# [Sheep Farm](/knowledge/animal-farming/sheep/sheep-flock-planning-setting-up-a-profitable-operation) Business Planning Before Buying a Flock ## Key Takeaways - **Financial Viability Hinges on Pre-Acquisition Planning:** Acquiring a sheep flock without a detailed enterprise budget, validated market access, accurate carrying capacity assessments, and confirmed labor availability significantly increases the risk of financial failure within the first three production cycles. - **Biosecurity and Health Protocols are Paramount:** Implementing strict biosecurity measures, including a minimum 30-day isolation period for all purchased stock and adherence to WOAH Terrestrial Animal Health Code standards for quarantine and disease reporting, is critical to prevent pathogen introduction and manage flock health. - **Carrying Capacity and Forage Management Dictate Flock Size:** Stocking rates must be aligned with calculated animal unit months (AUM) per hectare, ideally at 70-80% of theoretical carrying capacity, to prevent pasture degradation and mitigate increased internal parasite loads, which necessitate anthelmintic use and fecal egg count monitoring. - **Labor and Skill Assessment is Non-Negotiable:** A full-time person can manage approximately 200-400 ewes in a mid-intensity system, but the plan must detail who performs critical tasks like lambing assistance, vaccination, and marketing, ensuring at least one individual possesses training in low-stress handling and basic veterinary skills. - **Market Validation and Cash Flow Projections are Essential:** Before purchasing animals, secure written purchase commitments or verified sale prices for at least two marketing windows, and meticulously estimate all variable costs (feed, veterinary, shearing, transport) for a minimum of two years to ensure realistic cash flow assumptions. - **Integrated Health Management Reduces Mortality:** A proactive health calendar, developed with veterinary consultation, must include protocols for common flock concerns such as foot rot, caseous lymphadenitis, and pregnancy toxemia, as mortality rates in newly assembled flocks can exceed 10% without such preventive measures. --- Acquiring a sheep flock without an enterprise budget and documented validation of markets, carrying capacity, and labor availability typically leads to financial failure within the first three production cycles. A commercial [sheep farming](/knowledge/animal-farming/sheep/sheep-farming-flock-nutrition-grazing-lambing-parasite-risk-and-welfare) business plan must integrate decisions on land tenure, flock size, enterprise type (e.g., feeder lamb versus ewe,lamb versus wool,focused), recordkeeping systems, and cash flow assumptions before any animal purchase. This article provides a decision framework based on published extension resources and biosecurity standards. ## At a Glance | Decision Area | Core Question | Standard Reference Source | | --- | --- | --- | | Land & forage | Does the farm’s carrying capacity match the planned flock size across seasons? | [FAO Animal Production and Health](https://www.fao.org/animal-production/en/) | | Labor & skill | Can at least one full,time person manage birthing, health checks, and marketing year,round? | [WOAH Terrestrial Animal Health Code](https://www.woah.org/en/what-we-do/standards/codes-and-manuals/terrestrial-code-online-access/) | | Enterprise choice | Does the target market support a ewe,lamb, feeder, or wool operation given local costs? | [USDA APHIS Livestock and Poultry Disease](https://www.aphis.usda.gov/livestock-poultry-disease) | | Records | Are inventory, health, and financial records in a format that permits monthly cash flow tracking? | [Merck Veterinary Manual](https://www.merckvetmanual.com/) | | Cash flow assumptions | Have all variable costs (feed, veterinary, shearing, transport) been estimated for two years? | [USDA National Animal Health Monitoring System](https://www.aphis.usda.gov/livestock-poultry-disease/nahms) | | Market validation | Are there written purchase commitments or verified sale prices for at least two marketing windows? | [Sustainable agricultural production: An investigation in Brazilian semi,arid livestock farms](https://api.elsevier.com/content/abstract/scopus_id/84890310190) | ## System Context and Production Cycle Sheep enterprises operate within an annual reproduction cycle that determines cash flow timing. Ewes typically lamb once per year, the lambing season concentrates labor demands for neonatal care, colostrum management, and early disease detection. [USDA APHIS Livestock and Poultry Disease](https://www.aphis.usda.gov/livestock-poultry-disease) emphasizes that all purchased stock should originate from flocks enrolled in a documented health program (e.g., scrapie free, OPP negative) and be isolated for a minimum of 30 days before introduction. The [WOAH Terrestrial Animal Health Code](https://www.woah.org/en/what-we-do/standards/codes-and-manuals/terrestrial-code-online-access/) provides the international