Pseudorabies

Pseudorabies, also known as Aujeszky's disease or mad itch, is a rare but invariably fatal viral disease that can affect dogs exposed to infected swine or contaminated pork products. The disease is caused by Suid herpesvirus 1, a member of the Herpesviridae family that primarily infects pigs but can spread to many other mammalian species including dogs, cats, cattle, sheep, and various wildlife. Despite its name, pseudorabies is not related to rabies virus, though some clinical signs may appear similar. The name derives from the intensely pruritic nature of the disease in non-pig hosts, which causes affected animals to scratch and bite at themselves with such ferocity that it resembles the aggressive behavior sometimes seen in rabies. For dogs, pseudorabies represents a devastating diagnosis with no known cure and progression to death typically occurring within 24 to 48 hours of symptom onset.

The virus causes disease by attacking the nervous system, spreading along peripheral nerves to the brain where it causes fatal encephalitis. In dogs, infection typically occurs through direct contact with infected pigs, consumption of infected raw pork products, or contact with nasal secretions from infected swine. Once the virus enters the body through mucous membranes or breaks in the skin, it replicates locally before traveling along nerve fibers to the central nervous system. The intense itching that characterizes the disease in dogs results from viral replication in sensory nerve ganglia, which sends aberrant signals interpreted by the brain as extreme pruritis. This neurotropic virus causes progressive and irreversible damage to the nervous system, leading to a rapid and fatal disease course.

The impact of pseudorabies on affected dogs is catastrophic, with the disease being uniformly fatal once clinical signs develop. The rapid progression from initial subtle signs to severe neurological symptoms and death, often within 24 to 48 hours, leaves little time for intervention. The intense self-mutilation that occurs due to uncontrollable itching causes significant suffering and is extremely distressing for owners to witness. Dogs may scratch and chew at their skin so severely that they cause deep wounds, particularly around the head and face. The disease affects dogs of all ages and breeds equally, with risk determined entirely by exposure opportunity rather than any inherent susceptibility factors.

While pseudorabies is treatable only in the sense of providing palliative care, the disease is preventable through avoiding exposure to infected swine and raw pork products. There is no vaccine available for dogs, unlike the situation in pigs where vaccination programs have successfully eradicated the disease from domestic swine populations in many countries including the United States. However, feral swine populations continue to harbor the virus and represent an ongoing risk for dogs that hunt, roam in areas with feral pigs, or consume feral pig carcasses. Understanding the risk factors and preventing exposure is the only effective strategy against this devastating disease. Veterinary care focuses on confirming diagnosis, providing comfort care, and making humane end-of-life decisions given the invariably fatal prognosis.

The primary cause of pseudorabies in dogs is infection with Suid herpesvirus 1, a highly neurotropic virus that naturally infects pigs. The virus is shed by infected pigs in nasal secretions, saliva, and other bodily fluids, creating opportunities for transmission to other species that contact these materials. Pigs, both domestic and feral, serve as the natural reservoir host for the virus and can remain latently infected for life, periodically shedding virus without showing clinical signs. For dogs, the most common route of infection is oral, through consumption of infected raw or undercooked pork products or through eating carcasses of infected feral swine. Direct contact with live infected pigs, particularly contact with nasal secretions, can also transmit the virus. Once a dog is infected, the virus travels along peripheral nerves to the central nervous system where it causes fatal encephalitis.

Pseudorabies has no genetic or hereditary component in dogs. The disease is purely infectious, resulting from exposure to the virus rather than any inherited susceptibility. All dogs are equally vulnerable to infection if exposed to sufficient quantities of the virus, regardless of breed, size, or genetic background. The only factors that influence whether a dog becomes infected are related to exposure opportunity rather than any inherent resistance or susceptibility. Understanding this helps clarify that prevention focuses entirely on avoiding exposure rather than identifying or breeding for resistance.

Environmental and lifestyle factors play the crucial role in determining which dogs are at risk for pseudorabies infection. Dogs that hunt feral swine face the highest risk due to direct contact with infected animals and potential consumption of infected tissues. Dogs in rural areas where feral pig populations are established have increased exposure opportunity compared to urban pets. Dogs fed raw pork diets, including raw food formulations containing pork or dogs given pork scraps, face risk if the pork originates from infected animals. Contact with pig farms, particularly those without adequate biosecurity or those with endemic infection, creates exposure potential. The virus can survive in the environment for limited periods, potentially creating indirect exposure opportunities through contaminated materials, though direct contact or consumption remains the primary transmission route.

