Quantitative and qualitative characteristics of blood cells in black-shouldered, Brahminy, and black kites.

BACKGROUND: Black-shouldered kites (BSK, Elanus caeruleus), Brahminy kites (BrK, Haliastur indus), and black kites (BK, Milvus migrans govinda) are medium-sized hawks found in Thailand, and little is known about the hematology of these three kite species. OBJECTIVE: This study reports basic hematologic values and describes the light microscopic, cytochemical, and ultrastructural characteristics of blood cells in these kites. METHODS: Blood samples were collected from 113 healthy kites (50 BSKs, 53 BrKs, and 10 BKs) from January 2012 to December 2017. Complete blood cell counts, cytochemical staining (Sudan black B, peroxidase [PO], periodic acid-Schiff, α-naphthyl acetate esterase, and ß-glucuronidase), and transmission electron microscopy were performed using standard methods. RESULTS: Hematology, morphometry, and cytochemical staining patterns of blood cells were tabulated. BSK erythrocytes were smaller than BrK and BK erythrocytes. Heterophils, the largest granulocytes, were the most prevalent leukocytes in all kites. Cytochemical reactions in blood cells from these three kite species were the same, except that heterophils from BrKs were the only cells positive for PO. The ultrastructure of heterophil and eosinophil granules from the BSKs were similar in their homogeneous electron densities but differed in shape. The eosinophil granules from BrKs and BKs revealed heterogeneous electron densities with central pallor in some granules. Basophils had different granular electron densities, and some granules were electron-lucent. CONCLUSION: The 23 baseline hematologic values and morphologic, cytochemical, and ultrastructural characteristics of all blood cell types in this study provide reference data for future kite healthcare.

Haemoproteus in barn and collared scops owls from Thailand.

The barn owl (BO) and the collared scops owl (CSO) are common nocturnal raptors throughout Thailand. Blood samples from 23 adult BOs and 14 CSOs were collected and processed for complete blood cell counts and parasite morphological examinations. Two Haemoproteus-positive samples were processed for ultrastructural observation. Polymerase chain reaction (PCR) analysis for a partial cytochrome b gene (cytb) from Haemoproteus was performed in all samples. Haemoproteus presence detected by light microscopy was lower than that detected by PCR (30.4% and 34.8%, respectively, in BO; and 50.0% and 78.6%, respectively, in CSO). Comparative hematology revealed that Haemoproteus-positive BOs had higher mean cell hemoglobin concentration, total leukocyte, absolute heterophil, basophil, and monocyte counts than Haemoproteus-negative BOs, but no significant differences between Haemoproteus-negative and -positive CSOs. Monocyte ultrastructure analysis revealed a role in the elimination of gametocytes. Morphologically, the Haemoproteus in 3 BOs and 6 CSOs were identified as H. noctuae, while that in 1 CSO was identified as H. syrnii. Phylogenetic analysis indicated the Haemoproteus spp. in 8 BOs and 7 CSOs were not closely related to H. noctuae or H. syrnii, and the cytb of 2 CSOs was that of H. syrnii. These results should be useful for study of Haemoproteus.

Quantitative and qualitative morphologic, cytochemical and ultrastructural characteristics of blood cells in the Crested Serpent eagle and Shikra.

The Crested Serpent eagle (Spilornis cheela) is a bird of prey found in the tropical rain forest in Thailand. The Shikra (Accipiter badius) is a sparrow hawk and common resident in Thailand. Blood samples from 9 Crested Serpent eagles and 12 Shikras were obtained from September 2010 to November 2014. They were clinically healthy and negative for blood parasites detectable by light microscopy and molecular techniques (partial cytochrome b gene for avian malaria and partial 18S rRNA gene for trypanosome). Cytochemical staining (Sudan black B, peroxidase, α-naphthyl acetate esterase, and ß-glucuronidase) and transmission electron microscopy were performed. Hematological results were reported as the mean ± standard deviation and median. Heterophils were the most prevalent leukocytes in the Crested Serpent eagle, but in the Shikra, lymphocytes were the most prevalent leukocytes. In the Shikra, some vacuoles were observed in the cytoplasm of the eosinophils. All blood cells in both types of raptors stained positively for ß-glucuronidase but negatively for peroxidase. The ultrastructure of heterophils showed more clearly differentiate long rod granules in Crested Serpent eagle and spindle-shaped granules in Shikra. The ultrastructure of the eosinophils in the Crested Serpent eagle revealed varied electron-dense, round-shaped granules with round, different electron-dense areas in the centers of some granules, which differed from the structure reported for other raptors. These quantitative results may be useful for clinical evaluations of Crested Serpent eagles and Shikras that are undergoing rehabilitation for release.

