Macaw Wasting Disease

Macaw Wasting Disease, also known as Proventricular Dilatation Disease (PDD), is a serious neurological and gastrointestinal condition that primarily affects macaws and other psittacine birds. This devastating disease is caused by avian bornavirus (ABV), which targets the nervous system, particularly the nerves supplying the gastrointestinal tract. The resulting nerve damage impairs normal digestive function, leading to the characteristic dilation of the proventriculus (the glandular stomach) and progressive weight loss that give the disease its name. While the term "Macaw Wasting Disease" reflects the prominence of this condition in macaws and its wasting effects, the disease affects a wide range of parrot species and is now more commonly referred to as PDD in veterinary literature.

The discovery that avian bornavirus causes PDD represented a major breakthrough in understanding this previously mysterious disease. Before the viral cause was identified in 2008, the condition was recognized clinically but its etiology remained uncertain despite extensive research efforts. Avian bornavirus infects nerve cells throughout the body, triggering an inflammatory response called lymphoplasmacytic ganglioneuritis that damages the nerves and impairs their function. The gastrointestinal tract is most commonly affected because the extensive nerve network controlling digestive function is particularly vulnerable, but the central nervous system and nerves in other body regions can also be involved, producing varied clinical presentations.

The impact of Macaw Wasting Disease on affected birds is profound, often progressing to severe disability or death despite treatment efforts. The gastrointestinal form causes progressive loss of digestive function, with birds unable to properly process and absorb nutrients regardless of food intake. Affected macaws pass undigested food in their droppings while slowly starving despite eating normally or even excessively. Weight loss progresses relentlessly as the body cannot obtain nutrition from consumed food. The neurological form can cause ataxia, weakness, seizures, and other signs of nervous system dysfunction. The combination of malnutrition, immune suppression, and progressive nerve damage makes this one of the most feared diseases in aviculture.

While no cure exists for Macaw Wasting Disease, advances in understanding have improved management options and outcomes for some affected birds. Anti-inflammatory medications, particularly nonsteroidal anti-inflammatory drugs (NSAIDs), can reduce the inflammatory nerve damage driving disease progression in some cases. Supportive care focusing on optimized nutrition and treatment of secondary complications helps maintain quality of life. Some birds stabilize on treatment and live for extended periods with good quality of life, while others progress despite aggressive management. The variable course and incomplete understanding of factors determining individual outcomes make this a challenging disease to manage. Avian veterinary expertise is essential for diagnosis, treatment planning, and ongoing care of macaws with this serious condition.

Avian bornavirus (ABV) is the causative agent of Macaw Wasting Disease, with this viral etiology definitively established through research identifying the virus in affected birds and demonstrating disease transmission. Avian bornaviruses belong to the family Bornaviridae and are related to mammalian bornaviruses that cause neurological disease in horses and other species. Multiple genotypes of avian bornavirus have been identified, designated as parrot bornavirus 1 through 8 (PaBV-1 through PaBV-8), with different genotypes showing some variation in host preference and possibly pathogenicity. The virus has an affinity for nerve tissue, establishing persistent infection in neurons and triggering the inflammatory responses that damage the nervous system.

Transmission of avian bornavirus between birds occurs through various routes, though the exact mechanisms continue to be investigated. Fecal-oral transmission appears significant, as the virus is shed in droppings of infected birds. Direct contact between birds facilitates transmission, and the close social interactions characteristic of psittacine birds promote viral spread. Parent-to-offspring transmission during feeding of young birds transmits infection to the next generation. Some evidence suggests possible airborne transmission over short distances or through inhalation of contaminated material. The virus can persist in the environment for some time, allowing indirect transmission through contaminated surfaces, though survival outside the host is limited compared to some other avian viruses.

The relationship between bornavirus infection and clinical disease is complex and not fully understood. Many birds become infected with avian bornavirus without developing clinical PDD, remaining apparently healthy carriers that can transmit virus to others. The factors determining why some infected birds develop disease while others remain asymptomatic are not completely characterized but likely involve interactions between viral factors, host immunity, and environmental influences. Stress, concurrent illness, and immune status may influence whether infection progresses to clinical disease. Different viral genotypes might vary in their propensity to cause disease. This variability means that a positive bornavirus test does not necessarily predict clinical illness, complicating both diagnosis and management decisions.

