’s (USDA) Animal and Plant Health Inspection Service (APHIS) has provided an important update on New World Screwworm which has been detected in a bovine in Zavala County, Texas. Read the full press release here: https://www.aphis.usda.gov/news/agency-announcements/usda-confirms-presence-new-world-screwworm-united-states

General information about New World Screwworm (NWS) can be found in the text below and in the attached infographic.

The adult screwworm fly is about the size of a common housefly (or slightly larger), with orange eyes, a metallic blue or green body, and three dark stripes along its back. It gets its name from the behavior of its larvae (maggots) as they burrow (screw) into the wound, feeding as they go. The maggots (larvae) cause extensive damage by tearing at the hosts’ tissue with sharp mouth hooks. The wound can quickly become enlarged and deeper as more maggots hatch and feed on living tissue.

Because they feed on live flesh, NWS maggots may burrow deep into wounds or openings, while other species of maggots may appear around the outer surface of the wound. In addition, even the smallest wounds have the potential to attract flies, so it is imperative that you keep a close eye on your animals for any signs of wounds.

Lastly, NWS infestations are a reportable disease! Immediately report any suspicious wounds, maggots, or infestations to a local accredited veterinarian, your State Animal Health Official, or a USDA veterinarian.

For more information, reference this resource from the U.S. Department of Agriculture: https://www.aphis.usda.gov/animals/animal-health/livestock-and-poultry-disease/stop-screwworm

05/21/2026

As the temperatures rise and the sun stays out longer, make sure your equine friends are adequately protected from harmful UV rays. ☀️

Hot summer weather puts horses at risk not only for dehydration and heat stress but also the skin damage and discomfort that accompany a sunburn— just like humans.

A lot of equestrians love some chrome on a horse, but it's important to remember that those beautiful white markings and the non-pigmented pink skin underneath are more likely to suffer from sunburn, especially in areas where the skin is more sensitive — like around the eyes and the nostrils.

In addition to the pain and discomfort, horses that are prone to recurrent sunburn may also face other long-term consequences, like the increased likelihood of developing squamous cell carcinoma (a common cancer).

If your horse is susceptible to sunburn, contact your veterinarian for more information about sun damage and recommendations to keep your equine protected this summer.

02/06/2026

01/21/2026

I’m not even sure where this myth came from, but it’s definitely a myth!

11/22/2025

𝐄𝐇𝐕-𝟏 𝐚𝐧𝐝 𝐄𝐇𝐌 𝐒𝐞𝐫𝐢𝐞𝐬: 𝐂𝐮𝐫𝐫𝐞𝐧𝐭 𝐭𝐫𝐚𝐧𝐬𝐩𝐨𝐫𝐭 𝐫𝐞𝐜𝐨𝐦𝐦𝐞𝐧𝐝𝐚𝐭𝐢𝐨𝐧𝐬 𝐚𝐧𝐝 𝐫𝐞𝐪𝐮𝐢𝐫𝐞𝐦𝐞𝐧𝐭𝐬

The initial outbreak of EHV-1 with an EHM (Equine Herpes Myeloencephalopathy) form occurred after a Women’s Professional Rodeo Association (WPRA) World Finals event in Waco, TX (Nov. 5-9). After this event, many of the same horses attended other events in TX and OK before experiencing any clinical signs (average of 4-7 day incubation period), which is what contributed to the multi-state spread of this disease. After the BFA event in Guthrie, OK was cancelled, owners were advised to leave the premises, bringing potentially exposed horses back to their home states and is another reason why we are seeing the disease in so many areas now.

As of 12:00pm on 11/21/2025, there are 15 confirmed cases of EHM and 1 confirmed case of EHV-1 without neurologic signs in the states of Texas, Oklahoma, Louisiana, Colorado and New Mexico. There is one unrelated case (not associated with this event/outbreak) reported in Maryland. There are many other horses undergoing testing without confirmed, reported numbers at this time.

So, what does this mean for current travel recommendations, health certificate requirements and upcoming events?

𝐀𝐫𝐢𝐳𝐨𝐧𝐚 & 𝐍𝐞𝐯𝐚𝐝𝐚 𝐃𝐞𝐩𝐚𝐫𝐭𝐦𝐞𝐧𝐭 𝐨𝐟 𝐀𝐠.: Horses that have been at the following locations will not be allowed entry into the state for 21 days following potential exposure even if they are not symptomatic if they have been on the following premises (subject to change):

- Extraco Events Center (Waco, TX)
- 377 Arena (Stephenville, TX)
- Lazy E Arena (Guthrie, OK)
- Jackson County (Edna, TX)

Health certificates for the horses traveling into these states will require a statement from the veterinarian filling out the health certificate stating that the horse has not been on one of these premises (or any that come up with an EHV-1/EHM positive case) for the 21 days leading up to the date of the health certificate.