Specific risk factors that increase a dog's chances of contracting pseudorabies include hunting activities involving feral swine, residence in or travel to areas with endemic feral pig populations, access to pork processing areas, and consumption of raw or inadequately cooked pork products. Feral pig populations in the southern United States, particularly Texas and surrounding states, harbor significant levels of pseudorabies virus. Dogs that accompany hunters on feral hog hunts face repeated exposure opportunities. Farm dogs on properties adjacent to feral pig habitat may encounter infected carcasses or interact with infected animals. The increasing popularity of raw feeding diets creates potential risk if pork products from infected sources are included.

The mechanism of disease development in pseudorabies involves the virus's neurotropic nature and its ability to travel along nerve pathways. Following entry through oral mucosa, nasal passages, or skin wounds, the virus replicates at the site of entry and then invades peripheral nerve endings. The virus travels centripetally along nerve axons toward the spinal cord and brain, a process that takes several days and accounts for the incubation period. During this neural transit, the virus replicates in sensory nerve ganglia, causing the intense pruritis characteristic of the disease by disrupting normal sensory nerve function. Upon reaching the central nervous system, the virus causes progressive encephalitis with destruction of brain tissue. This neurological damage is irreversible and rapidly fatal, with the entire process from initial infection to death typically occurring within two to ten days.

The early warning signs of pseudorabies in dogs are often subtle and nonspecific, making early recognition challenging. Initial symptoms typically appear two to nine days after exposure, with most dogs showing signs within three to six days. Early changes may include mild lethargy, decreased appetite, and subtle behavioral alterations that owners might attribute to minor illness or simply not feeling well. Some dogs develop a low-grade fever in the early stages. Restlessness or anxiety may be noted, with dogs appearing uncomfortable or unable to settle. These nonspecific prodromal signs typically last only hours to a day before more characteristic symptoms develop, leaving little time for intervention even if the disease is suspected.

The hallmark symptom of pseudorabies in dogs is the intensely pruritic sensation known as mad itch, which represents the most characteristic and distressing aspect of the disease. Affected dogs experience what appears to be unbearable itching, typically focused on the head and face but potentially affecting any body region. The pruritis is so severe that dogs will scratch, rub, and bite at themselves frantically and continuously. This self-directed behavior can become violent, with dogs causing severe self-inflicted wounds including deep lacerations, exposed tissue, and significant blood loss. The itching provides no relief when scratched and dogs may rub their faces on rough surfaces, roll on the ground, or contort their bodies trying to reach affected areas. This symptom is essentially pathognomonic for pseudorabies when seen in dogs with appropriate exposure history.

Behavioral changes associated with pseudorabies reflect the progressive neurological damage caused by the virus. Dogs may become increasingly anxious and agitated as the disease progresses. Some dogs become uncharacteristically aggressive, while others may seem dull and withdrawn. Hypersalivation or excessive drooling commonly develops, leading to the historical confusion with rabies. Vocalization changes may occur, with dogs whining, howling, or making unusual sounds. Disorientation and confusion become apparent as the brain becomes more severely affected. Some dogs appear to hallucinate or respond to stimuli that are not present. The behavioral changes progress rapidly and deteriorate over hours rather than days.

Physical signs of pseudorabies beyond the self-mutilation become increasingly apparent as the disease advances. Excessive salivation creates strings of drool and wet fur around the mouth. Facial swelling may develop from inflammation or self-trauma. Difficulty swallowing occurs as the virus affects nerves controlling the throat muscles. Dilated pupils that respond poorly to light reflect brainstem involvement. Muscle tremors, twitching, and involuntary movements develop as motor nerves become affected. The gait may become uncoordinated and wobbly as cerebellar function deteriorates. Temperature regulation fails, potentially causing either fever or hypothermia in late stages.

Symptom progression in pseudorabies is devastatingly rapid once clinical signs appear. From the onset of noticeable symptoms to death, most dogs survive only 24 to 48 hours. The pruritis typically appears first and intensifies relentlessly. Neurological signs progress from subtle behavioral changes to obvious impairment within hours. Seizures may develop as the encephalitis worsens. Paralysis, often beginning in the hindquarters and progressing forward, occurs in many cases. Loss of consciousness precedes death, which typically results from respiratory failure as the brainstem becomes overwhelmed. The entire clinical course, from first symptoms to death, usually spans less than two days, with some dogs progressing even more rapidly.

