Pneumonia (bacterial, viral)

Pneumonia is one of the most significant health challenges facing goat producers worldwide, causing substantial economic losses through mortality, reduced growth rates, treatment costs, and long-term production impacts. This inflammatory condition of the lungs can be caused by bacterial, viral, parasitic, or mixed infections, with bacterial pneumonia being the most common and clinically significant form in goats. The disease typically develops when environmental stressors, viral infections, or management factors compromise the respiratory defenses, allowing opportunistic bacteria that normally reside in the upper respiratory tract to colonize the lungs and cause disease. Understanding the complex interplay between pathogens, host factors, and environmental conditions is essential for effective prevention and treatment.

Pneumonia affects goats of all ages and breeds, though certain populations are at particularly high risk. Young kids between two weeks and four months of age are especially vulnerable due to their immature immune systems and the waning of maternal antibody protection. Recently weaned animals, those that have been transported or undergone other stressful events, and goats introduced into new herds face elevated risk. Dairy goats in intensive housing systems may experience higher pneumonia rates due to increased pathogen exposure and environmental challenges. Prevalence varies widely depending on management systems, geographic location, and seasonal factors, but pneumonia consistently ranks among the top causes of mortality and morbidity in goat herds worldwide.

The economic and welfare impact of pneumonia in goats is substantial. Acute mortality during outbreaks can reach 10 to 30 percent in susceptible populations, with young kids suffering the highest death rates. Survivors often experience permanent lung damage that reduces lifetime productivity, including impaired growth rates in meat animals and decreased milk production in dairy goats. Treatment costs including veterinary services, medications, and labor add to direct losses. Perhaps most significantly, the pain and distress experienced by animals with pneumonia represents a serious welfare concern that demands attention through prevention and prompt treatment.

Pneumonia in goats is highly treatable when detected early and managed appropriately, though delayed or inadequate treatment often results in poor outcomes. The key to successful management lies in recognizing the early warning signs, implementing prompt antibiotic therapy effective against the likely pathogens, providing supportive care to maintain hydration and nutrition, and addressing the underlying risk factors that predisposed to disease. Prevention through vaccination, good management practices, and reduction of environmental stressors is far more effective and economical than treating established disease. This comprehensive approach to respiratory health should be a cornerstone of every goat health management program.

Bacterial pneumonia in goats most commonly involves Mannheimia haemolytica, Pasteurella multocida, and Bibersteinia trehalosi, organisms collectively referred to as the Pasteurellaceae family. These bacteria are normal inhabitants of the upper respiratory tract of healthy goats and only cause disease when host defenses are compromised. Mannheimia haemolytica produces potent leukotoxins that destroy white blood cells and damage lung tissue, making it particularly pathogenic. Mycoplasma species, especially Mycoplasma ovipneumoniae, are important causes of chronic pneumonia and predispose to secondary bacterial infections. Other bacteria including Corynebacterium pseudotuberculosis (the cause of caseous lymphadenitis), Trueperella pyogenes, and various streptococcal species may also be involved in pneumonia cases.

Viral infections frequently initiate the disease process by damaging respiratory epithelium and suppressing local immunity, allowing secondary bacterial colonization of the lungs. Important respiratory viruses in goats include parainfluenza virus type 3, respiratory syncytial virus, adenovirus, and caprine herpesvirus. While these viruses may cause mild illness on their own, their primary significance lies in their role as predisposing factors for bacterial pneumonia. In some regions, more severe viral diseases such as peste des petits ruminants and contagious caprine pleuropneumonia contribute to respiratory disease complexes. Mixed infections involving multiple viruses and bacteria are common and typically produce more severe disease than single-agent infections.

Environmental and management factors play crucial roles in determining whether exposure to respiratory pathogens results in clinical disease. Poor ventilation in housing leads to accumulation of ammonia, dust, and airborne pathogens that damage respiratory defenses. Overcrowding increases pathogen transmission and competition stress. Temperature extremes, particularly cold and damp conditions, challenge thermoregulation and compromise immunity. Dusty bedding, poor air quality from nearby feeding operations, and housing near roadways increase respiratory irritation. Sudden weather changes, especially cold fronts accompanied by wind and precipitation, consistently precede outbreaks of respiratory disease.

