RESUMEN
Cardiovascular diseases in the common mynah (Acridotheres tristis) often go undiagnosed due to limitations with the physical examination and common concurrent illnesses. The aim of this study was to establish accurate reference intervals for cardiac size based on radiographs for this species. All birds were considered healthy based on physical examination. High-quality ventrodorsal radiographic images were obtained from 34 healthy common mynah birds. The cardiac width (CW), thoracic width, distance between third and fourth ribs, synsacral width, coracoid width, and distance between clavicular bones were evaluated on the ventrodorsal radiographic images. Additionally, the ratio between the CW and these anatomical indices were measured. In order to evaluate the correlation between CW and the radiographic indices, a linear regression model was used. The mean ± SD for CW in the 34 birds was 16.1 ± 0.9 mm (95% confidence interval: 14.1-18 mm). Significant moderate correlation was found for CW with thoracic width (R2 = 0.37; P < 0.001), coracoid width (R2 = 0.25; P = 0.002), and the distance between the third and fourth ribs (R2 = 0.34; P < 0.001). The radiographic reference intervals calculated in this study can be used to evaluate cardiac size in the common mynah bird.
Asunto(s)
Estorninos , Animales , Valores de Referencia , Estado de Salud , Corazón/diagnóstico por imagen , Modelos LinealesRESUMEN
Although serum protein electrophoresis is a diagnostic tool available through many veterinary laboratories, there currently are no reference intervals for protein fractions in healthy common mynahs (Acridotheres tristis). Therefore, electrophoretic patterns of proteins in serum and heparinized plasma of the common mynah were evaluated. Blood specimens were collected from 55 healthy adult common mynahs of unknown age (26 males and 29 females). The serum total protein and protein fractions were measured using the biuret method followed by cellulose acetate electrophoresis (CAE). The serum level of albumin was compared with bromocresol green (BCG) dye-binding and CAE methods. Four protein fractions, including albumin and α, ß, and γ globulins, were recorded in the electrophoretogram of serum specimens. Sex appeared to have no significant effect on the measured parameters. The serum BCG albumin fraction was significantly higher than the CAE albumin fraction (P = .01). Also, the comparison of total protein and protein fractions in serum and plasma specimens of 25 of the 55 birds sampled showed that total protein (Cohen index d = 0.66, P = .03), gamma globulin (d = 1.13, P = .00), and total globulin (d = 0.67, P = .00) in plasma samples were significantly higher than those in serum samples. The results of this study provide the specific reference intervals for total protein and protein fractions in common mynahs, which are essential for proper interpretation of laboratory results and also revealed that the albumin measurement by the BCG method yields unreliable results in common mynahs.
Asunto(s)
Estorninos , Animales , Electroforesis de las Proteínas Sanguíneas/veterinaria , Proteínas Sanguíneas , Electroforesis/veterinaria , Electroforesis en Acetato de Celulosa/veterinaria , Femenino , Masculino , Plasma , Albúmina SéricaRESUMEN
Theory suggests that overcrowding and increased competition in urban environments might be detrimental to individual condition in avian populations. Unfavourable living conditions could be compounded by changes in dietary niche with additional consequences for individual quality of urban birds. We analysed the isotopic signatures, signal coloration, body condition, parasitic loads (feather mites and coccidia), and immune responsiveness of 191 adult common (Indian) mynas (Acridotheres tristis) captured in 19 localities with differing levels of urbanization. The isotopic signature of myna feathers differed across low and high urbanized habitats, with a reduced isotopic niche breadth found in highly urbanized birds. This suggests that birds in high urban environments may occupy a smaller foraging niche to the one of less urbanized birds. In addition, higher degrees of urbanization were associated with a decrease in carotenoid-based coloration, higher ectoparasite loads and higher immune responsiveness. This pattern of results suggests that the health status of mynas from more urbanized environments was poorer than mynas from less modified habitats. Our findings are consistent with the theory that large proportions of individual birds that would otherwise die under natural conditions survive due to prevailing top-down and bottom-up ecological processes in cities. Detrimental urban ecological conditions and search for more favourable, less crowded habitats offers the first reasonable explanation for why an ecological invader like the common myna continues to spread within its global invasive range.
Asunto(s)
Especies Introducidas , Urbanización , Animales , Aves , Dieta/veterinaria , EcosistemaRESUMEN
Producing colored signals often requires consuming dietary carotenoid pigments. Evidence that food deprivation can reduce coloration, however, raises the question of whether other dietary nutrients contribute to signal coloration, and furthermore, whether individuals can voluntarily select food combinations to achieve optimal coloration. We created a two-way factorial design to manipulate macronutrient and carotenoid access in common mynas (Acridotheres tristis) and measured eye patch coloration as a function of the food combinations individuals selected. Mynas had access to either water or carotenoid-supplemented water and could either eat a standard captive diet or choose freely between three nutritionally defined pellets (protein, lipid or carbohydrate). Mynas supplemented with both carotenoids and macronutrient pellets had higher color scores than control birds. Male coloration tended to respond more to nutritional manipulation than females, with color scores improving in macronutrient- and carotenoid-supplemented individuals compared with controls. All mynas consuming carotenoids had higher levels of plasma carotenoids, but only males showed a significant increase by the end of the experiment. Dietary carotenoids and macronutrient intake consumed in combination tended to increase plasma carotenoid concentrations the most. These results demonstrate for the first time that consuming specific combinations of macronutrients along with carotenoids contributes to optimizing a colorful signal, and point to sex-specific nutritional strategies. Our findings improve our knowledge of how diet choices affect signal expression and, by extension, how nutritionally impoverished diets, such as those consumed by birds in cities, might affect sexual selection processes and, ultimately, population dynamics.