Risk factors for Macaw Wasting Disease include exposure to infected birds, stress, and factors affecting immune function. Birds in collections or breeding facilities where bornavirus circulates face elevated exposure risk. Introduction of new birds without appropriate testing and quarantine can introduce virus to previously unaffected collections. Stress from various sources may contribute to disease development in infected birds. Concurrent diseases affecting immune function could influence susceptibility and disease progression. Young birds may be particularly vulnerable during the period of declining maternal antibody protection. Social housing with close contact between birds increases transmission opportunity.

The mechanism by which bornavirus infection leads to clinical disease involves viral infection of neurons and subsequent immune-mediated damage. The virus establishes persistent infection in nerve cells throughout the body, with particular affinity for autonomic ganglia controlling gastrointestinal function. The immune system recognizes viral antigens in infected nerve tissue and mounts an inflammatory response attempting to eliminate the infection. This inflammatory response, characterized by infiltration of lymphocytes and plasma cells around affected nerves (lymphoplasmacytic ganglioneuritis), damages the nerves and impairs their function. The result is progressive neuropathy affecting the organs supplied by damaged nerves. In the classic gastrointestinal form, damage to nerves controlling stomach function causes the proventriculus to lose motility and dilate, impairing digestion.

Early warning signs of Macaw Wasting Disease are often subtle and nonspecific, making early diagnosis challenging. Initial symptoms may include slight decreases in weight that are difficult to notice without regular weighing. Subtle changes in droppings, including slightly increased volume or occasionally visible undigested food particles, may occur but are easily overlooked. Some birds show mild lethargy or slightly decreased activity that could be attributed to many causes. Appetite may appear normal or even increased in early stages as birds attempt to compensate for malabsorption. The gradual onset of symptoms and birds' tendency to mask illness often delays recognition until disease has progressed substantially.

Gastrointestinal symptoms dominate the clinical picture in the most common presentation of Macaw Wasting Disease. Regurgitation becomes increasingly frequent as proventricular function deteriorates. Undigested food appears in droppings, indicating failure of the proventriculus to properly digest food before it passes into the intestines. The presence of whole seeds or identifiable food particles in droppings is highly suggestive of proventricular dysfunction. Droppings may increase in volume and change in consistency. Some birds develop crop stasis, with food accumulating in the crop rather than passing normally into the proventriculus. Despite eating adequate or even increased amounts, birds progressively lose weight as they cannot absorb nutrients from food.

Behavioral changes accompanying Macaw Wasting Disease reflect both the physical effects of illness and possible direct nervous system involvement. Affected birds often become quieter, vocalizing less frequently and with reduced intensity. Activity levels decline progressively as weakness from malnutrition increases. Social interactions decrease as birds feel unwell and lack energy for normal behaviors. Some birds show changes in personality, becoming either withdrawn or irritable. Appetite changes may include increased eating attempts reflecting hunger from malabsorption, or decreased interest in food as illness progresses. Sleep patterns may change with increased sleeping and reduced alertness during normal active periods.

Neurological symptoms occur when bornavirus infection affects the central nervous system or peripheral nerves outside the gastrointestinal tract. Ataxia, characterized by incoordination and unsteady movement, may develop when cerebellar or vestibular function is affected. Weakness affecting one or more limbs can occur from peripheral nerve involvement. Some birds develop blindness from optic nerve damage. Seizures may occur with brain involvement. Head tilt, circling, or abnormal postures indicate vestibular dysfunction. Muscle wasting and paralysis can develop in advanced neurological disease. Birds may show proprioceptive deficits, being unaware of limb position. Neurological signs may occur alone, accompany gastrointestinal disease, or precede digestive symptoms depending on the pattern of nerve involvement.

Symptom progression in Macaw Wasting Disease typically follows a chronic, progressive course over weeks to months, though acute presentations occur occasionally. Weight loss progresses as malabsorption continues regardless of food intake. Body condition deteriorates with loss of muscle mass and pectoral muscle wasting becoming prominent. Weakness increases as malnutrition advances. Secondary infections become more likely as immune function declines. Some birds develop a distended abdomen from proventricular enlargement. Feather quality may decline with prolonged illness. Without effective intervention, progression continues toward cachexia and death, though the timeline varies considerably between individuals.