Emergency symptoms requiring immediate veterinary attention include any combination of intense scratching or self-mutilation, sudden behavioral changes, hypersalivation, and difficulty swallowing in a dog with potential swine exposure. Any dog that has recently hunted feral pigs, consumed raw pork, or had contact with swine that develops neurological signs should be evaluated immediately. While treatment cannot save affected dogs, prompt veterinary attention allows for appropriate diagnosis, differentiation from rabies, humane euthanasia to prevent suffering, and proper public health notification. Dogs showing these symptoms should be handled carefully to avoid bites, and owners should seek immediate veterinary care while reporting the dog's exposure history.

The initial veterinary examination for suspected pseudorabies focuses heavily on exposure history and characteristic clinical signs. The veterinarian will ask detailed questions about any contact with pigs, consumption of raw pork products, hunting activities involving feral swine, and timeline of symptom development. Physical examination reveals the characteristic signs of intense pruritis with self-inflicted wounds, excessive salivation, and progressive neurological deficits. The presence of violent self-trauma, particularly when focused on the head and face in combination with appropriate exposure history, is highly suggestive of pseudorabies. Body temperature may be elevated or subnormal. Neurological examination documents deficits in cranial nerve function, coordination, and mental status.

Diagnostic testing for pseudorabies in dogs is complicated by the rapid disease course and the importance of ruling out rabies. Because of the similarity to rabies and the significant public health implications, suspected cases must be handled carefully. Blood tests are generally not diagnostic for pseudorabies. Cerebrospinal fluid analysis may show nonspecific inflammatory changes but is not definitive. The definitive diagnosis is typically made post-mortem through detection of the virus in brain tissue using PCR, immunohistochemistry, or virus isolation. In live animals, PCR testing of oropharyngeal swabs or blood may detect viral DNA but is not always reliable. The primary diagnostic approach in practice is strong clinical suspicion based on characteristic signs and confirmed exposure history, with post-mortem confirmation.

Differential diagnosis is crucial because pseudorabies must be distinguished from rabies due to the public health implications. Rabies causes similar neurological signs including behavioral changes, hypersalivation, and aggression, but typically lacks the intense pruritis characteristic of pseudorabies. The exposure history differs significantly, with rabies acquired through bites from infected animals rather than contact with swine. Other conditions in the differential include epilepsy, which causes seizures but not the progressive deterioration seen in pseudorabies. Toxicosis from various agents can cause neurological signs but typically has a different presentation. Encephalitis from other causes may appear similar but usually has a more gradual onset. Severe allergic reactions can cause intense itching but lack the neurological component. Given the rabies concern, animals that die from suspected pseudorabies should be tested for rabies as part of the diagnostic workup.

Diagnosis confirmation typically occurs post-mortem through examination of brain tissue. Histopathology reveals characteristic viral inclusion bodies and inflammatory changes consistent with viral encephalitis. Immunohistochemical staining identifies the specific presence of pseudorabies viral antigens in neural tissue. PCR testing of brain tissue provides highly sensitive and specific identification of viral genetic material. Virus isolation from brain tissue can be performed but takes longer than molecular methods. In cases where pseudorabies is confirmed, public health authorities and animal health officials should be notified, as the disease has implications for surveillance of feral swine populations. The diagnosis, while invariably fatal for the affected dog, provides important information for preventing future cases by identifying exposure sources.

Emergency and immediate management of suspected pseudorabies focuses on patient safety, caregiver safety, and appropriate diagnostic workup. Because rabies cannot be immediately ruled out, the dog should be handled with appropriate caution to prevent bite exposure to humans and other animals. The dog should be isolated and confined to prevent self-injury from continued violent scratching while awaiting veterinary evaluation. Sedation may be necessary to prevent further self-mutilation and to allow for safe handling. Supportive care including intravenous fluids may be initiated, though owners should understand this does not alter the fatal prognosis. Preventing additional exposure of other animals in the household is important, though dog-to-dog transmission of pseudorabies does not occur.

