Arthritis (infectious, degenerative)

Arthritis in farm animals encompasses a range of joint disorders characterized by inflammation, cartilage degradation, and impaired joint function that significantly impacts animal welfare, production, and economic returns. This broad category includes both infectious arthritis, where bacterial or other microbial agents directly invade joint structures causing acute inflammation and tissue destruction, and degenerative arthritis, where progressive wear and aging lead to cartilage breakdown and chronic joint dysfunction. These conditions represent major causes of lameness across all major livestock species and present substantial challenges for diagnosis, treatment, and prevention in commercial farm animal production systems.

Arthritis affects virtually all farm animal species, though the specific forms and prevalence vary considerably. In cattle, both infectious and degenerative arthritis are common, with infectious forms particularly affecting young calves through navel infection routes and degenerative forms becoming increasingly prevalent in older dairy cows subjected to the demands of high production. Sheep and goats experience arthritis from various infectious agents including Mycoplasma species and Chlamydia, as well as degenerative changes in aging animals. Swine frequently develop both infectious polyarthritis in young pigs and degenerative joint disease in breeding stock. The combined impact of arthritic conditions across species makes this category one of the most significant musculoskeletal disorders in livestock production.

The economic and welfare impact of arthritis in farm animals is substantial and multifaceted. Lame animals experience chronic pain that affects behavior, feed intake, and productive performance. Dairy cows with arthritis show reduced milk production, impaired reproductive efficiency, and shortened productive lifespans. Beef cattle with joint problems gain weight poorly and may be severely discounted at market. Breeding animals of all species may become unable to perform natural mating due to joint pain or instability. The cost of treating arthritic animals includes veterinary fees, medications, additional labor, and extended care requirements. Severe or refractory cases often result in premature culling or salvage slaughter, representing significant economic loss.

Early detection and appropriate intervention significantly improves outcomes for animals with arthritis, though prognosis varies substantially between infectious and degenerative forms. Acute infectious arthritis treated promptly with appropriate antimicrobials may resolve completely, while delayed treatment often results in permanent joint damage despite aggressive therapy. Degenerative arthritis is typically manageable but not curable, with treatment focused on pain control and slowing disease progression. Regular observation of animals for early signs of lameness, combined with systematic lameness scoring programs, enables timely identification and treatment. Understanding the specific etiology of arthritis in affected animals guides treatment selection and prevention strategies for the broader herd.

The primary causes of arthritis in farm animals divide into infectious and non-infectious categories with distinct etiologies and pathogenic mechanisms. Infectious arthritis results from bacterial, mycoplasmal, or viral invasion of joint structures, with multiple routes of entry depending on age and circumstances. In neonates, umbilical infection provides a direct pathway for bacteria to enter the bloodstream and localize in joints, a condition commonly called navel ill or joint ill. Wounds, including tail docking sites, castration sites, and traumatic injuries, may serve as entry points for bacteria that spread hematogenously to joints. Direct inoculation through penetrating injuries that breach the joint capsule can introduce bacteria directly into synovial fluid. Extension from adjacent bone infections (osteomyelitis) or soft tissue abscesses may involve joints secondarily.

Genetic and breed predisposition influences susceptibility to both infectious and degenerative forms of arthritis. For infectious arthritis, genetic variation in immune function affects the ability to resist bacterial invasion and clear established infections. Breeds with known immunodeficiency traits show elevated susceptibility to septic arthritis. For degenerative arthritis, conformation plays a critical role, with animals possessing poor leg structure experiencing greater joint stress and earlier cartilage breakdown. Rapid growth rates selected in meat-producing livestock can outpace skeletal development, predisposing to joint problems. Certain bloodlines within breeds demonstrate higher rates of developmental orthopedic disease that predisposes to later degenerative changes. The heritability of conformational traits allows genetic progress in reducing arthritis susceptibility through selection.

Environmental and management factors substantially influence arthritis risk across all farm animal species. Poor hygiene in calving or lambing areas increases neonatal exposure to environmental bacteria that cause joint infections. Inadequate colostral immunity leaves young animals susceptible to septicemia and joint localization. Hard flooring surfaces in confinement housing accelerate wear on articular cartilage and contribute to degenerative changes. Overcrowding increases traumatic injuries that may lead to infectious or degenerative joint disease. Nutritional imbalances, including mineral deficiencies or excesses, affect cartilage and bone quality. Rapid growth promoted by high-energy diets may exceed the capacity of developing joints to adapt.

