Geriatric avian medicine (Proceedings)


Over the past twenty-five years, avian husbandry and medicine have undergone drastic changes, including a significant increase in domestically raised pet birds and major advances in avian nutrition. Despite the potentially adverse psychological effects of incubator hatching and hand-raising (which is a separate but critical concern), these changes have resulted in birds that are living longer. Just as in human medicine, coping with the process of aging is a necessary consequence of greater longevity.

This lecture will address the aging pet psittacine population's geriatric disease conditions and quality of life questions. Over the past twenty-five years, avian husbandry and medicine have undergone drastic changes, including a significant increase in domestically raised pet birds and major advances in avian nutrition. Despite the potentially adverse psychological effects of incubator hatching and hand-raising (which is a separate but critical concern), these changes have resulted in birds that are living longer. Just as in human medicine, coping with the process of aging is a necessary consequence of greater longevity.

A list of the more common problems in aging birds follows:


Cataracts are found in many species of psittacine birds as they age—notably macaws, Amazons, and cockatiels. It may be that these species are more prone to this disorder or merely that they are overrepresented in the older pet bird population. If the onset of cataracts is gradual, adaptation to decreased vision usually occurs. Occasionally cataracts will occur very suddenly and the bird has insufficient time to adapt. A literature search did not reveal documentation of correlations between metabolic disease (e.g., hyperglycemia) and sudden onset of cataracts in birds. However, potential concurrent disease should be investigated.

Decreased vision or blindness understandably can frighten a bird, causing it to startle easily. The fear that comes with vision loss can also lead to increased screaming or biting. If the cataract(s) is not noticed, the owner may attribute the bird's altered behavior to other factors.

The eyes should be examined at each annual visit to detect early changes in lens opacity. Due to the small size of the exposed cornea and pupil in pet psittacines, examination of any bird with suspected ocular abnormalities by an ophthalmologist is recommended. In the past five years alone, with in-house access to ophthalmologists, the following additional ocular diseases have been detected in this author's practice when an avian patient presented for a possible cataract: KCS, corneal ulcerations, third eyelid anatomic abnormalities, hypopyon, anterior uveitis, conjunctival granulomas and infectious diseases involving the conjunctiva (Chlamydophila, Mycoplasma, pox virus), cryptophthalmia, Harderian gland adenoma and lymphoma.

Although in smaller birds, there is no treatment for cataracts that will restore vision, other diseases that may be detected by an ophthalmologic examination may have medical treatments and/or may be of significant medical import. In larger psittacines, surgical removal of cataracts is successful in many cases. A bird's general health and the degree to which the cataracts are affecting its quality of life should be evaluated prior to surgery. Commonly used mydriatics are not useful in birds due to the skeletal (as opposed to smooth) muscle found in the iris.

In any bird with decreased vision, minimal alteration of the home environment is critical. The placement of food and water dishes and perches should not be altered if at all possible. If, despite environmental accommodations, a bird with decreased vision or blindness cannot be made to feel relatively secure, humane euthanasia may need to be considered.


Septic and traumatic arthritis may occur at any age. Septic arthritis is most commonly noted in the digits of birds. Geriatric onset arthritis occurs in many species, and birds are no exception. Their small size makes radiographic diagnosis difficult. The stifles seem to be the most obviously affected, although coxofemoral joint range-of-motion limitations are common in older birds. The weight of the bird, its general physical condition, any previous injuries, and any concurrent medical conditions can all contribute to the onset and severity of arthritis. Concurrent pododermatitis is often present; likely both a cause and result of decreased activity. Malnutrition, which decreases the integrity of the plantar epithelium, and concurrent obesity are often noted in affected birds.

The cage environment, especially the variety, diameter and texture of perches, can be important in providing comfort and stability for arthritic birds, while preventing or minimizing pododermatitis. The nails should be left with sharp points if possible, to add strength and stability to the grip. Wings should not be over-clipped, so they can be used to help with balance. Some medications, such as meloxicam, are being successfully used in birds, as well as acupuncture and other holistic treatments, to decrease inflammation and discomfort.

Articular gout is also common in birds. Differentiation between arthritis and articular gout is critical due the vast differences in progression, quality of life issues and prognosis. Articular gout is excruciatingly painful, and if the bird cannot be made comfortable, euthanasia should be considered.

