Starr County Judge Eloy Vera on Monday signed a disaster declaration after the Rio Grande Valley's first confirmed case of the New World screwworm was found in the county.

The Texas Animal Health Commission confirmed the case in a calf somewhere north of Roma. The state has declared most of western Starr County an infested zone.

Cattle in that area cannot leave without the state signing off first. Anyone planning to move cattle or other game out of the infested zone must get clearance from the Texas Animal Health Commission first.

"It would facilitate getting the medicines and equipment and things that we need to fight the screwworm," Vera said.

The New World screwworm is a parasite that eats the live flesh of warm-blooded animals. It comes from larvae laid by screwworm flies, similar to blow flies, and may kill livestock if left untreated.

Vera also warned pet owners to check their animals. 

"Any domestic animal that you might have that has a wound, you need to keep a close eye on it," Vera said.

The situation is bringing back memories for Starr County cattle owner John "Jackie" Ramirez. His father treated screwworm-infested cattle in the 1970s.

"I remember going with him," Ramirez said. "When he had his days off, we would go to the ranch, and he would doctor the mares."

More than 50 years later, Ramirez believes he may have to deal with the same pest. He has three heifers set to give birth to calves within the next month.

Ramirez plans to keep a close eye on his heifers and buy medication if needed. Anyone who spots an infected wound is asked to call the Texas Animal Health Commission.

Watch the video above for the full story.