Quantitative and qualitative morphologic, cytochemical, and ultrastructural characteristics of blood cells in captive Asian water monitors.

BACKGROUND: The Asian water monitor (Varanus salvator) is the most common monitor lizard in Thailand. Reported data regarding hematology and morphology of blood cells for this species are scarce. OBJECTIVES: The objective of this study was to assess routine hematologic variables and characterize the morphology, cytochemical staining, and ultrastructural features of blood cells in the Asian water monitor. METHODS: Blood samples from 55 monitors (22 males and 33 females) were obtained for a CBC. Cytochemical staining (Sudan black B [SBB], peroxidase [PO], α-naphthyl acetate esterase [ANAE], and beta-glucuronidase [BG]), and scanning and transmission electron microscopy were performed using standard methods. RESULTS: Determined mean (range) hematologic results of all monitors included PCV 0.32 L/L (0.20-0.44 L/L), HGB 106 g/L (62-157 g/L), WBC 15.9 × 10(9) /L (4.0-34.0 × 10(9) /L), heterophil 6.3 × 10(9) /L (1.5-17.1 × 10(9) /L, azurophil 2.6 × 10(9) /L (0.7-9.5 × 10(9) /L), basophil 0.1 (0.1-0.5 × 10(9) /L), lymphocyte 6.8 × 10(9) /L (0.5-13.1 × 10(9) /L), and monocyte 0.2 × 10(9) /L (0.04-1 × 10(9) /L) counts. Heterophils and basophils stained strongly positive with SBB, ANAE, and BG. Heterophils contained 2 types of granules, round SBB-positive and PO-negative granules, and electron-dense, large rod-shaped granules. Gamonts of Hepatozoon sp. were found in <1% RBC of 43 monitors. There was no significant difference between hematologic variables in Hepatozoon-positive and -negative monitors. CONCLUSION: Heterophils in Asian water monitors may also function as eosinophils based on cytochemical and ultrastructural features. The quantitative results may be used as base for further studies in healthy and diseased Asian water monitors.

Plasmodium circumflexum in a Shikra (Accipiter badius): phylogeny and ultra-structure of the haematozoa.

A wild-caught, juvenile Shikra (Accipiter badius) was evaluated for rehabilitation at the Kasetsart University Raptor Rehabilitation Unit (KURRU) with a history of weakness. Plasmodium sp. was observed by both light and electron microscopy in blood obtained on day 1 of evaluation. Based on the appearance of erythrocytic meronts and gametocytes, the parasites were defined as Plasmodium (Giovannolaia) circumflexum. The sequence analysis of the mitochondrial cytochrome b gene from the plasmodia was closely related to parasites found in the Grey-headed woodpecker from Myanmar and the Brown hawk-owl from Singapore. Transmission electron microscopic examination revealed organelles in the haematozoa and heterophils that ingested the plasmodia. This is the first recorded case of Plasmodium circumflexum in a wild Shikra. This note emphasises the molecular characterisation and ultra-structure of the haematozoa.

Characterization of blood cells in the Leopard Cat (Prionailurus bengalensis).

BACKGROUND: The Leopard Cat (Prionailurus bengalensis) is the most frequently encountered wild cat in most of Southeast Asia. Limited hematologic investigation exists for this species. OBJECTIVES: The objectives of this study were to assess routine hematologic measurements and parameters and characterize the morphology, cytochemical staining, and ultrastructural features of blood cells in Leopard Cats. METHODS: Blood samples were collected from 12 adult healthy captive Leopard Cats (7 males and 5 females). Complete blood counts were performed using an automated hematology analyzer and manual differential counts. Cytochemical staining (Sudan black B [SBB], peroxidase [PO], periodic acid-Schiff [PAS], alpha-naphthyl acetate esterase [ANAE], and beta-glucuronidase [BG]) and scanning and transmission electron microscopy were performed using standard methods. RESULTS: Median (range) hematologic results were as follows: PCV 0.46 L/L (0.30-0.55 L/L), hemoglobin 136.5 g/L (100-183 g/L), WBC 9.0 x 10(9)/L (6.9-15.2 x 10(9)/L), band neutrophils 0.07 x 10(9)/L (0-0.30 x 10(9)/L), segmented neutrophils 2.9 x 10(9)/L (1.2-6.34 x 10(9)/L), lymphocytes 5.3 x 10(9)/L (2.7-8.1 x 10(9)/L), eosinophils 0.14 x 10(9)/L (0-0.73 x 10(9)/L), basophils 0/L (0-0.22 x 10(9)/L), and monocytes 0.08 x 10(9)/L (0-0.30 x 10(9)/L). Neutrophils stained strongly positive for SBB, PO, and PAS; lymphocytes had fine granular positivity for ANAE and BG; monocytes were weakly positive for ANAE and BG; and basophils were strongly positive for BG. Ultrastructurally, eosinophils contained many large rod-shaped granules with prominent crystalloid core structures, ribosomes, and mitochondria. Basophils contained many round to oval specific granules with homogeneous contents. Low number of basophils contained a few small vacuoles that usually were not detected by light microscopy. CONCLUSION: These findings will facilitate interpretation of hematologic results for future investigative and diagnostic studies of this species.