Emergency symptoms requiring immediate veterinary attention include severe weakness, collapse, or inability to stand or perch. Seizures or sudden severe neurological deterioration constitute emergencies. Severe crop stasis with inability to pass food requires urgent attention. Signs of aspiration pneumonia from regurgitation need immediate treatment. Extreme weight loss with visible cachexia indicates critical illness. Any sudden worsening of previously stable disease warrants emergency evaluation. Respiratory distress from any cause in a bird with PDD requires urgent care. Given the serious nature of this disease, owners should maintain close contact with their avian veterinarian and seek care promptly for any concerning changes.

Initial examination of a macaw with suspected Wasting Disease involves comprehensive assessment of clinical status and detailed history review. The avian veterinarian obtains history including duration and progression of symptoms, weight changes, appetite and droppings observations, and any exposure to birds of unknown health status. Physical examination evaluates body condition, with particular attention to pectoral muscle mass and evidence of weight loss. Crop palpation assesses for retained food or abnormal distension. Neurological examination evaluates coordination, strength, reflexes, and mental status. The veterinarian looks for signs of concurrent conditions that might contribute to symptoms or complicate management.

Diagnostic imaging plays a crucial role in evaluating birds with suspected Macaw Wasting Disease. Radiographs may reveal the characteristic proventricular dilation that gives the disease its clinical name, appearing as an enlarged, gas-filled proventricular silhouette on X-rays. However, proventricular dilation is not always present, particularly in birds with primarily neurological disease or early in the disease course. Contrast radiography using barium can demonstrate delayed gastric emptying and proventricular dysfunction more sensitively than plain radiographs. Fluoroscopy allows real-time observation of gastrointestinal motility. Advanced imaging such as CT scanning may provide additional detail in complex cases.

Laboratory testing supports diagnosis and assesses overall health status. Complete blood count and biochemistry panels evaluate for secondary effects of malnutrition and concurrent conditions. Fecal examination may reveal undigested food particles supporting the clinical picture. Testing for avian bornavirus can be performed through PCR detection of viral RNA in various samples or through serologic testing for antibodies against the virus. However, interpretation of bornavirus testing is complex because many healthy birds test positive while some clinically affected birds may test negative. A positive test indicates exposure but does not confirm that current clinical signs result from PDD. Negative tests do not definitively rule out the disease.

Definitive diagnosis of Macaw Wasting Disease historically required histopathological demonstration of lymphoplasmacytic ganglioneuritis in nerve tissue, typically obtained through biopsy of the crop or proventriculus or at necropsy. Crop biopsy, performed surgically or endoscopically, allows examination of nerve tissue associated with the crop wall. Finding characteristic inflammatory infiltrates in nerve ganglia confirms the diagnosis. However, because disease distribution can be patchy, negative biopsy does not definitively exclude PDD if other clinical evidence is suggestive. The combination of compatible clinical signs, supportive imaging findings, positive bornavirus testing, and potentially biopsy results informs the diagnostic conclusion in most clinical cases.

Emergency treatment for macaws with acute deterioration from Wasting Disease focuses on immediate supportive care and stabilization. Fluid therapy addresses dehydration that commonly develops from vomiting, regurgitation, and reduced food absorption. Nutritional support through assisted feeding provides calories and essential nutrients to birds unable to maintain intake through normal eating. Temperature support maintains body warmth, important for weakened, malnourished birds. Treatment of acute complications such as aspiration pneumonia or severe crop stasis addresses immediate threats. Seizure management with appropriate anticonvulsant therapy controls acute neurological crises. Stress reduction through quiet housing and gentle handling minimizes metabolic demands on the compromised bird.

Anti-inflammatory therapy represents the primary disease-modifying treatment approach for Macaw Wasting Disease. Nonsteroidal anti-inflammatory drugs (NSAIDs), particularly celecoxib and meloxicam, have shown benefit in some affected birds by reducing the inflammatory damage to nerve tissue that drives disease progression. By suppressing the immune-mediated inflammation around infected nerves, these medications may slow or stabilize disease in some individuals. Response to anti-inflammatory therapy varies considerably, with some birds showing substantial improvement while others continue to progress despite treatment. Long-term NSAID administration requires monitoring for potential side effects including gastrointestinal and renal complications.