Hepatic disease

Poor nutrition is a definite cause of liver diseases in birds of all ages. The function of the liver as a filtering organ makes it susceptible to infection, toxins, dyes, pesticides, heavy metals, and aflatoxins. Older birds often present with clinical signs of chronic hepatic disease, such as an overgrown beak, overly curled nails, lack of powder down in applicable species, pododermatitis, and poor feather quality. These conditions may not be recognized as abnormal by the owner. It may not be until the liver decompensates and /or the bird succumbs to secondary infection that the clinical signs become sufficiently pronounced for the owner to seek medical assistance. The clinical signs of a bird with active liver disease often include depression, decreased appetite, increased urination, and a discoloration of the urate and fecal portions of the dropping. Biopsy and histopathology of the liver often reveal fibrosis, cirrhosis, hepatic lipidosis and chronic hepatitis. Supportive care, including antibiotics, lactulose, supplemental feeding, parenteral fluids, and vitamin/nutritional supplements may be warranted.

Cardiac disease

As our birds live longer and our diagnostics improve, we are detecting a greater incidence of cardiac disease. These can be difficult to detect and may mimic other problems, such as respiratory disease. The bird may present weak, lethargic, and/or with increased respiratory rate and effort. With right-sided heart disease, hepatomegaly and ascites are common. Disease may also be sub clinical, then present acutely, with the bird expiring when diagnostics or treatment are attempted. Right heart disease is more prevalent in birds than left-sided cardiac disease, as discussed below.

Pulmonary hypertension

The avian cardiovascular system differs anatomically and physiologically from mammalian in several parameters. The right A/V value is a single, muscular value with no chordae tendinae. Unlike mammals, the physiologic responses that maintain low pulmonary vascular resistance, (both vascular distensibility and vasculature recruitment) are absent in birds. Practically, this results in the inability of the pulmonary vasculature to accommodate increased cardiac output by either altering vasculature diameter, or changing the percentage of vasculature channels being utilized. This is, at least in part, responsible for the high incidence of pulmonary hypertension syndrome (PHS) in the poultry industry as well as right-sided heart disease in psittacine patients. Due to the financial impact of PHS in broiler hens, much research has been conducted in this area. In addition to the lack of vascular accommodation in avian species as noted above, studies have demonstrated that the response to pulmonary arterial hypertension in chickens is an increase in two vasoactive substance, a vasodilator nitric oxide (NO) and the vasoconstrictor serotonin (5-HT). The vasoconstrictor 5-HT predominates over the vasodilator NO in broiler hens susceptible to pulmonary hypertension syndrome. For our geriatric psittacine patients, this indicates that vasodilator therapy in cases of pulmonary hypertension should be explored. Macaw asthma may theoretically cause pulmonary hypertension, both from chronic air capillary hypoxia and subsequent polycythemia. No published data on pulmonary hypertension in macaws diagnosed with this syndrome was located.


Atherosclerosis is common in psittacine birds. It is generally a geriatric condition, with the exception of African Grey parrots, in which this disease has been noted with some frequency in very young animals. Radiographically, the right aortic arch may be enlarged with increased density. Lipemia is often noted, and marked elevations in cholesterol and triglycerides maybe seen. Unfortunately, definitive ante mortem tests are lacking. At necropsy, grossly thickened arterial walls are noted.


The response to the stress of handling can increase intracardiac blood flow velocity 300% in avian patients; therefore, inhalant anesthesia is preferred over manual restraint for performance of echocardiograms in all but the most docile of birds. Equipment constraints noted include an ultrasound unit with Doppler function, 100 frames /second minimum speed and micro curved or phased array probes with minimum 7.5 MHz frequency. Anatomical constraints in birds also limit the echocardiograph windows available. Parameters for chamber sizes, blood flow velocities, functional contractility, and valvular insufficiency have been determined for several species and studies are ongoing in this area.

The avian veterinarian is well-advised to work in conjunction with a cardiologist on any avian patient with suspected cardiac disease. Diagnosis of the cardiovascular abnormality present and formulation of a therapeutic plan will require both your knowledge of avian anatomy and physiology and the cardiologist's diagnostic skills and pharmacologic recommendations. Although most avian therapeutic regimes are still extrapolated from mammalian, numerous reports indicate that cardiac drug therapy can improve cardiac function, thereby increasing the quality and length of the bird's life.

