African Swine Fever (ASF)

African Swine Fever (ASF) is a devastating and highly contagious viral disease that affects domestic pigs and wild boar, caused by the African Swine Fever Virus (ASFV), a large double-stranded DNA virus belonging to the family Asfarviridae. This disease represents one of the most serious threats to global swine production, characterized by high fever, hemorrhages in the skin and internal organs, and mortality rates approaching 100% in naive pig populations. Unlike many other viral diseases, ASF is not zoonotic and poses no direct threat to human health, but its economic and agricultural consequences are catastrophic for affected regions and the global pork industry.

African Swine Fever affects all breeds of domestic pigs (Sus scrofa domesticus) and their wild relatives, including European wild boar and various African wild suid species such as warthogs, bushpigs, and giant forest hogs. While African wild suids have co-evolved with the virus and typically serve as asymptomatic reservoir hosts, domestic pigs and European wild boar experience severe clinical disease with extremely high mortality. The disease affects pigs of all ages, from nursing piglets to mature breeding stock, with no age group showing resistance to infection. Geographic distribution has expanded dramatically in recent years, with ASF now present across Africa, Europe, Asia, and Oceania, representing a truly global threat to swine populations.

The economic impact of African Swine Fever on affected countries and the global pork industry is staggering and multifaceted. Direct losses include mortality of infected animals, costs associated with mandatory culling and disposal of affected and contact herds, and implementation of movement restrictions and quarantine zones. Indirect economic consequences encompass trade embargoes imposed on affected countries, reduced consumer confidence, market disruptions, and long-term impacts on pig farming infrastructure. Countries experiencing ASF outbreaks often face years of recovery before regaining disease-free status and restoring international trade relationships. The 2018-2019 ASF epidemic in China alone resulted in the loss of approximately 40% of the national pig herd, fundamentally disrupting global pork markets and protein supply chains.

There is currently no approved vaccine or effective treatment for African Swine Fever, making prevention through strict biosecurity the only viable approach to protecting swine populations. Early detection is absolutely critical for containing outbreaks and minimizing spread, as the virus can survive for extended periods in the environment, in pork products, and on contaminated fomites. Producers, veterinarians, and animal health officials must maintain constant vigilance and implement comprehensive surveillance programs. Any suspicion of ASF requires immediate reporting to veterinary authorities, as this is a notifiable disease in virtually all countries with regulatory oversight of livestock health. The importance of rapid response and transparent communication during suspected outbreaks cannot be overstated in limiting the devastating consequences of this disease.

African Swine Fever is caused by the African Swine Fever Virus (ASFV), the sole member of the genus Asfivirus within the family Asfarviridae. This large, complex, icosahedral virus contains double-stranded DNA and is notable for being the only known DNA arbovirus (arthropod-borne virus). The ASFV genome encodes over 150 proteins, many of which help the virus evade host immune responses, contributing to the difficulty in developing effective vaccines. Multiple genotypes of ASFV exist, with at least 24 genotypes identified based on the p72 capsid protein gene, though all cause similar clinical disease in susceptible pigs. The virus demonstrates remarkable stability in the environment and can remain infectious in blood, feces, tissues, and pork products for extended periods.

While there is no genetic predisposition to ASF susceptibility among domestic pig breeds, certain wild African suid species have developed tolerance to infection through millennia of co-evolution with the virus. Warthogs (Phacochoerus africanus), bushpigs (Potamochoerus larvatus), and giant forest hogs (Hylochoerus meinertzhageni) can harbor the virus asymptomatically and serve as natural reservoir hosts. European wild boar populations are fully susceptible to disease and have become a critical factor in ASF maintenance and spread in affected European and Asian countries. The absence of genetic resistance in domestic pigs of any breed means that biosecurity and prevention remain the only protective strategies available to producers.

Environmental and management factors play crucial roles in ASF transmission and outbreak dynamics. The virus spreads through direct contact between infected and susceptible pigs, as well as through indirect routes including contaminated feed, water, equipment, vehicles, and clothing. Feeding of swill or food waste containing infected pork products has historically been a major route of long-distance viral transmission and remains illegal in most countries specifically because of ASF risk. Soft ticks of the genus Ornithodoros serve as biological vectors in Africa and parts of Europe, maintaining the virus in sylvatic cycles involving wild suids and potentially reintroducing infection to domestic pig populations.

