[4] Due to a very high mortality rate within these susceptible species, concerns are brought to companion bird markets and breeders.

[16][5] They can experience mucoid discharges from the nostrils, such as in blue-and-gold macaws and Amazon parrots, or a regurgitation of clear sanguineous fluids.

[17][5] As the disease progresses, birds can become difficult to arouse, experience lethargy and somnolence as well as lose interest in eating and its normal daily activities.

[7] However, due to the short duration of infection and lack of severe clinical signs indicating a presence of the herpesvirus, birds that experience a rapid death are found in excellent bodily conditions with full crops.

[14] Laboratory tests can also display the abnormalities of tissues, such as a liver with pale yellow to brown patches in necrotic areas.

[17] Examinations mainly present lesions in the liver and spleen, such as an enlargement of both organs with diffuse patches of necrosis and the bleeding of broken capillaries (petechial haemorrhage).

[16] Importing birds from a warm to cold environment and stress due to overcrowding can trigger outbreaks of Pacheco's disease.

[2] It was initially identified as a herpesvirus by examining its virion size, sensitivity to ether, the formation of intranuclear inclusions, its ability to thicken the nuclear membranes of the host cells.

[14] It is also not transmissible to other common laboratory animals, including guinea pigs, mice as well as other certain bird species, such as pigeons and canaries.

[18] The main sources of contraction is through the faeces, oral and pharyngeal secretions of carrier birds where the virus has shed, or through contaminated food or water.

[14][23] This makes it essential for all recently imported psittacine birds to be tested for the presence of the herpesvirus before entering a resident of aviaries.

[23][3] However, readings can often present a misleading indication that there is no presence of Pacheco's disease as a result of samples being collected at the time the bird is not shedding the herpesvirus.

[25] An indirect immunoperoxidase method is another chemically sensitive and specific testing that laboratories have used to arrive at a reliable result in making a histopathological diagnosis of Pacheco's disease.

[11] By applying this test on post-mortem tissues, dark dispersed spotting on the liver and small intestines in necrotic areas display an indication of a reaction to the viral antigen.

[11] However, there have been successful uses of acyclovir, an antiviral medication, in reducing high death rates by rapidly inhibiting the virus replication within the birds.

[14] An autogenous, formalin-inactivated vaccine, with an adjuvant of aluminium, hydroxide gel, has similarly been used in an outbreak, in 1999, to successfully protect psittacine birds from Pacheco's disease.

[13] This vaccine was used to stop the rapid spread of the virus and helped maintain morbidity and mortality rates in psittacine birds within the zoo.

[27] It contained macaws, Amazon parrots, conures and parakeets, who were all transferred to quarantine premises and were housed in cages, based on its size and genera.

[27] The US has encountered numerous psittacine-disease related incidents linking to Pacheco's disease: In December 1977 and January 1978, multiple outbreaks had occurred in a privately owned bird import quarantine station that was located in Miami, Florida.

[29] Medical examinations showed an absence of gross lesions while the clinical signs confirmed Pacheco's disease as cause of death.