Risk factors for developing arthritis include age, production demands, housing conditions, and previous joint injury. Young animals are most susceptible to infectious arthritis through navel or wound contamination. Older animals are more likely to develop degenerative arthritis from accumulated wear. High-producing dairy cows experience greater joint stress from body weight and metabolic demands. Animals housed on concrete develop more degenerative joint disease than those on softer surfaces or pasture. Previous joint trauma, even if healed, predisposes to later degenerative changes. Systemic illness that compromises immune function increases susceptibility to infectious arthritis.

The pathophysiology of infectious arthritis involves bacterial invasion of the synovial membrane and joint space, triggering intense inflammatory responses. Bacteria may reach joints via bloodstream (hematogenous spread) or direct introduction. Within the joint, bacterial proliferation stimulates recruitment of inflammatory cells and release of destructive enzymes. The resulting inflammatory process degrades articular cartilage and may damage underlying bone. Fibrin accumulation and pus formation impair joint nutrition and function. If not rapidly controlled, permanent cartilage destruction occurs within days to weeks. Degenerative arthritis follows a different pathway, beginning with mechanical cartilage damage that initiates inflammatory cascades. Progressive loss of cartilage exposes subchondral bone, causing pain and bony remodeling. Osteophyte formation and joint capsule thickening develop over time, limiting range of motion.

Early warning signs of arthritis in farm animals often manifest as subtle changes in movement and behavior that require careful observation to detect. Animals in the early stages may show slight stiffness, particularly when first rising or beginning to walk after rest. Reluctance to move with the group or lagging behind during movement to pasture or between facilities may indicate developing joint discomfort. Subtle changes in gait, including shortened stride length or slight head bobbing, precede obvious lameness. Reduced feed intake and time spent at feed bunks can reflect early joint pain, especially in cattle where prolonged standing is required. Young animals with developing joint infections may show mild fever and reduced nursing activity before lameness becomes apparent.

Common symptoms of established arthritis vary somewhat between infectious and degenerative forms but share features of lameness and joint dysfunction. Infectious arthritis typically presents with sudden-onset severe lameness, often affecting one or more joints that become visibly swollen, hot, and painful on palpation. Affected animals may hold the limb up or show non-weight-bearing lameness. Fever and systemic illness commonly accompany acute joint infection. Degenerative arthritis presents more gradually, with progressive lameness that may initially be intermittent and worsen over time. Affected joints may show subtle enlargement from bony changes and capsular thickening. Pain on joint manipulation and reduced range of motion are characteristic. Morning stiffness that improves with movement suggests degenerative rather than infectious etiology.

Behavioral changes in animals with arthritis reflect chronic pain and functional limitations. Reluctance to rise, prolonged time spent lying, and difficulty achieving standing position indicate joint discomfort. Animals may isolate from herd or flock mates and show reduced social interaction. Feed intake typically decreases, with weight loss following in chronic cases. Breeding animals may refuse to mount or be mounted due to joint pain. Cattle with hindlimb arthritis may show characteristic stance alterations and reluctance to walk or turn. Sheep and goats often kneel to graze when front limb joints are affected. Pigs with arthritis may sit dog-fashion to relieve pressure on affected limbs.

Physical signs of arthritis on examination depend on the type and duration of joint involvement. Acute infectious arthritis produces marked joint effusion with fluctuant swelling around the joint. The affected area is hot to touch and intensely painful, causing withdrawal response on palpation. Surrounding soft tissue may show cellulitis or evidence of wound or umbilical infection that served as bacterial entry point. Degenerative arthritis presents with firmer, less painful joint enlargement from bone proliferation and capsular fibrosis. Crepitus, a grinding sensation felt during joint manipulation, indicates cartilage loss and bone-on-bone contact. Range of motion is reduced, and extremes of flexion or extension elicit pain response. Joint instability from ligament damage or severe cartilage loss may be detected.

Symptom progression differs substantially between infectious and degenerative forms of arthritis. Untreated infectious arthritis progresses rapidly over days, with worsening lameness, increasing systemic illness, and expanding joint destruction. Multiple joints may become involved through continued bacteremia. Severely affected animals may become recumbent and unable to rise. Death can result from overwhelming sepsis if treatment is not instituted. Degenerative arthritis follows a more protracted course over months to years. Gradual worsening of lameness occurs with periodic acute flare-ups. Progressive loss of function limits productive activities and quality of life. End-stage degenerative arthritis results in severely compromised animals unable to ambulate normally.

