Diagnostic Approach to Downer Sow Syndrome: Metabolic, Traumatic, and Infectious Causes

By Dr. Zubair Khalid, DVM, MS, PhD · 2026-08-11

Key Takeaways

• Downer sow syndrome is a clinical presentation, not a definitive diagnosis, requiring systematic differentiation between metabolic, traumatic, and infectious etiologies, as the prognosis and herd-level implications vary significantly.
• The peripartum period is a critical risk window for downer sow presentation due to physiological stresses like lactogenesis and parturition, which can precipitate metabolic derangements (e.g., hypocalcemia) or cardiovascular events (e.g., heart failure).
• A thorough physical and neurological examination is paramount, with fever indicating infection, hypothermia suggesting shock or terminal states, and asymmetric limb findings pointing towards trauma or suppurative arthritis, while symmetric deficits may suggest metabolic causes.
• Key diagnostic laboratory tests include serum biochemistry for calcium, phosphorus, magnesium, and creatinine kinase to assess metabolic status and muscle damage, alongside hematology to detect signs of infection or inflammation.
• Radiography is crucial for identifying fractures and joint disease, particularly in the pelvis and femurs, while ultrasonography aids in evaluating reproductive tract and mammary gland pathology, and cerebrospinal fluid analysis is indicated for suspected meningitis.
• Suppurative arthritis and spondylitis are frequently identified causes of recumbency in growing pigs, but in sows, periparturition metabolic disturbances, reproductive tract pathology, and cardiovascular events are more prominent differentials, necessitating stage-specific diagnostic prioritization.

The downer sow is a recumbent, non-ambulatory female that cannot or will not rise despite stimulation. This presentation is a clinical syndrome instead of a single diagnosis, and the underlying cause determines whether the animal can recover, requires euthanasia, or dies before intervention. For the practicing swine veterinarian, the immediate challenge is to distinguish a primary metabolic derangement from a traumatic injury or an infectious process, because the diagnostic path, prognostic outlook, and herd-level implications differ substantially across these categories.

This article provides a systematic diagnostic framework for the downer sow, with emphasis on the metabolic, traumatic, and infectious differentials most relevant to breeding-age females. It is written for veterinarians who manage individual animals and herd health programs, and it addresses the clinical question of how to structure a recumbent sow workup when time, handling constraints, and on-farm diagnostic capacity are limited. Treatment and nursing care are excluded from this reference, the focus is on recognition, classification, and diagnostic decision-making.

The epidemiology of sow mortality provides context for the downer presentation. In a prospective study of 24 breeding herds with an average inventory of 3,755 sows, the average annual death rate was 3.3%, with 42% of deaths occurring in the peripartum period. Heart failure accounted for 31.4% of deaths, torsions and abdominal organ accidents for 15.3%, and cystitis-pyelonephritis for 8.0%, while downer sow syndrome was recorded as the cause in only 2.2% of cases, and 14.6% of deaths remained undiagnosed. These figures from a prospective study of sow mortality in breeding herds indicate that the downer label is often assigned without a confirmed etiology, and that concurrent or alternative conditions may be present in animals that present as recumbent.

At a Glance

Defining the Downer Syndrome in Sows

The term downer sow syndrome is used inconsistently in the literature and in practice. Some authors apply it to any non-ambulatory sow regardless of cause, while others reserve it for animals with no identifiable lesion at necropsy. The 2.2% mortality attribution in the prospective breeding herd study reflects this latter, narrower usage, and the high proportion of unknown causes in the same study suggests that many recumbent sows are never given a definitive diagnosis. The practical implication is that the clinician should treat downer sow syndrome as a working diagnosis to be refined through examination and ancillary testing, not as a final conclusion.