Nutritional management is fundamental to supporting birds with Macaw Wasting Disease. Because the disease impairs normal digestion, dietary modifications can improve nutrient absorption and reduce gastrointestinal workload. Easily digestible foods that require less proventricular processing may be better tolerated. Small, frequent feedings rather than large meals reduce gastrointestinal burden. Soft foods or those processed to smaller particle size digest more easily. Supplementation with digestive enzymes may assist food breakdown in some birds. High-calorie, nutrient-dense foods help maintain weight despite impaired absorption. Monitoring weight regularly guides nutritional intervention intensity.

Supportive care measures address secondary problems and maintain quality of life in birds with chronic Wasting Disease. Treatment of secondary infections that develop due to immune suppression prevents complications. Management of crop stasis through motility-enhancing medications or manual crop emptying when necessary maintains food passage. Environmental modifications including easily accessible perches and food for weak or ataxic birds accommodate physical limitations. Padded cage bottoms reduce injury risk for birds prone to falling. Temperature regulation reduces metabolic demands. Stress reduction through appropriate housing and handling supports overall health.

Antiviral therapy remains an area of investigation for Macaw Wasting Disease, though no proven effective antiviral treatment exists. Various antiviral agents have been tried with inconsistent results, and no consensus treatment protocol has emerged. The persistent nature of bornavirus infection, with the virus residing within nerve cells, presents challenges for antiviral approaches. Research continues to investigate potential antiviral strategies. Currently, treatment focuses on managing inflammation and providing support rather than directly targeting the virus.

Treatment decisions for Macaw Wasting Disease involve weighing disease severity, treatment response, quality of life, and practical considerations. The lack of curative treatment means that management goals focus on maintaining quality of life and slowing disease progression rather than achieving cure. Some birds respond well to anti-inflammatory therapy and supportive care, stabilizing for extended periods with good quality of life. Others progress despite aggressive treatment, and decisions about treatment intensity must consider the bird's comfort and wellbeing. Cost of long-term treatment and monitoring can be substantial. Owners need realistic expectations about possible outcomes and should work closely with their avian veterinarian to develop appropriate management plans and reassess as the situation evolves.

The concept of recovery from Macaw Wasting Disease differs from traditional recovery because this is a chronic, incurable condition rather than an illness that resolves with treatment. Instead of recovery in the conventional sense, the goal becomes disease stabilization, symptom management, and quality of life maintenance. Some birds achieve stable disease states with treatment where symptoms remain controlled and quality of life is acceptable for extended periods. These birds are not cured but are effectively managed, maintaining body weight and function with ongoing treatment. The timeline to achieve stabilization, if it occurs, varies from weeks to months of treatment adjustment and optimization.

Ongoing care requirements for birds living with Wasting Disease are substantial and lifelong. Daily medication administration continues indefinitely for birds on anti-inflammatory therapy. Dietary management with appropriate food selection and feeding strategies must be maintained. Regular weight monitoring tracks disease stability or progression. Environmental accommodations for any physical limitations remain in place. Frequent observation for signs of disease progression, secondary complications, or medication side effects guides management adjustments. Regular veterinary monitoring, frequency depending on disease stability, allows assessment and treatment optimization.

Prognosis for Macaw Wasting Disease remains guarded overall, though individual outcomes vary considerably. Some birds respond well to treatment, achieving long-term stability with good quality of life for months to years. Others progress despite aggressive management, with disease advancing to severe debilitation and death. Factors associated with better outcomes may include early disease detection, prompt treatment initiation, good initial response to anti-inflammatory therapy, and absence of severe neurological involvement. Birds presenting with advanced disease, severe cachexia, or significant neurological deficits generally have poorer prognosis. The unpredictable course makes prognostication challenging for individual birds.

Long-term outlook for macaws with Wasting Disease requires acceptance of chronic disease management and uncertain future. Birds that stabilize on treatment may continue doing well for extended periods, but the possibility of future deterioration exists. Treatment plans may require adjustment over time based on disease activity and response. Quality of life assessment should guide ongoing management decisions, with the goal of maintaining comfort and reasonable function rather than prolonging life at the expense of wellbeing. Some birds maintain good quality of life for years with appropriate management, demonstrating that while this disease is serious, it is not necessarily an immediate death sentence. Ongoing research may yield improved treatments, offering hope for better outcomes in the future.

Environmental prevention of Macaw Wasting Disease centers on biosecurity measures to limit avian bornavirus exposure and transmission. Maintaining closed flocks without introduction of birds from unknown sources provides the strongest protection against introducing virus to unaffected collections. Where new bird introduction is necessary, rigorous quarantine and testing protocols reduce transmission risk. Physical separation between birds from different sources limits direct and indirect contact transmission. Appropriate disinfection of housing, food and water containers, and equipment reduces environmental viral contamination. Air handling systems that limit airborne pathogen spread between areas may provide additional protection in larger facilities.

