Thoracic imaging and bronchoalveolar lavage findings in captive Black-footed cats (Felis nigripes) in South Africa

Abstract

Black-footed cats (BFCs) are endemic to southern Africa, and due to their vulnerable status (IUCN), research efforts are focused on identifying risks in wild populations, and captive population management. Evidence shows that this species suffers high stress and reduced survivorship in captivity, the latter primarily due to renal amyloidosis. Unpublished post-mortem examinations in South Africa have noted excess mucus in respiratory tracts as a cause of death, with the presence of goblet cell hyperplasia in a number of animals from captive populations. This pilot study aimed to investigate bronchoalveolar lavage (BAL) cytology, explore lung pathology and develop standardised imaging protocols for BFCs in captivity. Sixteen cats from two captive breeding facilities were sampled opportunistically during annual health examinations. Eight (50%) of the animals sampled showed radiographic signs of lung pathology, particularly a bronchial pattern. An ultrasound examination technique adapted from the Thoracic Focused Assessment with Sonography in Trauma (TFAST) method, found that all animals sampled exhibited a degree of lung consolidation. In addition, mean vertebral heart scores were 8.84 ± 0.42, which were greater than standard normal ranges for domestic cats, suggesting that the species' standard range is not comparable to that of domestic cats. Moderate to high amounts of clear mucus were found in 13/15 (87%) of BAL samples. Cytological evaluation confirmed the presence of mucus, mucus-associated goblet cells and high numbers of neutrophils. Bacterial culture of BAL samples (n=14) exhibited no significant growth. Further investigation is needed to identify risk factors associated with this severe chronic bronchitis.