Myxoid leiomyosarcoma of the oviduct and uterus in a Cockatiel (Nymphicus hollandicus).

An 11-year-old female cinnamon cockatiel (Nymphicus hollandicus) was presented with a coelomic distention. Dystocia was suspected, given its previous history of a calcium-deficient diet and multiple instances of nonobstructive dystocia. Exploratory coeliotomy revealed a large intraluminal mass extending through the magnum to the uterus (shell gland). Metastasis and multiorgan involvement were not seen. Histopathologically, malignant and invasive fascicles of spindle cells were associated with abundant myxoid matrix and hypocellular areas. Multinucleation, bizarre cells and atypical mitotic figures were prominent. Masson's trichrome staining verified the muscular origin, and the myxoid matrix was demonstrated utilizing Alcian blue. The neoplastic cells exhibited alpha-smooth muscle actin and desmin immunoreactivity and were negative for vimentin. Thus, the patient was diagnosed with oviductal and uterine myxoid leiomyosarcoma (LMS). The patient survived 34 days post-surgery before death associated with suspected enteritis. Myxoid LMS is an extremely rare neoplasm in animals. To our knowledge, myxoid LMS has not been reported previously in pet birds.

The pharmacokinetics of single-dose oral atorvastatin and its metabolites support therapeutic use in cockatiels (Nymphicus hollandicus).

OBJECTIVE: To evaluate the plasma concentrations and determine the pharmacokinetic parameters of atorvastatin and its primary active metabolites (para- and orthohydroxyatorvastatin) after administration of a single oral dose in cockatiels (Nymphicus hollandicus). ANIMALS: 14 adult cockatiels (7 male, 7 female) around 2 years of age. METHODS: A compounded oral suspension of atorvastatin 10 mg/mL made with an oral suspending agent and an oral sweetener was administered via oral gavage at 20 mg/kg to each bird. Blood samples were collected at 7 different time points from 0.5 to 24 hours postadministration in a balanced incomplete block design with 3 blood samples per bird and 6 replicates per time point. Plasma concentrations of atorvastatin, parahydroxyatorvastatin, and orthohydroxyatorvastatin were determined by liquid chromatography-tandem mass spectrometry. Pharmacokinetic analysis was performed using noncompartmental analysis. RESULTS: The estimated time to maximum concentration (tmax) for atorvastatin, parahydroxyatorvastatin, and orthohydroxyatorvastatin was 3 hours for each. The estimated maximum plasma concentration (Cmax) for atorvastatin, parahydroxyatorvastatin, and orthohydroxyatorvastatin was 152.6, 172.4, and 68.8 ng/mL, respectively. The terminal half-lives were 4, 6.8, and 4.6 hours, respectively. CLINICAL RELEVANCE: These results support the therapeutic use of atorvastatin at the dose evaluated in this species based on human pharmacokinetic data. A starting dose of 20 mg/kg PO every 12 to 24 hours could be used to treat lipid disorders in cockatiels pending more data on multidose use and hypolipidemic efficacy.

The evolution of social play in songbirds, parrots and cockatoos - emotional or highly complex cognitive behaviour or both?

Social play has been described in many animals. However, much of this social behaviour among birds, particularly in adults, is still relatively unexplored in terms of the environmental, psychological, and social dynamics of play. This paper provides an overview of what we know about adult social play in birds and addresses areas in which subtleties and distinctions, such as in play initiation and social organisation and its relationship to expressions of play, are considered in detail. The paper considers emotional, social, innovative, and cognitive aspects of play, then the environmental conditions and affiliative bonds, suggesting a surprisingly complex framework of criteria awaiting further research. Adult social play has so far been studied in only a small number of avian species, exclusively in those with a particularly large brain relative to body size without necessarily addressing brain functions and lateralization. When lateralization of brain function is considered, it can further illuminate a possibly significant relevance of play behaviour to the evolution of cognition, to management of emotions, and the development of sociality.

Gross and histopathological findings in hindlimb paralysis syndrome in wild Carnaby's black cockatoos (Zanda laitirostris).