Neoplastic disease


Benign xanthomas are generally friable, yellow-colored fatty-appearing masses that may be located anywhere on the body, but are often seen on the distal wing, in the sterno-pubic area and on the keel. The origin of xanthomas is unknown, however, dietary improvement, including sufficient Vitamin A or Vitamin A precursors, has been noted to be curative in less advanced cases. Xanthomas tend to be very vascular and surgical excision, when necessary, should be undertaken with due attention to hemostasis. Diffuse xanthomas may be amenable to cryotherapy, but attention must be paid to maintenance of the vascular supply.

Lipomas occur most frequently in budgerigars, and are usually located on the keel or in the sternopubic area. Lipomas that cause clinical signs can be addressed via surgical excision. Malignant liposarcomas are rare in psittacines.

Malignant Fibrosarcomas can occur anywhere on the body, but are most commonly seen in the oral cavity, associated with long bones, or in the abdominal cavity. They tend to be locally invasive and often recur with conservative surgical excision. Local treatment in the form of radiation therapy is often indicated for providing long-term control. The metastatic rate is low, so local disease management is paramount. Surgical excision followed by both radiation and chemotherapy has been reported with some success. Strontium radiation therapy, although limited by depth of penetration, has been anecdotally reported as efficacious in several instances.

Squamous cell carcinomas also may occur anywhere on the body, being most prevalent at mucocutaneous junctions of the head, on the distal wing, the phalanges, and the uropygial gland. Squamous cell carcinomas tend to be aggressively locally invasive, and complete excision is rarely accomplished. Radiation therapy has been attempted with some success, however squamous cell carcinoma appears to be an exceptionally radioresistant tumor and long-term control is rare. Anecdotal reports indicate that radioresistance may be even greater in birds than in mammals. Strontium therapy when tumor depth is not a limiting factor has shown some promise in selected psittacine cases. Distant metastasis is rare, therefore chemotherapy is not commonly utilized. Photodynamic therapy has been attempted in two reported cases. One case of SCC in the beak of a hornbill showed a positive result in decreasing tumor size but failure to eliminate the neoplasia. The second case demonstrated a positive response to PDT after each treatment, but treatments were not able to be administered at regular intervals. Intralesional cisplatin has been used successfully in one case of SCC of the lower beak and sub-mandibular skin.

Musculoskeletal system

Chondroma, hemangioma, and malignant tumors including osteosarcoma, chondrosarcoma, spindle cell sarcoma and leiomyosarcoma have all been reported. Wide surgical resection or amputation are generally the suggested methods of treatment, as benign lesions are often cured with complete excision and a decrease in tumor burden can be accomplished in malignant lesions. Extrapolation from canine and feline oncology may suggest other modalities, such as radiation therapy for additional local treatment and chemotherapy for systemic control. A biopsy should be obtained from patients where radiographic bony lesions are present. Under inhalant anesthesia, a 22–20 gauge needle can be surgically introduced into the bone. A sufficient sample is usually obtained and subsequently retained in the hub of the needle. The sample can them be dislodged with smaller gauge wire and submitted.

Internal carcinomas

Ovarian neoplasias, (various cell origins), renal carcinomas, hepatic adenocarcinoma, hepatobiliary and pancreatic adenocarcinoma (related to papillomas in Amazons), splenic, and gastric carcinomas are all encountered.

Anecdotal reports exist indicating intralesional carboplatin therapy may be useful in ovarian and renal adenocarcinoma, generally following surgical debulking and confirmation of the neoplasia via histopathology. Bile duct carcinoma has also been treated with carboplatin successfully in one report. Toxicity studies with cisplatin in cockatoos indicate that psittacine tolerance for this drug may be greater than that of mammals.

Tamoxifen administration has not been evaluated for efficacy in cases of avian ovarian carcinoma, but anti-estrogenic activity was suggested and side effects were minimal in one drug trial. GnRH agonists (i.e., Depo-Lupron) have been effective empirically, (dosed at 200–800 ug/kg) however, confirmation of neoplasia (as opposed to cystic ovarian disease) has often not been obtained.

