What is Papillomatosis (Psittacine) ?

Papillomatosis, with the accompanying abnormal papilloma development, can occur anywhere on the non-feathered skin of the bird as well in the mucous membranes or on the surface layers of the mucous membranes of the host bird, both externally as well as internally. These papillomas can be either benign or malignant and predominantly affect birds in the Psittacine family, (all types of parrots, macaws, lovebirds, conures, cockatoos, cockatiels and parakeets as well as related species).  This condition has been noted in other species and families of birds as well, though less frequently.

Papillomatosis is defined as a condition or disorder in which there are abnormal multiple papillomas (also referred to as warts) that have developed in the non-feathered skin or mucous membranes of the host.

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Symptoms of Papillomatosis (Psittacine) in Birds

Papillomatosis can be noted in a variety of mucosa as well as on the non-feathered areas of the skin of your birds.  Here are some of the symptoms you will likely see:

  • Blood (coming from the papilloma) being present in the droppings
  • Papilloma prolapsing through the cloaca (defined as the common opening of urinary, gastrointestinal and genital tracts)
  • Soiling on the feathers surrounding the cloaca that come from the blood noted above or from loose droppings
  • Lesions of various sizes on the skin of the non-feathered areas of the bird’s body 

You will most likely be aware of internal papillomas unless a prolapse occurs from the cloaca.  Noting these lesions or symptoms should prompt you to get medical assessment from your veterinary professional as soon as possible.


The types of papillomatosis would relate to the location of the abnormal papilloma development and possibly the virus responsible if known:

  • Cutaneous - Those papillomas relating to skin or non-feathered areas
  • Mucocutaneous - Those papillomas relating to mucous membranes and skin
  • Mucosal epithelial surfaces - Those papillomas relating to the outermost layer of mucous tissues

Some of the abnormal papilloma development can occur externally in these areas when they can be seen relatively easily but others can occur internally, where their presence is less likely to be noted until after the bird has died, being found on post-mortem examination.

Causes of Papillomatosis (Psittacine) in Birds

The primary cause of papillomatosis in Psittacine birds is not completely known but it is felt that Psittacine herpesvirus and the other papillomaviruses (of which there are many) are actively involved.  The virus can be shed in the feces and nasal discharge of the host very early on after the bird has become infected.  The virus also lives outside the body quite well, making it available for transmission by contact with the viral dust or the virus in an aerosol form for long periods of time.  The virus is quite contagious and deadly as most birds don’t display clinical signs and very few symptoms before they expire.  The mortality rate is 100 percent in birds who are less than 15 days old.

Diagnosis of Papillomatosis (Psittacine) in Birds

Diagnosis will be done using your bird’s complete history to your veterinary professional and his thorough physical examination of the afflicted bird.  In view of the fact that the disease is so aggressive and doesn’t present with signs and symptoms early on, if ever, many if not most birds die before medical attention can be obtained.  Blood and various tissue samples will need to be tested, regardless of whether the bird is alive or decreased.  

Pathological evaluation will be required to determine the cause of the virus and very likely the death of the afflicted avian.  It is important to proceed with the recommended testing of your bird even if it has succumbed to the virus, if for no other reason than for the protection of the remaining birds in your aviary.  The disease can be spread to other birds so very rapidly as noted above and steps will need to be taken to test other birds for possible infection or to see if they are carriers of the virus.

Treatment of Papillomatosis (Psittacine) in Birds

There is no cure for the virus that is thought to cause papillomatosis in Psittacine and other birds.  Treatment for the abnormal external papillomas involves removal with cautery or surgical excision of the papilloma once it has been identified.  This treatment is generally short-term at best as they tend to come back with a vengeance (larger and more extensive) again and again.  For those birds suffering from abnormal internal papilloma development, the morbidity rate is much higher since those papillomas are much less likely to be found before the bird succumbs to the disease.  

Some researchers and veterinary professionals feel that, ultimately, those birds suffering from internal papillomatosis of parrots (IPP), for example, will develop bile duct carcinomas or pancreatic carcinomas or both.  Many of the research models currently being studied for internal papillomatosis in parrots are also consistent with those models being studied on Pacheco’s herpesvirus which seem to be related in the herpesvirus family, which includes the various viruses that are felt to be at the root of papillomatosis in this bird family.

Recovery of Papillomatosis (Psittacine) in Birds

The morbidity or mortality rate of this disease is extremely high, especially in those birds who become infected who are under the age of 15 days.  The virus that is felt to be at the root of this disease is extremely contagious and can run its course to devastate an aviary within weeks. You may not be aware of the virus until you find one of your birds dead, and if this happens, be sure to get your vet involved as soon as possible so that appropriate testing can be done to ascertain what caused the death of your bird.  If this virus is responsible, the rest of your aviary population will need to be tested and retested to ascertain if any others are infected or if any are carriers.  

Isolation may be required and special hygiene measures may be necessary to stay the course of the spread of the disease to your other birds. When new birds are brought into your aviary, testing must be done on them as well and they will need to be isolated and monitored (most likely with additional testing) for a minimum of 6 weeks before introducing them to your other birds.  Prevention is the best course of action for you to protect the investment in your aviary, both in terms of costs and emotional connection.