The aim of this study was to describe the gross and histopathological features of a neurological syndrome in endangered Western Australian Carnaby's black cockatoos (Zanda laitirostris) that was first observed in 2012. The syndrome, named hindlimb paralysis syndrome in Carnaby's cockatoos (CHiPS), is characterized by annual outbreaks of hindlimb paralysis with occasional loss of deep pain and cloacal tone, typically occurring between January and March. Previous limited investigations suggested a possible toxic aetiology. Full gross necropsy and histopathology examinations were performed on 17 CHiPS cases and on 11 control birds for reference. Histopathological examination was carried out on all major organs including brain, spinal cord, brachial plexus, sciatic nerve and wing and hindlimb muscles. Gross and histopathological examinations did not elucidate a definitive cause of the clinical signs seen in CHiPS cases. There were no substantial gross or histopathological changes within the brain, spinal cord, sciatic nerve or brachial plexus that could explain the hindlimb paralysis. The most noteworthy changes were seen in the hindlimb and wing muscles, with a monophasic to polyphasic myopathy present in the hindlimb muscles of 15 of the 17 CHiPS cases and in the wing muscles in 11 of those cases. The cause and significance of the myopathy is unclear and requires further investigation. Based on the above findings, the most likely differential diagnoses include neurotoxicoses (eg, organophosphate, organochlorine and carbamate) and, less likely, myotoxicosis (eg, ionophore toxicosis), nutritional myopathy (eg, vitamin E/selenium deficiency) or botulism.

Spontaneous tempo production in cockatiels (Nymphicus hollandicus) and jungle crows (Corvus macrorhynchos).

Musical and rhythmical abilities are poorly documented in non-human animals. Most of the existing studies focused on synchronisation performances to external rhythms. In humans, studies demonstrated that rhythmical processing (e. g. rhythm discrimination or synchronisation to external rhythm) is dependent of an individual measure: the individual tempo. It is assessed by asking participants to produce an endogenous isochronous rhythm (known as spontaneous motor tempo) without any specific instructions nor temporal cue. In non-human animal literature, studies describing spontaneous and endogenous production of motor tempo without any temporal clue are rare. This exploratory study aims to describe and compare the spontaneous motor tempo of cockatiels and jungle crows. Data were collected on spontaneous beak drumming behaviours of birds housed in laboratory. Inter beak strokes intervals were calculated from sound tracks of videos. The analyses revealed that inter beak strokes intervals are non-randomly distributed intervals and are isochronous. Recorded spontaneous motor tempos are significantly different among some cockatiels. Since we could only conduct statistical analysis with one corvid, we cannot conclude about this species. Our results suggest that cockatiels and jungle crows have individual tempos, thus encouraging further investigations.

The effect of four different object properties on latency to approach in Goffin's cockatoos (Cacatua goffiniana).

Neophobia and neophilia can be lifesaving as they can facilitate foraging while avoiding predation or intoxication. We investigated the extent to which Goffin's cockatoos (Cacatua goffiniana) exhibit ecollogically relevant and quantifiable neophobic responses toward specific object properties. Twelve cockatoos were presented with 12 novel objects grouped into four distinct categories with unique features: size, color, reflective capacity, and shape. The cockatoos were tested by measuring their latency to approach a high-quality food reward for both novel and control scenarios. Age and sex did not affect the latency to approach food in the presence of a novel object in this species. Additionally, we found no significant differences between the objects of the reflective and color categories. This result is likely due to the plasticity of neophobic behavior related to the benefits and costs of approaching novel stimuli. The cockatoos were significantly slower to approach food in the presence of objects larger than their body size than objects of a similar or smaller size, a phenomenon possibly explained by the increased risk of approaching unknown objects large enough to be a potential predator. They were also significantly more hesitant to approach food in the presence of elongated objects, a phenomenon potentially explained by an ecologically relevant avoidance of snakes. The extent of this neophobia was statistically similar at a group level, indicating that avoidance of elongated and large objects could be an adaptive response aiding survival under natural circumstances and that snakes may impose strong selective pressures on this species. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Osteosarcoma of the wing in a sulfur-crested cockatoo.

