Vestibular Disease

Vestibular disease in birds refers to any condition affecting the vestibular system, the sensory apparatus responsible for maintaining balance, spatial orientation, and coordinating eye movements. The vestibular system consists of components in the inner ear (peripheral vestibular system) and the brainstem and cerebellum (central vestibular system), working together to provide the brain with information about the body's position and movement in space. When this system is disrupted by disease, injury, or dysfunction, affected birds experience profound difficulties with balance and coordination that can significantly impact their ability to perform normal activities including flying, perching, eating, and interacting with their environment.

Vestibular disease can develop from numerous underlying causes affecting either the peripheral or central components of the balance system. Inner ear infections, whether bacterial, fungal, or parasitic, represent common causes of peripheral vestibular dysfunction in birds. Trauma to the head or ear, toxic exposures, tumors, and degenerative changes can affect vestibular structures. Central vestibular disease may result from infectious diseases affecting the brain, stroke-like events, tumors, trauma, or inflammatory conditions. In some cases, the underlying cause cannot be definitively identified, resulting in a diagnosis of idiopathic vestibular disease. The distinction between peripheral and central disease has important implications for prognosis and treatment.

The impact of vestibular disease on affected birds is often dramatic and distressing for both the bird and owner. Birds with acute vestibular dysfunction may be unable to stand, perch, or move normally, often falling or spinning in circles. Head tilt, where the head is held tilted toward one side, is a characteristic finding. Abnormal eye movements called nystagmus may be visible. Affected birds may be unable to eat or drink normally due to their disorientation. The severity of symptoms varies from mild balance impairment to complete incapacitation. Quality of life is significantly impacted during acute episodes, and some birds may have permanent residual deficits affecting their daily function.

Treatment and prognosis for vestibular disease depend heavily on the underlying cause. Some causes, such as bacterial inner ear infections, respond well to appropriate antibiotic therapy with good potential for recovery. Other causes may be more difficult to treat or may cause permanent damage before intervention is possible. Supportive care during the acute phase is essential to prevent secondary complications and help the bird compensate for its vestibular dysfunction. Many birds show significant improvement over time as the nervous system adapts and compensates for vestibular damage, even when complete resolution is not achieved. Understanding vestibular disease helps owners recognize this condition and seek appropriate veterinary care promptly.

The primary causes of vestibular disease in birds can be broadly categorized into peripheral causes affecting the inner ear structures and central causes affecting the brainstem and cerebellum. Infection represents one of the most common causes, with bacterial otitis interna (inner ear infection) occurring when bacteria spread from the external or middle ear or arrive via the bloodstream. Common pathogens include Pseudomonas, Staphylococcus, Streptococcus, and Escherichia coli. Fungal infections, particularly aspergillosis, can invade inner ear structures. Less commonly, parasitic organisms may affect the vestibular apparatus. Infectious causes often have identifiable risk factors including respiratory infections, poor husbandry, or immunocompromise.

Trauma to the head or ear represents another significant cause of vestibular dysfunction in birds. Direct impact injuries from collision with windows, walls, or ceiling fans can damage inner ear structures or the brain regions involved in balance. Falls from perches or play structures may cause head trauma. Rough handling or attacks by other animals can result in vestibular damage. The delicate structures of the inner ear are vulnerable to traumatic disruption, and even relatively minor head trauma may cause vestibular signs in some cases. Trauma-induced vestibular disease may involve hemorrhage, concussion, or direct structural damage.

Environmental and toxic factors can cause vestibular dysfunction through various mechanisms. Exposure to certain toxins, including heavy metals, some medications, and environmental chemicals, can damage vestibular structures or nerve pathways. Aminoglycoside antibiotics, while sometimes necessary for treating infections, have well-documented ototoxic potential that may affect vestibular function. Extreme temperature changes, severe dehydration, and metabolic derangements can impair vestibular function. Chronic exposure to loud noise may contribute to inner ear damage over time. Nutritional deficiencies, particularly thiamine (vitamin B1) deficiency, can cause vestibular dysfunction as part of broader neurological impairment.