Risk factors for ASF introduction and spread include proximity to affected areas, movement of live pigs and pork products, inadequate biosecurity practices, presence of wild boar populations, and human activities that can mechanically transport the virus. Small-scale or backyard pig operations often face heightened risk due to limited biosecurity infrastructure, mixed feeding practices, and informal pig trading networks. Large commercial operations may experience rapid within-herd spread once the virus is introduced due to high animal densities and shared ventilation systems. International travel and trade present ongoing risks for viral introduction to ASF-free countries through contaminated meat products or fomites.

The pathophysiology of ASF involves viral replication primarily in cells of the monocyte-macrophage lineage, leading to profound disruption of immune function and vascular integrity. Following infection, the virus disseminates throughout the body via the lymphatic and circulatory systems, targeting lymph nodes, spleen, liver, and other tissues rich in macrophages. Infected cells undergo apoptosis or necrosis, releasing inflammatory mediators and viral particles that perpetuate tissue damage. Vascular endothelial damage results in the characteristic hemorrhagic lesions, while lymphoid depletion compromises immune responses. The virus effectively subverts and destroys the very immune cells that should combat it, explaining the lack of protective immunity in survivors and the extreme virulence observed in naive populations.

Early warning signs of African Swine Fever may be subtle and easily overlooked, particularly in the initial stages of an outbreak when the disease is not yet suspected. The incubation period typically ranges from 4 to 19 days depending on the viral strain, dose, and route of exposure. Initial signs often include reduced appetite, lethargy, and a reluctance to move, with affected pigs appearing dull and spending more time lying down than their herdmates. Producers may notice decreased water consumption and reduced interest in feeding, which can precede other clinical signs by 24 to 48 hours. In breeding herds, subtle declines in reproductive performance or sudden abortion storms may be early indicators of disease introduction.

The classic presentation of acute ASF in domestic pigs includes high fever ranging from 40.5°C to 42°C (105°F to 108°F), severe depression, and progressive weakness. Pigs typically huddle together or seek isolation from the group, showing marked reduction in activity and responsiveness. Respiratory signs including increased respiratory rate, labored breathing, and occasional coughing may be observed. Gastrointestinal disturbances manifest as vomiting, diarrhea (which may be bloody in later stages), and complete anorexia. Affected animals show progressive deterioration over several days, with death typically occurring within 7 to 10 days of initial clinical signs in acute cases.

Behavioral changes in ASF-affected pigs are pronounced and should alert producers to investigate further. Sick pigs typically separate themselves from the group, seeking dark corners or isolated areas of the pen. Normal social interactions cease, with affected animals showing no interest in exploring, rooting, or engaging with enrichment materials. Pregnant sows may abort, and boars may show complete loss of libido. Pigs that normally respond enthusiastically to feeding become completely disinterested in food and may not rise when feed is presented. These behavioral changes, particularly when occurring in multiple animals simultaneously, warrant immediate veterinary investigation.

Physical signs of ASF are often dramatic and characteristic, though similar lesions can occur with other hemorrhagic diseases. Skin lesions include reddening or cyanosis (bluish discoloration) of the ears, tail, lower limbs, and ventral abdomen. Hemorrhagic lesions may appear as petechiae (pinpoint hemorrhages) or larger ecchymoses on the skin, particularly notable in white-skinned breeds. Conjunctivitis with ocular discharge and swelling of the eyelids is common. Bloody discharge from the nose or rectum may occur in advanced cases. Swelling of lymph nodes, particularly those of the head and neck region, may be palpable in some animals.

Symptom progression in acute ASF follows a predictable pattern leading to death in the vast majority of affected domestic pigs. Early fever and depression give way to increasing hemorrhagic manifestations over 3 to 5 days. Neurological signs including incoordination, trembling, and posterior paresis may develop as the disease progresses. Terminally ill pigs become recumbent, unable to rise, and may exhibit paddling movements or convulsions before death. Some animals die suddenly without obvious preceding signs, particularly with highly virulent strains. Subacute and chronic forms of ASF, seen with less virulent strains, present with prolonged illness, intermittent fever, respiratory signs, and variable survival times, though survivors remain potential virus shedders.

Emergency symptoms requiring immediate intervention and notification of veterinary authorities include the sudden death of multiple pigs, high fever in several animals simultaneously, widespread hemorrhagic skin lesions, bloody diarrhea, and abortion storms in breeding herds. Any combination of high mortality with hemorrhagic signs in a pig operation warrants immediate action. Producers should immediately isolate affected animals, cease all pig and equipment movements, and contact their veterinarian and animal health authorities. Given that ASF is a reportable disease with no treatment available, rapid identification and response are essential for containment efforts. Delay in recognition and reporting can result in catastrophic spread within herds and to neighboring operations.