A 26-year-old female sulfur-crested cockatoo (Cacatua galerita) was evaluated for vocalizing through the night and extending her right wing. Physical examination revealed a large, firm mass extending from the humerus to the distal aspect of the elbow. Computed tomography confirmed a large aggressive mass of the right distal humerus with a large soft tissue component, severe osteolysis, and adjacent periosteal proliferation. Fine-needle aspirates of the mass were most compatible with sarcoma, and osteosarcoma was prioritized. An unstained slide was treated with nitroblue tetrazolium chloride/5-bromo-4-chloro-3-indolyl phosphate toluidine salt-phosphatase (NBT/BCIP) substrate for ALP detection and was strongly positive, confirming a diagnosis of osteosarcoma. A month later, the patient underwent wing amputation and arrested during recovery from anesthesia. Post-mortem examination and histopathology were consistent with osteosarcoma. This case report highlights a rare occurrence of osteosarcoma in a cockatoo as well as its cytologic and histologic features. Additionally, this report provides support for NBT/BCIP application in ALP-expressing tumors, a cytochemical stain that has been minimally investigated in avian species.

The genus Neopsittaconirmus (Psocodea: Ischnocera: Philopteridae) from parrots of Pakistan, and evaluation of its distribution on captive parrots (Psittaciformes) around the world.

The genus Neopsittaconirmus Conci, 1942 is a host-specific genus, found on both wild and captive parrots and love birds (order Psittaciformes). Two species of this genus: N. lybartota (Ansari, 1947) and N. chandabani (Ansari, 1947) have been previously reported from the Punjab province, Pakistan. We recorded N. lybartota from Psittacula eupatria nipalensis (n = 2), Psittacula krameri borealis (n = 13), and captive Psittacula krameri krameri (n = 4) with the mean intensity of 2.0 ± 1, 2.13 ± 0.35 and 2.25 ± 0.47, respectively; the prevalence of louse infestation was 62% in P. krameri borealis and 100% in P. krameri krameri and P. eupatria nipalensis. From this material, we redescribed its morphological variations in taxonomic features. Records on P. eupatria nipalensis and P. krameri krameri represent new host associations for this species of louse. We also present a new record of Neopsittaconirmus vendulae from a captive cockatiel, Nymphicus hollandicua (n = 3) in Pakistan, with mean intensity of 2.6 ± 0.66. Intraspecific variability of this species is described in detail, with special reference to the male and female terminalia, and male genitalia. We aimed to update and extend the fauna of chewing lice infesting birds of Pakistan. Previous records of Neopsittaconirmus on captive parrots around the world are summarized and discussed. Despite long-standing systematic veterinary care, some Neopsittaconirmus have cosmopolitan distribution and they are able to survive and successfully reproduce in captivity with their hosts, and even colonize novel hosts.

Macroscopic, cytological and histological diagnosis of proventricular adenocarcinoma in a sulphur-crested cockatoo (Cacatua galerita).

An adult sulphur-crested cockatoo (Cacatua galerita) was unexpectedly found dead and was presented for post-mortem examination. Macroscopically, the proventricular wall was expanded by an infiltrative off-white mass, 10 mm in diameter, with secondary mucosal ulceration. Cytological examination of impression smears revealed a neoplastic epithelial cell population forming occasional well-defined acini with secretory product. Histologically, the neoplastic cells were predominantly arranged in acini and tubules, with fewer in small clusters, supported by a desmoplastic stroma. Neoplastic cells were polygonal, with mostly well-demarcated cell boundaries and a moderate amount of eosinophilic cytoplasm that was multifocally markedly distended by more intensely eosinophilic material. There was an increased nuclear-to-cytoplasmic ratio with moderately sized to large nuclei (approximately 15 µm diameter) with lightly to densely stippled chromatin and single or paired prominent basophilic nucleoli. The mitotic count was 19 in 10 high-power fields (2.37 mm2), with scattered bizarre mitotic figures and atypia including moderate anisocytosis and anisokaryosis and moderate cellular and nuclear pleomorphism. There was frequent intratubular brightly eosinophilic proteinaceous material, which was Alcian blue and periodic acid‒Schiff positive. Proventricular lymphovascular invasion was detected, with metastases within the ventriculus and lungs. The macroscopic, cytological and histological appearance of the neoplasm was consistent with a proventricular adenocarcinoma.