Medical management of pseudorabies is purely palliative and cannot alter the inevitably fatal outcome. There is no antiviral medication effective against the pseudorabies virus in dogs. Aggressive sedation using medications such as phenobarbital, diazepam, or acepromazine may be necessary to control the violent self-directed behavior caused by the intense pruritis. Pain management with opioids can provide some comfort. Anti-inflammatory medications have no proven benefit but may be administered. Supportive care including intravenous fluids addresses dehydration. Wound care for self-inflicted injuries may be attempted, though continued self-trauma makes healing impossible. Owners must understand that all medical treatment is aimed at comfort during the dying process rather than recovery.

Surgical intervention has no role in pseudorabies treatment. The disease is purely medical in nature, caused by an incurable viral infection of the nervous system. No surgical procedure can address the underlying pathology or alter the outcome. Wound repair from self-mutilation injuries is generally futile given the continued scratching behavior and the rapid progression to death. The focus remains on medical management of symptoms and, ultimately, humane euthanasia.

Supportive care for pseudorabies is limited in effectiveness but attempts to minimize suffering during the terminal phase. Heavy sedation reduces awareness and may decrease the subjective experience of pruritis. Padding the environment prevents additional injury from thrashing. Darkening and quieting the environment may reduce sensory stimulation. Maintaining hydration through intravenous fluids supports physiological function. Temperature support prevents hypothermia in obtunded patients. Careful monitoring allows recognition of disease progression and informs decisions about timing of euthanasia. Despite supportive care, death typically occurs within 24 to 48 hours of symptom onset.

Alternative and complementary treatments have no proven benefit in pseudorabies. Given the rapid and invariably fatal nature of the disease, there is no time or scientific basis for attempting unproven therapies. The focus must be on conventional supportive care and appropriate end-of-life decisions. Owners seeking alternatives should understand that no treatment, conventional or otherwise, has ever successfully reversed the course of pseudorabies in dogs.

Treatment decisions in pseudorabies inevitably focus on the timing and method of humane euthanasia. Given the invariably fatal prognosis, the severe suffering caused by the intense pruritis and self-mutilation, and the rapid disease progression, euthanasia is the most humane option in virtually all cases. Attempting prolonged treatment only extends the suffering of the animal. The veterinarian should have an open and compassionate discussion with the owner about the diagnosis, the uniformly fatal prognosis, and the recommendation for humane euthanasia to prevent further suffering. Post-mortem examination of brain tissue is recommended to confirm the diagnosis and rule out rabies, with results reported to appropriate authorities.

There is no recovery from pseudorabies in dogs. The disease is universally fatal once clinical signs develop, with death typically occurring within 24 to 48 hours of symptom onset. No dog has ever been documented to survive pseudorabies, and there are no case reports of partial recovery or extended survival following confirmed infection. The virus causes irreversible destruction of neural tissue that is incompatible with life. Owners must understand that a diagnosis of pseudorabies means their dog will not survive, regardless of the treatment provided.

The terminal phase of pseudorabies involves progressive neurological deterioration. Following the onset of clinical signs, dogs experience worsening mental status, progressing from agitation to obtundation to coma. Motor function deteriorates, with coordination becoming increasingly impaired before paralysis develops. Respiratory function fails as brainstem control of breathing is lost. Cardiovascular function becomes unstable as autonomic regulation fails. Most dogs die or are humanely euthanized within 24 to 48 hours of first showing symptoms. Those that are not euthanized experience increasing suffering before succumbing to the disease.

Prognostic factors in pseudorabies are irrelevant to survival, as all infected dogs die. However, the timing and severity of symptom onset may vary slightly between cases. Dogs with larger viral exposure may progress more rapidly. The route of infection does not appear to significantly affect the disease course. No factors such as age, breed, or overall health status alter the uniformly fatal outcome. The only meaningful prognostic discussion involves the expected timeline to death, which is typically one to two days from symptom onset.

The long-term outlook following pseudorabies is applicable only to surviving household members and focuses on prevention of additional cases. Other dogs in the household are not at risk from the infected dog, as dog-to-dog transmission does not occur. However, if the source of exposure was consumption of infected pork or contact with an infected pig, other dogs with the same exposure are at risk. Owners should evaluate all potential exposure sources and eliminate them. This may include ceasing raw pork feeding, preventing access to areas where feral pigs are present, or discontinuing hunting activities involving feral swine. Understanding how the infection was acquired is essential for protecting remaining pets.