Recumbency in sows can be classified by onset, by lesion location, and by the primary pathophysiologic mechanism. Onset is acute when the animal is found down without prior observed illness, or progressive when lameness, lethargy, or inappetence preceded the recumbent state. Lesion location is determined by neurologic examination and separates cerebral, brainstem, spinal cord, peripheral nerve, and musculoskeletal causes. The pathophysiologic classification used in this article groups causes into metabolic, traumatic, and infectious categories, with the recognition that overlap occurs. A sow with suppurative spondylitis may become recumbent acutely when vertebral collapse compresses the spinal cord, and a sow with hypocalcemia may develop secondary muscle and nerve damage if she remains down for hours.

Physiologic Basis of Recumbency

Normal standing and locomotion require intact function across multiple systems. The sow must have sufficient conscious perception and motivation to rise, intact motor pathways from the cerebral cortex through the spinal cord to the peripheral nerves, functional neuromuscular junctions, and muscles capable of generating force. She must also have adequate cardiovascular reserve to perfuse these tissues, normal electrolyte and mineral balance for nerve and muscle excitability, and a skeletal system that can bear weight without pain or fracture. Failure at any of these points can produce recumbency, and the diagnostic approach must therefore be systematic instead of reflexive.

The peripartum period imposes unique physiologic stress. Lactogenesis and parturition create sudden demands for calcium, phosphorus, and energy, and the physical exertion of farrowing can precipitate cardiovascular events in sows with marginal cardiac reserve. The high proportion of peripartum deaths attributed to heart failure in the breeding herd study underscores the need to consider cardiac causes in any downer sow, particularly one that is found acutely recumbent, dyspneic, or cyanotic. Abdominal organ torsion produces rapid cardiovascular collapse and can be mistaken for a primary downer syndrome if the clinician does not palpate or image the abdomen.

Diagnostic Reasoning Structure

The recumbent sow workup follows a sequence: stabilize the animal for examination, obtain a focused history, perform a physical and neurologic examination, generate a prioritized differential list, and select ancillary tests that will discriminate among the leading candidates. The order of these steps matters because the downer sow is often in a compromised state, and the examination must be efficient without sacrificing diagnostic accuracy.

History should include parity, stage of gestation or lactation, days since farrowing, group housing or individual stalls, recent handling or transport, observed lameness or gait abnormality, appetite and fecal output, and any prior episodes of recumbency. The peripartum timing of the presentation narrows the differential toward metabolic and cardiovascular causes, while a sow that becomes recumbent in mid-gestation is more likely to have a traumatic or infectious process. Group-housed sows are at risk for fighting injuries and tail-biting sequelae, whereas stalled sows may develop compartmental compression injuries from prolonged lying on concrete.

Physical examination begins with assessment of mentation, respiratory rate and effort, mucous membrane color, and body temperature. Fever directs the differential toward infectious causes, while hypothermia in a recumbent sow suggests shock, terminal cardiac failure, or prolonged environmental exposure. The cardiovascular examination includes heart rate, pulse quality, and auscultation for arrhythmias or murmurs. The abdomen is palpated for distension, pain, or a palpable mass, and the udder is examined for signs of mastitis, which may be present in sows with coliform or other bacterial infections.

The neurologic examination is the most informative component of the downer sow workup. The clinician assesses cranial nerve function, postural reactions, spinal reflexes, and the presence or absence of voluntary movement in each limb. A sow that is bright, alert, and eating but unable to stand has a different lesion distribution than one that is depressed and non-responsive. Hindlimb paralysis with intact forelimb function localizes the lesion to the thoracolumbar spinal cord, while tetraplegia with cranial nerve deficits suggests a brainstem or cervical spinal cord process. The presence of deep pain perception in the hindlimbs is a critical prognostic indicator in spinal cord injury, and its absence carries a grave prognosis.

Classification of Causes

The differential diagnosis for the downer sow is broad, but the causes can be organized into the three categories that form the structure of this reference. Metabolic causes include hypocalcemia, hypoglycemia, electrolyte disturbances, and energy deficits that impair muscle function or consciousness. Traumatic causes include fractures, spinal cord compression, muscle damage, and nerve injury from handling, fighting, or inappropriate flooring. Infectious causes include suppurative arthritis, spondylitis, meningitis, myelitis, and systemic bacterial infections that produce fever, pain, or neurologic deficits.