Quarantine protocols for newly acquired macaws should specifically address bornavirus exposure risk. New birds should be isolated in completely separate airspace from existing collections for extended quarantine periods of at least 90 days, with some recommendations extending to 6 months or longer given the complexities of bornavirus testing. Avian bornavirus testing through PCR and serology should be performed during quarantine, ideally with multiple tests over the quarantine period. Negative tests provide some reassurance but do not definitively rule out infection due to test limitations. Monitoring for any clinical signs suggestive of PDD during quarantine allows detection of developing disease. Only birds completing quarantine without evidence of bornavirus infection or clinical disease should be introduced to collections containing naive birds.

Dietary and general health maintenance support immune function, which may influence whether bornavirus infection progresses to clinical disease. Providing optimal nutrition through complete, balanced diets maintains overall health and immune competence. Avoiding nutritional deficiencies that could impair immunity reduces disease risk. Minimizing stress through appropriate husbandry, stable social environments, and consistent routines may reduce factors that could trigger disease development in infected birds. Maintaining overall excellent health through appropriate veterinary care addresses any concurrent conditions that could affect disease susceptibility.

Regular health maintenance enables early detection of developing Wasting Disease when intervention may be most effective. Routine veterinary examinations should include monitoring of body weight trends, assessment of body condition, and evaluation for early signs of disease. Screening testing for bornavirus exposure may be appropriate for birds at elevated risk. Early detection of infection before clinical disease develops allows informed management decisions regarding isolation and monitoring. For collections with known bornavirus presence, regular screening of all birds helps track infection status and identify newly affected individuals.

Early intervention when signs of possible Wasting Disease first appear may improve outcomes by initiating treatment before advanced disease develops. Any unexplained weight loss in macaws warrants prompt veterinary evaluation including consideration of PDD. Changes in droppings, regurgitation, or neurological signs should prompt immediate investigation. Early diagnosis allows treatment initiation when disease burden may be lower and response potentially better. Owners of macaws should be educated about early warning signs and the importance of prompt veterinary attention for any concerning changes.

Daily management of macaws living with Wasting Disease requires consistent attention to medication, nutrition, monitoring, and overall care. Medication administration must occur reliably at prescribed intervals, which may be challenging for medications requiring multiple daily doses. Dietary management involves preparing appropriate foods, ensuring adequate intake, and adjusting feeding strategies based on the bird's current condition. Daily observation should assess appetite, food consumption, dropping characteristics, activity level, and any signs of disease progression or complications. Regular weighing, ideally daily or at minimum weekly, tracks weight trends that indicate disease stability or progression. Maintaining these routines consistently supports optimal disease management.

Home environment modifications accommodate the limitations that may accompany Wasting Disease, particularly in birds with neurological involvement. Cage setup should place food, water, and perches at easily accessible locations appropriate for birds with coordination difficulties. Lowered perches reduce fall distance for ataxic birds, and padded cage bottoms cushion any falls that occur. Multiple feeding stations may be helpful for birds with mobility limitations. Temperature regulation prevents additional stress from environmental extremes. Quiet housing locations reduce stress and support rest. For birds with severe coordination problems, modified housing that limits fall risk while maintaining quality of life may be necessary.

Maintaining quality of life for macaws with Wasting Disease balances health management needs with the bird's psychological and social wellbeing. Even ill birds need mental stimulation, social interaction, and opportunities for positive experiences within their capabilities. Adapting enrichment and interaction to accommodate physical limitations allows continued engagement. Social time with family members remains important, with interaction modified to the bird's energy level and physical abilities. Favorite activities that remain possible should be encouraged. Recognizing and responding to individual preferences and comfort needs maintains quality of life even as physical capabilities may be limited.

Ongoing monitoring and veterinary coordination are essential for optimal outcomes in birds with Wasting Disease. Regular veterinary rechecks at intervals determined by disease stability allow assessment of treatment effectiveness and overall health status. Owners should maintain detailed records of weight, appetite, dropping observations, and any concerns to share with the veterinary team. Clear communication about what changes warrant urgent evaluation versus routine monitoring helps owners respond appropriately to evolving situations. Treatment adjustments based on ongoing assessment optimize management. Planning for potential deterioration and discussing end-of-life considerations in advance ensures readiness to make appropriate decisions if the situation changes.