Risk factors that increase susceptibility to vestibular disease include age, concurrent illness, and species factors. Older birds may have age-related degeneration of vestibular structures and may be more susceptible to vascular events affecting the brain. Birds with chronic respiratory infections or sinus disease are at increased risk for spread of infection to the inner ear. Immunocompromised birds, whether from disease, stress, or other factors, may be more susceptible to infections affecting the vestibular system. Species that are prone to certain conditions, such as atherosclerosis in some parrot species, may have elevated risk for central vestibular events. Certain genetic conditions may affect vestibular development or function.

The mechanism by which vestibular disease causes its characteristic symptoms relates to how the vestibular system normally functions. The semicircular canals and otolith organs in the inner ear detect head movement and position, sending signals via the vestibular nerve to the brainstem. These signals are integrated with visual and proprioceptive information to maintain balance and coordinate eye movements. When vestibular input is disrupted on one side, the brain receives asymmetric signals that it interprets as continuous rotation, causing the sensation of vertigo and triggering compensatory responses including head tilt toward the affected side, nystagmus (rhythmic eye movements), and postural adjustments. The severity of symptoms depends on how completely and how suddenly vestibular function is lost.

Early warning signs of vestibular disease may be subtle in cases with gradual onset, though many cases present acutely without preceding warning signs. Birds with developing vestibular problems may show mild unsteadiness or balance disturbances that might be attributed to other causes. Subtle changes in how the bird holds its head or slight reluctance to fly may precede more obvious symptoms. Some birds may seem slightly disoriented or less coordinated than normal. Appetite changes may occur if the bird is experiencing vertigo-related nausea. These early signs, when present, typically progress over hours to days to the more characteristic symptoms of established vestibular disease.

Common symptoms of vestibular disease are typically dramatic and distinctive. Head tilt is a hallmark finding, with the head tilted toward the side of a peripheral vestibular lesion, giving the bird an asymmetric appearance. Nystagmus, an involuntary rhythmic movement of the eyes, is commonly present and may be horizontal, vertical, or rotational depending on the location of the lesion. Affected birds show obvious loss of balance and may lean, fall, or roll toward the affected side. Circling or spinning behavior may occur, again typically toward the affected side. Walking becomes difficult or impossible, with birds appearing drunk or disoriented. Some birds may be unable to stand at all during acute episodes.

Behavioral changes associated with vestibular disease reflect the disorientation and distress caused by the condition. Birds often appear frightened or anxious, which is understandable given their loss of spatial orientation. Activity decreases dramatically as movement becomes difficult and potentially dangerous. Appetite typically decreases both due to difficulty accessing food and possible nausea associated with vestibular dysfunction. Vocalization may change, with some birds calling more due to distress while others become quiet. Social interaction decreases as the bird focuses on maintaining what balance it can. Some birds may become more receptive to handling as they seek stability and comfort.

Physical signs of vestibular disease extend beyond the classic findings of head tilt and nystagmus. Ataxia, or incoordination, affects the bird's ability to move purposefully. The bird may flip or roll over when attempting to move. Difficulty perching is common, with birds often unable to grip securely or maintain position on perches. Wing drooping may occur on the affected side in some cases. Vomiting or regurgitation may occur due to nausea associated with vestibular dysfunction. Signs of the underlying cause may be apparent, such as discharge from the ear in cases of otitis or respiratory signs in birds with aspergillosis. Body condition may deteriorate if the condition persists and the bird cannot eat normally.

Symptom progression in vestibular disease varies depending on the underlying cause and whether treatment is instituted. In many cases, symptoms are most severe at onset and gradually improve over days to weeks as the brain learns to compensate for the vestibular dysfunction, even without specific treatment. Central vestibular disease may have more gradual progression if caused by a growing mass. Infectious causes may worsen without treatment but often improve with appropriate antimicrobial therapy. Some birds make complete recoveries while others retain permanent residual deficits, typically a mild head tilt. The timeline for improvement varies from days to weeks to months depending on the cause and severity.

Emergency symptoms requiring immediate veterinary care include severe vestibular episodes where the bird is completely unable to function, continuously rolling or spinning, or injuring itself due to loss of balance. Signs suggesting central nervous system involvement beyond vestibular dysfunction, such as seizures, loss of consciousness, or paralysis, warrant urgent evaluation. Birds that are unable to eat or drink for more than 24 hours require intervention. Signs of severe underlying disease, such as severe respiratory distress in a bird with suspected aspergillosis, constitute emergencies. Any bird with sudden onset of severe vestibular signs should be seen promptly to identify the underlying cause and begin appropriate treatment.

