Name two dairy cattle diseases commonly targeted by vaccination programs.

• A. Mastitis and ketosis.
• B. Bovine respiratory disease complex and telemetry disease.
• C. Bovine spongiform encephalopathy and leptospirosis.
• D. Bovine respiratory disease complex and mastitis.

Answer: (D)

Vaccination programs in dairy cattle focus on diseases that most affect production and can be reasonably prevented by immunization. The two most commonly targeted are respiratory disease complexes and udder infections. Bovine respiratory disease complex involves a mix of viruses and bacteria that cause illness in calves and dairy cattle, leading to reduced growth, milk production, and overall herd health. Vaccinating against the common respiratory pathogens helps shorten outbreaks and lowers losses from illness. Mastitis, an infection of the udder, is extremely costly due to treatment, reduced milk yield, and possible culling. Vaccines against certain mastitis-causing organisms exist and are used as part of a broader udder-health program, along with good hygiene and Milking practices. Other choices involve metabolic diseases or conditions not routinely addressed by vaccination in standard dairy programs, so they don’t fit as well.