Swine Production Medicine Flashcards

A large farrow-to-finish operation experiences a sudden increase in late-term abortions, stillbirths, and pre-weaning mortality. Sows are anorexic and lethargic. Concurrently, nursery pigs are showing severe respiratory distress, characterized by dyspnea and cyanosis of the ears. What is the most likely causative agent?

Answer: Porcine Reproductive and Respiratory Syndrome Virus (PRRSV)

The combination of severe reproductive failure (late-term abortions, stillbirths) and severe respiratory disease across different age groups is the classic presentation for an acute outbreak of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV). While other agents cause either respiratory or reproductive signs, PRRSV is unique in causing both with such high severity simultaneously.

In a modern swine biosecurity program, what is the primary purpose of the acclimatization period for incoming gilts?

Answer: To expose them to and develop immunity against the endemic pathogens of the recipient farm in a controlled manner.

Acclimatization is a critical biosecurity step designed to safely expose new animals (gilts) to the specific viruses and bacteria present on the destination farm. This controlled exposure, often through vaccination and contact with cull animals, allows them to build immunity before entering the main breeding herd, preventing disease outbreaks in both the new and resident animals.

A veterinarian performs a necropsy on several finisher pigs that died suddenly. The carcasses are pale, and their stomachs are filled with large amounts of clotted blood. The pars esophagea of each stomach shows severe erosion and ulceration. Which of the following is the most significant contributing factor to this condition?

Answer: Finely ground feed with a small particle size

Gastric ulcers in swine, specifically at the pars esophagea, are strongly associated with finely ground feed (e.g., <700 microns). Small particle size increases stomach fluidity and acidity, which damages the unprotected non-glandular pars esophagea. The clinical signs of acute hemorrhage, pale carcasses, and sudden death in well-conditioned pigs are classic for this condition.

Which of the following represents the MOST significant risk for introducing African Swine Fever (ASF) virus into a naive herd?

Answer: Feeding the pigs uncooked or undercooked food scraps (garbage/swill) containing pork.

The African Swine Fever virus is highly resistant and can survive for long periods in pork products. Feeding uncooked or undercooked pork-containing food scraps (garbage/swill) to pigs is a major and well-documented route of transmission that has been responsible for numerous international outbreaks. While other fomites are a risk, this practice is considered one of the highest risk factors for introducing the virus.

What is the primary reason for administering an iron injection to piglets within the first 3-4 days of life in a commercial indoor production system?

Answer: To compensate for the low iron content of sow's milk and prevent anemia.

Sow's milk is very low in iron, and piglets are born with minimal iron reserves. Due to their extremely rapid growth, they quickly deplete these stores. Without supplementation, they develop severe iron-deficiency anemia, leading to poor growth, paleness, and increased susceptibility to disease. This is a standard and necessary practice in modern indoor confinement systems where piglets cannot get iron from the soil.

A group of 150-pound finishing pigs experiences a sudden onset of severe respiratory disease. Several pigs are found dead. Affected live pigs are febrile, anorexic, and exhibit labored, open-mouth breathing ('thumping'), with some showing a blood-tinged, frothy nasal discharge. What is the most likely diagnosis?

Answer: Pleuropneumonia caused by *Actinobacillus pleuropneumoniae* (APP)

The peracute to acute presentation with sudden death, severe dyspnea ('thumps'), high fever, and fibrinohemorrhagic necrotizing pleuropneumonia (indicated by the bloody nasal discharge) is characteristic of *Actinobacillus pleuropneumoniae* (APP). While other agents cause respiratory disease, APP is known for this rapid and severe clinical picture in finishing pigs.