Stress is the unifying factor that predisposes goats to pneumonia by suppressing immune function and allowing opportunistic pathogens to overcome host defenses. Transportation stress, often called shipping fever when it results in pneumonia, involves the combined effects of handling, confinement, fasting, dehydration, temperature fluctuations, and exposure to novel pathogens. Weaning stress occurs as kids lose the nutritional and immunological support of nursing and face social reorganization. Introduction to new herds exposes animals to unfamiliar pathogens while simultaneously creating social stress. Concurrent illness, parasitism, or poor nutrition further compromises the ability to resist respiratory infection.

The pathophysiology of pneumonia begins when pathogenic organisms reach the lower respiratory tract and overwhelm local defenses. In bacterial pneumonia, organisms multiply in lung tissue and produce toxins that cause inflammation, edema, and consolidation. White blood cells migrate to the site of infection, releasing inflammatory mediators that cause fever and systemic signs of illness. Damaged lung tissue cannot effectively exchange gases, resulting in hypoxemia and respiratory distress. Fibrin and inflammatory exudates fill airways, further compromising ventilation. Without effective treatment, progressive lung destruction leads to respiratory failure and death. Survivors may develop chronic lung damage with adhesions, abscesses, or fibrosis that permanently impairs respiratory function.

Clinical signs of pneumonia in goats range from subtle early indicators that require careful observation to detect, through classic respiratory symptoms, to life-threatening emergency presentations. The speed of progression varies depending on the causative agents involved, the immune status of the animal, and environmental conditions. Some cases develop acutely over one to two days, while others progress more gradually over a week or more. Early recognition of symptoms allows prompt treatment before irreversible lung damage occurs, making regular close observation of animals essential for effective pneumonia management.

The earliest warning signs of developing pneumonia are often behavioral rather than obvious respiratory symptoms. Affected animals may appear slightly depressed, spending more time lying down and showing less interest in their surroundings. Appetite typically decreases before other signs become apparent, and kids may nurse less frequently or with less vigor. Animals may separate from the group or lag behind during movement to pasture. A subtle increase in respiratory rate may be noticed by observant caretakers who know what is normal for their animals. Body temperature elevation to 40 to 41 degrees Celsius often precedes other clinical signs but requires taking rectal temperatures to detect. These subtle changes precede obvious illness by 12 to 48 hours and represent the optimal window for treatment initiation.

Classic respiratory symptoms develop as the infection progresses and lung involvement increases. Nasal discharge that initially may be serous becomes mucopurulent as secondary bacterial infection establishes. Coughing develops, ranging from occasional soft coughs to frequent paroxysms of harsh, painful coughing. The respiratory rate increases above the normal 15 to 30 breaths per minute, and breathing becomes more labored. Animals may stand with neck extended, elbows abducted, and reluctance to move in an effort to facilitate breathing. Abnormal lung sounds including wheezes, crackles, and areas of consolidated lung without normal breath sounds can be detected on auscultation with a stethoscope.

Behavioral changes become more pronounced as disease severity increases. Affected goats become increasingly depressed and may stop eating entirely. They resist being moved and prefer to stand or lie in one place. Social animals become isolated from the herd. Does may reject kids due to illness and discomfort. Milk production drops dramatically in lactating animals. Weight loss becomes apparent as the illness continues. Eyes may appear dull and sunken as dehydration develops from fever and reduced water intake. The hair coat becomes rough and unkempt as animals stop normal grooming behaviors.

Physical examination reveals additional signs of respiratory compromise. Fever persists or may spike higher as disease progresses. Heart rate increases in response to hypoxemia and dehydration. Mucous membrane color may change from healthy pink to pale, congested, or cyanotic depending on the degree of respiratory compromise. Dehydration is evident from loss of skin elasticity and dry mucous membranes. In severe cases, subcutaneous emphysema may be palpable along the neck and back if air has escaped from ruptured airways. Swelling in the throat region may indicate involvement of upper respiratory structures or retropharyngeal lymph nodes.

Emergency symptoms requiring immediate veterinary intervention include severe respiratory distress with open-mouth breathing, extended head and neck, and frothy discharge from the nose. Cyanosis of the mucous membranes indicates life-threatening hypoxemia. Collapse or inability to stand suggests circulatory compromise. Complete refusal of food and water for more than 24 hours indicates severe systemic illness. Multiple animals in a group showing acute respiratory signs simultaneously may indicate a highly virulent pathogen or toxic exposure requiring urgent investigation. Young kids can deteriorate rapidly and should be treated as emergencies when showing moderate to severe respiratory signs.

