t appeared to be a problem with the food.
In February, dairy cattle in multiple herds in northern Texas were suddenly producing less milk, and what they gave was abnormal and thick.
And the typically voracious eaters had seemingly lost their appetites.
For weeks in March, veterinarian Dr. Barb Petersen, who lives in Amarillo, Texas sought an answer. She talked to dairy owners and exchanged notes with fellow vets in the panhandle of Texas. She submitted numerous samples to labs that tested for more than 200 potential causes.
“Any fluid you can collect from a live animal, I collected it,” said Petersen, who was raised on a dairy farm near Davenport, Iowa. “As did many others. There were so many of us at the same time texting each other and trying to figure this out.”
She started messaging Dr. Drew Magstadt, who she had studied alongside at Iowa State University years before. He now works at the ISU Veterinary Diagnostic Laboratory — a preeminent national animal lab in Ames — and researches infectious disease in cattle.
When the voluminous amount of testing in Texas failed to find any clues, Magstadt and Petersen concluded that a likely cause was ill-made food.
“The affected cattle were very high-producing dairy cows, and they are on a race-car ration,” Magstadt said. “If you mess with that a little bit, it can cause problems.”
Petersen agreed to send Magstadt some samples of the feed and animals for testing.
But then the cats started dying.
Barn cats are common on farms. They kill rodents, provide companionship and need little help to survive.
Some dairy farmers also feed them milk from their cows, and sick cows can shed viruses in their milk.
“A colleague of mine, he told me, ‘You know what’s strange? I went to one of my dairies last week, and all their cats were missing. I couldn’t figure it out — the cats usually come to my vet truck,’ ” Petersen recalled. “And then someone called me and said half of his cats had passed away without warning, and so then all the alarm bells start going off in your head.”