Dunking rusk: innovative food soaking behaviour in Goffin's cockatoos (Cacatua goffiniana).

Foraging innovations in animals involving the processing of resources that are already edible in an unprocessed state, yet of improved quality in a processed state, are rare but important to study the evolution of food preparation. Here, we present the first scientific report of food dunking behaviours in parrots by Goffin's cockatoos, a model species for innovative problem solving. Observations during lunch showed seven out of 18 cockatoos placing their food into water and soaking it prior to consumption. This was largely done with dry rusk which was eaten almost exclusively when dunked. Furthermore, their transport effort and waiting times before retrieving food from the water indicate their willingness to invest considerable time to prepare a soaked rusk piece of a higher texture quality. Our present results suggest that the function of this behaviour is to soak the food. Because only some individuals dunked food and dunking has not been observed in the wild, we believe this to be a spontaneous foraging innovation either by one or multiple individuals.

Individual preferences for sound tool design in a parrot.

The rarity of tool manufacture in wild parrots is surprising because they share key life-history traits with advanced tool-using species, including large brains, complex sociality and prolonged parental care. When it does occur, tool manufacture in parrots tends to be innovative, spontaneous and individually variable, but most cases have been in captivity. In the wild, only palm cockatoos (Probosciger aterrimus) have been observed using tools regularly. However, they are unusual because they use tools to enhance their displays rather than for foraging or self-maintenance. Males in northern Australia make two types of tool from sticks and seed pods, which they tap rhythmically against a tree during display. We analysed 256 sound tools retrieved from 70 display trees. Drumsticks (89% of tools) were used more often than seed pod tools; most males manufactured only drumsticks, but some made both types. Individual males differed significantly in the design of their drumsticks including the length, width and mass but we found no evidence that neighbours copied each other. We discuss the highly individualized preferences for sound tool design in context of the behavioural predispositions behind the rarity of tool manufacture in wild parrots.

Carrageenan-induced inflammation elicits behavioral changes in cockatiels (Nymphicus hollandicus) for potential pain scale development.

OBJECTIVE: To evaluate behaviors associated with inflammatory pain induced by carrageenan injection in the cockatiel and determine interobserver agreement. ANIMALS: 16 adult cockatiels. METHODS: Cockatiels were randomly assigned as either treatment (carrageenan injection) or control (sham injection) group. The treatment group received a subcutaneous injection of 0.05 mL of a 1% lambda carrageenan solution into the left footpad. Following treatment or control procedures, all cockatiels were video recorded individually for 9.5 hours. Ten minutes of video at each of 11 time points postinjection and/or handling were evaluated by 3 different observers. Twenty-five behaviors within 6 categories (resting, locomotion, maintenance, intake, interaction with environment, and limb and body posture) were assessed, in addition to crest position and mentation. Differences in individual behaviors tallies were assessed using serial Wilcoxon sum rank tests. Interobserver agreement was assessed using an intraclass correlation coefficient for a 2-way design for consistency among multiple observers. RESULTS: Treatment cockatiels exhibited significantly increased focal preening (q = .023) and increased burst preening (q = .036), while control cockatiels spent significantly more time in an upright stance (q = .036). Although the remainder of behaviors observed were not statistically significant between groups, additional variables of interest seen more frequently in treatment cockatiels included non-weight-bearing stance, holding of the body low, and being nonvigilant. The level of agreement between observers was variable based on the specific behaviors; nevertheless, the dynamic behaviors were substantial to strong. CLINICAL RELEVANCE: Carrageenan-induced inflammation-associated behaviors may be valuable in developing a pain scale and evaluating mild inflammatory pain in small psittacine species.

Liver virome of a Little Corella (Cacatua sanguinea) reveals coinfection with a novel parvovirus and two beak and feather disease viruses.

