A 2-year old male Humboldt penguin (Spheniscus humboldti) presented for initial evaluation following a 2-day history of intermittent non-productive sneezing. No physical exam abnormalities and no other abnormal behaviors were found on initial examination.
The patient was started on meloxicam for suspected upper respiratory tract inflammation and after 4 days of treatment, no additional sneezing was heard by animal keepers. One week later, keepers reported a recurrence of sneezing and no other behavioral abnormalities. On recheck physical exam, again no abnormalities were detected. A complete blood count revealed an inflammatory leukogram (total white blood cell count 37.9×103/uL) with heterophilia (30.3×103/uL) and monocytosis (4.2×103/uL). The bird was treated with injectable ceftiofur crystalline free acid intramuscularly and started on oral itraconazole and doxycycline for potential infection. A combined conjunctival, choanal, and cloacal swab tested negative for Chlamydophila spp. based on PCR testing. Blood plasma testing was moderately positive for Aspergillus antibodies and negative for Aspergillus antigen.
Over the following week, the bird continued to sneeze that progressed to produce white mucoid discharge. In addition, the bird began to exhibit hyporexia and an exam under anesthesia was recommended to better evaluate the bird for respiratory disease. Before anesthesia was induced, the bird was bright, eupneic, no adventitious sounds were ausculted in the lungs or air sacs, and no other abnormal physical exam findings were noted. Complete blood count revealed a marked increase in leukocytosis (total white blood cell count 80.5×103/uL) with heterophilia (45.9×103/uL), monocytosis (19.3×103/uL), and eosinophilia (4.8×103/uL). Computed tomography of the skull and whole body was performed. Intravenous contrast medium was not used.
Transverse CT images of the lung, lung window
Transverse CT images of the lung, bone window
Transverse CT images of the head, bone window
Transverse CT images of the abdomen, soft tissue window
Heterogeneous soft tissue is within the dependent aspect of the cranial right principal bronchus. There is a severe amount of soft tissue within lateral aspect of the mid to caudal right lung. There are numerous soft tissue striations that span from the dorsal and lateral aspects of the pleural surface of the right lung to the air sac lining. There are few, thinner soft tissue striations along the pleural margin of the left lung. There is a large amount of heterogeneous soft tissue within the cranial thoracic air sac, caudal thoracic air sac, and the abdominal air sac. The right caudal thoracic air sac and abdominal air sac are most affected – there is more hyperattenuating material peripherally with centrally hypoattenuating material that has a dorsal (non-dependent meniscus shape. There is also thickening of the lining of the air sacs; the right side is more affected. The skull is unremarkable. There is right principal bronchial intubation. The osseous structures of the skeleton are unremarkable. Punctate mineral is within the proventriculus and ventriculus. The spleen is enlarged; the spleen measures 5.127 x 1.543 x 1.670 cm. The hepatic margins are mildly rounded. Remaining coelomic structures are unremarkable.
1) Right-sided pneumonia with primarily right-sided cranial thoracic, caudal thoracic, and abdominal air sacculitis. There is abscessation or purulent fluid within the right caudal thoracic air sac and abdominal air sac. There is dependent tracheal luminal material that is pus, phlegm, or mucous. Infectious etiologies were considered most likely with fungal agents like Aspergillosis sp. the top differential. Bacterial infectious disease was less likely. Trauma resulting in tracheal hemorrhage, pulmonary contusions, and hematoma within the air sacs was less likely since no trauma was observed and no signs of trauma were identified.
2) Splenitis secondary to infectious etiologies. Alternatively, lymphoid hyperplasia or extramedullary hematopoiesis.
3) Possible hepatitis.
4) Proventriculus/ventriculus grit – common finding.
No additional imaging recommendations. Based on abnormalities seen in the trachea, air sacs, and lungs, a transoral tracheal airway wash was performed. Sample collection yielded turbid fluid containing white flocculent material that yielded Aspergillus spp. on fungal culture. No additional organisms were isolated on aerobic bacterial culture. Following the anesthetized exam approximately 1 month ago, the bird continued on itraconazole and doxycycline treatment orally, and was started on meloxicam orally, terbinafine orally, and terbinafine via nebulization. Over the following 2 weeks, the bird improved clinically and exhibited an improved appetite and a gradual decrease in sneezing. The bird remains on daily treatment with itraconazole orally, terbinafine orally, and terbinafine via nebulization. No respiratory or other behavioral abnormalities have been seen in the last 2 weeks. A recheck exam under anesthesia is planned in approximately 2 weeks (about 6 weeks after the initial anesthetized examination).
References:
Beernaert LA, Pasmans F, van Waeyenberghe L, Haesebrouck F, Martel A. Aspergillus infections in birds: a review. Avian Pathol. 2010;39(5): 325–331.
Schwarz T, Kelley C, Pinkerton ME, Hartup BK. Computed tomographic anatomy and characteristics of respiratory aspergillosis in juvenile whooping cranes. Vet Radiol Ultrasound. 2016;57(1): 16–23.
Rivas AE, Fischetti AJ, Roux ABL, Hollinger C, Oehler DA, et. al. Standing computed tomography in unanesthetized little penguins (Eudyptula minor) to assess respiratory system anatomy and minor disease. J Zoo Wildl Med. 2019 Jun 13;50(2):396-404. doi: 10.1638/2018-0189.