Gastric carcinomas are generally diagnosed at necropsy, are often found at the proventricular/ventricular junction. Death from gastric neoplasia may be due to hemorrhage, gastric perforation and sepsis or endotoxic shock, or inanition and subsequent wasting. Metastasis to the lungs has been confirmed in one case report.

Biliary and pancreatic carcinomas are frequently diagnosed in the genus Amazona and to a lesser degree, Ara, in conjunction with internal papillomatosis. A recent connection to a Herpes virus has been identified. Carboplatin has been used in several cases with equivocal results, but with no apparent toxicity.


Pituitary adenomas have been documented in multiple avian species but are most prevalent in budgerigars and cockatiels. Affected animals may present with acute neurologic conditions (seizures/opisthotonos). They may also present with conditions related to the pituitary hormone(s) that are affected. Usually, this will be pronounced polydipsia and polyuria. Occasional presentations will be that of a retrobulbar mass and subsequent exophthalmia. In human medicine, surgical resection and radiation therapy (if needed) are utilized for treatment. Size and monetary constraints make routine treatment by these methods unlikely in our small psittacine patients.


Numerous reports of exophthalmos in psittacines, particularly young African Grays, have been diagnosed as retrobulbar lymphoma. Lymphoma may have many presentations in older pet birds, including lymphatic, hemopoietic, hepatic and subcutaneous lymphoma. Chemotherapy is the treatment of choice for systemic disease and surgery and radiation therapies have been successfully employed in cases of solitary lymphoma. To date, no evidence of retroviral activity has been associated with psittacine lymphoma.

Respiratory neoplasia

Primary respiratory neoplasia is uncommon in psittacines. An exception seems to be an intra thoracic neoplasia reported in cockatiels. It is characterized by the inclusion of two cell types, having both mesenchymal and epithelial cell components. Few other primary pulmonary neoplasias have been reported in the literature. Metastatic pulmonary neoplasia may occur, but it is not noted with the same frequency as is documented in dogs.

Note regarding treatment of psittacine neoplasia

The presentation of anecdotal treatments is problematic. Failure to include preliminary information regarding efficacy and/or clinical response may reduce the practitioner's willingness and ability to recommend treatment. However, future studies may either reinforce these experimental protocols, or they may demonstrate a lack of efficacy or serious side effects of these regimes.

To date, the treatment of avian neoplasia has mirrored treatment in other domestic species. Generally, solid tumors are best treated with surgical excision, while systemic neoplastic processes (i.e., systemic lymphoma, metastatic conditions) are most effectively managed with use of systemic chemotherapy. Cases in which surgical excision is incomplete or impossible may benefit from alternative forms of local therapy, including external beam radiation (Cobalt 60 or linear accelerator), cryotherapy, photodynamic therapy or hand-held radiation applicators.

When confronted with a confirmed diagnosis of neoplasia, a current literature search is warranted due to the rapid advances and changes in treatment recommendations. Consultation with a veterinary oncologist will increase the likelihood of selecting an appropriate treatment regime and properly administering the chosen therapy.


Awareness of the various syndromes that accompany aging allows the bird owner to recognize clinical signs and to seek medical assistance. Proper care and early detection can delay or prevent many geriatric illnesses.

Note: The preceding is a summary of clinically relevant avian geriatric disease and current treatment. Much research is still to be accomplished on the affect of aging on our psittacine pets. Additionally, avian species are serving as models for several areas of research into human aging. The extensive reference list that follows includes areas that may be of interest, but which were not discussed in this lecture.

References/Recommended reading

Wilson L, Lightfoot TL:Concepts in Behavior: Section III Pubescent and Adult Psittacine Behavior, in Clinical Avian Medicine, Harrison GJ, Lightfoot TL. Editors. 2006, Spix: Lake Worth, FL. p. 73-83.

Haussler B. [Definition, procedures and goals of evidence-based medicine]. Dtsch Med Wochenschr, 2005. 130 Suppl 2: p. S66-71.

Ian A. How Should Physicians Treat Evidence-Based Medicine?, in Super Crunchers, A. Ian, Editor. 2007, Bantam Dell: New York. p. 88-111.