Initial examination for suspected vestibular disease involves comprehensive history-taking and thorough neurological examination. The avian veterinarian will ask about the onset and progression of symptoms, any trauma, potential toxin exposures, and the bird's overall health history. The neurological examination systematically evaluates the vestibular system, assessing the character and direction of head tilt, presence and type of nystagmus, postural reactions, and coordination. The examination attempts to distinguish peripheral from central vestibular disease based on specific neurological findings. For example, central vestibular disease may show vertical nystagmus and more severe postural deficits, while peripheral disease typically shows horizontal or rotational nystagmus with the quick phase away from the lesion. The ears are examined for signs of infection or trauma.

Diagnostic testing for vestibular disease aims to identify the underlying cause and assess the extent of involvement. Blood tests including complete blood count and biochemistry panel evaluate overall health and may reveal evidence of infection or metabolic problems. Otoscopic examination evaluates the external ear canal and tympanic membrane. Radiographs of the skull may show changes in the bulla or inner ear structures in cases of chronic otitis. Advanced imaging including CT scan or MRI provides detailed visualization of inner ear structures and the brain, helping distinguish peripheral from central disease and potentially identifying masses, hemorrhage, or other structural abnormalities. Testing for specific infections, including cultures and sensitivity testing from ear samples when accessible, guides antimicrobial selection.

Differential diagnosis for vestibular disease includes consideration of both peripheral and central causes as well as conditions that may mimic vestibular dysfunction. Peripheral causes include otitis interna, ototoxicity, trauma, and idiopathic vestibular syndrome. Central causes include brainstem infections (bacterial, viral, fungal, parasitic), stroke-like vascular events, trauma, tumors, and inflammatory conditions. Other conditions that may be confused with vestibular disease include systemic illness causing weakness (which may look like balance problems), metabolic disorders affecting neurological function, heavy metal toxicity, and other brain diseases. The pattern of clinical signs combined with diagnostic test results helps narrow the differential diagnosis.

Diagnosis confirmation in vestibular disease often relies on the combination of characteristic clinical signs, results of diagnostic testing, and response to treatment. When advanced imaging is available and performed, direct visualization of lesions may confirm the diagnosis. In cases of suspected otitis interna, positive culture results from ear samples support the diagnosis. Response to antibiotics in a bird suspected of having bacterial inner ear infection provides supportive evidence. Unfortunately, not all cases achieve definitive diagnosis, particularly when advanced imaging is not available or affordable. In these cases, treatment is often initiated based on the most likely cause given the clinical presentation, with response to treatment helping to confirm or refute the presumptive diagnosis.

Emergency and immediate treatment for birds with severe vestibular disease focuses on stabilization, supportive care, and prevention of secondary complications. Birds that are severely ataxic or rolling need to be confined in a safe environment where they cannot injure themselves, such as a well-padded container or cage without perches. Supportive care including appropriate temperature, fluid therapy for birds that are dehydrated or unable to drink normally, and assisted feeding for birds unable to eat may be necessary. Anti-vertigo or anti-nausea medications may be administered to help reduce symptoms and make the bird more comfortable. If the underlying cause is suspected, specific treatment may begin immediately, such as antibiotics for suspected bacterial infection.

Medical management of vestibular disease is directed at the underlying cause when identified. Bacterial otitis interna is treated with systemic antibiotics, with selection guided by culture and sensitivity results when available, or using broad-spectrum antibiotics effective against common pathogens empirically. Treatment typically continues for several weeks to ensure complete resolution of infection. Fungal infections require appropriate antifungal therapy, often for extended periods. Inflammatory conditions may be treated with anti-inflammatory medications. For idiopathic vestibular disease where no underlying cause is identified, treatment is supportive while monitoring for improvement. Medications to reduce vertigo and nausea may be continued during recovery.

Surgical treatment for vestibular disease is occasionally indicated depending on the underlying cause. Surgery may be performed to address severe chronic otitis that has not responded to medical management, potentially including procedures to drain or remove infected tissue. Masses affecting the vestibular system or brain may be amenable to surgical removal in some cases, though access to these structures in birds is challenging. Surgical intervention is relatively uncommon for vestibular disease compared to medical management and is typically reserved for specific situations where medical treatment is insufficient. The decision to pursue surgery depends on the specific cause, location of disease, the bird's overall condition, and available surgical expertise.

