Fechamento epifisário do úmero, rádio e ulna da paca (Agouti paca) / Epiphyseal closure of the paca’s humerus, radius and ulna (Agouti paca)

Background: After the capybara, the Agouti paca is the largest rodent in the neotropical region, with a body weight that usually varies from 5 to 10 kg, but may reach up to 14 kg. Pacas reach sexual maturity at around 10 months of age. Recently, this species has been increasingly being subject of studies on tissue morphology, placentation, and experimental surgery. The time at which epiphyseal plates close varies according to each bone; some can close during intrauterine life, while some can persist for many years. The aim of this research was to examine, through radiography, the long bones of the thoracic limbs (humerus, radius, and ulna) of the paca, and correlate their epiphyseal closure times with the animal’s age. Materials, Methods & Results: Eight animals born in captivity were radiographically evaluated monthly from birth until 22 months of age. The animals were kept in stalls made of masonry, with an area of approximately 15 m2 . Each stall had one burrow with three internal interconnected sub-sections. Each stall housed one male and two or three females with microchip implants applied dorsally in the cervical region. The animals were fed rodent chow (1.0% of body weight per day) and fruits of the season (10% of body weight per day), which were offered daily in the afternoon. The animals were radiographed at the Division of Radiology of the Veterinary Hospital of the School of Veterinary Medicine, São Paulo State University, Jaboticabal, SP, Brazil. Craniocaudal and mediolateral views of the humerus, radius, and ulna were performed. Sedation was performed using meperidine (2.5 mg/kg) and diazepam (0.5 mg/kg) in a single intramuscular injection. For anesthesia, ketamine (20 mg/kg) and xylazine (1.5 mg/kg) were administered in leg muscles 10 minutes after sedation. The anesthesia used proved to be efficient for transportation, handling, and positioning of the animals for radiographic exams.[...]

Fechamento epifisário do úmero, rádio e ulna da paca (Agouti paca) / Epiphyseal closure of the pacas humerus, radius and ulna (Agouti paca)

Background: After the capybara, the Agouti paca is the largest rodent in the neotropical region, with a body weight that usually varies from 5 to 10 kg, but may reach up to 14 kg. Pacas reach sexual maturity at around 10 months of age. Recently, this species has been increasingly being subject of studies on tissue morphology, placentation, and experimental surgery. The time at which epiphyseal plates close varies according to each bone; some can close during intrauterine life, while some can persist for many years. The aim of this research was to examine, through radiography, the long bones of the thoracic limbs (humerus, radius, and ulna) of the paca, and correlate their epiphyseal closure times with the animals age. Materials, Methods & Results: Eight animals born in captivity were radiographically evaluated monthly from birth until 22 months of age. The animals were kept in stalls made of masonry, with an area of approximately 15 m2 . Each stall had one burrow with three internal interconnected sub-sections. Each stall housed one male and two or three females with microchip implants applied dorsally in the cervical region. The animals were fed rodent chow (1.0% of body weight per day) and fruits of the season (10% of body weight per day), which were offered daily in the afternoon. The animals were radiographed at the Division of Radiology of the Veterinary Hospital of the School of Veterinary Medicine, São Paulo State University, Jaboticabal, SP, Brazil. Craniocaudal and mediolateral views of the humerus, radius, and ulna were performed. Sedation was performed using meperidine (2.5 mg/kg) and diazepam (0.5 mg/kg) in a single intramuscular injection. For anesthesia, ketamine (20 mg/kg) and xylazine (1.5 mg/kg) were administered in leg muscles 10 minutes after sedation. The anesthesia used proved to be efficient for transportation, handling, and positioning of the animals for radiographic exams.[...](AU)