Clinical examination for suspected African Swine Fever begins with careful observation and physical assessment while maintaining strict biosecurity precautions to prevent potential spread. Veterinarians assess body temperature, looking for the characteristic high fever, and examine skin for hemorrhagic lesions, cyanosis, and edema. Mucous membranes of the eyes and mouth are inspected for petechiation and pallor. Palpation of superficial lymph nodes may reveal enlargement, particularly of the gastrohepatic and renal nodes. Clinical history including mortality patterns, recent pig introductions, feed sources, and potential exposure routes is critically important. While clinical signs can be suggestive, they are not pathognomonic for ASF, and laboratory confirmation is absolutely essential for definitive diagnosis.

Laboratory diagnostic testing for ASF relies on detection of the virus, viral DNA, or antibodies in samples from affected or exposed animals. Polymerase chain reaction (PCR) testing, specifically real-time quantitative PCR targeting the p72 gene, is the gold standard for detecting active infection and can identify viral DNA in blood, tissues, and environmental samples. Virus isolation in cell culture provides definitive diagnosis but requires specialized biosafety facilities and takes longer than molecular methods. Antigen detection tests including direct immunofluorescence and enzyme-linked immunosorbent assay (ELISA) can be performed on tissue samples. For antibody detection in recovered or chronically infected animals, ELISA and immunoblotting techniques are employed. All diagnostic testing for ASF should be performed by accredited laboratories with appropriate containment facilities.

Differential diagnosis for ASF is extensive due to overlapping clinical presentations with other swine diseases causing fever, hemorrhage, or high mortality. Classical swine fever (CSF) presents with nearly identical clinical and pathological features and must always be considered concurrently. Other differential diagnoses include porcine reproductive and respiratory syndrome (PRRS), erysipelas, salmonellosis, Aujeszky's disease, porcine dermatitis and nephropathy syndrome (PDNS), and acute poisoning. Necropsy findings can help differentiate these conditions but are not definitive without laboratory testing. Given the similarities between ASF and CSF, samples should routinely be tested for both viruses when either is suspected.

Herd-level diagnostics and surveillance are essential components of ASF detection, control, and eradication programs. Active surveillance involves systematic sampling and testing of pig populations in at-risk areas, at slaughter, and in wild boar populations. Passive surveillance relies on producer and veterinarian reporting of suspicious clinical cases or mortality events. Seroprevalence surveys help identify regions with ongoing circulation or previous exposure. Wild boar surveillance programs using hunter-harvested animals and carcass testing are critical in countries where sylvatic cycles are established. Epidemiological investigations following confirmed cases include trace-back and trace-forward investigations to identify the source of infection and potential spread to other premises. Diagnostic capacity building and rapid response planning are essential elements of national ASF preparedness programs in disease-free countries.

There is no specific treatment or cure for African Swine Fever, making this disease uniquely devastating among major swine pathogens. Unlike bacterial infections that respond to antibiotics or other viral diseases for which supportive care may allow recovery, ASFV infections in domestic pigs are almost universally fatal, and no therapeutic interventions have proven effective in altering disease outcome. Experimental antiviral compounds and immunomodulatory therapies have been investigated in research settings but have not demonstrated sufficient efficacy to warrant clinical use. The complexity of the ASFV genome and its multiple mechanisms for evading host immunity have frustrated drug development efforts. For these reasons, treatment of individual ASF-infected animals is neither practiced nor recommended.

Emergency response to confirmed ASF cases focuses on immediate containment measures rather than treatment of affected animals. Upon confirmation of ASF, regulatory authorities typically implement immediate movement restrictions on the affected premises and surrounding area. Quarantine zones and surveillance zones are established according to national and international guidelines, with restrictions on pig movements, pork products, and potentially contaminated materials. Veterinary officials work with affected producers to conduct epidemiological investigations, identify potential sources and spread, and implement control measures. International notification through the World Organisation for Animal Health (WOAH) is required, triggering potential trade implications.

Humane depopulation of affected and exposed pig populations is the standard approach for ASF control and eradication in commercial settings. All pigs on infected premises are typically euthanized using approved humane methods, with carcasses disposed of through rendering, burial, or incineration depending on local regulations and capacity. Depopulation of contact herds and pigs within defined control zones may also be required. These measures, while economically devastating for affected producers, are necessary to eliminate sources of viral shedding and prevent further spread. Financial compensation programs in many countries provide partial reimbursement to producers for mandated depopulation, though compensation rarely covers full production losses.