Diagnosis of pneumonia in goats relies primarily on clinical examination findings, with laboratory testing providing confirmation and guidance for treatment in complicated cases or herd outbreaks. A thorough physical examination should be performed on affected animals, including careful auscultation of the lungs in a quiet environment. The pattern of illness in the herd, recent management events, and environmental conditions provide important contextual information. Veterinary involvement is recommended for severe cases, treatment failures, and situations where multiple animals are affected to ensure accurate diagnosis and appropriate management.

Clinical examination findings consistent with pneumonia include elevated body temperature, increased respiratory rate and effort, abnormal lung sounds on auscultation, nasal discharge, and coughing. Auscultation may reveal wheezes and crackles in affected lung regions, increased bronchial sounds, or areas of absent breath sounds where consolidation has occurred. The location and extent of abnormal sounds helps assess severity. Percussion of the chest may reveal areas of dullness corresponding to consolidated lung or pleural fluid. Assessment of hydration status, body condition, and concurrent health issues guides overall management decisions.

Laboratory diagnostic testing can identify specific pathogens and guide treatment selection. Nasal or nasopharyngeal swabs provide samples for bacterial culture and sensitivity testing, though organisms isolated from the upper respiratory tract may not perfectly reflect lower respiratory pathogens. Transtracheal wash or bronchoalveolar lavage provides samples more representative of lower respiratory flora but requires specialized technique. Blood work may reveal leukocytosis with neutrophilia in bacterial infections, though white blood cell counts can be variable. Serology can detect antibodies to specific respiratory viruses but is more useful for herd-level diagnosis than individual case management. Necropsy examination with submission of fresh and fixed lung samples provides definitive diagnosis in fatal cases and should be performed on animals that die during outbreaks.

Differential diagnosis for respiratory disease in goats includes several conditions that may present with similar clinical signs. Lungworm infection causes chronic respiratory signs and may predispose to secondary bacterial pneumonia. Contagious caprine pleuropneumonia, caused by Mycoplasma capricolum subspecies capripneumoniae, is a severe respiratory disease of goats that is reportable in many countries. Caseous lymphadenitis with internal abscesses can produce respiratory signs. Pulmonary adenomatosis, a viral tumor of sheep and goats, causes progressive respiratory disease. Heart failure from various causes can produce respiratory distress and exercise intolerance. Hyperthermia in hot weather may be confused with fever from infection. In young kids, aspiration pneumonia from improper bottle feeding technique should be considered.

Treatment of pneumonia in goats should begin as soon as clinical signs are recognized, as early intervention dramatically improves outcomes. The goals of therapy include eliminating the bacterial infection, reducing inflammation and fever, maintaining hydration and nutrition, and supporting respiratory function during recovery. Treatment protocols should be developed in consultation with a veterinarian familiar with the specific pathogens and resistance patterns in the region. Antibiotic selection should be guided by knowledge of likely causative organisms, culture and sensitivity results when available, and consideration of withdrawal times for food-producing animals.

Emergency treatment of severe pneumonia cases requires immediate aggressive intervention. Animals with severe respiratory distress may benefit from placement in a well-ventilated area with fresh air flow. Administration of anti-inflammatory drugs such as flunixin meglumine or meloxicam reduces fever, alleviates pain, and may improve lung function by reducing inflammation. Rapid-acting antibiotics should be administered by injection to achieve therapeutic blood levels quickly. Intravenous fluid therapy corrects dehydration and supports circulation in severely compromised animals. Oxygen supplementation may be beneficial if available. Animals in respiratory crisis that do not respond to initial treatment have a grave prognosis and humane euthanasia should be considered.

Antibiotic therapy is the cornerstone of bacterial pneumonia treatment. Commonly effective antibiotics for respiratory infections in goats include oxytetracycline, florfenicol, tulathromycin, tilmicosin, and ceftiofur. Long-acting formulations are advantageous as they maintain therapeutic levels with fewer injections, reducing stress on sick animals. Oxytetracycline at elevated doses provides broad-spectrum coverage and is economical for treating multiple animals. Tulathromycin is highly effective and requires only a single injection but is more expensive. The choice of antibiotic should consider the likely pathogens, previous treatment history and potential resistance, cost, and withdrawal times. All withdrawal periods must be strictly observed for meat and milk from treated animals.