The necropsy-based study of 76 non-ambulatory grower-finisher pigs provides a useful reference for the relative frequency of these causes, even though it was conducted in growing pigs instead of sows. Suppurative arthritis was the most common diagnosis at 29 of 76 cases, followed by suppurative spondylitis at 10 cases, and bone fracture at 7 cases. Non-suppurative meningoencephalomyelitis and suppurative meningoencephalitis together accounted for 10 cases, fibrocartilaginous thromboembolism for 3 cases, and epiphysiolysis for 3 cases. These findings from a clinic, etiological and pathological perspective on non-ambulatory pigs demonstrate that infectious and traumatic causes dominate in growing pigs, and they provide a template for the necropsy-based diagnostic approach that is often required when a downer sow does not recover.

The clinician should recognize that the distribution of causes in sows may differ from that in growing pigs. The peripartum metabolic demands, the higher body mass, and the reproductive tract pathology unique to breeding females all shift the differential. Nevertheless, the diagnostic principles established in the growing pig study, including the need for systematic necropsy with histopathology, bacteriology, and molecular testing to reach a definitive diagnosis, apply equally to the downer sow.

Initial Examination and Triage

The first encounter with a downer sow should follow a fixed sequence that separates immediate life threats from diagnostic refinement. Begin with distant observation before entering the pen. Note the sow's position, limb placement, respiratory effort, and response to human presence. A sow that is sternally recumbent, alert, and eating carries a different urgency than one that is laterally recumbent, dyspneic, or obtunded.

Approach the sow quietly and assess mentation. Normal sows resent handling and will attempt to rise or vocalize. Absence of this response suggests either severe pain, neurologic depression, or advanced metabolic compromise. Check mucous membrane color, capillary refill time, and rectal temperature. Hypothermia in a downer sow is an unfavorable sign and often indicates prolonged recumbency or circulatory failure. Hyperthermia above 40.0°C should prompt immediate consideration of infectious or inflammatory causes.

Evaluate hydration status by skin turgor over the shoulder and by eye position within the orbit. Dehydration compounds every metabolic differential and alters the interpretation of laboratory values. Assess respiratory rate and pattern. Labored breathing with abdominal effort may indicate pneumonia, pleuritis, or the restrictive effects of severe abdominal distension.

The physical examination must include a systematic assessment of the limbs. Palpate each limb from the hoof to the shoulder and hip. Look for swelling, heat, crepitus, or abnormal mobility. Examine the coronary bands and interdigital spaces for lesions. Check the claws for cracks, overgrowth, or separation. A sow that refuses to bear weight on a specific limb before becoming recumbent likely has a traumatic or arthritic condition instead of a primary metabolic problem.

Differentiating the Recumbent Sow by Physical Findings

The examination findings guide the initial classification of the downer sow into one of three working categories: metabolic, traumatic, or infectious. This triage determines the urgency of intervention and the selection of diagnostic tests.

Sows with suspected metabolic disease typically present with normal mentation, symmetric limb function, and no localizing signs. They may be sternally recumbent with the hindlimbs folded beneath them, appearing comfortable but unable to rise. The classic presentation is a periparturient sow that farrowed normally but is found recumbent within 24 to 48 hours. These sows often eat and drink if feed and water are placed within reach. The absence of pain responses during limb manipulation supports a metabolic diagnosis, though this must be confirmed by laboratory testing.

Traumatic causes produce asymmetric findings. The sow may have a visibly swollen joint, a fractured limb with crepitus, or a pelvic fracture that prevents weight bearing on one hindlimb. Pain responses during palpation are usually pronounced. The history often includes a recent move to a new pen, fighting with penmates, or slipping on wet flooring. Pelvic fractures deserve particular attention because they may not produce obvious external swelling but reliably prevent standing. Digital rectal examination in a sow small enough to examine safely may reveal crepitus or instability of the pelvic canal.

