I found this, and it doesn't quite sound as dire as the percentage you mentioned.
http://tscra.org/texas-anthrax-update-july-16-2019/There's links in the story to more info.
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Texas anthrax update, July 16, 2019
Source: Texas Animal Health Commission | July 16, 2019
Since July 9, 2019, anthrax has been detected on 3 additional properties in southwest Sutton County and 1 site in south-central Crockett County. The Texas Animal Health Commission quarantined the premises after animals tested positive for the reportable disease.
To date, 8 premises in 3 Texas counties have had animals confirmed with anthrax. Animals include the following species: antelope, goat, horses, and cattle. Producers have been advised on vaccinating exposed animals and instructed on the proper disposal of affected carcasses, as outlined by TAHC’s rules. Anthrax quarantines are typically lifted 10 days from vaccination or the last death loss.
It is common to see an increase in anthrax cases after periods of wet, cool weather, followed by hot, dry conditions. During these conditions, animals ingest the anthrax bacteria when they consume contaminated grass and hay, or inhale the spores. Outbreaks usually end when cooler weather arrives.
There is an effective anthrax vaccine available for use in susceptible livestock, including but not limited to, swine, equine, sheep, goats, cattle, etc. TAHC encourages livestock owners to consult with a local veterinary practitioner and consider vaccinating livestock if owners live within the triangular area bound by the towns of Uvalde, Ozona and Eagle Pass. Producers may order anthrax vaccines directly from the manufacturer.
After exposure to anthrax, it usually takes 3 to 7 days for animals to show symptoms. Once symptoms begin, death will usually occur within 48 hours. Acute fever followed by rapid death with bleeding from body openings are all common signs of anthrax in livestock. Owners of livestock and animals displaying symptoms consistent with anthrax or experiencing death of animals should contact a private veterinary practitioner or a TAHC official.
Producers are encouraged to follow basic sanitation precautions when handling affected livestock or carcasses. It is recommended to wear protective gloves, long sleeve shirts and to wash thoroughly afterward to prevent accidental spread of the bacteria to people. For more information on how anthrax affects humans please visit
https://www.dshs.state.tx.us/idcu/disease/anthrax/information/faqs/.The Livestock Indemnity Program (LIP) provides benefits to eligible livestock owners for livestock deaths caused by eligible loss conditions. Anthrax is identified as an eligible disease. For more information about the LIP program visit
https://www.fsa.usda.gov/Assets/USD...vestock_indemnity_program-fact_sheet.pdf or call your local Farm Service Agency office.
For more information about Anthrax, visit
http://www.tahc.texas.gov/news/brochures/TAHCBrochure_Anthrax.pdf.Past 2019 Anthrax Situational Updates:
July 9, 2019 Update:
https://www.tahc.texas.gov/news/2019/2019-07-09_AnthraxUpdate.pdf June 21, 2019 Initial Case:
https://www.tahc.texas.gov/news/2019/2019-06-21_Anthrax.pdf. TAHC will continue to issue weekly updates as long as new cases are confirmed.