Supportive care is essential for pneumonia recovery and may determine survival in severe cases. Fluid therapy combats dehydration from fever and reduced intake and can be provided orally to mildly affected animals or intravenously to those severely compromised. Nutritional support through provision of palatable, easily digestible feeds encourages intake. Fresh, clean water should be available at all times. Housing in a dry, draft-free but well-ventilated area reduces environmental stress during recovery. Separating sick animals from the herd reduces transmission and allows for individual monitoring. Vitamin and mineral supplementation may support immune function during recovery.

Herd-level treatment decisions arise when multiple animals are affected during an outbreak. Metaphylactic treatment, or treating all at-risk animals in a group with antibiotics before clinical signs develop, may be appropriate in high-risk situations such as after transportation or during severe weather events when pneumonia rates are expected to be high. This approach should be used judiciously to limit antimicrobial resistance development. Mass treatment adds expense and requires attention to withdrawal times. Environmental modifications including improved ventilation, reduced crowding, and dust control benefit the entire group. Vaccination of unaffected animals may help limit outbreak spread.

Treatment decisions for individual animals should consider disease severity, likelihood of recovery, animal value, and economic factors. Mild to moderate cases detected early have good prognosis with appropriate antibiotic therapy and supportive care. Severe cases with extensive lung involvement, prolonged illness before treatment, or poor response to initial therapy have guarded prognosis. Animals that fail to respond after 48 to 72 hours of appropriate treatment should be reassessed for possible antibiotic resistance, mixed infections, or complications such as lung abscesses. Chronically affected animals with permanent lung damage may not be economically viable for continued production. Humane euthanasia is appropriate when prognosis is hopeless and continued treatment would only prolong suffering.

Recovery from pneumonia depends on the severity of initial disease, the promptness and appropriateness of treatment, and the overall health status of the animal. Mild cases detected and treated early typically show improvement within 24 to 48 hours, with resolution of fever and return of appetite. More severe cases may require five to seven days of treatment before substantial improvement is evident. Complete clinical recovery in moderate to severe cases takes two to four weeks, though lung healing continues for much longer. Some animals suffer permanent lung damage that affects long-term productivity despite apparent clinical recovery.

Post-treatment care and monitoring are essential for ensuring complete recovery and preventing relapse. Antibiotic treatment should continue for the full prescribed course, typically five to seven days, even if animals appear improved. Abruptly stopping treatment may allow residual bacteria to rebound and cause relapse. Daily monitoring of appetite, demeanor, and respiratory rate helps assess recovery progress. Body temperature should be checked if animals seem to regress. Animals should be maintained in a low-stress environment with good nutrition and clean, comfortable housing during convalescence. Avoiding exposure to extreme weather, dust, and other respiratory stressors supports lung healing.

Prognostic factors that influence outcome include the duration of illness before treatment, the severity of lung involvement, the presence of complications, and the age and overall health of the animal. Animals treated within 24 hours of symptom onset have the best outcomes. Extensive lung consolidation visible on ultrasound or detected on physical examination indicates severe disease with more guarded prognosis. Complications such as lung abscesses, pleuritis, or pericarditis significantly worsen outcomes. Young kids and animals debilitated by concurrent disease or parasitism recover more slowly and have higher mortality rates. Animals that respond quickly to treatment and regain normal appetite within three to four days usually make full recoveries.

Return to production for recovered animals requires assessment of their respiratory function and overall condition. Animals should be fully recovered clinically with normal respiratory rate and no residual coughing before returning to normal activities. Dairy goats can return to production after withdrawal times are observed, though milk yield may be reduced for the remainder of the lactation. Growing animals may take several weeks to resume normal weight gains after illness. Breeding should be delayed until animals have fully recovered their body condition. Animals with significant permanent lung damage may not perform at expected levels and should be evaluated individually for continued production viability. Record keeping of affected animals helps identify those with repeated problems that may warrant culling.

Vaccination provides important protection against some of the pathogens involved in pneumonia, though no vaccine prevents all causes of respiratory disease. Multivalent clostridial vaccines containing respiratory organisms such as Mannheimia haemolytica and Pasteurella multocida are available and recommended for goats at risk. Primary vaccination requires two doses given three to four weeks apart, with annual boosters before high-risk periods. Kids from vaccinated does should be vaccinated starting at six to eight weeks of age. Animals being transported or entering stressful situations benefit from vaccination two to three weeks before the anticipated stress. Vaccines do not provide complete protection and must be combined with good management practices for optimal respiratory health.