Mueller A. Relative longevity and field metabolic rate in birds. J Evol Biol, September 2008: 21(5): p. 1379-86.

Haussmann, MF, et al., Telomerase activity is maintained throughout the lifespan of long-lived birds. Exp Gerontol, 2007. 42(7): pp. 610-8.

Swanberg SE, Delany ME. Dynamics of telomere erosion in transformed and non-transformed avian cells in vitro. Cytogenet Genome Res, 2003. 102(1-4): p. 318-25.

Ladage LD, Fox RA, Pravosudov VV. Effects of captivity and memory-based experiences on the hippocampus in mountain chickadees. Behav Neurosci, 2009. 123(2): p. 284-91.

Mileusnic, R., Lancashire CL, Rose SP; Amyloid precursor protein: from synaptic plasticity to Alzheimer's disease. Ann N Y Acad Sci, 2005. 1048: p. 149-65.

Naidoo V., et al., The pharmacokinetics of meloxicam in vultures. J Vet Pharmacol Ther, 2008. 31(2): p. 128-34.

Baert K, De Backer P. Disposition of sodium salicylate, flunixin and meloxicam after intravenous administration in broiler chickens. J Vet Pharmacol Ther, 2002. 25(6): p. 449-53.

Baert K, Comparative pharmacokinetics of three non-steroidal anti-inflammatory drugs in five bird species. Comp Biochem Physiol C Toxicol Pharmacol, January 2003. 34(1): p. 25-33.

Wilson H. Pharmacokinetics and Use of Meloxicam in Psittacine Birds. in AAV. 2004.

Hussain, I, et al., Toxicological effects of diclofenac in four avian species. Avian Pathol, 2008. 37(3): p. 315-21.

Naidoo V., et al. Veterinary diclofenac threatens Africa's endangered vulture species. Regul Toxicol Pharmacol, 2009.

Naidoo V, Swan VE. Diclofenac toxicity in Gyps vulture is associated with decreased uric acid excretion and not renal portal vasoconstriction. Comp Biochem Physiol C Toxicol Pharmacol, 2009. 149(3): p. 269-74.

Daniel M, et al. Differential Mortality of Male Spectacled Eiders (Somateria fischeri) and King Eiders (Somateria spectabilis) Subsequent to Anesthesia With Propofol, Bupivacaine, and Ketoprofen J Avian Med Surg., September 2003. 17(3): p. 117-123.

Pereira ME, Werther K. Evaluation of the renal effects of flunixin meglumine, ketoprofen and meloxicam in budgerigars (Melopsittacus undulatus). Vet Rec, 2007. 160(24): p. 844-6.

Paul-Murphy JR. Analgesic effects of butorphanol and bupreorphine in conscious African Grey parrots (Psittacus erithacus erithacus). Am J Vet Res, 1999. 60: p. 1218-1221.

Concannon KT, Hellyer PW. Influence of a mu-and kappa opiod agonist on isoflurne minimal anesthetic concentration in chickens Vet Res, 1995. 56: p. 806-811.

Souza MJ, Cox SA. Pharmacokinetics of Tramadol in Bald Eagles (Haliaeetus leucocephalus). in AAV. 2007.

Riggs SM, et al. Pharmacokinetics of butorphanol tartrate in red-tailed hawks (Buteo jamaicensis) and great horned owls (Bubo virginianus). Am J Vet Res, May 2008. 69(5): p. 596-603.

Sladky KK, Serum concentrations and analgesic effects of liposome-encapsulated and standard butorphanol tartrate in parrots. 67, 2006 May 5: p. 775-81.

Hoppes S. Disposition and Analgesic Effects of Fentanyl in White Cockatoos (Cacatua alba). J Avian Med Surg, 2003. 17((3)): p. 124-130.

Gilron I, et al. A randomized, double-blind, controlled trial of perioperative administration of gabapentin, meloxicam and their combination for spontaneous and movement-evoked pain after ambulatory laparoscopic cholecystectomy. Anesth Analg, 2009. 108(2): p. 623-30.

Devor, M. How does gabapentin relieve neuropathic pain? Pain, 2009.

de Medicis, E., Gabapentin and post-thoracotomy shoulder pain. Can J Anaesth, 2008. 55(12): p. 878-9; author reply 879.

