Avian Bornavirus (aka Proventricular Dilatation Disease/Syndrome and Macaw Wasting Syndrome)
General Information: There are four distinct strains of Avian bornavirus, and it is unclear which one or more of the four viruses is responsible for clinical disease.
Transmission: Though not completely known, direct contact and contact with infected fecal material are thought to be major means of viral transmission.
Clinical Signs: Clinical signs include one or more of the following: vomiting; crop stasis and impaction; weight loss; undigested feed in feces; normal or decreased appetite; abdominal distension; neurologic abnormalities; ataxia (lack of balance or stumbling as if drunk); lethargy; weakness; polyuria (increased urination); diarrhea; seizures; and sudden death.
Clinical Course: The clinical course of this disease is currently unknown. There is a vast range of survival intervals ranging from days to years. To date, there has been no report of a parrot being cured, and the condition is invariably fatal.
Diagnosis: At this time, there is not an accurate ante-mortem test for the diagnosis of proventricular dilatation disease. There is a polymerase chain reaction (PCR) assay available for avian bornavirus, but a positive result for avian bornavirus does not conclusively indicate proventricular dilatation disease. It merely indicates exposure to the virus. Additionally, there is no published data as to the specificity or sensitivity of this assay, therefore it is unknown how many false positive and false negative test results occur. A serology assay (ELISA) is also available but with similar limitations. Ante-mortem diagnosis of this condition is typically based upon clinical history; non-specific diagnostic results obtained from blood work (complete blood count and biochemical profile including bile acids), fecal exam, radiography, endoscopy, and fluoroscopy; and ruling out other conditions which may result in similar clinical findings. Additionally, crop biopsies are sometimes employed for ante-mortem diagnosis. A lack of the characteristic inflammation within the crop, though, does not rule out this condition. Post-mortem histologic examination of numerous organs to evaluate for the characteristic lymphoplasmacytic inflammation of the central and peripheral nervous systems is currently the best means of diagnosis.
Treatment: Treatment is purely symptomatic. Anti-inflammatory medications such as Celebrex or Metacam are commonly employed. Additionally, medications (i.e., metoclopramide)or supplements (i.e., ginger) that increase gastrointestinal motility may be helpful in addition to omega-3/6 balanced fatty acid, vitamin B, and vitamin E supplements. Anti-viral medications such as interferons may also be beneficial. Affected parrots may require syringe feeding and watering to help maintain weight and hydration, as well as environmental modifications in cases exhibiting neurologic abnormalities.
Prevention: The prevalence of this virus within the parrot population is unknown and may be wider spread than previously thought. The best means of prevention include precluding exposure to other parrots and their fecal material and employing strict quarantine standards. The resilience of the virus is also unknown, so toys, clothing, and other implements exposed to unknown parrots should be removed and thoroughly sanitized prior to interacting with your parrot. If a parrot is exposed to an affected parrot, there is no way to determine whether or not he/she will develop clinical disease. Current thoughts suggest that if three years pass without development of clinical disease that the likelihood of future development is low, but there is no proven data to support this claim. There have been rare anecdotal reports of parrots developing disease up to eight years following known exposure.
General Information: There are four distinct strains of Avian bornavirus, and it is unclear which one or more of the four viruses is responsible for clinical disease.
Transmission: Though not completely known, direct contact and contact with infected fecal material are thought to be major means of viral transmission.
Clinical Signs: Clinical signs include one or more of the following: vomiting; crop stasis and impaction; weight loss; undigested feed in feces; normal or decreased appetite; abdominal distension; neurologic abnormalities; ataxia (lack of balance or stumbling as if drunk); lethargy; weakness; polyuria (increased urination); diarrhea; seizures; and sudden death.
Clinical Course: The clinical course of this disease is currently unknown. There is a vast range of survival intervals ranging from days to years. To date, there has been no report of a parrot being cured, and the condition is invariably fatal.
Diagnosis: At this time, there is not an accurate ante-mortem test for the diagnosis of proventricular dilatation disease. There is a polymerase chain reaction (PCR) assay available for avian bornavirus, but a positive result for avian bornavirus does not conclusively indicate proventricular dilatation disease. It merely indicates exposure to the virus. Additionally, there is no published data as to the specificity or sensitivity of this assay, therefore it is unknown how many false positive and false negative test results occur. A serology assay (ELISA) is also available but with similar limitations. Ante-mortem diagnosis of this condition is typically based upon clinical history; non-specific diagnostic results obtained from blood work (complete blood count and biochemical profile including bile acids), fecal exam, radiography, endoscopy, and fluoroscopy; and ruling out other conditions which may result in similar clinical findings. Additionally, crop biopsies are sometimes employed for ante-mortem diagnosis. A lack of the characteristic inflammation within the crop, though, does not rule out this condition. Post-mortem histologic examination of numerous organs to evaluate for the characteristic lymphoplasmacytic inflammation of the central and peripheral nervous systems is currently the best means of diagnosis.
Treatment: Treatment is purely symptomatic. Anti-inflammatory medications such as Celebrex or Metacam are commonly employed. Additionally, medications (i.e., metoclopramide)or supplements (i.e., ginger) that increase gastrointestinal motility may be helpful in addition to omega-3/6 balanced fatty acid, vitamin B, and vitamin E supplements. Anti-viral medications such as interferons may also be beneficial. Affected parrots may require syringe feeding and watering to help maintain weight and hydration, as well as environmental modifications in cases exhibiting neurologic abnormalities.
Prevention: The prevalence of this virus within the parrot population is unknown and may be wider spread than previously thought. The best means of prevention include precluding exposure to other parrots and their fecal material and employing strict quarantine standards. The resilience of the virus is also unknown, so toys, clothing, and other implements exposed to unknown parrots should be removed and thoroughly sanitized prior to interacting with your parrot. If a parrot is exposed to an affected parrot, there is no way to determine whether or not he/she will develop clinical disease. Current thoughts suggest that if three years pass without development of clinical disease that the likelihood of future development is low, but there is no proven data to support this claim. There have been rare anecdotal reports of parrots developing disease up to eight years following known exposure.
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