standard for quarantine, vaccination schedules, and reporting of notifiable diseases such as bluetongue and foot,and,mouth disease. From a [veterinary management](/blog/careers/veterinary-management-running-a-successful-practice) perspective, the [Merck Veterinary Manual](https://www.merckvetmanual.com/) details common flock health concerns,parasite burdens, foot rot, caseous lymphadenitis, and pregnancy toxemia,that require preventive protocols. A business plan must include a written health calendar with veterinary consultation for diagnosis and treatment protocols. Without such protocols, mortality rates in newly assembled flocks often exceed 10 % in the first season, eliminating any profit margin. ## Planning Decisions Before Acquisition ### Land and Carrying Capacity Assessment Forage availability, water access, and fencing condition are the physical constraints on flock size. A land assessment should calculate the number of animal,unit months (AUM) per hectare across the growing season and the deficit period (dormant season, drought). The [FAO Animal Production and Health](https://www.fao.org/animal-production/en/) resources recommend stocking at 70,80 % of the theoretical carrying capacity to provide a safety margin. Overstocking degrades pasture and increases internal parasite loads, which in turn raises anthelmintic costs and labor for fecal egg count monitoring. In semi,arid Mediterranean environments, small,scale sheep and [goat farming](/knowledge/animal-farming/goats/goat-farming-dairy-and-meat-production-browse-kidding-parasite-risk-and-welfare) faces acute water and feed scarcity, a recent study of such systems highlights that stocking rate and forage supplementation are the primary drivers of economic sustainability ([The sustainability of small-scale sheep and goat farming in a semi,arid Mediterranean environment](https://api.elsevier.com/content/abstract/scopus_id/85197663516)). In any region, a written forage budget covering 12 months,with worst,case drought contingency,should be completed before acquiring animals. ### Labor Requirements and Skill Set Sheep require daily attention, especially during lambing. One full,time person can manage approximately 200,400 ewes in a mid,intensity system, depending on terrain and confinement. The [USDA National Animal Health Monitoring System](https://www.aphis.gov/livestock-poultry-disease/nahms) has documented that labor availability and experience are among the top constraints reported by U.S. sheep producers. The business plan should specify who performs each task (e.g., lambing assistance, vaccination, marketing) and confirm that at least one person has received training in low,stress handling, lamb resuscitation, and basic veterinary skills. If hired labor is needed, a budget must include wages, housing, and liability insurance. ### Enterprise Choice and Flock Type Commercial sheep operations differ fundamentally in their revenue stream and risk profile. A ewe,lamb enterprise generates income primarily from the sale of weaned lambs, a feeder operation purchases weaned lambs, finishes them on grain or pasture, and sells to slaughter, a wool enterprise cycles cash only once yearly at shearing. Market prices for lamb and wool are volatile and regional. The [USDA National Animal Health Monitoring System](https://www.aphis.usda.gov/livestock-poultry-disease/nahms) provides periodic surveys of production costs and prices that can inform assumptions. Before buying a flock, the producer must validate the local market by contacting at least two buyers (slaughter plants, livestock auctions, or direct,to,consumer channels) and obtaining written price ranges or contract terms. Without this validation, cash flow projections are speculative. ## Facilities and Environment The physical infrastructure of a sheep operation must support animal health, labor efficiency, and biosecurity before a single animal arrives. Facilities design begins with climate,both the macroclimate of the region and the microclimate within pens, sheds, and pastures. In arid or semi,arid environments, shade structures and adequate ventilation reduce heat stress, which depresses feed intake, reproduction, and immune function. Research from Mediterranean small,scale sheep and goat farming confirms that housing modifications to moderate temperature extremes improve flock survival and productivity, especially during summer months ([The sustainability of small-scale sheep and goat farming in a semi-arid Mediterranean environment](https://api.elsevier.com/content/abstract/scopus_id/85197663516)). In cold or wet climates, dry bedding, windbreaks, and sheltered lambing areas reduce neonatal mortality and respiratory disease. Pasture and confinement systems each carry distinct environmental risks. Rotational grazing can improve soil health and forage utilization, but overstocking leads to erosion, parasite buildup, and nutrient loading. The New England region of New South Wales survey of graziers found that managers who routinely