Emergency symptoms requiring immediate veterinary intervention include signs of septic shock accompanying infectious arthritis, including severe depression, cold extremities, rapid weak pulse, and recumbency. Sudden complete inability to bear weight on a limb suggests severe joint compromise. High fever with multiple swollen joints indicates life-threatening polyarthritis. Evidence of joint rupture with discharge of purulent material requires urgent attention. Young animals with rapid deterioration despite initial treatment may need reassessment and treatment modification. Any recumbent animal with arthritic disease requires immediate evaluation to address both the joint condition and complications of recumbency.

Clinical examination for arthritis combines systematic lameness evaluation with detailed assessment of affected joints. Observation of the animal at rest notes posture, weight distribution, and obvious joint swelling. Gait evaluation at walk assesses stride length, head movement, and limb placement. Each joint of affected limbs is examined through inspection, palpation, and manipulation. Visual assessment identifies swelling, asymmetry, and overlying skin changes. Palpation evaluates temperature, consistency of swelling, and pain response. Manipulation assesses range of motion, stability, and crepitus. Comparison with contralateral joints and expected normal findings guides interpretation. Systematic lameness scoring using validated scales standardizes evaluation and tracks changes over time.

Diagnostic tests for arthritis help distinguish infectious from non-infectious causes and guide treatment selection. Joint fluid analysis (arthrocentesis) provides essential information about joint inflammation and infection. Fluid from infected joints appears turbid or purulent with elevated cell counts dominated by neutrophils. Bacterial culture of joint fluid identifies the causative organism and enables antimicrobial sensitivity testing. Radiography reveals bony changes including osteoarthritis, osteomyelitis extension, and chronic joint destruction. Ultrasonography can evaluate soft tissue structures, joint effusion, and guide arthrocentesis. Advanced imaging including computed tomography or MRI provides detailed assessment of complex cases. Blood work evaluates systemic inflammatory response and identifies concurrent disease.

Differential diagnosis of arthritis must consider other causes of lameness and joint swelling. Traumatic injuries including fractures, sprains, and lacerations can cause acute lameness and swelling that mimics infectious arthritis. Foot rot and other foot diseases cause lameness but examination localizes the problem to the foot rather than joints. Bone tumors may involve joints secondarily. Nutritional diseases including rickets and white muscle disease cause musculoskeletal signs but have different presentations. Developmental orthopedic diseases including osteochondrosis and angular limb deformities may be confused with arthritis. Careful examination distinguishing joint involvement from adjacent structure pathology guides diagnosis.

Herd-level diagnostics become important when multiple animals develop arthritis, suggesting common risk factors or infectious disease. Analysis of age distribution and temporal clustering helps identify outbreak patterns. Review of management practices including navel care, hygiene, and vaccination protocols reveals potential intervention points. Bacterial culture of cases identifies pathogens and antimicrobial resistance patterns relevant to treatment decisions. Necropsy of animals that die or are euthanized provides detailed assessment of joint pathology and may identify underlying conditions. Evaluation of facility design and flooring assesses contribution to degenerative disease. Nutritional analysis ensures mineral balance supports musculoskeletal health.

Emergency and immediate treatment of infectious arthritis focuses on controlling systemic infection and initiating antimicrobial therapy. Broad-spectrum antibiotics should be administered immediately upon diagnosis, adjusted based on culture results when available. Supportive care including anti-inflammatory medications reduces pain and inflammation, noting withdrawal time requirements in food animals. Fluid therapy addresses dehydration in systemically ill animals. Affected animals should be moved to comfortable, well-bedded housing to reduce further joint stress. Young animals with joint ill require aggressive treatment given rapid disease progression. Emergency drainage of severely distended joints may provide mechanical relief and therapeutic samples. Initial treatment intensity establishes trajectory for recovery.

Medical management of arthritis varies between infectious and degenerative forms. Infectious arthritis requires prolonged antimicrobial therapy, typically three to six weeks, to adequately treat the avascular joint environment. Antibiotic selection should be guided by culture and sensitivity when possible, with empirical choices favoring drugs with good bone and joint penetration. Commonly used antibiotics include ceftiofur, florfenicol, and oxytetracycline, all subject to withdrawal time regulations. Non-steroidal anti-inflammatory drugs reduce pain and inflammation but require attention to withdrawal times and potential side effects. Joint lavage, where the joint is flushed with sterile fluid, removes inflammatory debris and bacteria. Intra-articular injection of antibiotics delivers high local concentrations but requires sterile technique. Degenerative arthritis treatment focuses on pain management with NSAIDs and management modifications to reduce joint stress.