Davis JL, Posner LP, Elce Y. Gabapentin for the treatment of neuropathic pain in a pregnant horse. J Am Vet Med Assoc, 2007. 231(5): p. 755-8.

Hendrix DVH, et al. Electroretinography in the Hispaniolan Amazon Parrot (Amazona ventralis). J Avian Med Surg., 2004. 18(2): p. 89-94.

Egemen Turhan, et al. Unilateral enucleation affects the laterality but not the incidence of scoliosis in pinealectomized chicken. Spine (Phila Pa 1976), January 2006. 31(2): p. 133-8.

Schmidt RE, Reavill DR, Phalen DN. Endocrine System, in Pathology of Pet and Aviary Birds, R.D. Schmidt RE, Phalen DN, Editor. 2003, Blackwell: Ames, Iowa. p. 121.

Romagnano A. Pituitary Adenoma in an Amazon Parrot,. J Avian Med Surg, 1995. 9(4): p. 263-270.

Stiles J, et al. Tonometry of normal eyes in raptors. Am J Vet Res, 1994. 55(4): p. 477-9.

Roberson DW, Alosi JA, Cotanche DA. Direct transdifferentiation gives rise to the earliest new hair cells in regenerating avian auditory epithelium. J Neurosci Res, 2004. 78(4): p. 461-71.

Muller M, Smolders JW. Responses of auditory nerve fibers innervating regenerated hair cells after local application of gentamicin at the round window of the cochlea in the pigeon. Hear Res, 1999. 131(1-2): p. 153-69.

Cobb, S. A note on the size of the avian olfactory bulb. Epilepsia, 1960. 1: p. 394-402.

Steiger S.S, et al. Avian olfactory receptor gene repertoires: evidence for a well-developed sense of smell in birds? Proc Biol Sci, 2008. 275(1649): p. 2309-17.

Balthazart J. Underestimated role of olfaction in avian reproduction? Behav Brain Res, 2009. 200(2): p. 248-59.

Rothschild RM. Osteoarthritis is for the birds. Clin Rheumatol, September 2006. 25(5): p. 645-47.

Rothschild B, Panza R. Inverse relationship of osteoarthritis to weight: The bird lesson. Clin Exp Rheumatol, 2006. 24(2): p. 218.

Norden CW. Lessons learned from animal models of osteomyelitis. Rev Infect Dis, 1988. 10(1): p. 103-10.

Schmidt RE, Reavill DR, Phalen DN. The Musculoskeletal System, in Pathology of Pet and Aviary Birds, R.D. Schmidt RE, Phalen DN., Editor. 2003, Blackwell: Ames, Iowa. p. 149-63.

Stanford M., Calcium Metabolsim, in Clinical Avian Medicine, Harrison GJ, Lighfoot TL, Editors. 2006, Spix: Lake Worth. p. 141-152.

Rhoden EL, et al., The role of colchicine in prevention of hepatic cirrhosis induced by carbon tetrachloride. Hepatogastroenterology, 1999. 46(26): p. 1111-5.

Echols S. Renal Disease in Birds. in Western Veterinary conference. 2004. Las Vegas, NV USA.

Echols S. Evaluating and Treating the Kidneys, in Clinical Avian Medicine, Harrison GJ, Lightfoot T, Editors. 2006, Spix: Lake Worth.

McDonald DM. Nutritional Considerations, in Clinical Avian Medicine, Harrison GJ, Lightfoot TL, Editors. 2006, Spix: Lake Worth. p. 1125.

Dudas PL, et al., Transepithelial urate transport by avian renal proximal tubule epithelium in primary culture. J Exp Biol, 2005. 208(Pt 22): p. 4305-15.

Wideman R.F, et al. An inadequate pulmonary vascular capacity and susceptibility to pulmonary arterial hypertension in broilers. Poult Sci, 2007. 86(5): p. 984-98.

Tan X. Hu SH, Wang XL. Possible role of nitric oxide in the pathogenesis of pulmonary hypertension in broilers: a synopsis. Avian Pathol, 2007. 36(4): p. 261-7.

Pees M, Krautwald-Junghanns M. Evaluating and Treating the Cardiovascular System, in Clinical Avian Medicine, Harrison GJ, Lightfoot TL, Editors. 2006, Spix: Lake Worth. p. 379-94.