Asunto(s)
Plumas , Pigmentación , Animales , Carotenoides , Dieta , Ingestión de Alimentos , Femenino , Humanos , MasculinoRESUMEN
Mynahs are popular pet and aviary birds. Captive mynahs are prone to metabolic disorders, such as obesity, hepatic lipidosis, and atherosclerosis, and determination of a plasma biochemical reference interval is essential for diagnosis, treatment, and monitoring of these disorders. To establish reference intervals for the lipoprotein panel and plasma activity of liver enzymes in common mynahs (Acridotheres tristis), glucose, cholesterol, triglycerides, high and low density lipoprotein concentrations, and activities of aspartate aminotransferase, alkaline phosphatase, gamma-glutamyl transferase, and lactate dehydrogenase were measured in 56 adult healthy individuals. The data were grouped according to sex and body weight. For all variables, no significant differences were found between male and female mynahs, and body weight had no effect on lipoprotein fractions. Our results provide a reliable reference interval for some blood biochemical values in healthy common mynahs that could be useful for diagnosing and monitoring disease problems.
Asunto(s)
Enfermedades de las Aves/diagnóstico , Análisis Químico de la Sangre/veterinaria , Lípidos/sangre , Estorninos/sangre , Fosfatasa Alcalina/sangre , Animales , Enfermedades de las Aves/sangre , Colesterol/sangre , HDL-Colesterol/sangre , LDL-Colesterol/sangre , Creatina Quinasa/sangre , Femenino , L-Lactato Deshidrogenasa/sangre , Hígado/enzimología , Masculino , Mascotas , Valores de Referencia , Caracteres Sexuales , Triglicéridos/sangreRESUMEN
Coccidian parasites, especially Isospora, are prevalent parasites in Passeriformes. Isosporan oocysts from common mynahs (Acridotheres tristis) are incompletely described. Detailed knowledge on biology, prevalence, pathogenesis and treatment of avian isosporiasis is scant. In this study, isosporan oocysts isolated from common mynahs were morphologically and molecularly characterized. The medication efficiencies of diclazuril and sulfadiazine-trimethoprim in isosporiasis in naturally infected mynahs were evaluated. Isosporan oocysts from common mynahs were described morphologically by microscopic imaging. The 18S rRNA and COI genes were amplified using PCR and the resultant products were sequenced and analysed phylogenetically. To evaluate the efficiencies of diclazuril and sulfadiazine-trimethoprim, two experimental treatment groups and a null control were assigned. General health status, weight and oocysts per gram of faeces were evaluated. Oocysts from all birds contained isosporan oocysts that were morphologically and dimensionally similar (P < 0.05). The oocysts were spherical; with no oocyst residuum, micropyle or polar granules. At both loci, phylogenetic analyses placed the Isospora isolate in the same clade with Isospora spp. from other Passeriformes. Both of the anticoccidials were well tolerated by the birds, a rapid reduction in oocyst excretion was noted at the commencement of treatment and 72â h after drug administration, oocyst excretion zeroed in all treated birds. Based on morphological and molecular data, this isolate does not resemble any previously described isosporas, hence Isospora tristum n. sp. is proposed for the current species. Both evaluated anticoccidials seemed to be efficient in reduction of oocyst production and can be recommended for the treatment of mynah isosporiasis.
Asunto(s)
Enfermedades de las Aves/parasitología , Isospora/aislamiento & purificación , Isosporiasis/veterinaria , Nitrilos/uso terapéutico , Passeriformes/parasitología , Sulfadiazina/uso terapéutico , Triazinas/uso terapéutico , Trimetoprim/uso terapéutico , Animales , Antiprotozoarios/uso terapéutico , Enfermedades de las Aves/tratamiento farmacológico , Combinación de Medicamentos , Isospora/clasificación , Isospora/genética , Isosporiasis/tratamiento farmacológico , Isosporiasis/parasitología , FilogeniaRESUMEN
BACKGROUND: In Seychelles, the common myna has been shown to have a negative impact on endangered endemic birds on Denis Island, interfering with breeding attempts and attacking adult endemic birds at their nests. This stimulated an attempt to eradicate the island's mynas. RESULTS: The eradication was undertaken in three phases, overall killing 1186 mynas and lasting 5 years. Decoy trapping was the most effective method for catching mynas, but the last birds were shot. Decoy trapping was compromised by catches of non-target species. Data collection from killed birds indicated that trapping did not favour either sex, and that most breeding occurred during the wetter season, November to March. CONCLUSIONS: Eradication of mynas from small tropical islands is feasible. The Denis Island eradication was prolonged by difficulties in management and staffing. Using volunteers, the cost of the eradication was similar to that of eradicating rodents from the island. In future eradication attempts in Seychelles, possible food stress during the drier season (May to September) might facilitate trapping at this time. Habitat management, especially the removal of short mown grass, could enhance eradication progress. Continued monitoring is needed to confirm eradication and detect any immigration, and also to record responses in the endemic birds. © 2016 Society of Chemical Industry.