Supportive care for suspect cases prior to diagnosis confirmation should focus on isolation rather than treatment. Any pigs showing signs consistent with ASF should be immediately separated from the main herd and movement of potentially contaminated people, equipment, and materials should be restricted. Maintaining sick animals separately reduces the viral load exposure to the rest of the herd during the diagnostic period. However, extensive supportive care efforts are not recommended given the lack of treatment options and the importance of conserving resources for diagnostic testing and biosecurity measures. Humane euthanasia of severely affected animals may be appropriate pending diagnosis confirmation.

Herd treatment protocols for ASF outbreaks are fundamentally different from other disease situations because they center on depopulation, thorough cleaning and disinfection, and eventual restocking rather than treating and maintaining existing animals. Following depopulation, extensive cleaning and disinfection of facilities is required, with the virus being susceptible to various disinfectants including sodium hypochlorite, glutaraldehyde, and various oxidizing agents. Extended downtime of several months is typically required before restocking to ensure complete environmental decontamination. Sentinel animals may be introduced to confirm successful decontamination before full restocking. Biosecurity upgrades are implemented before resuming pig production.

Treatment decisions in ASF situations are not about individual animal therapy but rather about herd-level and regional disease control strategies. Economic considerations, while devastating for individual producers, are secondary to the broader goal of disease containment and eradication to protect the national and international swine industry. The decision framework involves rapid diagnosis, immediate containment, mandatory reporting and compliance with regulatory requirements, humane depopulation, and structured recovery planning. Producers facing ASF should work closely with veterinary officials and industry organizations to navigate the complex regulatory requirements and access available support programs. The absence of treatment options underscores the critical importance of prevention through rigorous biosecurity.

Recovery from African Swine Fever at the individual animal level is exceedingly rare with highly virulent viral strains, and survivors of less virulent strains pose ongoing biosecurity risks as potential long-term virus carriers. Pigs that survive acute ASF infection may continue shedding virus for weeks to months, presenting a persistent threat of transmission to susceptible animals. Chronic ASF survivors often experience long-term health problems including respiratory issues, joint problems, and reduced growth performance. For these reasons, recovery of individual animals is not a management goal, and surviving pigs from infected herds are typically included in depopulation efforts rather than being retained.

Recovery at the farm and regional level following an ASF outbreak is a lengthy process measured in months to years. Following depopulation, premises must undergo thorough cleaning and disinfection with documented protocols meeting regulatory standards. The ASFV virus is remarkably stable in organic matter and environmental contamination, requiring meticulous attention to removing all biological material before disinfection can be effective. Specific attention must be paid to porous surfaces, drainage systems, and areas where organic matter accumulates. Environmental sampling may be conducted to verify decontamination success before restocking is permitted.

Prognosis for herd recovery depends heavily on the timeliness of detection, effectiveness of containment measures, and availability of resources for proper decontamination. Premises with good infrastructure that allows thorough cleaning have better prospects for successful restocking than older facilities with deteriorated surfaces and complex layouts. Financial recovery depends on compensation programs, insurance coverage, and the producer's ability to remain economically viable during the extended downtime period. Market conditions at the time of restocking and ongoing trade implications also affect the recovery trajectory for individual operations and the broader industry.

Return to production following an ASF event requires regulatory approval, demonstration of successful decontamination, and implementation of enhanced biosecurity measures. Restocking typically begins with the introduction of a small number of sentinel animals that are monitored intensively for any signs of disease before full repopulation proceeds. Ongoing surveillance and testing requirements may apply to restocked premises for extended periods. Industry-wide recovery in affected countries involves sustained surveillance, continued trade negotiations to restore export markets, and long-term maintenance of biosecurity improvements. Complete recovery, including restoration of disease-free status and normalization of international trade, can take years even with successful domestic eradication efforts.

Currently, there is no commercially available vaccine against African Swine Fever that provides reliable protection without significant limitations. Decades of research into ASF vaccines have been hampered by the complexity of the virus and its sophisticated mechanisms for evading host immunity. Inactivated vaccines have proven ineffective, while live attenuated vaccines have shown promise but carry risks of reversion to virulence, establishment of chronic infections, and recombination with field strains. Several candidate vaccines are in advanced development stages, with some receiving conditional approvals in severely affected countries, but widespread deployment of a safe and effective vaccine remains a future goal rather than current reality. In the absence of vaccine protection, strict biosecurity is the only means of preventing ASF.