Blackburn R, Prashad D. The avian renal portal system: a model for studying nephrotoxicity of xenobiotics. Toxicol Lett, 1990. 53(1-2): p. 219-21.

Schmidt RE, Reavill DR, Phalen DN,. Cardiovascular System, in Pathology of Pet and Aviary Birds, R.D. Schmidt RE, Phalen DN,, Editor. 2003, Blackwell: Ames, Iowa. p. 51.

Krista, LM, et al. Histological evaluation of the vascular system for the severity of atherosclerosis in hyper and hypotensive male and female turkeys: comparison between young and aged turkeys. Poult Sci, 1987. 66(6): p. 1033-44.

Bavelaar FJ, Beynen AC. Atherosclerosis in parrots. A review. Vet Q, 2004. 26(2): p. 50-60.

Dashti N, et al., Concurrent inductions of avian hepatic lipogenesis, plasma lipids, and plasma apolipoprotein B by estrogen. J Lipid Res, 1983. 24(4): p. 368-80.

Simone-Freilicher E. Use of isoxsuprine for treatment of clinical signs associated with presumptive atherosclerosis in a yellow-naped Amazon parrot (Amazona ochrocephala auropalliata). J Avian Med Surg, 2007. 21(3): p. 215-9.

Sedacca CD, et al. Chronic cor pulmonale secondary to pulmonary atherosclerosis in an African Grey parrot. J Am Vet Med Assoc, 2009. 234(8): p. 1055-9.

Shrubsole-Cockwill A, Wojnarowicz C, Parker D. Atherosclerosis and ischemic cardiomyopathy in a captive, adult red-tailed hawk (Buteo jamaicensis). Avian Dis, 2008. 52(3): p. 537-9.

Mans C, Brown CJ. Radiographic evidence of atherosclerosis of the descending aorta in a grey-cheeked parakeet (Brotogeris pyrrhopterus). J Avian Med Surg, 2007. 21(1): p. 56-62.

Bavelaar FJ, Beynen AC. Severity of atherosclerosis in parrots in relation to the intake of alpha-linolenic acid. Avian Dis, 2003. 47(3): p. 566-77.

Phalen D.N, et al. Heart failure in a macaw with atherosclerosis of the aorta and brachiocephalic arteries. J Am Vet Med Assoc, 1996. 209(8): p. 1435-40.

Muwalla MM, Abuirmeileh NM. Suppression of avian hepatic cholesterogenesis by dietary ginseng. J Nutr Biochem, 1990. 1(10): p. 518-21.

Acierno MJ, et al. Agreement between direct and indirect blood pressure measurements obtained from anesthetized Hispaniolan Amazon parrots. J Am Vet Med Assoc, 2008. 233(10): p. 1587-90.

Rembert MS, et al. Intermittent bradyarrhythmia in a Hispaniolan Amazon parrot (Amazona ventralis). J Avian Med Surg, 2008. 22(1): p. 31-40.

Schmidt RE, Reavill DR, Phalen DN. Reproductive Sysem, in Pathology of Caged and Aviary Birds. Schmidt RE, Reavill DR, Phalen DN, Editors. 2003, Blackwell: Ames, Iowas. p. 109-20.

Bentley GE, et al.,Gonadotropin-inhibitory hormone and its receptor in the avian reproductive system. Gen Comp Endocrinol, 2008. 156(1): p. 34-43.

Schmidt R, Lightfoot TL. Integument, in Clinical Avian Medicine, Harrison GJ, Lightfoot TL, Editors. 2006, Spix: Lake Worth, FL. p. 395-409.

Lightfoot TL. Clinical Avian Neoplasia and Oncology, in Clinical Avian Medicine, Harrison GJ, Lighfoot TL, Editors. 2006, Spix publishing: Lake Worth, Florida. p. 560-66.

Tully TN. Liposarcomas In A Monk Parakeet (Myiopsitta monachus). J Assoc Avian Vet, 1994. 8(3): p. 120-124.

Schmidt RE, Reavill DR, Phalen DN Integumentary System, in Pathology of Caged and Aviary Birds. Schmidt RE, Reavill DR, Phalen DN, Editors. 2003: Ames, Iowa. p. 21.