Surgical options for arthritis depend on the specific condition and joint involved. Joint lavage and drainage can be performed through needle aspiration or arthroscopy. Surgical drainage and debridement may be necessary for severe joint infections with abscess formation. Arthrodesis, surgical fusion of the joint, eliminates motion and pain in severely damaged joints where fusion is compatible with function. Amputation may be considered for distal limb involvement in small ruminants or young animals. Surgical intervention is generally reserved for cases failing medical management or requiring drainage of loculated infection. Economic considerations often limit surgical options in food animals compared to companion species.

Supportive care during arthritis treatment addresses both the joint condition and overall animal welfare. Housing on soft, clean bedding reduces further joint trauma and promotes comfort. Provision of easily accessible feed and water ensures adequate nutrition during recovery. Assistance with rising may be needed for animals with severe lameness or multiple affected limbs. Physical therapy including passive range of motion exercises may prevent contracture development. Weight management reduces load on affected joints. Hoof trimming corrects any conformational abnormalities that add joint stress. Monitoring for secondary complications including pressure sores and pneumonia is important for recumbent animals.

Herd treatment protocols for arthritis focus primarily on prevention when infectious disease is involved and management modification for degenerative conditions. When outbreaks of infectious arthritis occur in young animals, evaluation and improvement of navel care protocols is essential. Prophylactic antibiotic administration may be considered in high-risk situations but should be used judiciously. For degenerative arthritis problems, evaluation of flooring, stocking density, and nutrition guides herd-level interventions. Implementation of lameness scoring programs enables early identification and treatment. Genetic selection against poor conformation reduces future disease incidence.

Treatment decision factors for arthritis include animal value, disease severity, treatment cost, and prognosis. High-value breeding animals may warrant aggressive treatment including surgery and prolonged therapy. Commercial animals with severe or chronic arthritis may be better served by humane slaughter than extended treatment with poor prognosis. Food safety regulations regarding withdrawal times influence treatment selection and timing of marketing. Early-stage disease responds better than advanced cases, favoring prompt intervention. Multiple joint involvement carries worse prognosis than single joint disease. Animal welfare must guide decisions, with euthanasia appropriate for animals experiencing uncontrollable pain or severely compromised quality of life.

Recovery timeline for arthritis varies dramatically based on type, duration before treatment, and severity of joint damage. Acute infectious arthritis treated within the first few days of symptoms may resolve within two to four weeks with appropriate therapy, though full joint healing continues over months. Delayed treatment of infectious arthritis typically results in some degree of permanent joint damage despite treatment. Degenerative arthritis does not truly recover but can be managed; initial response to treatment may be seen within one to two weeks, with ongoing management required indefinitely. Animals with chronic arthritis may show improvement with management changes but rarely return to normal joint function. Setting appropriate expectations helps guide management decisions.

Post-treatment care and monitoring for arthritis extends well beyond initial treatment completion. Animals recovering from infectious arthritis should have joints monitored for resolution of effusion and return of normal function. Antibiotic courses must be completed even when clinical improvement occurs early. Gradual return to normal activity prevents reinjury of healing joints. For degenerative arthritis, ongoing monitoring assesses treatment effectiveness and disease progression. Lameness scores tracked over time indicate whether management is adequate. Regular hoof trimming and attention to housing conditions continue throughout the animal's life. Production records help assess economic impact and guide culling decisions.

Prognosis factors for arthritis include the specific condition, timing of treatment, joint involved, and animal age. Infectious arthritis caught and treated within forty-eight hours of onset has fair to good prognosis for functional recovery. Treatment delayed beyond one week carries poor prognosis due to cartilage destruction. Weight-bearing joints have worse prognosis than peripheral joints. Multiple joint involvement indicates more severe systemic disease with guarded outlook. Young animals have better healing capacity but may be more severely affected initially. Degenerative arthritis prognosis depends on severity; early-stage disease is manageable while advanced cases may warrant culling.

Return to production considerations after arthritis depend on the role of the affected animal. Breeding animals must be able to perform mating activities comfortably; residual joint stiffness may preclude natural service. Dairy cows need adequate mobility for daily trips to the milking facility and should not experience pain severe enough to affect production. Beef cattle must gain weight efficiently; chronic lameness typically reduces gains below profitable levels. Animals recovered from infectious arthritis should be monitored for recurrence, which may indicate inadequate initial treatment or persistent infection focus. Economic analysis comparing treatment costs, ongoing management needs, and production losses guides decisions about retaining recovered animals versus culling.