Emerging diseases are acknowledged as a growing threat to wildlife, with the continued identification of pathogenic and potentially pathogenic viruses in avian species resulting from ongoing advances in molecular diagnostic techniques. Parvoviruses under the genus Chaphamaparvovirus (subfamily Hamaparvovirinae) are highly divergent. The detection and characterisation of parvoviruses in psittacine birds is limited. This study reports a novel parvovirus, tentatively named psittaciform chaphamaparvovirus 3 (PsChV-3) under the genus Chaphamaparvovirus, identified in an Australian free-ranging little corella (Cacatua sanguinea). The PsChV-3 genome is 4277 bp in length and encompasses four predicted open-reading frames, including two major genes, a nonstructural replicase gene (NS1), and a structural capsid gene (VP1). The NS1 and VP1 genes showed the closest amino acid identities of 78.8% and 69.7%, respectively, with a recently sequenced psittaciform chaphamaparvovirus 2 from Australian Neophema species grass parrots. In addition, the presence of two complete novel beak and feather disease (BFDV) genomes, 1993 and 1868 nt in length, respectively, were detected from the same bird. Both these BFDV genomes contained two bidirectional ORFs encoding the putative Rep and Cap proteins. Phylogenetic analysis showed that the sequenced novel BFDV genomes clustered in a distinct subclade with other BFDVs isolated from Australian cockatoos. This study contributes to the characterisation chaphamaparvoviruses and BFDV in Australian parrots and supports the need for ongoing monitoring and molecular studies into the avian virome in native Australian psittacine bird species.

Visceral Haemoproteus minutus Infection in a Major Mitchell's Cockatoo (Lophochroa leadbeateri).

A 1-year-old major Mitchell's cockatoo (Lophochroa leadbeateri) was presented for evaluation of weakness, diarrhea with undigested seeds in the droppings, and weight loss. Leukocytosis with severe heterophilia, monocytosis, and lymphocytosis was noted on the complete blood count. Altered plasma biochemical parameters included a slight increase in creatine kinase and mild hypoproteinemia. Two blood smears before and after 2 days of treatment revealed mild polychromasia and anisocytosis but no blood parasites. Radiographic and computed tomographic imaging of the cockatoo were helpful in identifying airsacculitis, pneumonia, and gastrointestinal motility disorders. The patient died 5 days after treatment for the presenting clinical problems. On the gross postmortem examination, dark red foci in the ventricular muscle layers and 1-3-mm white foci in the myocardium, opaque air sacs, and dark lungs were identified. Histopathologic examination of submitted tissue samples found severe granulomatous ventriculitis and myocarditis with intralesional Haemoproteus species megalomeronts. Qualitative polymerase chain reaction testing for the cytochrome b (cyt b) gene performed on pooled heart, liver, kidney, and intestinal tissues identified 99.5% homology to Haemoproteus minutus. This case report demonstrates the expansion of the geographic range of H minutus to France and potentially to Belgium, which may compromise breeding and conservation of Australian parrots living outdoors. Challenging diagnosis, rapid disease progression, and the absence of validated treatment protocols for psittacine patients suggest that the use of preventive measures to reduce the presence of insect vectors such as hippoboscid flies and biting midges (Culicoides) should be considered. Haemoproteus minutus should be considered and potentially screened by polymerase chain reaction testing on blood samples, especially in the case of highly susceptible avian species (eg, Australian parrots in Europe) that present with sudden weakness, heterophilic leukocytosis, and monocytosis associated with mild anemia.

Bilateral Cubital Lymphoma and Mycobacteriosis in a Salmon-Crested Cockatoo (Cacatua moluccensis).

A 32-year-old male salmon-crested cockatoo (Cacatua moluccensis) was diagnosed by cytology with bilateral cubital lymphoma and mycobacteriosis. Polymerase chain reaction assay testing confirmed Mycobacterium genavense. This patient was subsequently humanely euthanized. Postmortem histopathology confirmed both diagnoses with findings of multicentric lymphoma, acid-fast bacilli, and severe degenerative changes in all synovial joints examined. Immunohistochemical staining for paired box protein 5 of the cubital mass was positive for a high percentage of B-cell lymphocytes, consistent with B-cell lymphoma. This unusual case of two major diseases presenting concurrently in one patient raises the question of whether the pathogenesis could have an interdependent relationship. Mycobacteriosis, severe degenerative joint changes, or both may have stimulated lymphocytes, eventually leading to lymphoma. Additional screening and monitoring for comorbidities may be advised if 1 of these diseases are diagnosed in companion avian species.