Biosecurity measures for ASF prevention must address all potential routes of viral introduction to pig populations. Perimeter security includes fencing to prevent contact with wild boar, controlled access points for personnel and vehicles, and measures to exclude unauthorized entry. Incoming animals should originate only from known ASF-free sources with appropriate health documentation and should undergo quarantine periods before introduction to the main herd. Vehicle and equipment biosecurity requires designated parking areas away from pig housing, cleaning and disinfection protocols for essential vehicles entering the premises, and ideally farm-specific equipment that never leaves the property.

Nutritional prevention of ASF centers on feed biosecurity and the absolute prohibition of swill feeding. The practice of feeding food waste containing pork products to pigs has been responsible for numerous long-distance introductions of ASF to new regions and remains a critical risk factor. Commercial feed should be sourced from suppliers with appropriate biosecurity protocols, and feed storage should protect against contamination by wild animals or other vectors. Some countries have implemented requirements for feed treatment, such as extended storage times or heat treatment, to reduce the risk of viral survival in potentially contaminated ingredients.

Management practices for ASF prevention encompass all aspects of daily operations on pig farms. Personnel biosecurity includes shower-in and shower-out protocols, farm-specific clothing and footwear, and restrictions on contact with other pig populations or hunting activities. Visitor access should be strictly limited and controlled, with documentation of all personnel entering the premises. Deadstock removal and manure management should be conducted in ways that minimize environmental contamination and prevent access by wild boar or other potential mechanical vectors. Regular training and awareness programs help ensure that all farm personnel understand and consistently implement biosecurity protocols.

Quarantine and testing protocols are essential components of ASF prevention at both farm and national levels. New animal introductions should undergo defined quarantine periods with health monitoring before joining the main herd. Active health surveillance programs including regular testing allow early detection of any disease incursion. National-level surveillance of domestic pigs, wild boar, and at-risk populations such as feral pigs provides early warning of ASF presence. Border controls and import regulations restrict the movement of live pigs, pork products, and potentially contaminated materials from affected regions. International cooperation and information sharing support global efforts to contain ASF spread and protect unaffected regions.

Daily management and monitoring for ASF prevention requires constant vigilance and systematic observation of pig health status. Producers should conduct daily health checks of all animals, looking for any signs of fever, reduced appetite, respiratory distress, or behavioral changes that could indicate early disease. Recording and tracking mortality rates allows rapid detection of unusual patterns that warrant investigation. Feed and water consumption should be monitored at the group level, as declining intake often precedes clinical signs. Any unexplained illness or death should trigger immediate isolation of affected animals and notification of the herd veterinarian. Maintaining detailed records supports both daily management decisions and epidemiological investigations if needed.

Housing and environmental management play critical roles in ASF prevention by reducing exposure risks and supporting overall pig health. Facilities should be designed or modified to prevent contact between domestic pigs and wild boar populations, including appropriate fencing, barriers, and elimination of attractants around pig housing. All-in-all-out production systems reduce disease transmission risks by limiting the mixing of animals from different sources and ages. Proper ventilation, temperature control, and stocking densities support immune function and reduce stress that could increase disease susceptibility. Environmental cleaning and disinfection between production groups removes potential pathogen accumulation, including any undetected ASFV contamination.

Herd health programs in the context of ASF prevention integrate disease surveillance with overall health management objectives. Veterinary oversight should include regular herd health visits with clinical examination of animals and review of production records and health indicators. Diagnostic testing protocols may include periodic PCR testing of dead animals, particularly in regions with known ASF risk, to enable early detection of any virus introduction. Vaccination programs for other diseases help maintain overall herd immunity and reduce clinical signs that could mask or be confused with ASF. Parasite control, nutritional management, and reproductive health programs contribute to a robust herd less susceptible to disease challenges.

Record keeping and monitoring systems are essential tools for both daily management and disease response. Production records should track mortality, treatments, movement of animals, and any unusual health events. Biosecurity logs documenting personnel entry, visitor access, vehicle movements, and incoming materials provide critical information for epidemiological investigations if disease occurs. Digital record systems can facilitate rapid analysis of health trends and automatic alerts for unusual patterns. These records also demonstrate due diligence and compliance with industry standards and regulatory requirements, which may be important for trade access and compensation eligibility.