assessed pasture condition and adjusted stocking rates reported fewer animal health problems and greater long,term pasture persistence ([Surveying the management practices and research needs of graziers in the New England region of New South Wales](https://api.elsevier.com/content/abstract/scopus_id/84884545263)). Fencing must be predator,proof and contain sheep securely: woven wire or high,tensile electric fence, with corner braces and gates designed for easy movement of animals and equipment. Water access points should be distributed so that no sheep walks more than 250 m to drink, avoiding excessive energy expenditure and trampling of wet areas that become pathogen reservoirs. Biosecure entry points, including a dedicated quarantine area for incoming sheep, are essential. The [WOAH Terrestrial Animal Health Code](https://www.woah.org/en/what-we-do/standards/codes-and-manuals/terrestrial-code-online-access/) outlines separation distances, sanitation protocols, and animal movement controls to prevent introduction of contagious diseases such as foot,and,mouth disease, scrapie, and contagious ecthyma. Any new flock should be isolated for at least 30 days, with separate equipment and footwear. The facility layout must allow quarantine to be downwind and downhill from the main flock to limit aerosol and drainage transmission. ## Nutrition and Water Nutritional planning begins with forage testing and supplement budgeting. A sheep enterprise budget must include the cost of hay, grain, minerals, and by,product feeds, but also the opportunity cost of grazing land if it could be used for other crops. The [USDA APHIS Livestock and Poultry Disease](https://www.aphis.usda.gov/livestock-poultry-disease) monitoring programs emphasize that feed,related metabolic diseases such as pregnancy toxemia and hypocalcemia arise from mismatched energy supply during late gestation and lactation. Farmers should contract feed analysis through a certified laboratory to determine crude protein, energy, calcium, phosphorus, and trace mineral levels before making any purchase commitment. Water quality is equally critical. Sheep consume 2 to 4 times more water than dry matter on a cool day, and up to 10 times more during heat stress. Sources must be tested for salinity, sulfate, nitrate, and bacterial contamination. High water salinity reduces feed intake and can cause diarrhea or abortions. In the aftermath of large,scale environmental disturbances such as volcanic ashfall, water sources become contaminated with heavy metals and sediment, requiring immediate testing and alternative supply arrangements ([Impacts on agriculture following the 1991 eruption of Vulcan Hudson, Patagonia: Lessons for recovery](https://api.elsevier.com/content/abstract/scopus_id/79955523294)). A backup water system, such as a storage tank or second well, should be part of the business plan. ## Production,Stage Decisions The choice of production system,farm flock, feeder lamb, or seedstock,must align with land base, labor availability, and market demand. A farm flock (breeding stock producing lambs for slaughter or feeder sale) requires a longer capital commitment to ewes, rams, and replacement heifers. Feedlots or custom grazing contracts reduce breeding risk but depend on consistent source of weaned lambs and reliable feed prices. The FAO [Animal Production and Health](https://www.fao.org/animal-production/en/) resources note that many small producers fail because they choose a system based on personal preference instead of market validation. A formal market assessment, including conversations with packers, auction barns, and direct,to,consumer channels, should precede any purchase. Lambing or kidding twice per year is biologically feasible under controlled breeding conditions but imposes higher management intensity, more labor during birthing, and greater nutritional demand on dams. A once,per,year spring lambing schedule, while slower to generate cash flow, reduces mortality risk and allows use of natural forage peaks. Whatever schedule is chosen, the business plan must include a written health protocol for each production stage: pre,breeding vaccination (clostridial diseases, caseous lymphadenitis), pregnancy diagnosis, lambing assistance criteria, and weaning procedures. ## Records Complete, accurate records are not optional, they are the basis for every financial and health decision. A paper or digital system must capture individual animal identification (ear tags, tattoos, or electronic identifiers), birth dates, dam,sire records, weaning weights, health treatments, and culling reasons. The [USDA National Animal Health Monitoring System](https://www.aphis.usda.gov/livestock-poultry-disease/nahms) collects producer data to identify disease prevalence and management risk factors at national scale. On,farm records that track mortality, morbidity, and treatment outcomes allow the owner to detect emerging disease patterns before they become epidemics. For tax and lending purposes, records