Flexible tool set transport in Goffin's cockatoos.

The use of tool sets constitutes one of the most elaborate examples of animal technology, and reports of it in nature are limited to chimpanzees and Goffin's cockatoos. Although tool set use in Goffin's was only recently discovered, we know that chimpanzees flexibly transport tool sets, depending on their need. Flexible tool set transport can be considered full evidence for identification of a genuine tool set, as the selection of the second tool is not just a response to the outcomes of the use of the first tool but implies recognizing the need for both tools before using any of them (thus, categorizing both tools together as a tool set). In three controlled experiments, we tested captive Goffin's in tasks inspired by the termite fishing of Goualougo Triangle's chimpanzees. Thereby, we show that some Goffin's can innovate the use and flexibly use and transport a new tool set for immediate future use; therefore, their sequential tool use is more than the sum of its parts. VIDEO ABSTRACT.

Reproductive status of a female white cockatoo (Cacatua alba) based on relationships among urofecal steroid hormone dynamics, molting, and body weight.

The detailed reproductive physiology of cockatoos based on gonadal hormone dynamics is unclear. In this study, we aimed to investigate ovarian activity by monitoring urofecal sex steroid hormone profiles in a captive female white cockatoo (Cacatua alba) and to noninvasively reveal basic reproductive physiology by comparing the hormone profiles with the laying dates, body mass changes, and molt progress. Urofeces were collected regularly for approximately 4 years from one female that frequently laid unfertilized eggs under single-rearing conditions. Urofecal progesterone (P4) and estradiol-17ß (E2) were measured by enzyme immunoassay. In addition, body mass and the number of fallen feathers were measured periodically. The urofecal P4 concentration peaked at an average of 17.7 days after the start of the rise in urofecal E2 concentration, and egg laying began on the day after the peak urofecal P4 concentration. The clutch size was usually two eggs, with an average interval of 4.5 days between eggs in each egg-laying cycle. There was a significant correlation between the dynamics of E2 concentration in urofeces and body mass. The results strongly suggest that E2 and P4 reflect the follicle growth and ovulation status, respectively, and that noninvasive monitoring of hormone dynamics using urofeces can accurately capture ovarian activity in the white cockatoo. Furthermore, changes in body mass can predict follicular growth, and reproduction and molt are antagonistic.

Social network analysis reveals context-dependent kin relationships in wild sulphur-crested cockatoos Cacatua galerita.

A preference to associate with kin facilitates inclusive fitness benefits, and increased tolerance or cooperation between kin may be an added benefit of group living. Many species exhibit preferred associations with kin; however, it is often hard to disentangle active preferences from passive overlap, for example caused by limited dispersal or inheritance of social position. Many parrots exhibit social systems consisting of pair-bonded individuals foraging in variably sized fission-fusion flocks within larger communal roosts of hundreds of individuals. Previous work has shown that, despite these fission-fusion dynamics, individuals can exhibit long-term preferred foraging associations outside their pair bonds. Yet the underlying drivers of these social preferences remain largely unknown. In this study, we use a network approach to examine the influence of kinship on social associations and interactions in wild, communally roosting sulphur-crested cockatoos, Cacatua galerita. We recorded roost co-membership, social associations and interactions in 561 individually marked birds across three neighbouring roosts. We then collected genetic samples from 205 cockatoos, and conducted a relationship analysis to construct a kinship network. Finally, we tested correlations between kinship and four social networks: association, affiliative, low-intensity aggression and high-intensity aggression. Our result showed that while roosting groups were clearly defined, they showed little genetic differentiation or kin structuring. Between roost movement was high, with juveniles, especially females, repeatedly moving between roosts. Both within roosting communities, and when visiting different roosts, individuals preferentially associated with kin. Supporting this, individuals were also more likely to allopreen kin. However, contrary to expectation, individuals preferred to direct aggression towards kin, with this effect only observed when individuals shared roost membership. By measuring social networks within and between large roosting groups, we could remove potential effects of passive spatial overlap on kin structuring. Our study reveals that sulphur-crested cockatoos actively prefer to associate with kin, both within and between roosting groups. By examining this across different interaction types, we further demonstrate that sulphur-crested cockatoos exhibit behavioural and context-dependent interaction rules towards kin. Our results help reveal the drivers of social association in this species, while adding to the evidence for social complexity in parrots.

