Dave Lansing can walk through his feedlot among his 800 to 900 beef cattle and spot those that are ailing.

The animals bow their heads, pull their ears back and stop eating.

After some of his cattle developed pneumonia recently, he contacted his longtime veterinary provider, Tri-Vet Associates, which has offices in Farley, Dyersville and Holy Cross.

Veterinarian Tim Sprank visited Lansing's Worthington farm to treat the animals and administer routine vaccinations.

Without treatment, cattle "won't last long," Lansing said.

"It's just like a human," he said. "If you're sick, you go to the doctor. Same thing."

While Lansing routinely receives farm calls from a veterinarian, some regions in the tri-states are experiencing a shortage of providers, primarily among those who deal with large animals. In those areas, veterinarians have full caseloads and cannot accept new clients. The problem is exacerbated as the workforce ages and practitioners retire, the Telegraph Herald reported .

Maintaining access to veterinary services is crucial for managing disease, ensuring a stable and safe food supply and keeping the livestock industry profitable, according to Iowa's state veterinarian, David Schmitt.

"We have such large numbers of livestock in our state, and protecting the health of those livestock is invaluable," he said.

Each year, he and other animal health officials around the country nominate locations for federal designation as veterinary shortage situations.

Jones County, Iowa, and the county's contiguous neighbors were designated as critical priority areas in 2017. About 55 mixed animal practitioners serve the region, which includes more than 1.6 million head of livestock.

In 2016, southwest Wisconsin counties, including Crawford and Grant counties, were designated high-priority shortage areas, as were northwest Illinois counties, including Jo Daviess County.

About 114,000 veterinarians were employed in the U.S. in 2016, according to American Veterinary Medical Association. About 75 percent who enter private clinical practice treat companion animals most or all of the time. About 7 percent treat food animals, and 6 percent treat both.

The U.S. Bureau of Labor Statistics predicts that employment of veterinarians will increase 18 percent from 2016 to 2026. However, practicing in under-served, rural areas might remain out of reach for those who are coping with student debt.

Graduating veterinary students on average carry about $144,000 in debt, according to the AVMA.

"The pay isn't what it used to be," said Lancaster (Wis.) Vet Clinic owner Cari Schaffer, who has practiced for almost 20 years. "To come into a rural area and make $45,000 to $60,000 a year, it's really difficult to do."

Jentry Fane, an associate veterinarian at Risius Family Veterinary Service in Maquoketa, Iowa, graduated from Iowa State University in May with more than $150,000 in debt.

He intends to apply to the U.S. Department of Agriculture's Veterinary Medicine Loan Repayment Program. It provides food animal and public health veterinarians up to $75,000 in exchange for serving at least three years in a shortage area. Several veterinarians have been placed in Iowa.

Fane treats both companion and food animals and said his days are full.

"There may be days where you may go on eight or 10 calls, where you go from farm to farm treating sick calves," he said.

Alex Ramirez, Iowa State interim assistant dean of academic and student affairs, said the university provides veterinary students with a strong foundation in all areas of veterinary practice before they specialize during their final year of study.

Shortage or not, tracking students into specific areas too soon could have unintended consequences, he noted.

"It is hard to predict what opportunities are going to be available at the time of graduation," Ramirez said. "Markets change."