Infectious causes present with fever, lethargy, and often a identifiable focus. Suppurative arthritis produces hot, swollen joints with reduced range of motion. Meningitis produces neurologic signs including paddling, opisthotonos, or cranial nerve deficits. Endometritis or mastitis may be detected by vaginal discharge or firm, painful mammary glands. The periparturient period is the highest risk window for sow mortality across all causes, which makes the distinction between post-farrowing sepsis and metabolic recumbency particularly urgent Chagnon et al., prospective study of sow mortality in breeding herds.

Laboratory Assessment and Diagnostic Sampling

Blood sampling is the central element of the metabolic workup. Collect blood from the jugular vein or cranial vena cava using a 16- or 18-gauge needle. The cranial vena cava approach is preferred in sows because it is reliable and causes minimal restraint stress. Collect serum for biochemistry and whole blood for hematology. If the sow is already receiving treatment, note this on the submission form because it may alter laboratory values.

The minimum biochemistry panel should include calcium, phosphorus, magnesium, glucose, and creatinine kinase. Total calcium is the most commonly measured parameter, but ionized calcium is more physiologically relevant. Many laboratories report ionized calcium from a separately collected heparinized sample. A total calcium below 8.0 mg/dL in a periparturient sow supports a diagnosis of hypocalcemia, but normal total calcium does not exclude a metabolic contribution to recumbency. Magnesium and phosphorus should be interpreted together because they interact with calcium metabolism.

Creatinine kinase is the most useful muscle enzyme for confirming prolonged recumbency. Elevated values confirm that the sow has been down for some time and help distinguish primary recumbency from secondary muscle damage. A sow with a creatinine kinase in the tens of thousands has significant muscle ischemia and carries a guarded prognosis regardless of the inciting cause.

Hematology provides supportive information. Leukocytosis with a left shift supports an infectious or inflammatory process. The absence of leukocytosis does not exclude infection, particularly in periparturient sows with uterine or mammary disease. Fibrinogen is an acute phase protein that rises within 24 to 48 hours of an inflammatory stimulus and may be more sensitive than white blood cell count alone.

Imaging and Ancillary Diagnostics

Radiography is the primary imaging modality for suspected fractures and joint disease. The challenge in sows is size and positioning. A recumbent sow can be rolled onto a radiolucent table or imaged in place with a portable unit. The pelvis and proximal femur are the most commonly fractured sites in downer sows. Pelvic radiographs require two views and careful interpretation because the overlapping bony structures can obscure subtle fractures. If a pelvic fracture is confirmed, the prognosis for recovery is poor because the sow cannot bear weight during the 6 to 8 weeks required for healing.

Ultrasonography is useful for evaluating the reproductive tract and mammary glands. Transabdominal scanning can identify retained fetuses, uterine fluid, or uterine wall thickening. Mammary ultrasound can distinguish mastitis from normal involution. The equipment required is a 3.5 to 5.0 MHz convex probe for transabdominal work and a 7.5 MHz linear probe for mammary evaluation. These are standard machines found in most mixed or food animal practices.

Cerebrospinal fluid collection is indicated when meningitis is suspected. The lumbosacral site is accessible in the sow, but the procedure requires heavy sedation or general anesthesia. The value of cerebrospinal fluid analysis lies in distinguishing suppurative meningitis, which shows neutrophilic pleocytosis and elevated protein, from non-suppurative conditions. This distinction changes both prognosis and treatment approach.

Diagnostic Decision Framework

The following table summarizes the diagnostic prioritization based on clinical presentation. Use this framework to select the most efficient diagnostic path for each individual case.