Hematologic Reference Intervals and Comparison of Natt-Herrick Technique and Smear-Based Leukocyte Estimation in Cockatiels (Nymphicus hollandicus).

Although cockatiels are among the most common avian species maintained as companion animals in the United States, information on standard hematologic reference values for this species is limited. The objectives of this study were to establish hematologic reference intervals (RI) for cockatiels, compare methods using both the Natt-Herrick technique (NHT) and the smear-based estimation technique (SBT), explore age and sex differences in the hematologic findings for this species, and produce the first cockatiel RI for fibrinogen concentration and thrombocyte estimate. Healthy cockatiels (60 males and 60 females, 2-11 years old) from a research colony were included in this study. Blood samples were placed in dipotassium ethylenediaminetetraacetic acid tubes, and erythrocyte counts and thrombocyte estimates were determined via automated analyzer (ADVIA 120) and SBT, respectively. Moreover, leukocyte concentrations were determined using both NHT and SBT to compare these common methods for measuring a complete blood count in cockatiels. Data were analyzed for outliers, distributions, descriptive statistics, and RI via Reference Value Adviser, a set of macroinstructions for Microsoft Excel (Microsoft, Redmond, WA, USA). Lymphocytes were the predominant leukocyte across both methods. According to the NHT, females had significantly higher concentrations of total leukocytes, heterophils, bands, lymphocytes, basophils, and total plasma protein compared with males. Significant inverse polynomial relationships were noted between total leukocyte count and age and lymphocyte counts and age for NHT. Total leukocyte count produced via NHT and SBT were compared using Passing-Bablok and Bland-Altman plots, and no significant constant or proportional biases were found. However, these methods showed wide limits of agreement. While the RI were interchangeable between methods from a clinical standpoint, the same method should be used to assess changes in an individual. The reported RI are uniquely robust given the sample size, balanced sex and age distributions, inclusion criteria, and control over sample collection.

Factors Influencing Vertical Transmission of Psittacine Bornavirus in Cockatiels (Nymphicus hollandicus).

The transmission of parrot bornavirus is still not fully understood. Although horizontal transmission through wounds can be one route, vertical transmission is still discussed. PaBV RNA and PaBV antigen were detected in psittacine embryos, but isolation of the virus failed, raising doubts about this route. In this study, cockatiels were infected either as adults (adult group) or during the first 6 days after hatching (juvenile group) and raised until sexual maturity to breed and lay eggs. A total of 92 eggs (adult group: 49, juvenile group: 43) were laid and incubated until day 17. The embryos and yolk samples were examined by RT-PCR for PaBV RNA and by infectivity assay for infectious virus. In the adult group, 14/31 embryos (45.2%) and 20/39 (51%) of the yolk samples demonstrated PaBV RNA in the PCR. Isolation of PaBV was not possible in any embryo of this group, but it was achieved in six yolk samples from one female. Anti-PaBV antibodies were detected in the yolk samples after seroconversion of all female parents. In the juvenile group, 22/29 embryos (74.9%) were positive for PaBV RNA. In 9/21 embryos (42.9%), PaBV isolation was possible. PaBV RNA was detected in 100% and infectious virus in 41% of the yolk samples. Anti-PaBV antibodies were detected in all yolk samples. For the first time, successful vertical transmission of PaBV was proven, but it seems to depend on the age when the parent birds are infected. Therefore, the age of the bird at time of infection may be an important factor in the occurrence of vertical transmission.