Vaccination protocols play an important role in preventing infectious arthritis caused by specific pathogens. Clostridial vaccines protect against some causes of septic arthritis in ruminants. Mycoplasma vaccines are available for some species and reduce the incidence of mycoplasmal polyarthritis. Erysipelas vaccination in swine prevents this significant cause of arthritis. Autogenous vaccines may be developed for herds with specific bacterial isolates causing recurrent problems. Vaccination timing should ensure protection during high-risk periods, with young animal protection requiring maternal immunization for colostral transfer. No vaccines prevent degenerative arthritis, which requires management-based prevention strategies.

Biosecurity measures for preventing infectious arthritis focus on reducing bacterial exposure and preventing disease introduction. Calving and lambing areas should be clean, dry, and well-bedded to minimize neonatal exposure to environmental bacteria. Navel dipping with appropriate antiseptics immediately after birth reduces umbilical infections that lead to joint ill. Isolation and treatment of animals with infectious arthritis prevents spread to herdmates. Quarantine protocols for new arrivals include observation for lameness and joint swelling. Control of blood-sucking insects reduces transmission of some arthritic pathogens. General herd health management that reduces stress and maintains immune function supports disease resistance.

Nutritional prevention of arthritis addresses both direct effects on joint tissue and indirect effects through body condition management. Adequate mineral nutrition, particularly calcium, phosphorus, copper, and zinc, supports skeletal health. Vitamin D sufficiency ensures proper calcium metabolism and bone quality. Avoiding rapid growth in young animals through appropriate energy restriction reduces developmental orthopedic disease that predisposes to later arthritis. Preventing excessive body condition reduces load on weight-bearing joints. Adequate protein intake supports tissue maintenance and repair. Trace mineral programs should be evaluated and adjusted based on regional deficiencies and production demands.

Management practices for preventing arthritis encompass housing, handling, and genetic selection. Flooring surfaces should provide adequate traction without being abrasive; rubber matting over concrete significantly reduces degenerative joint disease. Adequate space prevents crowding injuries and allows normal movement. Handling facilities should allow safe movement without traumatic events. Regular hoof trimming maintains correct leg conformation and reduces abnormal joint forces. Exercise opportunities support joint health and prevent stiffness. Appropriate stocking density and group management reduces social stress and competition injuries. Genetic selection for sound conformation produces animals with more durable musculoskeletal systems.

Quarantine and testing protocols for arthritis-related conditions apply particularly to prevention of infectious forms. New arrivals should be observed during quarantine for signs of lameness or joint swelling that could indicate infectious arthritis. Animals with history of chronic lameness should be carefully evaluated before purchase. Testing for specific pathogens such as Mycoplasma may be appropriate for herds with ongoing problems. Genetic evaluation of breeding stock for conformational soundness reduces introduction of traits predisposing to degenerative arthritis. Pre-purchase examination should include careful evaluation of leg conformation and joint health.

Daily management and monitoring of animals at risk for or affected by arthritis requires systematic observation integrated into routine procedures. Regular lameness scoring of all animals enables early identification of developing problems. Observation of animals rising and lying provides information about joint comfort. Feed intake monitoring may reveal early pain-related decreases in consumption. Animals with known arthritis history should be tracked more closely for recurrence or progression. Training personnel to recognize early signs of lameness improves detection rates. Documentation of observations enables trend analysis and treatment evaluation.

Housing and environmental management significantly impact both development and progression of arthritis. Flooring choices represent one of the most impactful decisions; softer surfaces dramatically reduce joint stress compared to concrete. Rubber matting, deep bedding, or dirt lots provide more joint-friendly environments. Adequate bedding depth in resting areas cushions joints during lying and rising. Stall dimensions should allow comfortable lying without joint strain from awkward positions. Non-slip surfaces prevent traumatic injuries that can initiate infectious or degenerative arthritis. Protection from extreme cold, which exacerbates arthritis pain, benefits affected animals. Facility design that minimizes distance traveled reduces joint loading in lame animals.

Herd health programs should incorporate systematic lameness assessment as a core component. Regular locomotion scoring using validated systems tracks herd lameness prevalence. Target levels for lameness prevalence guide intervention decisions. Protocols specify treatment thresholds and therapeutic approaches. Root cause analysis when lameness prevalence exceeds targets identifies contributing factors. Integration with other health monitoring programs ensures comprehensive assessment. Veterinary involvement provides expertise for complex cases and program evaluation. Benchmarking against industry standards or comparable operations provides context.