Primary prevention of pseudorabies in dogs focuses entirely on avoiding exposure to infected swine and contaminated pork products. Dogs should be prevented from having any contact with feral swine populations, which remain the primary reservoir of the virus in the United States. Hunting dogs used for feral hog hunting face the highest risk and owners must decide whether the hunting activity is worth the potential consequences. Dogs should not be allowed to consume carcasses of feral pigs or any wild swine. Domestic pig farms with adequate biosecurity and disease-free certification present minimal risk, but contact with backyard pigs of unknown health status should be avoided. Understanding the geographic distribution of infected feral pig populations helps assess local risk levels.

Breeding and commercial practices can reduce pseudorabies risk in susceptible populations. Commercial pork production in the United States has successfully eradicated pseudorabies through vaccination and surveillance programs, making commercially processed pork very low risk. However, pork from feral swine, small unregulated farms, or international sources may carry the virus. Raw food diet manufacturers should ensure pork ingredients originate from pseudorabies-free domestic sources. Breeders and kennels should have policies against feeding raw pork products of uncertain origin. Dogs bred or sold for hunting feral hogs should come with clear disclosure of the pseudorabies risk associated with this activity.

Nutritional considerations for pseudorabies prevention center on avoiding potentially contaminated pork products. Dogs should not be fed raw pork from unknown sources, as cooking destroys the virus but raw consumption creates infection risk. Commercially processed, properly cooked pork products are safe for dogs to consume. Owners who choose to feed raw diets should select manufacturers that source pork from certified pseudorabies-free domestic suppliers. Pork scraps from home cooking are safe if thoroughly cooked. The simplest approach for concerned owners is to avoid feeding any pork products to their dogs, though this is not strictly necessary if products are from safe sources.

Health maintenance practices for pseudorabies prevention involve awareness and exposure avoidance rather than vaccination, as no pseudorabies vaccine is available for dogs. Regular veterinary care should include discussion of any potential exposure risks, particularly for hunting dogs or dogs in areas with feral swine. Keeping dogs confined or leashed prevents unsupervised encounters with wild pigs or their carcasses. Training hunting dogs to avoid consuming game reduces risk during hunts. Awareness of local feral pig populations and their disease status helps owners make informed decisions about outdoor activities.

Early intervention is not meaningful for pseudorabies once exposure has occurred, as there is no post-exposure prophylaxis or treatment that can prevent disease development. If an owner knows their dog has been exposed to potentially infected pork or swine, monitoring for symptom development is appropriate, but no preventive treatment is available. The incubation period is typically two to nine days, during which time the owner can prepare for the possibility of illness. If symptoms develop, immediate veterinary attention should be sought for humane management and proper diagnosis, but owners should understand that the outcome is invariably fatal.

Daily management considerations for pseudorabies are relevant only during the brief terminal phase of the disease and focus on providing comfort during the dying process. Dogs with pseudorabies require constant supervision to prevent self-injury from the violent scratching behavior. Heavy sedation may be necessary to reduce suffering and prevent self-mutilation. The dog should be kept in a padded, safe area where thrashing cannot cause additional injury. Fluid therapy may be continued if intravenous access is maintained. Keeping the environment quiet and dimly lit may reduce stimulation. However, the focus should be on preparing for and ultimately proceeding with humane euthanasia rather than prolonged management of a terminal case.

Home environment modifications for a dog with pseudorabies are minimal given the brief survival time. Isolation from other pets is appropriate, though dog-to-dog transmission does not occur. Protecting other animals from stress of witnessing the affected dog's condition may be beneficial. Children should be kept away from the affected dog both for safety and to spare them from witnessing the distressing symptoms. Contaminated materials should be handled with gloves, though the virus does not pose a significant risk to humans. The home does not require special disinfection after the dog dies, as the virus is relatively fragile in the environment and does not persist.

Quality of life assessment in pseudorabies is straightforward: there is no meaningful quality of life once symptoms develop. The intense, uncontrollable pruritis causes constant distress. The self-mutilation causes pain and further distress. The progressive neurological deterioration impairs all normal function. There is no period during the clinical phase when the dog experiences comfort or normalcy. These factors strongly support the recommendation for humane euthanasia as soon as a confident diagnosis is made, rather than allowing the disease to run its natural course.