Supportive care is a crucial component of vestibular disease management regardless of the underlying cause. Housing modifications keep affected birds safe, with padding to prevent injury from falls, food and water placed where the bird can access them despite its disability, and removal of perches during acute phases when the bird cannot perch safely. Assisted feeding may be necessary for birds unable to eat normally, ensuring adequate nutrition during recovery. Fluid therapy prevents dehydration in birds that cannot drink adequately. Physical therapy through gentle assisted movement may help birds adapt to their vestibular dysfunction more quickly. The environment should be kept calm and stress-free to support healing.

Alternative and complementary treatments can support recovery from vestibular disease within the framework of conventional care. Acupuncture has been used in some avian patients for neurological conditions and may provide benefit. Nutritional support ensures the bird has all necessary nutrients for nervous system health and recovery. Herbal preparations with anti-inflammatory or nervous system supportive properties have been suggested, though evidence for their effectiveness in avian vestibular disease is limited. Environmental management including reduced stress and appropriate temperature supports recovery. These approaches complement rather than replace conventional treatment and should be discussed with the attending veterinarian.

Treatment decisions for vestibular disease consider the likely underlying cause, severity of symptoms, the bird's overall condition, available diagnostic and treatment options, and financial constraints. Cases with treatable underlying causes such as bacterial infection generally warrant aggressive treatment given good potential for recovery. Idiopathic cases often improve with supportive care and time. Cases with suspected tumors or other structural causes have more variable prognosis depending on specific findings. Cost considerations include diagnostic testing, which can be substantial for advanced imaging, as well as medications and supportive care needs. Expected outcomes vary widely depending on the cause, from full recovery to permanent disability or death in severe cases.

Recovery timeline for vestibular disease varies considerably depending on the underlying cause and the individual bird's ability to compensate for vestibular damage. Many birds with acute vestibular syndrome, regardless of cause, show significant improvement within the first one to two weeks as the brain begins to adapt to the altered vestibular input. This process, called vestibular compensation, allows the nervous system to recalibrate and regain functional balance even when the underlying vestibular damage has not fully healed. Complete recovery may take several weeks to months, and some birds are left with permanent mild residual deficits, typically a slight head tilt, even after maximal recovery has been achieved.

Post-treatment care during recovery focuses on providing a safe environment for the bird while allowing gradual return to normal function. Housing should continue to be modified for safety until the bird demonstrates stable balance and ability to perch. Perches can be gradually reintroduced, starting with low, wide, stable perches and progressing to normal perching as ability improves. Food and water should remain easily accessible throughout recovery. If medications are prescribed, they should be continued for the full course as directed. Gentle encouragement of movement and activity supports the compensation process. Follow-up veterinary appointments allow assessment of progress and adjustment of the treatment plan as needed.

Prognosis factors for vestibular disease recovery include the underlying cause, severity of initial symptoms, location of the lesion (peripheral versus central), and the bird's age and overall health. Peripheral vestibular disease generally carries a better prognosis than central disease because the brain can more effectively compensate for peripheral lesions. Idiopathic vestibular syndrome often has a favorable prognosis with good potential for recovery. Bacterial otitis interna, if treated promptly and effectively, may resolve completely. Central causes have more variable prognosis depending on the specific condition. Younger birds and those in good overall health tend to compensate more effectively. The severity of initial symptoms does not necessarily predict outcome, as even severely affected birds may recover well.

Long-term outlook for birds that recover from vestibular disease depends on the underlying cause and the degree of permanent damage sustained. Many birds make excellent functional recoveries and return to normal or near-normal activity, even if they retain mild residual signs such as slight head tilt. Birds with permanent vestibular damage typically learn to compensate effectively and can have good quality of life with some accommodations. Recurrence is possible if the underlying cause is not fully addressed, particularly for infectious causes that may recrudesce. Birds that have had vestibular disease should be monitored for any signs of recurrence or progression. Life expectancy is typically not significantly affected for birds that recover from vestibular episodes, though this depends on the underlying cause.