𝐘𝐨𝐮𝐫 𝐭𝐲𝐩𝐢𝐜𝐚𝐥 𝟑𝟎 𝐝𝐚𝐲 𝐡𝐞𝐚𝐥𝐭𝐡 𝐜𝐞𝐫𝐭𝐢𝐟𝐢𝐜𝐚𝐭𝐞 𝐰𝐢𝐥𝐥 𝐧𝐨𝐰 𝐨𝐧𝐥𝐲 𝐛𝐞 𝐯𝐚𝐥𝐢𝐝 𝐟𝐨𝐫 𝟓 𝐝𝐚𝐲𝐬 𝐢𝐟 𝐭𝐡𝐞 𝐬𝐭𝐚𝐭𝐞 𝐲𝐨𝐮 𝐚𝐫𝐞 𝐭𝐫𝐚𝐯𝐞𝐥𝐢𝐧𝐠 𝐟𝐫𝐨𝐦 𝐡𝐚𝐬 𝐡𝐚𝐝 𝐚 𝐩𝐨𝐬𝐢𝐭𝐢𝐯𝐞 𝐜𝐚𝐬𝐞 𝐨𝐟 𝐄𝐇𝐕-𝟏/𝐄𝐇𝐌.

The National Finals Rodeo Committee released the following statement this morning in regards to the NFR event happening in December:
- “All horses must have a 7 day Certificate of Veterinary Inspection (CVI) and unique entry permit number obtained from the NV Dept. of Ag.
- All participants and competitors are responsible for daily temperature monitoring of their horses.
- There is a no-travel advisory for all horses participating and competing at the NFR.
- Enhanced verification and check-in procedures will be in place at the Thomas & Mack Center.
- Biosecurity measures will be maintained throughout the event.”

𝐓𝐡𝐞 𝐎𝐫𝐞𝐠𝐨𝐧 𝐃𝐞𝐩𝐚𝐫𝐭𝐦𝐞𝐧𝐭 𝐨𝐟 𝐀𝐠𝐫𝐢𝐜𝐮𝐥𝐭𝐮𝐫𝐞 (𝐎𝐃𝐀) has additionally released new rules to mitigate EHV risk. Exhibitions/events where other equines will be present need to register with the ODA at least 20 days prior to the event. Additionally, event organizers/producers need to have a record of all animals/competitors for 90 days following the event, which will only need to be made available to the ODA in the case of an outbreak. They recommend consulting with your licensed veterinarian on protocols to establish if a sick animal is discovered during the event, and a licensed veterinarian of record must be available to provide services during the event. If any animals show potential signs of infectious, contagious or communicable disease they will not be allowed entry to exhibitions/events, and should remain isolated until they are able to be examined by a veterinarian.

As this is an evolving situation, guidelines will likely continue to change. Please feel free to ask questions in the comments below.

Up to date information on reported positive cases can be found here: https://equinediseasecc.org/news/article/Equine-Herpesvirus-Myeloencephalopathy-(EHM)-Outbreak

Rules for the state of OR can be found here: https://www.oregon.gov/oda/animal-health-feeds-livestock-id/exhibitions/pages/exhibition-rules.aspx

-Dr. Cooper

02/22/2025

01/22/2025

It’s not uncommon to find horses and ponies living well into their 20s and 30s, thanks to continuous advances in nutrition and health care.

Horse owners have a big impact as well and can help their horses thrive in their golden years through proper management practices like those illustrated in the graphic. But remember, although there is much you can do on your own to keep your older horse happy and spry, some conditions associated with aging require medical intervention.

Scheduling regular visits and keeping a good line of communication with your veterinarian will allow you to respond quickly to any ailments or injuries that could cause your horse a serious or prolonged set back. That means less worry for you, and a better quality of life for your old friend!

01/13/2025

WHAT TO EXPECT WHEN YOU'RE EXPECTING (A FOAL) 🐴

If your mare has made it through 11 months of pregnancy, you're almost there. Labor and delivery, while momentous, are generally uncomplicated — however, being a prepared and informed owner will help you keep your anxiety in check so you can assist the new mother and foal get off to a great start.

Here are some things you can do to prepare for the arrival of the foal:

• Consult with your veterinarian well in advance of the birth. Know how to reach your regular veterinarian after hours and ask about a back-up or referring veterinarian in case your regular horse doctor is not available.

• Clean and disinfect the stall as thoroughly as possible. Provide adequate bedding.

• Wash the mare's udder, v***a and hindquarters with a mild soap and rinse thoroughly.

• Wrap the mare's tail with a clean wrap when you observe the first stage of labor. Be sure that the wrap is not applied too tightly or left on too long, as it can cut off circulation and permanently damage the tail.

• Time each stage of labor, to help you keep accurate track of the mare's progress. Take written notes! When you're worried or anxious, your perception of time can become distorted.

As always, these are general guidelines, and you should contact your veterinarian for more information specific to your situation. Good luck!