08 setembro, 2006

Psittacine beak and feather disease







Psittacine beak and feather disease (PBFD) was first recognised and described thoroughly in 1975 by Dr Ross Perry, a veterinary practitioner in Sydney. It has since been recognised as the most significant disease of psittacine birds in Australia Numerous reasons were put forward from veterinarians around the world to explain the cause of PBFD. Some blamed "sunflower seeds", whilst others thought that the disease was caused by in-breeding. Research at Murdoch University by Drs David Pass, Ross Perry and Sarah Wylie demonstrated that PBFD was caused by a new type of virus which has since been characterised by researchers at the University of Georgia.
Recent research at the University of Sydney by Drs Garry Cross and Shane Raidal demonstrated that the disease is widespread in wild cockatoos and other psittacine birds. They also demonstrated that the disease can be prevented by vaccination.

PBFD is caused by a relatively simple virus which infects and kills the cells of the feather and beak. The virus also kills the cells of the immune system. Consequently many diseased birds succumb to bacterial and other infections.
Psittacine circovirus measures 16 nm in diameter and the genome is a circular single-stranded DNA molecule. These characteristics make it the smallest known virus capable of causing disease.
The psittacine circovirus only causes problems for psittacine birds. As far as we know, no other bird or animal species is susceptible. A similar PBFD-like disease recently seen in doves is probably caused by similar but antigenically different circovirus.

Diagnosis
Severe on-going PBFD is not difficult to diagnose. The difficult cases to diagnose are those birds (and species) which only showing subtle signs either because of their age or immunity.
Histological examination of feather follicles has been routinely used to confirm clinical disease but it is not suitable for diagnosing incubating infections.
Psittacine circovirus can be detected in affected feathers by haemagglutination assay (HA) and HI antibodies can be detected in blood, serum, plasma or yolk.
Virus detection by HA is currently the best method available in Australia for detecting circovirus. It is a valuable tool for detecting virus in feathers, liver and faeces. It can be performed on actively growing feather pulp or dry feathers. In cockatoos the powder-down feathers are the best feathers to test for HA because they are often the first to become affected. Feather testing is preferred over faecal because acutely PBFD-affected birds do not excrete high concentrations of virus in faeces and some chronically affected birds only excrete intermittently.
Serology is useful for detecting PBFDV-infected flocks and for demonstrating antibodies in individual birds. The presence of antibody means that the bird has been exposed to circovirus and a high HI antibody titre in an adult bird is a good indicator that it does not have chronic PBFD. Nestlings with incubating infection or acute disease may have low and declining antibody titres. The test fails to detect passively derived maternal antibody.
Blood can be collected directly onto filter-paper - only a few drops are required, thus small parrots can be easily tested. The paper is allowed to dry and does not have to be refrigerated for transportation to the laboratory. The blood test detects antibodies to the virus.
HA and HI testing cannot identify young birds which are incubating the infection.
Psittacine circovirus can also be detected by Polymerase Chain Reaction (PCR). This is currently not available for diagnosis in Australia.

24 julho, 2006

Anisognathus somptuosus


Se o tasco fosse uma coisa decente eu dizia coisas como isto: olha este pardal tão bonito, os pardais bonitos e os feios não deviam estar dentro de capoeiras. Se fosse um pardal era feio e ia para o inferno; enforcava-me no pescoso de uma girafa, pendurado numa corda fora da capoeira, saia dali a andar de balão.

21 julho, 2006

Fazer olhinhos





















Pinning and flashing explained
How come parrots' pupils get small when they talk?

IN MOST ANIMALS, the pupil, the black opening in the middle of the iris, changes size for a number of reasons. For one, pupil size controls the amount of light that can enter the eye. Changes in pupil size can also signal a change in blood pressure or an emotion such as fear, aggression, or excitement. Changes in pupil size even have been recorded during the processing of new information. In mammals such as humans, these changes are involuntary. A signal comes from a nerve in the brain and travels to the eye, telling the muscular iris to open or close the pupil.
Birds' pupils change in size for all the same reasons as humans' do. However, they also enjoy conscious control over the iris and other eye muscles. According to avian veterinarian Dr. Susan Orosz, the signals sent from the brain to a birds' eyes travel from some of the same nerves as in mammals, but they take a different path that allows the bird discretion over the results. In addition, a bird's eye muscles are different from ours - they are more like the muscles in our arms and legs. As a result, birds can control how and when the muscles in their eyes move, and make their pupils small or large whenever they want or need to.
This type of control is what allows a falcon traveling at over 200 mph to instantaneously change focus from a faraway object to one that is near, or vice versa. If we tried to do that we’d probably fly into something! That same control allows a parrot to use his eyes to convey that he is feeling afraid, aggressive or interested. By constricting, or "pinning," and opening, or "flashing," his pupils while he is talking, your bird is letting you know just how excited he is at that moment.


-- Emily Insalaco, trainer
ParrotChronicles.com

30 junho, 2006

Só à noitinha...







Força Portugal!!!


21 maio, 2006

OLHOS NOS OLHOS






10 maio, 2006

Saltava-lhe em cima a pés-juntos!



Gostava de comer a gaja...

És tão boa!

23 abril, 2006

Rupicola rupicola

Quando a beijei fingiu que estava a dormir e eu fingi que acreditei, na manhã seguinte perguntou-me se a beijei a dormir ou se tinha sonhado, eu disse-lhe que tinha sonhado, que me podia ter acordado.

21 abril, 2006

Tiffany Lanco



Os papagaios são vertebrados de temperatura constante, cerca de 40-41 ºC. Têm o corpo coberto de penas e um bico especializado, em forma de pinça ou por vezes em forma de gancho, único na sua classe tanto pela precisão como pela potencia.

12 abril, 2006

Passarola

esta é das lindas

31 março, 2006

Outra passarinha



Os fósseis mais antigos de papagaios foram encontrados em Allier (França), e remontam a 30 milhões de anos atrás. Trata-se de um tarso-metatarso- uma pata-, em todo semelhante as patas dos papagaios actuais. A origem dos papagaios é muito mais antiga do que o exemplar encontrado em Allier, provavelmente remonta a um periodo indeterminado do mesozoico, muitas dezenas de milhões de anos antes do fóssil de Allier.

09 março, 2006

Cantar-te



Os primeiros papagaios a chegarem à Europa foram importados no ano 327 a.c. por um marinheiro chamado Honéscrito, que fazia parte da expedição à Asia de Alexandre Magno. Tratava-se de periquitos do genero Psittacula, talvez o periquito alexandrino Psittacula eupatria.

20 fevereiro, 2006

Erwin Olaf



Basta-me um olhar teu.
Ver-te a passar de um compartimento fechado para outro fechado.
uma careta que termina em sorriso nos teus olhos.
Tu.

)

Cup of cheer

19 fevereiro, 2006

Carol

12 fevereiro, 2006

Bubo philippensis

Quando os olhos dela veem os meus sinto-me sob o efeito de morfina e pairo a cinco centimetros do chão. Sofro uma redução dos sentidos o cerebro tropeça e as palavras caem soltas sem sentido.

01 janeiro, 2006

Mônica


Todos cagam. Todos dormem.
Mas é utópico.
Eu não sou muito magro, é que tive muito tempo ao sol.