must also include purchase receipts, veterinary invoices, feed purchases, and sales receipts. Banks and USDA Farm Service Agency loan officers will require multi,year cash flow projections that incorporate realistic mortality rates (typically 5,10% for lambs and 2,5% for mature ewes) and replacement culling. ## Welfare, Worker Safety, and [Food Safety](/knowledge/bacteria/livestock-bacteria/cooking-chicken-bacteria-prevention) Sheep welfare standards demand that animals are free from hunger, thirst, discomfort, pain, injury, disease, fear, and distress. The [Merck Veterinary Manual](https://www.merckvetmanual.com/) provides guidelines for humane handling facilities: low,stress chutes, non,slip flooring, and avoidance of electric prods on adult sheep. Footrot, flystrike, and internal parasites cause chronic pain and economic loss. A planned health program includes fecal egg counts, foot trimming schedules, and fly strike preventive shearing. Worker safety requires training in safe animal handling, proper use of syringes and needles, and management of [zoonotic diseases](/knowledge/veterinary-medicine/veterinary-pathology-microbiology/zoonotic-diseases-mechanisms-and-veterinary-public-health) such as Q fever and orf. Sharp object disposal and biosecure footwear should be standard. Food safety begins on the farm. Pre,harvest practices such as avoiding fecal contamination of fleece and meat, withholding antibiotics to meet withdrawal times, and maintaining clean water sources reduce the risk of foodborne pathogens entering the supply chain. Establish a record of all drug withdrawals and verify compliance with FARAD withdrawal intervals. ## Failure Patterns and Practical Monitoring The most common failure patterns in new sheep operations are: (1) underestimating labor requirements, (2) overestimating stocking rate, (3) inadequate cash reserves for feed or veterinary emergencies, and (4) lack of market outlet. The case study of reconstructing anthropogenic disturbances in Swiss forests illustrates that agricultural recovery after a major setback depends on pre,existing contingency plans and adaptive management ([Reconstructing anthropogenic disturbance regimes in forest ecosystems: A case study from the Swiss Rhone valley](https://api.elsevier.com/content/abstract/scopus_id/43149122450)). Similarly, a survey of Brazilian semi,arid livestock farms found that greater diversity of production enterprises and adoption of drought,resistant forage species mitigated economic losses during dry periods ([Sustainable agricultural production: An investigation in Brazilian semi-arid livestock farms](https://api.elsevier.com/content/abstract/scopus_id/84890310190)). Practical monitoring includes weekly walk,throughs of all pastures and pens, group behavior assessment, [body condition scoring](/knowledge/animal-farming/farm-management/body-condition-scoring-a-tool-for-feed-management) (BCS 1,5 scale) at breeding and weaning, and tracking feed consumption and water flow. Any unexplained drop in feed intake or group huddling requires immediate veterinary consultation. A written contingency plan for catastrophic events,extreme weather, disease outbreak, feed shortage,should be reviewed annually with the farm’s veterinarian and extension agent. Finally, all financial projections must be stress,tested with a 25% drop in lamb prices and a 20% increase in feed costs. If the business remains solvent under those assumptions, the land, labor, and facility plan is likely robust. Without that validation, purchasing a flock is a high,risk gamble instead of a calculated enterprise. ### Health Observation, Biosecurity, Diagnostics, and Sustainability Health observation begins with daily, systematic inspection of the flock. The producer must train eyes and ears to detect subtle changes in posture, gait, appetite, and social behavior that precede clinical disease. Routine monitoring of fecal consistency, respiratory rate, and body condition score provides baseline data. The [Merck Veterinary Manual](https://www.merckvetmanual.com/) emphasizes that early detection of lameness, nasal discharge, or altered rumination limits the spread of infectious agents and reduces treatment costs. A daily written health log that records observed signs and environmental conditions allows the producer and veterinarian to identify patterns, such as seasonal parasitism or nutritional deficiency, that require management changes. Biosecurity is a continuous operational requirement, not a one-time event. The [WOAH Terrestrial Animal Health Code](https://www.woah.org/en/what-we-do/standards/codes-and-manuals/terrestrial-code-online-access/) provides international standards for preventing introduction of pathogens into a naive flock. For a new operation, this means sourcing replacement animals from flocks with documented health status, isolating new arrivals for a minimum of 30 days in a separate facility, and using dedicated footwear and equipment for the quarantine area. The [USDA APHIS Livestock