Radiographic Imaging, Endoscopy and Haematological Profile as Indispensable Diagnostic Tools in Falcon Health and Disease

Abstract

This study was undertaken to assess the heath status of saker falcons (Falco cherrug) based on the results of radiographic, endoscopic and haematological examination. The study was also intended to investigate the xii significance of haematology as a useful health assessment diagnostic tool in falcons in correlation with some common abnormal radiographic findings in these birds. The degree of heterophil toxicity was also assessed on a scale of +1 to +4 as classified by Campbell. Clinical records including case history of the avian patient, radiographic, endoscopic and haematological findings were reviewed for 898 captive female saker falcons of different ages, which presented for clinical examination at the Fahad Bin Sultan Falcon Center (FBSFC), Riyadh, Kingdom of Saudi Arabia, from July 12, 2011, to July 11, 2012. Out of the total number of falcons presented for clinical examination, 407(45.32%) falcons presented for health screening and 491(54.68%) falcons because of sickness. The sick birds exhibited varied clinical signs. However, dyspnoea, poor flight performance, reduced appetite and passage of lime green feces were the most common complaints by the falconers. Predominant radiographic abnormalities identified in falcons examined were homogeneous (15.37%) and non-homogeneous (11.36%) increased radiopacity of the lung fields and air sacs, excessive amounts of sand in the gastrointestinal tract (10.91%), splenomegaly (10.02%), hepatomegaly (9.47%), gas formation in the gastrointestinal tract with or without an accompanying dilatation (8.91%), bone fractures due to trauma (6.68%), overdistended air sacs (6.24%), and reduction or loss of muscle mass (6.12%). The most common abnormalities detected by esophago-ingluvioscopy in all birds examined, were trichomonal and candida lesions in the esophagus and/or crop (confirmed by cytology). Other disorders affecting the esophagus and/or crop were detected by endoscopy; they included presence of decomposed food materials, paleness and redness of crop mucosa, injury to crop mucosa, presence of foreign body and bacterial lesions in the crop (confirmed by cytology), and infestation with Physaloptera species worms, presence of stuck bone in the esophagus and displaced esophageal wall. Of the total falcons that presented for clinical examination, tracheoscopy was performed selectively on 288 falcons, namely only on birds with breathing abnormalities, change or loss of voice, and/or when radiographs showed abnormalities in the respiratory system. Based on the result of tracheoscopy, 30 falcons were diagnosed with tracheal abnormalities. Among these syringeal aspergilloma (confirmed by cytology) was the most common abnormality detected (13/30).Other abnormalities xiii detected by tracheoscopy included presence of foreign body and excessive accumulation of mucous in the trachea, and displaced trachea. Endoscopic examination of air sacs and pulmonary base (laparoscopy) was performed selectively on 26 falcons with breathing difficulty and radiographic abnormalities of the distal respiratory tract; of these, 17 birds were diagnosed with aspergillosis (confirmed by cytology), one of the most lethal diseases in captive falcons, while 9 birds were found infested with filarial worms (air sac worms) of the genus Serratospiculum. The most common haematological abnormalities identified in falcons examined were eosinophilia (51.34%), increased Hb and PCV values (50.67%), thrombocytosis (47.77%), heterophilia (38.98%), leucocytosis (23.72%), monocytosis (15.48%) and presence of Haemoproteus species (9.02%). Haemoproteus tinnunculi infection was associated with an increase in the splenic size. The infection also produced a strong eosinophilic response. Monocytosis was the most common feature observed in falcons with non-homogeneous increased radiopacity of the lung fields and air sacs which is more likely to be seen in birds with aspergillosis. Of the total number of falcons examined, toxic heterophils were identified in the blood films of 391(43.54%) falcons; out of these 70 (7.8%) falcons showed severe cytotoxic changes (+3 or +4). The prevalence of other haematological changes observed in the falcons included in descending order, lymphocytosis, heteropenia, leucopenia, thrombocytopenia, anemia and lymphocytopenia. An adult female saker falcon presented with a history of intermittent regurgitation, dyspnea, and squawking sound. Physical, radiographic, and endoscopic examination revealed a markedly enlarged thyroid gland. On further examination the condition was diagnosed clinically as unilateral thyroid hyperplasia, a condition which has not been previously reported in saker falcons. Out of the total falcons examined, only 104 (11.58%) birds were diagnosed negative in all categories (radiography, endoscopy and haematology). These findings indicate that radiography, endoscopy and haematological profile are important diagnostic tools in falcon medicine. These findings also contribute to the scant information available about health and diseases of falcons in the Kingdom of Saudi Arabia in particular and the Middle East in general.