The necropsy-based study of non-ambulatory pigs in growing-finishing herds identified suppurative arthritis and suppurative spondylitis as the most common causes of recumbency in that age group, followed by viral-associated disease and bone fractures clinic, etiological and pathological perspective on 76 cases. This distribution differs from the breeding herd, where periparturient metabolic and reproductive conditions dominate. The production stage of the affected animal must therefore shape the diagnostic plan.

Documentation and Monitoring

Record the initial examination findings, laboratory results, and the working diagnosis in the herd health record. Include the sow's parity, stage of gestation or lactation, pen location, and the duration of recumbency before examination. This information supports both individual case management and herd-level pattern recognition. A cluster of downer sows in one pen or over a short period suggests an environmental or nutritional cause instead of an individual disease event.

Serial monitoring is essential because the downer sow's condition can change rapidly. Recheck temperature, mentation, and the ability to maintain sternal recumbency every 6 to 12 hours. A sow that deteriorates from sternal to lateral recumbency has a worse prognosis. Monitor urine output and fecal production as indicators of gastrointestinal and renal function. Document any change in limb position or the development of new swellings, which may indicate compartment syndrome or pressure necrosis.

The decision to continue diagnostic evaluation or to euthanize should be revisited at each monitoring point. A sow that remains recumbent beyond 48 to 72 hours with rising creatinine kinase and no identifiable correctable cause has a poor prognosis. The welfare implications of prolonged recumbency are substantial, and the veterinarian should not delay euthanasia when recovery is unlikely. The AVMA professional practice resources provide guidance on euthanasia decision-making and humane endpoints that apply to this situation.

Recognized Complications and Failure Modes

The downer sow deteriorates along predictable pathways, and early detection of each complication changes outcome. Recumbency exceeding 48 hours produces pressure-induced muscle ischemia, which compounds the original problem and can convert a recoverable metabolic case into a permanent one. Serial assessment of urine color provides the earliest practical screen. Dark brown or red urine indicates myoglobinuria from muscle necrosis, and the clinician should re-examine the sow for firm, painful muscle groups over the tuber coxae and caudal thigh.

Decubital ulcers develop over bony prominences within days of uninterrupted recumbency. The skin over the tuber ischii and lateral stifle should be inspected at every visit, with particular attention to moisture from urine scald. Early lesions appear as erythematous patches that progress to full-thickness necrosis. Detection requires lifting the tail and parting the perineal folds, a step that is frequently omitted in sows that are simply rolled for examination.

Joint contracture and muscle atrophy become clinically evident by the end of the first week. The stifle and hock lose range of motion when the limb is passively flexed during examination. This finding carries prognostic weight because it predicts that even a sow with resolving metabolic disease will struggle to regain standing posture.

Respiratory compromise from prolonged lateral recumbency manifests as increased respiratory effort and crackles on thoracic auscultation. Hypostatic congestion of the dependent lung is often mistaken for pneumonia. The discriminating feature is that congestion improves when the sow is turned to the opposite side, whereas infectious pneumonia does not resolve with repositioning.

Urinary tract infection secondary to recumbency is a recognized complication. The peripartum period already carries elevated risk for cystitis and pyelonephritis, and recumbency compounds this by reducing voiding frequency and promoting perineal soiling. A urinalysis with sediment examination should be repeated if the sow remains down beyond 72 hours.

Common Diagnostic Errors and Corrective Action

The most consequential error is attributing recumbency to a single cause when multiple factors coexist. A sow with mild hypocalcemia may remain down because of an undetected stifle injury sustained during the collapse. The examination must therefore proceed through the full diagnostic framework even when one abnormality is found. A second common error is failing to distinguish primary from secondary recumbency. The sow that goes down after a prolonged farrowing may have primary uterine inertia, but the recumbency itself can cause muscle damage that becomes the dominant problem.

Less experienced clinicians often overinterpret spinal hyperpathia. Sows resent palpation of the lumbar region for many reasons, including skin bruising and muscle pain, and this response does not reliably indicate vertebral fracture or discospondylitis. The diagnosis of spinal injury requires consistent neurologic deficits, not simply a painful response to handling.