Hematologic, cytochemical, ultrastructural, and molecular findings of Hepatozoon-infected flat-headed cats (Prionailurus planiceps).

BACKGROUND: The flat-headed cat (Prionailurus planiceps) is a small wild cat of Southeast Asia and is considered extremely endangered. Little is known about the hematologic values, blood cell morphology, or hemoparasites of this species in relation to other Felidae. OBJECTIVES: The objective of this study was to report basic hematologic values and describe the light microscopic, cytochemical, and ultrastructural characteristics of blood cells in 2 wild-caught flat-headed cats. In addition, molecular analysis was done of a Hepatozoon organism found in the neutrophils of both cats. METHODS: Blood samples were collected into EDTA from the cephalic vein. A CBC, manual differential count, manual reticulocyte count, cytochemical stains (Sudan black B [SBB], alpha-naphthyl acetate esterase [ANAE], and beta-glucuronidase), and scanning and transmission electron microscopy were done using standard methods. RESULTS: HCT was slightly lower and reticulocyte counts and red cell distribution width were higher than the expected values for other species of cats. Hepatozoon organisms were found in the cytoplasm of neutrophils in both cats, but the number of infected neutrophils was very low (1%-2%). Neutrophils stained strongly positive for SBB, but were negative for ANAE and beta-glucuronidase. Hepatozoon-infected neutrophils were negative for SBB, but focally positive for ANAE and beta-glucuronidase. By transmission electron microscopy, gamonts of Hepatozoon sp were observed in neutrophils, and rarely free in plasma. Infected neutrophils had fewer specific granules and more mitochondria compared with noninfected neutrophils. PCR products of partial 18S rRNA revealed that the isolate of Hepatozoon in the flat-headed cats was closely related to that of the frog Hepatozoon sp. CONCLUSIONS: These results add to our understanding of hematologic values and blood cell morphology in Hepatozoon-infected flat-headed cats as well as the molecular analysis of the Hepatozoon organism, and may be useful for the health management and evaluation of hemoparasitic disease in this species.

Hematology, morphology, cytochemical staining, and ultrastuctural characteristics of blood cells in king cobras (Ophiophagus hannah).

BACKGROUND: King cobras (Ophiophagus hannah) have been captive-bred at Queen Saovabha Memorial Institute since 1996 to supply venom for antivenom production. Hematologic tests would be useful for evaluating the health of the snakes, however, basic hematologic data and morphology have not been described for this species. OBJECTIVE: The purpose of this study was to determine basic hematologic values and evaluate light microscopic, cytochemical, and electron microscopic characteristics of king cobra blood cells. METHODS: Blood samples from 13 wild-caught and 15 captive-bred king cobras were collected into EDTA from the ventral caudal vein. A CBC was done using standard methods. Significant differences between groups were determined using t-tests. Cytochemical stains (periodic acid-Schiff [PAS], Sudan black B [SBB], alpha-naphthyl acetate esterase [ANAE], acid phosphatase [AcP], and beta-glucuronidase [beta-glu]), and scanning and transmission electron microscopy were done using standard techniques. RESULTS: Eighteen snakes (64.3%) were positive for Hepatozoon infection. Hepatozoon organisms were detected nearly twice as frequently in wild-caught (11/13) as in captive-bred (7/15) snakes. Total WBC, azurophil, and lymphocyte counts were higher and fibrinogen concentration was lower in Hepatozoon-positive snakes. Captive-bred snakes had higher RBC values, lower azurophil, heterophil, and punctate reticulocyte percentages, and higher lymphocyte numbers compared with wild-caught snakes. Lymphocytes were the most commonly observed WBCs, and stained positive with PAS, ANAE, AcP, and beta-glu. Azurophil granules stained positive with SBB, PAS, and ANAE. Heterophils were the largest WBCs; their granules stained with SBB, ANAE, and beta-glu. Basophil granules stained with PAS, SBB, ANAE, and beta-glu. Thrombocytes were strongly positive with PAS. Transmission electron microscopic examination revealed organelles within all WBCs except eosinophils and revealed the gamonts of Hepatozoon sp in RBCs and azurophils. CONCLUSIONS: These results provide comparative hematologic data and a guide for identification of blood cells in wild-caught and captive-bred king cobra snakes. Hepatozoon infection was relatively common, but was not associated with severe hematologic abnormalities.