Biosecurity measures help prevent introduction of respiratory pathogens and reduce transmission within herds. New animals should be quarantined for at least three weeks before introduction to the main herd, with observation for respiratory signs and ideally testing for specific pathogens. Avoiding purchase of animals from sales barns and unknown sources reduces exposure to new pathogens. Maintaining a closed herd or purchasing only from known, healthy sources minimizes disease introduction risk. Separating age groups prevents transmission from older animals that may be asymptomatic carriers to susceptible young stock. Isolation of sick animals limits spread within the herd.

Environmental management is critical for respiratory disease prevention and focuses on providing good air quality while minimizing stress. Housing should have adequate ventilation to remove ammonia, dust, and airborne pathogens without creating cold drafts on resting animals. Stocking density should allow at least 15 to 20 square feet per adult goat in indoor housing. Bedding should be kept dry and clean, with regular removal of wet material that generates ammonia. Dust from feeding hay should be minimized through use of feeders that prevent scattering and through selecting hay that is not excessively dusty. Good drainage prevents accumulation of moisture that promotes pathogen survival and respiratory irritation.

Nutritional management supports immune function and respiratory health. Balanced diets that meet energy, protein, mineral, and vitamin requirements maintain robust immune responses. Vitamin E and selenium supplementation may be beneficial in deficient areas. Adequate colostrum intake by newborn kids provides critical passive immunity during the vulnerable early weeks of life. Avoiding abrupt diet changes, especially around stressful events, maintains rumen function and overall health. Body condition should be maintained at appropriate levels for production stage to provide physiological reserves during health challenges.

Stress reduction is perhaps the most important preventive measure for pneumonia. Minimizing transportation time and providing rest stops with access to water and feed reduces shipping stress. Preconditioning programs that vaccinate, deworm, and acclimate animals to handling and feed changes before transportation dramatically reduce shipping fever incidence. Gradual weaning and maintaining familiar social groups reduces weaning stress. Providing shelter from weather extremes and avoiding handling during heat stress or cold rain events limits physiological stress. Planning management activities to avoid stacking multiple stressors simultaneously allows animals to cope more effectively. Regular, calm handling that familiarizes animals with routine procedures reduces stress during necessary management activities.

Daily management and monitoring should include observation of all animals for respiratory health as a routine part of animal husbandry. Respiratory rate, breathing effort, and presence of coughing or nasal discharge should be noted during daily feeding and animal checking. Any animal showing abnormal respiratory signs should be caught and evaluated more closely, with body temperature taken and lungs auscultated if equipment and training allow. Early intervention when respiratory signs are first noticed dramatically improves outcomes compared to waiting until animals are obviously ill. Particular attention should be paid to high-risk individuals including young kids, recently transported animals, and those undergoing other stressful events.

Housing and environmental management for respiratory health focuses on air quality and thermal comfort. Natural ventilation in open-sided structures works well in moderate climates, with adjustable openings to control airflow in cold weather. Enclosed buildings require mechanical ventilation sized appropriately for the number of animals housed. Air should flow from clean areas through animal space and out without recirculating. Ammonia levels should be undetectable by smell at animal height, with concentrations below 10 parts per million. Temperature fluctuations should be minimized through appropriate insulation and ventilation management. Separate airspaces for kidding and young stock areas reduce exposure of vulnerable animals to pathogens shed by adults.

Herd health programs should incorporate respiratory disease prevention as a core component. Working with a veterinarian to develop an appropriate vaccination protocol based on local disease pressures and herd history is recommended. Regular monitoring of respiratory disease incidence helps identify risk factors and evaluate prevention effectiveness. Pre-movement health assessments and preconditioning protocols for animals being transported reduce shipping fever risk. Treatment protocols should be established in advance so that appropriate medications are on hand and caretakers know when and how to intervene. Necropsy of animals that die with respiratory signs provides valuable diagnostic information.

Record keeping supports respiratory disease management by documenting incidence, treatments, and outcomes. Individual animal records should include dates of respiratory illness, clinical signs observed, treatments administered, and response to treatment. Herd-level records of outbreak timing, number affected, and environmental conditions help identify patterns and risk factors. Economic records including treatment costs, mortality losses, and production impacts inform management decisions. Vaccination records ensure animals receive appropriate protection. Records facilitate communication with veterinarians and support analysis of prevention program effectiveness over time.