Limitations of Current Evidence

The published evidence base for downer sow syndrome is thin. The prospective mortality study that identified downer sow syndrome as a distinct cause of death reported it in only 2.2% of necropsied females, and the authors acknowledged that many cases were classified as unknown. This suggests that the syndrome is either genuinely uncommon or frequently misclassified. Necropsy-based studies in growing-finishing pigs, such as the Brazilian series of 76 non-ambulatory animals, provide useful structural diagnoses including suppurative arthritis, spondylitis, and bone fracture, but these findings cannot be extrapolated directly to adult sows because the production stage and body weight differ substantially.

Expert opinion still diverges on the relative importance of metabolic versus traumatic triggers in the peripartum sow. Some clinicians emphasize hypocalcemia as the initiating event, while others argue that pelvic trauma and obstetrical injury are under-recognized because they are difficult to confirm without advanced imaging. The absence of validated diagnostic thresholds for serum calcium, phosphorus, and magnesium in recumbent sows compounds this uncertainty. Reference intervals for standing sows may not apply to the downer animal, and no published studies have established prognostic cut-offs.

Referral, Consultation, and Reporting

Referral to a diagnostic laboratory is warranted when the sow fails to improve within 48 to 72 hours despite supportive care and no clear diagnosis has been reached. Laboratory involvement should include complete blood count, serum biochemistry with muscle enzyme activity, urinalysis, and culture of any discharge. Serology and molecular testing for specific pathogens should be guided by herd history and lesion distribution instead of performed as a broad panel.

Specialist consultation with a veterinary neurologist or theriogenologist is appropriate when neurologic deficits are progressive, when spinal pain is severe, or when the sow has not regained sternal recumbency after one week. Imaging facilities capable of computed tomography or magnetic resonance imaging are rarely available on farm, but referral to a teaching hospital may be justified for breeding stock of high genetic value.

Regulatory reporting obligations vary by jurisdiction. The veterinarian should confirm whether recumbent sows with suspected notifiable diseases, including those with neurologic signs, must be reported to the relevant animal health authority. The World Organization for Animal Health terrestrial animal health standards provide the international framework for disease notification, and national programs may impose additional requirements. The USDA Animal and Plant Health Inspection Service publishes current disease control information for the United States, and the FAO provides international guidance on animal health services. The practitioner should consult these sources and their regional veterinary authority before ruling out reportable conditions in any downer sow with fever, neurologic signs, or unusual herd-level patterns.

Frequently Asked Questions

How Do I Prioritize Diagnostic Testing When Laboratory Access or Budget Is Limited?

Start with the physical examination and a targeted history, as these require no equipment and often separate traumatic from metabolic causes. When laboratory testing is restricted, prioritize a single serum biochemistry panel that includes calcium, phosphorus, magnesium, and creatinine kinase, since hypocalcemia and trauma are common findings. If only one test is possible, serum calcium is the most useful. Urine dipstick testing for ketones and hematuria is inexpensive and can be performed on farm. Post-mortem examination of a sow that dies or is euthanised provides the highest diagnostic yield when antemortem testing is incomplete, as demonstrated in a necropsy-based study of non-ambulatory pigs that identified definitive causes in nearly all cases Piva et al., 2022.

What Should I Do When Imaging and Advanced Diagnostics Are Unavailable?

Radiography and ultrasonography are helpful but not indispensable. A systematic physical examination, including assessment of pelvic symmetry, limb palpation, and response to stimulation, can identify fractures, joint swelling, and spinal pain. The response to empirical calcium therapy, when hypocalcemia is suspected, serves as both treatment and diagnostic test. If the sow does not improve within 12 to 24 hours, reconsider traumatic or infectious causes. Serial examination is critical because some conditions, such as fibrocartilaginous embolism, may show progressive neurological signs. When advanced imaging is unavailable, referral to a diagnostic laboratory for necropsy is the most reliable route to a definitive diagnosis.

