Veterinary Viewpoints: Disease Testing New Additions to a Herd

Friday 17th September 2021

Media contact: Derinda Blakeney, APR | OSU University of Veterinary Medicine | 405-744-6740 |

Adding new herd members is a significant investment. Typically, producers spend significant time evaluating pedigrees, genomics, and phenotypic appearance. Don’t overlook the individual animal’s health status, however.

Adding a new animal creates the potential to introduce disease into the resident herd. Work with your veterinarian to develop a protocol to prevent this from happening. The protocol can specify the required review of all new additions, whether purchased, leased or borrowed.

A plan to test new additions will likely be based on the manufacturer’s willingness to accept the risk of disease introduction combined with the known prevalence of the disease, the geographic origin of the cattle, and the health history provided or guaranteed by the seller. It is always best for buyers to request a written medical history of the prospect. Vaccination status, deworming history, reproductive assessment, and specific disease tests should be included.

In the case of new bulls, buyers should request written documentation of a timely breeding suitability assessment (BSE) by a veterinarian according to the standards set by the Society for Theriogenology (SFT). A full BSE includes a physical exam, a reproductive tract exam, and a semen exam. Sampling for reproductive infectious diseases such as Tritrichomonas fetus and Campylobacter fetus should also be urgently considered in all non-virgin bulls.

The addition of replacement females also requires an assessment of the reproductive parameters. The reproductive tract assessment can be a helpful assessment when considering replacement heifers. If the female has been artificially inseminated or exposed to a bull, the confirmation and stage of gestation should be determined. Reproductive disease testing can also be warranted.

Depending on the pedigree, buyers of bulls and surrogate bitches may also want DNA marker tests for hereditary diseases that cause genetic abnormalities such as tibial hemimelia (TH) and pulmonary hypoplasia with anasarca (PHA).

While these diseases are not contagious, the introduction of these genetics by a single sire or several closely related females can have significant adverse effects. In most cases, carriers of defects should not be used in a breeding program. When they need to be used because of superior genetics, breeders need to be deliberate and strategic when it comes to crossbreeding.

Infectious diseases introduced by a new arrival could injure the entire herd. Seed producers and commercial cow calves may wish to discuss tests for the following diseases and others with their herd veterinarian prior to purchasing or placing individual animals on their farms:

  • Bovine viral diarrhea
  • Johne’s disease
  • Bovine leukemia
  • tuberculosis
  • Brucellosis
  • Leptospirosis
  • Infectious rhinotracheitis in cattle
  • Blue tongue
  • Anaplasmosis

Additional exam requirements and a certificate of veterinary examination may be required when new animals travel between states. Interstate requirements should be confirmed with the country of destination prior to shipment. The requirements for intergovernmental movement can be found at

Even if a newcomer receives a clean report after inspection and mailing, a good biosecurity plan recommends isolating the animal for at least two weeks prior to contact with the resident herd. Following the protocol developed by the herd veterinarian will help prevent the introduction of new diseases and protect the producer’s investment.

About the author: Dr. Rosslyn Biggs is a clinical assistant professor in the College of Veterinary Medicine at Oklahoma State University. She earned her DVM degree from Oklahoma State University and currently works as a beef cattle stocking specialist and continuing education director.

Veterinary Viewpoints is offered by the faculty of the OSU Veterinary Medical Hospital. The American Animal Hospital Association-certified hospital is open to the public and provides routine and specialized care for all animal species, as well as 24-hour emergency care, 365 days a year. Call 405-744-7000 for an appointment or more information.

OSU’s College of Veterinary Medicine is one of 32 accredited veterinary colleges in the United States and the only veterinary college in Oklahoma. The college’s Boren Veterinary Medical Hospital is open to the public and provides routine and specialized care for small and large animals. The hospital provides 24-hour emergency care and is certified by the American Animal Hospital Association. For more information, visit or call 405-744-7000.

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