and Poultry Disease](https://www.aphis.usda.gov/livestock-poultry-disease) website offers guidance on reportable diseases such as scrapie, bluetongue, and foot and mouth disease, which must be notified to state or federal authorities upon suspicion. Failure to implement biosecurity protocols can introduce a pathogen that compromises the entire flock and surrounding operations. Diagnostic capability depends on a formal veterinary client patient relationship (VCPR). A VCPR is required in most jurisdictions for prescription medications, diagnostic testing, and official health certifications. The [USDA National Animal Health Monitoring System](https://www.aphis.usda.gov/livestock-poultry-disease/nahms) provides survey data on the prevalence of common pathogens such as *Mycoplasma ovipneumoniae*, *Clostridium perfringens*, and gastrointestinal nematodes. Producers should discuss with their veterinarian the appropriate diagnostic tests for their region and production system. Necropsy of any animal that dies without a clear cause is a critical diagnostic tool that can reveal herd level threats before they become clinical outbreaks. Uncertainty should be acknowledged when interpreting diagnostic results. Test sensitivity and specificity vary by pathogen, laboratory method, and stage of infection. The [Merck Veterinary Manual](https://www.merckvetmanual.com/) notes that a single negative test does not guarantee freedom from disease, especially during the incubation period. When unexpected morbidity or mortality occurs, the producer should contact the veterinarian immediately and preserve samples as directed, instead of administering treatments that may mask signs or interfere with testing. Sustainability in sheep farming integrates economic, environmental, and social dimensions. Research on small scale sheep and goat farming in semi arid Mediterranean environments indicates that enterprise resilience depends on diversification, efficient resource use, and adaptive management ([The sustainability of small-scale sheep and goat farming in a semi-arid Mediterranean environment](https://api.elsevier.com/content/abstract/scopus_id/85197663516)). Grazing management that matches stocking rate to forage availability improves soil health and reduces reliance on purchased feed, which buffers the operation against price volatility. A study of graziers in New England, New South Wales found that producers prioritize research on pasture management, weed control, and soil fertility as critical to long term productivity ([Surveying the management practices and research needs of graziers in the New England region of New South Wales](https://api.elsevier.com/content/abstract/scopus_id/84884545263)). Similarly, sustainable agricultural production in Brazilian semi arid livestock farms depends on integrated crop livestock systems and access to technical assistance ([Sustainable agricultural production: An investigation in Brazilian semi-arid livestock farms](https://api.elsevier.com/content/abstract/scopus_id/84890310190)). For the new sheep producer, sustainability means building a system that can withstand market fluctuations, climatic extremes, and disease challenges without depleting the resource base. Uncertainty is inherent in agricultural systems. Volcanic eruptions, droughts, and other large scale disturbances can disrupt feed supply and market access, as documented in the impacts on agriculture following the 1991 eruption of Vulcan Hudson in Patagonia ([Impacts on agriculture following the 1991 eruption of Vulcan Hudson, Patagonia: Lessons for recovery](https://api.elsevier.com/content/abstract/scopus_id/79955523294)). The reconstruction of disturbance regimes in forest ecosystems provides a framework for understanding how livestock operations can adapt to infrequent but high impact events ([Reconstructing anthropogenic disturbance regimes in forest ecosystems: A case study from the Swiss Rhone valley](https://api.elsevier.com/content/abstract/scopus_id/43149122450)). Producers should develop contingency plans for extreme weather, disease outbreak, and market collapse. These plans include maintaining a financial reserve, securing alternative feed sources, and having an agreed upon veterinary emergency protocol that specifies communication channels and response steps. ### Frequently Asked Questions **What is the first step in establishing biosecurity for a new flock?** Establish a quarantine protocol for all new animals. Isolate incoming sheep for a minimum of 30 days in a separate facility, use dedicated equipment, and monitor daily for signs of disease before introduction to the resident flock. Consult the [WOAH Terrestrial Animal Health Code](https://www.woah.org/en/what-we-do/standards/codes-and-manuals/terrestrial-code-online-access/) for international standards. **How often should I observe my sheep for health problems?