Veterinary Viewpoints

Amy B. Worell

Abstract


Question #1: My Yellow-collared Macaw is thought to have papilloma of the cloaca. This was noticed when I brought him in when he hurt his leg. The veterinarian said that it did not look too advanced, did a cloaca! culture which came back ok, and said to recheck him in three months. I'm not quite sure I understand what is going on with my bird. The vet said that it is thought to be due to a virus but they don't know for sure. He said to keep him away from other birds and not to breed him. What else do I need to know?

S. Thompson, California

Answer #l: Papillomas occur both in the oral cavity and lower digestive tract of macaws. These wart like growths form on the lining of the roof of the mouth and the lining of the cloaca and vent. They are believed to be caused by a virus. A thorough examination of a bird should include the oral cavity and cloaca. A moistened "Q tip" is used to evert the vent to look for suspicious lesions. Painting the tissue with a weak solution of acetic acid (vinegar) will "pucker up" the tissue making the tentative diagnosis easier. Confirmation of papillomas is based on a biopsy of the suspected tissue. The formation of carcinomas (cancer) of the bile duct is reported in birds with papillomas. It is assumed that there is a connection.

fames M. Harris, DVM

Oakland. CA

Answer #2: Papillomas in parrots, also known as internal papillomatosis, is· a disease that affects a number of parrots including macaws, Amazons. conures and Hawk-headed Parrots. Often the first noticeable sign is bleeding red tissue protruding from the cloaca. Additional lesions may be present in the oral cavity and throughout the digestive tract. Some affected birds may live for years, while others may be poor doers that eventually succumb

 

from complications resulting from the papillomas. A small percentage of affected birds may subsequently develop tumors involving the bile duct and pancreatic duct.

Although the cause of internal papillomatosis is not known. it is thought to be due to an infectious agent, in particular, a virus. Aviculturists have noted that birds housed in adjacent or nearby enclosures, may contract the disease. Affected birds often are still kept in breeding situations and the eggs are pulled for artificial incubation. One bird of a pair may be affected while the mate appears to be asymptomatic.

Different veterinarians have tried a variety of treatments with varying degrees of success. I have personally found that cryosurgery (freezing the tissues with liquid nitrogen compound), has visibly eliminated the cloaca! lesions. As was mentioned earlier, whether these birds may have additional non-visible lesions is not usually known. Affected birds are sedated with isoflurane and oxygen and a third of the affected cloaca! tissue is frozen each time. Birds are treated weekly until the affected tissue is no longer visible. Intermittent recheck examinations are recommended to monitor possible reoccurrence. You may want to talk to your veterinarian and determine what particular approach he or she recommends. Amy B. Worell, OVM, ABVP-Avian

Question #2: My pet Umbrella Cockatoo has not been doing well. She was given a bunch of tests and her· white blood cells were very high and she was positive on a stool test for tuberculosis. My veterinarian said that she may not have TB and that the bird would need to have a liver biopsy. My vet explained a lot to me but I am still confused about TB and my beloved bird. My vet does not treat birds with TB but she said some other vets do. Is mv bird going to die from TB? I don't

 

know what to do.

D. Lupian, Connecticut

Answer# 1: Tuberculosis is a serious. chronic, fatal disease of birds with public health significance as it can be transmitted to humans, especially if a person a has a weakened immune system. The finding of organisms in the stool, identified by special stains, is a presumptive diagnosis of tuberculosis. This can be confirmed by culturing the stool. Your veterinarian can arrange to do this for you. Since there is a serious human health risk, most veterinarians do not recommend treating cases of TB. Treatment may be a possible but requires daily administration of medicine for months to years with periodic lab evaluations. It is questionable as to whether the disease can ever be cured. Some types of TB in birds, if acquired by humans, are fatal, as they do not respond to drugs.

fames M. Hams, DVM

Oakland. CA

Answer #2: Tuberculosis, which is caused by a variety of Mycobacterium species, can be a common pathogen of birds. Affected birds may appear to be normal while carrying the organism in their body. Transmission of avian tuberculosis is not considered a significant problem unless an individual is immunosuppressed. People undergoing chemotherapy for cancer and those individuals affected with the HIV virus may fit in this category, depending on the individual. So, although transmission from birds to humans is not a concern for most people, the potential for transmission should be understood and acknowledged.

A definitive diagnosis in the live bird (such as your pet) often is difficult. A presumptive diagnosis can be concluded with the aid of fecal acidfast stains, clinical signs of the bird, changes noted on blood work, and biopsies of the liver and/or bone marrow.

Many veterinarians do not recommend treating birds that are definitively diagnosed with TB due to the potential of human transmission. I would suggest that you talk again with your veterinarian about your concerns. Amy B. Worell, DVM, ABVP-Avian .

 


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