Economic considerations for respiratory disease management include costs of prevention versus treatment, production losses from subclinical disease, and long-term impacts on herd productivity. Prevention investments in vaccination, facilities, and management practices generally provide excellent return through reduced disease losses. Early treatment of individual cases is far less expensive than treating advanced disease with poor prognosis. Chronic respiratory problems reduce growth rates and feed efficiency in meat animals and milk production in dairy goats, causing ongoing economic losses beyond direct mortality. Investment in appropriate housing and ventilation provides long-term benefits for respiratory health and overall herd productivity. Cost-benefit analysis should guide decisions about facility improvements and prevention program investments.

All breeds of goats are susceptible to pneumonia, with disease risk determined more by management factors, environmental conditions, and individual animal circumstances than by breed characteristics. However, certain breed types may face elevated risk due to typical management systems, anatomical features, or genetic susceptibility to stress. Dairy goats housed intensively in confinement systems may experience higher pathogen exposure than extensively managed meat goats, though inadequate shelter for pastured animals creates its own risks. Imported breeds from temperate climates may be less adapted to local environmental challenges when raised in different geographic regions, potentially increasing stress-related disease susceptibility.

Production type significantly influences pneumonia risk through associated management practices. Dairy goat operations with frequent kidding, intensive housing, and high production demands may see higher pneumonia rates than low-input extensive systems. However, meat goat operations that involve frequent buying and selling, transportation to market, and commingling of animals from multiple sources face substantial risk from shipping fever and exposure to novel pathogens. Show goats experience repeated transportation, commingling, and stress that elevate respiratory disease risk. Fiber goats such as Angoras have been reported to have increased susceptibility to respiratory disease, possibly related to their thin skin and high metabolic demands for fiber production. Young stock face the highest risk across all production types.

Genetic selection for pneumonia resistance is not currently practical as specific genetic markers for resistance have not been identified, and disease susceptibility involves complex interactions between genetics, management, and environment. Selection for overall robustness, health, and longevity indirectly supports respiratory disease resistance. Culling animals with repeated pneumonia episodes may be appropriate if individual susceptibility seems higher than herdmates under similar conditions. Avoiding inbreeding helps maintain immune system diversity and disease resistance. Selecting breeding stock from herds with strong health records contributes to long-term herd health improvement.

Several conditions commonly co-occur with or complicate pneumonia in goats. Parasitic infections, particularly heavy gastrointestinal nematode burdens and lungworm infection, compromise immune function and directly damage respiratory tissue, predisposing to bacterial pneumonia. Coccidia commonly affect the same young kids at high risk for pneumonia, and the combined stress of both infections worsens outcomes. Caseous lymphadenitis with internal abscesses can produce respiratory signs and may be confused with or occur alongside pneumonia. Nutritional deficiencies, particularly of selenium and vitamin E, impair immune function and increase respiratory disease susceptibility. Concurrent illness from any cause adds stress that promotes pneumonia development.

Conditions with similar symptoms that must be differentiated from infectious pneumonia include lungworm infection, which causes chronic coughing and respiratory signs without the acute fever and rapid deterioration typical of bacterial pneumonia. Contagious caprine pleuropneumonia is a severe, reportable respiratory disease with characteristic post-mortem lesions that must be considered in goats with respiratory disease. Heart failure from various causes produces respiratory distress and exercise intolerance but typically without fever. Anaphylactic reactions and acute respiratory distress from toxic exposures cause sudden onset breathing difficulty. Choke or esophageal obstruction may be confused with respiratory distress. Heat stroke produces elevated body temperature and respiratory effort without true infection.

Complications and sequelae of pneumonia can affect long-term health and productivity. Lung abscesses may develop when bacterial infection becomes walled off, causing chronic illness with periodic fever and persistent respiratory abnormalities. Pleuritis, or inflammation of the lung lining, can produce adhesions that restrict lung expansion. Pericarditis from extension of infection to the heart sac is a serious complication with poor prognosis. Chronic pulmonary fibrosis and scarring reduce lung capacity permanently. Animals with extensive lung damage may survive but perform poorly as production animals due to limited respiratory reserve. Secondary infections may develop in other body systems in immunocompromised animals. Full recovery without complications requires prompt, appropriate treatment.