** Conduct at least one complete visual inspection daily, ideally during feeding when animals are gathered and still. Observe posture, gait, appetite, and fecal consistency. The [Merck Veterinary Manual](https://www.merckvetmanual.com/) states that early detection of abnormalities reduces treatment cost and disease spread. **When should I call a veterinarian for a sick sheep?** Contact a veterinarian when you observe signs that do not resolve within 24 hours, such as persistent fever, anorexia, diarrhea, lameness, or respiratory distress. Always call for any sudden death, abortion storm, or neurologic signs. A valid veterinary client patient relationship is essential for timely diagnostic and therapeutic support. **What diseases are reportable in sheep?** Reportable diseases vary by jurisdiction but commonly include scrapie, foot and mouth disease, bluetongue, and rabies. The [USDA APHIS Livestock and Poultry Disease](https://www.aphis.usda.gov/livestock-poultry-disease) website provides a current list for the United States. Producers must notify state or federal authorities immediately upon suspicion. **How can I reduce the risk of internal parasite resistance?** Rotate anthelmintic drug classes based on fecal egg count reduction tests, avoid underdosing, and use targeted selective treatment protocols. Consult your veterinarian for a program specific to your farm's parasite ecology and regional resistance patterns. **What role does nutrition play in disease prevention?** Proper nutrition supports immune function and reduces susceptibility to infectious and metabolic diseases. Forage analysis and ration balancing ensure adequate energy, protein, minerals, and vitamins. Work with a nutritionist or veterinarian to adjust feeding during pregnancy, lactation, and growth. **How do I evaluate the sustainability of my sheep operation?** Assess soil health, forage quality, animal welfare, financial records, and community relationships. Participate in extension programs such as those offered through the [FAO Animal Production and Health](https://www.fao.org/animal-production/en/) network and review case studies like those in [The sustainability of small-scale sheep and goat farming in a semi-arid Mediterranean environment](https://api.elsevier.com/content/abstract/scopus_id/85197663516) for benchmarks. **What should I include in a contingency plan for disease outbreak or natural disaster?** Include contact information for your veterinarian and regulatory authorities, isolation protocols, euthanasia and disposal options, alternative feed and water sources, and financial reserves for at least three months of operating expenses. Review and update the plan annually. --- *Educational Veterinary Notice: The information presented here is for educational purposes and does not replace professional veterinary advice. Individual animal care and flock health management decisions should be made in consultation with a licensed veterinarian who is familiar with the specific farm conditions, regional disease risks, and applicable regulations. No treatment protocols or diagnostic thresholds are provided in this article because those must be tailored to the individual operation by a qualified professional.* ## Related Farming Guides - [Sheep Farming Flock Nutrition Grazing Lambing Parasite Risk And Welfare](/knowledge/animal-farming/sheep/sheep-farming-flock-nutrition-grazing-lambing-parasite-risk-and-welfare) - [Pasture Management For Sheep](/knowledge/animal-farming/sheep/pasture-management-for-sheep) - [Integrated Parasite Management In Sheep](/knowledge/animal-farming/sheep/integrated-parasite-management-in-sheep) - [Sheep Farm Biosecurity Plan](/knowledge/animal-farming/sheep/sheep-farm-biosecurity-plan) - [Farm Health Intelligence Observation Records Biosecurity Diagnostics And Veterinary Escalation](/knowledge/animal-farming/farm-management/farm-health-intelligence-observation-records-biosecurity-diagnostics-and-veterinary-escalation) ## Related Clinical & Scientific Guides * [Sheep Grazing Lease: Terms, Rates, and Legal Considerations](/knowledge/animal-farming/sheep/sheep-grazing-lease-terms-rates-and-legal-considerations) * [Sheep Breed Selection for Meat, Wool, Dairy, and Low-Input Systems](/knowledge/animal-farming/sheep/sheep-breed-selection-for-meat-wool-dairy-and-low-input-systems) * [Sheep Barn Flooring for Hoof Health: Best Materials and Practices](/knowledge/animal-farming/sheep/sheep-barn-flooring-hoof-health-materials-practices) ## References and Further Reading - [FAO Animal Production and Health](https://www.fao.org/animal-production/en/) - [WOAH Terrestrial Animal Health Code](https://www.woah.org/en/what-we-do/standards/codes-and-manuals/terrestrial-code-online-access/) - [USDA APHIS Livestock and Poultry Disease](https://www.aphis.usda.gov/livestock-poultry-disease) - [Merck Veterinary Manual](https://www.merckvetmanual.com/) - [USDA National Animal Health Monitoring System](https://www.aphis.usda.gov/livestock-poultry-disease/nahms) > This article is educational and is not a substitute for veterinary diagnosis, treatment, public-health guidance, or regulatory reporting.