Environmental prevention of vestibular disease focuses on reducing risk factors for causes such as infection and trauma. Maintaining a clean environment reduces bacterial load and infection risk. Appropriate temperature and humidity help maintain respiratory health and reduce infection susceptibility. Air quality should be good, with adequate ventilation and minimization of airborne pathogens and irritants. The bird's housing should be designed to minimize trauma risk, including addressing collision hazards such as windows and mirrors, securing fans and other dangerous items, and ensuring stable perches. Preventing exposure to loud noises protects hearing and vestibular structures from noise-induced damage.

Quarantine protocols for new birds protect existing birds from introduction of infectious diseases that could affect vestibular function. New birds should be quarantined for an appropriate period, typically 30 to 90 days, during which they are observed for signs of illness and potentially tested for specific infections. Respiratory infections that could potentially spread to affect the inner ear should be diagnosed and treated before introducing new birds to the flock. Baseline veterinary examination during quarantine helps identify any existing problems. Good hygiene practices during quarantine prevent cross-contamination.

Dietary prevention considerations for vestibular disease relate primarily to supporting overall immune function and nervous system health. A balanced, species-appropriate diet provides the nutrients necessary for optimal immune function, reducing susceptibility to infections. Thiamine (vitamin B1) deficiency can cause vestibular dysfunction, so adequate B vitamin intake is important. Antioxidants support nervous system health. Avoiding nutritional deficiencies that could predispose to illness helps maintain overall health. Fresh, clean water is essential for hydration and health maintenance.

Health maintenance practices support vestibular health and allow early detection of problems. Regular veterinary care provides opportunity for early detection of conditions that could progress to vestibular involvement, such as respiratory or ear infections. Prompt treatment of any upper respiratory infections or signs of ear problems helps prevent progression to inner ear involvement. Maintaining healthy immune function through good husbandry reduces susceptibility to infections. Avoiding exposure to ototoxic substances, including certain medications when alternatives exist, protects vestibular structures. Regular observation of the bird for any changes in balance or coordination allows early recognition of problems.

Early intervention when potential vestibular problems are suspected can improve outcomes. Any signs of balance disturbance, head tilt, or unusual eye movements should prompt veterinary evaluation. Ear infections or respiratory infections should be treated promptly and completely to prevent spread to inner ear structures. Birds showing early signs of illness should receive prompt attention to prevent progression. Owner education about recognizing vestibular symptoms helps ensure early presentation. Working with an avian veterinarian to maintain optimal health provides the best chance of preventing vestibular disease and other health problems.

Daily management of a bird recovering from vestibular disease requires attention to safety, nutrition, and monitoring of progress. Housing should be set up to accommodate the bird's current level of balance impairment, with modifications adjusted as the bird improves. Food and water need to be placed where the bird can access them with its current limitations, and intake should be monitored to ensure adequate nutrition and hydration. If medications are prescribed, they must be administered consistently as directed. Daily observation assesses the bird's balance, coordination, and overall condition, noting any improvement or deterioration. Gentle handling and interaction provide comfort while avoiding excessive stress on the recovering bird.

Home environment modifications are essential for keeping birds with vestibular dysfunction safe and comfortable. During acute phases, perches should be removed to prevent dangerous falls, with the bird housed on a padded floor surface. As recovery progresses, low, wide, stable perches can be gradually reintroduced. Food and water containers should be stable and accessible, potentially positioned at multiple heights to accommodate the bird's changing abilities. Padding on cage walls and floor reduces injury risk from falls or collisions. The cage should be located in a quiet area to reduce stress and startling. Dim lighting may help reduce nystagmus and associated discomfort in some birds.

Maintaining quality of life for birds with vestibular disease involves balancing necessary restrictions with opportunities for normal activities as they become possible. Birds should be encouraged to move and exercise within their safe limitations, as activity promotes vestibular compensation. Social interaction with owners provides comfort and mental stimulation even when physical activity is limited. As balance improves, enrichment activities can be gradually reintroduced with appropriate modifications. Many birds with residual mild vestibular deficits adapt well and return to enjoying normal activities. Owner patience and consistent supportive care help birds through the recovery process.

Monitoring and ongoing care requirements include regular assessment of vestibular function and overall health. Owners should observe daily for changes in head position, balance, nystagmus, and coordination, noting trends over time. Weight should be monitored to ensure adequate nutritional status. Any deterioration or failure to improve as expected should prompt veterinary consultation. Follow-up veterinary appointments allow professional assessment of recovery progress and adjustment of treatment plans. For birds with permanent residual deficits, ongoing accommodations may be needed, such as modified cage setup and continued monitoring. Long-term, regular wellness examinations help ensure any recurrence is detected early.