Caregiver support helps owners manage the significant demands of caring for a macaw with this serious chronic disease. The emotional impact of caring for a bird with an incurable, potentially terminal illness requires acknowledgment and support. Practical demands including medication administration, specialized feeding, and frequent monitoring consume substantial time and energy. Financial costs of ongoing treatment, specialized nutrition, and veterinary care can be considerable. Connecting with other owners managing PDD through avian organizations or online communities provides peer support and practical advice. Veterinary teams can provide guidance, encouragement, and realistic expectations. Recognizing caregiver stress and seeking support when needed helps sustain quality care over potentially extended management periods.

Macaws are prominently affected by Wasting Disease, with the condition originally described in and named after these species. Multiple macaw species develop PDD, including Blue and Gold Macaws, Scarlet Macaws, Green-winged Macaws, Military Macaws, and various other macaw species. Hybrid macaws appear similarly susceptible. The prominence of macaws in the history of this disease reflects both their susceptibility and their popularity in aviculture, which brought affected birds to veterinary attention. Within macaws, no clear species-specific resistance patterns have been established, and owners of any macaw species should be aware of this disease risk.

Beyond macaws, Proventricular Dilatation Disease affects a wide range of psittacine species, making it a concern across aviculture. African Grey Parrots are frequently affected and appear particularly susceptible. Cockatoos, including various Cacatua and Eolophus species, commonly develop PDD. Amazon parrots across multiple species are affected. Conures, particularly larger species, develop the disease. Pionus parrots, Eclectus parrots, lovebirds, and many other psittacine species have been diagnosed with PDD. Even cockatiels and budgerigars can be affected, though prevalence may vary. The wide host range indicates that avian bornavirus can infect diverse psittacine species and that no parrot should be considered immune.

Screening and testing recommendations for macaws and other psittacine species address the complex relationship between bornavirus infection and clinical disease. Testing for avian bornavirus through PCR and serology can identify infected birds, though interpretation requires understanding that many infected birds remain clinically healthy. Pre-purchase testing of macaws from unknown backgrounds helps inform acquisition decisions. Quarantine testing of new birds before introduction to collections provides information about infection status. Screening of breeding birds informs breeding program decisions regarding potentially infected individuals. Testing of clinically suspicious birds supports diagnosis, recognizing the limitations of testing in confirming or excluding PDD. Working with avian veterinarians experienced in bornavirus interpretation helps ensure appropriate use of testing information.

Several conditions commonly occur alongside or complicate Macaw Wasting Disease. Secondary bacterial or fungal infections develop readily due to immune suppression from malnutrition and chronic illness. Aspergillosis represents a particularly concerning concurrent infection in immunocompromised birds. Crop infections from yeast or bacteria may accompany crop stasis. Malnutrition-related deficiencies compound the effects of impaired absorption. Hepatic lipidosis can develop in anorexic birds, particularly before PDD diagnosis prompts appropriate feeding support. Managing these concurrent conditions often requires attention alongside primary PDD treatment.

Conditions producing similar symptoms to Macaw Wasting Disease require differentiation for appropriate management. Heavy metal toxicosis, particularly lead and zinc poisoning, can cause gastrointestinal and neurological signs resembling PDD. Proventricular foreign bodies or impactions cause similar digestive symptoms. Gastrointestinal neoplasia may present with weight loss and digestive dysfunction. Other infectious diseases affecting the gastrointestinal tract require consideration. Metabolic conditions affecting digestion or nervous system function can mimic PDD. Thorough diagnostic evaluation distinguishes among these possibilities, though multiple conditions may coexist.

Potential complications of Macaw Wasting Disease extend the impact beyond the primary condition. Severe malnutrition with cachexia develops as disease progresses and absorption worsens. Secondary infections from immune suppression can become life-threatening. Aspiration pneumonia from regurgitation represents a serious complication. Seizures and severe neurological deterioration may occur with central nervous system involvement. Crop impaction from severe motility dysfunction requires intervention. Complete digestive failure with inability to process any nutrition represents end-stage disease. Early intervention with appropriate treatment may prevent or delay some complications, but the progressive nature of the disease makes eventual complications likely in many cases.