How Does the Diagnostic Approach Differ in Growing-Finishing Pigs Compared with Sows?

The same systematic framework applies, but the relative frequency of causes shifts. In growing-finishing pigs, suppurative arthritis and spondylitis are the most common necropsy-confirmed causes of recumbency, followed by porcine circovirus type 2-associated disease and bone fractures Piva et al., 2022. Metabolic causes such as hypocalcemia are far less common in growing pigs than in periparturient sows. Tail-biting lesions should be actively sought in younger pigs, as they are associated with ascending myelitis and sepsis. In sows, the peripartum period carries the highest mortality risk, and heart failure and abdominal organ torsions are prominent causes of death Chagnon et al., 1991. Adjust your differential list accordingly.

What Minimum Records Should I Keep for Each Downer Sow Case?

Record the sow's parity, stage of reproduction, days since last farrowing or service, and the onset and progression of recumbency. Document the physical examination findings, including temperature, heart rate, respiratory rate, posture, limb tone, and response to stimulation. Note any treatments administered, including doses and routes, and the timing of response. Record the date and method of euthanasia if the sow does not recover. These records support herd-level pattern recognition, allow retrospective analysis of recurring causes, and provide documentation for welfare assessments. Herd-level mortality data, including downer sow events, are valuable for identifying seasonal or management-related trends.

How Should I Communicate the Diagnostic Uncertainty to the Producer?

Explain that the downer sow syndrome is a clinical presentation, not a single disease, and that multiple causes can produce identical signs. Describe the diagnostic plan in steps, with the initial examination and laboratory tests as the first stage, and clearly state what each test will or will not rule out. Be explicit about the possibility that a definitive diagnosis may require necropsy. Provide a realistic timeline for expected improvement if a metabolic cause is treated, and state that failure to improve within that window warrants re-evaluation. This approach manages expectations while maintaining a systematic diagnostic process.

When Should I Consider a Notifiable or Reportable Disease in a Recumbent Sow?

Recumbency alone is rarely the presenting sign of a reportable disease, but it can occur in conditions with neurological or systemic involvement. Consult the relevant national veterinary authority or the WOAH terrestrial animal health standards for the current list of notifiable diseases in your region. If multiple sows are affected, if there is fever unresponsive to treatment, or if there are signs suggestive of a vesicular or neurological disease, contact your veterinary authority promptly. The USDA APHIS provides national program information for reportable livestock diseases in the United States. Regional requirements differ, so confirm the local reporting obligations before proceeding.

Related Clinical & Scientific Guides

• Rumen Health Assessment in Dairy Cows: Clinical and Subclinical Indicators
• Mastitis Control Programs in Dairy Herds: Monitoring and Prevention
• Swine Nutrition and Health: Feed-Related Disease Diagnosis

References and Further Reading

• A prospective study of sow mortality in breeding herds.. 1991.
• Non-ambulatory pigs in two Brazilian growing-finishing farms: a clinic, etiological and pathological perspective on 76 cases.. 2022.
• USDA APHIS Animal Health Information. USDA APHIS.
• FAO Animal Production and Health. FAO.
• MSD Veterinary Manual, Professional Edition. MSD Veterinary Manual.
• American Veterinary Medical Association Practice Resources. American Veterinary Medical Association.
• WOAH Terrestrial Animal Health Code. WOAH.

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• Diagnostic Approach to Downer Cow Syndrome: Metabolic vs. Traumatic Causes
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• Diagnostic Approach to Lameness in Feedlot Cattle: Differentiating Foot Rot from Other Causes
• Differential Diagnosis of Sudden Death in Dairy Cattle: Metabolic, Toxic, and Infectious Causes

This article is educational professional reference material for veterinary audiences. It is not a substitute for veterinary diagnosis, individual clinical judgment, current product labeling, or applicable regulatory requirements.