Record keeping and monitoring systems support effective arthritis management. Individual animal records document lameness episodes, treatments, and outcomes. Tracking treatment success rates evaluates protocol effectiveness. Recording lameness by location within facilities identifies problem areas. Genetic records allow analysis of sire effects on offspring soundness. Production records correlated with lameness history quantify economic impact. Analysis of accumulated data reveals patterns and guides intervention. Sharing records with advisors enables collaborative problem-solving.

Economic considerations for arthritis management include prevention investments, treatment costs, and production impacts. Prevention through improved facilities and management typically provides positive return through reduced disease incidence. Treatment costs include medications, veterinary services, and additional labor. Production losses from arthritis include reduced milk yield, poor weight gain, impaired reproduction, and shortened productive lifespan. Premature culling represents both direct loss and replacement cost. Cost-benefit analysis supports decision-making about treatment intensity and culling thresholds. Investment in genetic improvement for soundness provides long-term returns.

High-risk breeds and species for arthritis vary depending on the type of arthritis considered. For infectious arthritis, susceptibility relates more to management factors and pathogen exposure than breed. However, breeds with known immunodeficiency traits may be more susceptible to septicemia and joint localization. For degenerative arthritis, breeds and lines selected for rapid growth often experience higher rates due to skeletal stress from heavy muscling. In cattle, heavily muscled beef breeds and high-producing dairy breeds with large frames face elevated risk. Swine breeds selected for maximum growth show high rates of osteochondrosis and subsequent arthritis. Sheep breeds vary in susceptibility to specific infectious causes of arthritis.

Production type considerations strongly influence arthritis risk profiles. Dairy cattle experience high rates of degenerative arthritis due to the combined stresses of high production, large body size, and housing on hard surfaces. Beef cattle have lower overall arthritis rates but may develop problems in feedlot conditions or with rapid growth. Breeding males of all species face elevated risk due to the physical demands of mating. Young animals are most susceptible to infectious arthritis, while degenerative forms increase with age. Intensive production systems with confinement housing typically see more arthritis than extensive pasture-based systems. The economic pressure for early marketing may not allow time for degenerative changes to become apparent.

Genetic selection and testing offer opportunities to reduce arthritis prevalence over time. Sire evaluations for feet and leg conformation provide selection criteria for producing sounder offspring. Genomic testing can identify animals carrying unfavorable alleles for developmental orthopedic disease. Culling animals with chronic lameness removes susceptible genetics from the breeding population. Selection indexes that include structural soundness alongside production traits enable balanced improvement. Breed associations that publish feet and leg evaluations facilitate informed breeding decisions. Long-term genetic progress requires consistent selection pressure maintained over multiple generations.

Commonly co-occurring conditions with arthritis include other musculoskeletal and systemic disorders. Foot diseases including foot rot, digital dermatitis, and sole ulcers may coexist with joint problems and must be distinguished diagnostically. Osteomyelitis, infection of bone adjacent to joints, may be the primary condition with secondary joint involvement. In young animals with joint ill, concurrent infections including navel ill, pneumonia, and meningitis reflect the septicemic nature of disease. Metabolic conditions including hypocalcemia in cattle can cause weakness mimicking lameness. Degenerative arthritis often accompanies other aging-related conditions in older animals.

Conditions with similar symptoms to arthritis require differentiation for appropriate treatment. Fractures cause acute severe lameness that may be confused with septic arthritis. Nerve damage produces lameness with different characteristics on examination. Tendon and ligament injuries affect limb function without primary joint involvement. Foot lesions including abscesses, sole injuries, and interdigital problems cause lameness originating below the joint. Muscle conditions including white muscle disease in young animals and exertional rhabdomyolysis can affect gait. Spinal conditions may produce hindlimb weakness or abnormal gait. Careful localization of the problem through systematic examination distinguishes these conditions.

Complications and sequelae of arthritis include both joint-specific and systemic consequences. Chronic infectious arthritis may result in joint ankylosis, permanent stiffness from fibrous or bony fusion. Septic arthritis can spread to adjacent bone causing osteomyelitis. Systemic sepsis from joint infection can be life-threatening. Progressive degenerative arthritis leads to increasing disability and chronic pain. Secondary problems from altered gait and compensatory limb loading include opposite limb overload and muscle atrophy. Recumbency from severe bilateral involvement leads to pressure sores, aspiration pneumonia, and other complications. Quality of life concerns may necessitate euthanasia for severely affected animals.