Caregiver support addresses the challenges of caring for birds with vestibular disease. The dramatic presentation of vestibular symptoms can be frightening for owners, and understanding that many birds recover well provides reassurance. Learning proper supportive care techniques, including assisted feeding if needed and safe housing modifications, empowers owners to provide effective home care. Connecting with avian veterinary professionals for guidance throughout recovery provides ongoing support. Online communities and bird clubs can provide emotional support and practical advice from others who have experienced similar situations. Managing expectations regarding recovery timeline and potential for residual deficits helps caregivers maintain perspective during what may be a prolonged recovery process.

High-risk species for vestibular disease are not clearly defined in avian medicine, as this condition can affect virtually any bird species when causative factors are present. However, certain species and categories of birds may face elevated risk for specific causes of vestibular disease. Species prone to respiratory infections, including Amazon parrots and other psittacines commonly affected by Aspergillosis, may have elevated risk for fungal-related vestibular involvement. Species prone to atherosclerosis, including Amazon parrots, African Grey Parrots, and cockatoos, may have elevated risk for vascular-related central vestibular events, particularly as they age. Birds that are more likely to experience head trauma due to their activity patterns or housing situations face elevated traumatic vestibular disease risk.

Moderate-risk species include the broader population of pet psittacines that may develop vestibular disease from various causes. Poultry may develop vestibular disease, sometimes as part of broader infectious processes affecting multiple birds. Wild birds in rehabilitation settings may present with vestibular disease from trauma or infection. Older birds of any species face increased risk as age-related changes affect vestibular structures and predispose to conditions like vascular events. Immunocompromised birds from any species are more susceptible to infections that could affect the vestibular system. Species differences in vestibular disease incidence and causes remain an area where more research would be valuable.

Screening recommendations for vestibular disease focus on clinical monitoring rather than routine testing of asymptomatic birds. Regular veterinary examinations should include neurological assessment that would detect subtle balance abnormalities. Birds showing any early signs of balance disturbance, head position changes, or unusual eye movements should be promptly evaluated. Conditions that could predispose to vestibular disease, such as chronic respiratory infections or ear problems, should be treated promptly and monitored for resolution. Older birds and those with conditions predisposing to vascular disease may warrant enhanced monitoring. Owner education about recognizing vestibular symptoms supports early detection and intervention.

Commonly co-occurring conditions with vestibular disease depend on the underlying cause but may include respiratory infections when bacterial or fungal inner ear disease is involved. Sinusitis and upper respiratory infections may spread to cause otitis interna. Systemic infections may affect both the vestibular system and other body systems. Birds with atherosclerosis predisposing to vascular events may have concurrent cardiovascular disease. Chronic otitis externa and media often precede the development of otitis interna affecting vestibular function. Immunosuppressive conditions may predispose to the infections causing vestibular disease. Managing vestibular disease often requires addressing these related or contributing conditions.

Conditions with similar symptoms to vestibular disease include various other neurological and systemic conditions that can cause balance disturbance or abnormal head position. Heavy metal toxicosis, particularly lead poisoning, can cause neurological signs including ataxia that may resemble vestibular dysfunction. Other brain diseases including infections, tumors, and trauma may cause similar presentations depending on the location of lesions. Thiamine (vitamin B1) deficiency causes neurological signs including opisthotonus and ataxia. Hypocalcemia can cause muscle tremors and weakness affecting balance. Severe systemic illness causing weakness may be mistaken for vestibular disease. Careful neurological examination helps distinguish vestibular disease from these other conditions.

Potential complications of vestibular disease include secondary problems that may develop due to the bird's impaired function. Injury from falls is a significant concern for birds with poor balance, potentially causing fractures, head trauma, or soft tissue damage. Malnutrition and dehydration may result when birds cannot effectively access food and water. Aspiration pneumonia can occur if birds regurgitate or have difficulty swallowing due to disorientation. Stress and its physiological effects may complicate recovery. Psychological effects including anxiety and depression may affect quality of life. Prevention of complications requires appropriate supportive care throughout the acute phase of vestibular disease, including safe housing, assisted feeding when needed, and treatment of any secondary problems that develop.