Suedmeyer W. Attempted Photodynamic Therapy of Squamous Cell Carcinoma in the Casque of a Great Hornbill (Buceros bicornis). J Avian Med Surg, 2001. 15(1): p. 44-49.

Rosenthal K. A Report of Photodynamic Therapy for Squamous Cell Carcinoma in a Cockatiel,, in Proc Ann Conf AAV, R. K, Editor. 2001. p. 175-176.

MacWhirter P, Use of Carboplatin in the Treatment of Renal Adenocarcinoma in a Budgerigar. Exotic DVM, 2002. 4(2): p. 11-12.

Watson CL. Primary Appendicular Bone Tumors in Dogs. Compend Contin Educ Pract Vet 2002. 24(2): p. 128-38.

Zantopp DA. Treatment of Bile Duct Carcinoma in Birds with Carboplatin. Exotic DVM, 2000. 2(3): p. 76-78.

Filippich L. Intravenous Cisplatin Administration in Sulphur-Crested Cockatoos (Cacatua galerita) Clinical and Pathologic Observations. J Avian Med Surg 2001. 15(1): p. 23-30.

Filippich L, et al, Carboplatin Administration in Sulphur-Crested Cockatoos (Cacatua galerita): Clinical Observations. J Avian Med Surg, 2005. 19(2): p. 92-97.

Crosta L, et al. Physiology, diagnosis, and diseases of the avian reproductive tract. Vet Clin North Am Exot Anim Pract, 2003. 6(1): p. 57-83.

Urick ME, Giles JR, Johnson PA. Dietary aspirin decreases the stage of ovarian cancer in the hen. Gynecol Oncol, 2009. 112(1): p. 166-70.

Weniger JP, Samsel J. Tamoxifen and ovarian differentiation in birds. Arch Anat Microsc Morphol Exp, 1985. 74(1): p. 50-1.

Mani C. et al. Involvement of cytochrome P4503A in catalysis of tamoxifen activation and covalent binding to rat and human liver microsomes. Carcinogenesis, 1994. 15(12): p. 2715-20.

Lupu CA. Evaluation of Side Effects of Tamoxifen in Budgerigars (Melopsittacus undulatus). J Avian Med Surg., December 2000. 14(4): p. 237-242.

Schmidt RE, Reavill DR, Phalen DN. Gastrointestinal System and Pancreas, in Pathology of Pet and Aviary Birds, Schmidt RE, Reavill DR, Phalen DN, Editor. 2003, Blackwell: Ames, Iowa. p. 41-65.

Hillyer EV, et al. Bile duct carcinoma in two out of ten Amazon parrots with cloacal papillomas. J Assoc Avian Vet 1999. 5(2): p. 91-95.

Phalen D.N. Implication of Viruses in Clinical Disorders, in Clinical Avian Medicine, Harrison GJ, Lightfoot TL, Editors. 2006, Spix: Lake Worth. p. 721-45.

Schmidt RE, Reavill DR, Phalen DN, Hemopoetic and Lymphatic Systems, in Pathology of Caged and Aviary Birds, Schmidt RE, Reavill DR, Phalen DN, Editors. 2006, Blackwell: Ames, Iowas.

Garner MM. A Retrospective Study of Case Submissions to a Specialty Diagnostic Service, in Clinical Avian Medicine, Harrison GJ, Lightfoot TL, Editors. 2006, Spix: Lake Worth. p. 566-73.

Cambell TW. Carcinoma of the Ventriculus with Metastasis to the Lungs in a Sulphur-Crested Cockatoo (Cacatua galerita). J Avian Med Surg, 1999. 13(4): p. 265-268.

Jones MP, Orosz S. Pulmonary Carcinoma with Metastases in a Moluccan Cockatoo (Cacatua moluccensis). J Avian Med Surg, 2001. 15(2): p. 107-113.

Characterization of atherosclerosis by histochemical and immunohistochemical methods in African grey parrots (Psittacus erithacus) and Amazon parrots (Amazona spp.).

Avian Dis. September 2009;53(3):466-72.

Cornelia Fricke1, Volker Schmidt , Kerstin Cramer, Maria-Elisabeth Krautwald-Junghanns , Gerry M Dorrestein

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