Monitoring a dog with suspected or confirmed pseudorabies involves tracking disease progression to inform the timing of euthanasia. Increasing severity of pruritis, worsening neurological signs, decreasing responsiveness to sedation, and declining overall condition indicate disease advancement. Respiratory effort should be monitored as brainstem involvement leads to respiratory failure. Body temperature may become unstable. The appearance of paralysis indicates advanced disease. Rather than waiting for the dog to die naturally, veterinarians typically recommend euthanasia when diagnosis is confirmed or strongly suspected, to prevent unnecessary suffering.

Caregiver support is critically important for owners facing a pseudorabies diagnosis in their pet. The suddenness of the disease, the distressing symptoms, and the inevitably fatal outcome create significant emotional trauma. Owners need to understand they are not at fault and that nothing could have saved their dog once infection occurred. Grief counseling resources may be helpful. Veterinary staff should provide compassionate support during the euthanasia process. Connecting owners with others who have lost pets to pseudorabies may provide validation and support. If the dog was exposed through hunting activities, owners may need support in deciding whether to continue this activity with other dogs, understanding the ongoing risk.

No specific dog breeds have increased susceptibility to pseudorabies infection. The virus can infect any dog regardless of breed, size, age, or genetic background. The factors that determine which dogs become infected are entirely related to exposure opportunity rather than any inherent breed-related vulnerability. All dogs are equally susceptible if exposed to sufficient quantities of the virus through contact with infected swine or consumption of contaminated pork products. Therefore, prevention focuses on exposure avoidance rather than identifying high-risk breeds.

Certain types of dogs face elevated risk due to their lifestyle and activities rather than breed characteristics. Hunting dogs used for pursuing feral hogs represent the highest risk category due to direct contact with potentially infected wild swine. This includes hog-hunting breeds such as Black Mouth Curs, Catahoula Leopard Dogs, American Bulldogs, and various mixed breeds used for this purpose. Farm dogs in areas with feral pig populations may encounter infected carcasses or live infected swine. Dogs in rural areas of the southern United States where feral pig populations are endemic have greater environmental exposure risk. Dogs fed raw diets containing pork from unverified sources face dietary exposure risk regardless of breed.

Screening for pseudorabies susceptibility is not possible because no genetic or biological factors predict which dogs will become infected upon exposure. Prevention recommendations apply equally to all dogs and focus on avoiding exposure. Owners of hunting dogs used for feral hog hunting should carefully consider whether the activity is worth the fatal risk of pseudorabies. Dogs should be prevented from consuming feral pig carcasses. Raw pork products should only be fed if sourced from certified pseudorabies-free domestic suppliers. Owners in areas with endemic feral pig populations should be aware of the risk and take appropriate precautions to prevent their dogs from encountering wild swine or their remains.

The primary condition that must be differentiated from pseudorabies is rabies, due to the overlapping clinical presentations and significant public health implications. Both diseases cause progressive encephalitis with behavioral changes, hypersalivation, and neurological deterioration. The key distinguishing features include the intense pruritis of pseudorabies, which is absent in rabies, and the exposure history, with pseudorabies following swine contact while rabies follows bite wounds from infected mammals. Because rabies poses a public health threat, animals dying with neurological signs consistent with either disease should be tested for rabies. The diseases cannot be definitively distinguished without laboratory testing, making post-mortem examination important.

Other conditions with neurological manifestations may initially resemble pseudorabies. Canine distemper virus causes encephalitis with seizures and behavioral changes but typically includes respiratory and gastrointestinal signs and has a more prolonged course. Brain tumors can cause progressive neurological deterioration but develop over weeks to months rather than hours to days. Toxicosis from various agents including organophosphates, lead, and certain medications can cause acute neurological signs but typically lacks the intense pruritis. Epilepsy causes seizures but not the progressive deterioration or pruritis. Severe allergic reactions can cause intense itching but lack the neurological component and respond to antihistamines and corticosteroids.

Pseudorabies does not have common co-occurring conditions in dogs because of its rapid and fatal nature. The disease kills affected dogs before other conditions can develop or become relevant. However, owners whose dog dies of pseudorabies should be aware that other dogs with the same exposure are at risk of developing the disease. If multiple dogs consumed the same infected pork or had contact with the same infected swine, they should be monitored for symptom development during the incubation period. Environmental contamination is not a significant concern for spread to other dogs, as dog-to-dog transmission does not occur and the virus has limited environmental stability.