Asunto(s)
Control de Plagas/métodos , Estorninos , Animales , Femenino , Especies Introducidas , Masculino , Reproducción/fisiología , Estaciones del Año , SeychellesRESUMEN
Pathogens can influence the success of invaders. The Enemy Release Hypothesis predicts invaders encounter reduced pathogen abundance and diversity, while the Novel Weapons Hypothesis predicts invaders carry novel pathogens that spill over to competitors. We tested these hypotheses using avian malaria (haemosporidian) infections in the invasive myna (Acridotheres tristis), which was introduced to southeastern Australia from India and was secondarily expanded to the eastern Australian coast. Mynas and native Australian birds were screened in the secondary introduction range for haemosporidians (Plasmodium and Haemoproteus spp.) and results were combined with published data from the myna's primary introduction and native ranges. We compared malaria prevalence and diversity across myna populations to test for Enemy Release and used phylogeographic analyses to test for exotic strains acting as Novel Weapons. Introduced mynas carried significantly lower parasite diversity than native mynas and significantly lower Haemoproteus prevalence than native Australian birds. Despite commonly infecting native species that directly co-occur with mynas, Haemoproteus spp. were only recorded in introduced mynas in the primary introduction range and were apparently lost during secondary expansion. In contrast, Plasmodium infections were common in all ranges and prevalence was significantly higher in both introduced and native mynas than in native Australian birds. Introduced mynas carried several exotic Plasmodium lineages that were shared with native mynas, some of which also infected native Australian birds and two of which are highly invasive in other bioregions. Our results suggest that introduced mynas may benefit through escape from Haemoproteus spp. while acting as important reservoirs for Plasmodium spp., some of which are known exotic lineages.
Asunto(s)
Enfermedades de las Aves/epidemiología , Enfermedades de las Aves/parasitología , Haemosporida/aislamiento & purificación , Plasmodium/aislamiento & purificación , Infecciones por Protozoos/epidemiología , Infecciones por Protozoos/parasitología , Estorninos/parasitología , Animales , Australia/epidemiología , ADN Protozoario/química , ADN Protozoario/genética , Haemosporida/clasificación , Haemosporida/genética , Datos de Secuencia Molecular , Filogeografía , Plasmodium/clasificación , Plasmodium/genética , Prevalencia , Análisis de Secuencia de ADN , Estorninos/crecimiento & desarrolloRESUMEN
A 12-year-old female common mynah ( Acridotheres tristis ) was examined because of dyspnea and coelomic enlargement. Abdominal radiographs revealed hepatomegaly and a coelomic mass of unknown origin. Both brightness mode (2-dimensional; 2D) and 3-dimensional (3D) ultrasonography were performed to identify the origin of the mass. Ultrasonographic findings distinguished the mass from the liver and revealed high vascularization of the mass and a moderate increase in echogenicity of the liver. Three-dimensional ultrasonographic histogram analysis of the mass was performed. The mynah was treated with supportive care but died after 3 days. Histopathologic examination showed ovarian adenocarcinoma, with concurrent mild to moderate hepatopathy. In diagnostic imaging using ultrasound in birds, 3D ultrasonography allows perspective images of the internal organs to be obtained and is potentially superior to 2D ultrasonography in evaluating irregularly shaped objects.
Asunto(s)
Adenocarcinoma/veterinaria , Enfermedades de las Aves/diagnóstico por imagen , Neoplasias Ováricas/veterinaria , Estorninos , Adenocarcinoma/diagnóstico , Adenocarcinoma/patología , Animales , Enfermedades de las Aves/patología , Resultado Fatal , Femenino , Neoplasias Ováricas/diagnóstico , Neoplasias Ováricas/patología , UltrasonografíaRESUMEN
To evaluate tear production in the common mynah ( Acridotheres tristis ) using the phenol red thread test (PRTT) and to make a comparison of measurements with the PRTT placed in the fornices of lower and upper eyelids, tear production of both eyes in 22 healthy adult captive mynah birds was evaluated. After positioning of threads in the fornices of upper and lower eyelids, the PRTT values of the birds were 17.5 ± 3.1 mm/15 s and 19.2 ± 2.5 mm/15 s, respectively. A significant difference was found between PRTT values for upper eyelids and lower eyelids (P = 0.01). This study provides novel data for normal reference ranges of PRTT values in healthy common mynah birds and shows that a difference is found depending on where the PRTT thread is placed.