Economic considerations for ASF prevention must balance the costs of biosecurity investments against the potentially catastrophic losses from disease occurrence. Initial capital investment in facility upgrades, fencing, and biosecurity infrastructure may be substantial but should be weighed against the risk of total herd loss and extended business interruption. Ongoing operational costs include personnel time for biosecurity procedures, enhanced testing programs, and potentially higher input costs for biosecure feed and animal sources. Insurance options for ASF-related losses are limited in many markets, increasing the importance of prevention. Industry cooperation through regional biosecurity initiatives and sharing of surveillance information provides collective benefits that individual farms cannot achieve alone.

All breeds of domestic pigs (Sus scrofa domesticus) are fully susceptible to African Swine Fever without any known genetic resistance, making breed-based risk stratification ineffective for this disease. Commercial breeds commonly used in intensive pork production, including Large White (Yorkshire), Landrace, Duroc, Pietrain, and Hampshire, all experience severe disease with high mortality when infected with virulent ASFV strains. Heritage and traditional breeds have no advantage in ASF resistance. Miniature pigs, potbellied pigs, and other companion pig breeds are equally susceptible. The universal susceptibility of domestic pig genetics means that prevention through biosecurity rather than breed selection is the only viable approach.

Production type considerations affect ASF risk primarily through management and biosecurity factors rather than inherent differences in susceptibility. Large commercial operations may face heightened consequences from ASF introduction due to rapid within-herd spread in high-density housing, though they typically have more robust biosecurity infrastructure. Small-scale and backyard pig production systems often operate with minimal biosecurity and mixed feeding practices, increasing exposure risks despite smaller herd sizes. Outdoor or free-range pig production faces additional challenges in preventing contact with wild boar populations. Breeding herds represent particularly high-value animals whose loss can have multi-generational production impacts, emphasizing the importance of enhanced biosecurity for nucleus and multiplier operations.

Genetic selection for ASF resistance in domestic pigs is not currently feasible due to the absence of identified resistance traits. Research has explored potential genetic factors that might confer partial protection, including studies of warthog genetics that enable tolerance of infection, but practical applications for domestic pig breeding remain elusive. Some experimental work has investigated genetic modification approaches to introduce resistance, but these remain in early research stages with significant technical, regulatory, and market acceptance challenges. For the foreseeable future, genetic selection programs in pigs should focus on production traits, disease resistance for other pathogens, and animal welfare characteristics, while ASF prevention relies entirely on biosecurity and, eventually, vaccination when effective products become available.

Classical Swine Fever (CSF), also known as hog cholera, is the primary differential diagnosis for African Swine Fever and shares remarkably similar clinical and pathological presentations. Both diseases cause high fever, hemorrhagic lesions, depression, huddling, and high mortality in affected pig populations. CSF is caused by a pestivirus unrelated to ASFV, and the two diseases occur independently, but their clinical similarity means that both must always be considered when hemorrhagic disease is observed in pigs. Laboratory testing is essential to differentiate ASF from CSF, and samples should routinely be submitted for both diagnostic panels when either disease is suspected. Like ASF, CSF is a notifiable disease with significant trade implications.

Other conditions presenting with similar hemorrhagic or high-mortality syndromes in pigs include Porcine Reproductive and Respiratory Syndrome (PRRS), erysipelas, acute salmonellosis, porcine dermatitis and nephropathy syndrome (PDNS), and Glässer's disease. PRRS causes reproductive failure and respiratory disease but typically with lower mortality than ASF in grow-finish pigs. Acute erysipelas and salmonellosis can cause fever, skin lesions, and sudden death but usually affect scattered individuals rather than causing herd-wide epidemics. Septicemic conditions from various bacterial pathogens may cause hemorrhagic lesions requiring differentiation from ASF. Toxic causes of sudden death, including plant poisonings and chemical exposure, should also be considered in differential diagnosis.

Complications and sequelae of ASF in the rare surviving animals include chronic wasting, persistent respiratory disease, joint problems, and skin lesions. More importantly, survivors may remain persistently infected and shed virus intermittently for months, posing an ongoing transmission risk to susceptible pigs. Chronic ASF cases may show recurring fever episodes, poor growth, and reduced reproductive performance. Secondary bacterial infections often complicate the clinical picture in subacute and chronic cases. The long-term carrier state and associated complications underscore why affected herds are depopulated rather than attempting to manage around infected animals. Regional consequences of ASF outbreaks include disruption of normal pig production, trade embargoes, and potential establishment of endemic infection cycles involving wild boar populations that complicate long-term eradication efforts.