Diseases of the MSK in Farm Animals PDF

Musculoskeletal Diseases in Farm Species Festus Adejoro  Learning Objectives At the end of this session, you should be able to:  Acquire a general knowledge of the pathogenesis, predisposing factors, and clinical features of bones, muscles, and joint disorders.  Demonstrate profi...

Musculoskeletal Diseases in Farm Species Festus Adejoro  Learning Objectives At the end of this session, you should be able to:  Acquire a general knowledge of the pathogenesis, predisposing factors, and clinical features of bones, muscles, and joint disorders.  Demonstrate proficiency in recognising how musculoskeletal diseases result in clinical symptoms and execute proper diagnostic sample collection.  Articulate knowledge of prevalent diseases affecting the musculoskeletal system in farm animals, along with effective management strategies encompassing prevention and treatment for individual animals and groups.  Analyse the economic implications of lameness and other musculoskeletal disorders for farmers and the broader agricultural Overview of Musculoskeletal Disorders Diseases Production Health Welfare  Aetiology of Diseases Management Environment Breed Age Pathogens  Components of the Musculoskeletal system  Bones  Muscles  Joints  Tendons and Ligaments  *Hoof The major clinical manifestations of diseases that affect them are lameness, failure of support, insufficiency of movement and deformity  Classification of MSK Diseases Various classifications of the diseases of the musculoskeletal system: 1. Mode of origin or genesis: Hereditary, Congenital, Acquired 2. Involvement of the system: Localised or Generalised- toxaemia, Septicaemia 3. Changes in the organ: Structural disease-e.g. Osteomalacia, Nephtitis; or Functional disease e.g. Cardial arrhythmia, valvular inefficiency 4. Causes or aetiology: Bacterial, Viral, Parasitic, Fungal, Protozoal, nutritional, etc. -also be grouped as contagious (spread by contact), infectious (spread by infecting organisms), non-specific (multiple aetiology) e,g. Diarrhoea, Pneumonia.  Clinical manifestation of Diseases One of the simplest is that which divides the disease into: The degenerative diseases of muscles, bones and joints are: 1.Myopathy 2.Osteodystrophy 3.Arthropathy The inflammatory diseases are: 1.Myositis 2.Osteomyelitis 3. Arthritis  Diagnosis and Examination of MSK Disorders  Environment and housing: Floor; field- hoof condition  Nutritional history: many osteodystrophies and myopathies are nutritional in origin, diet and nutrient intake/nutrient interaction evaluation  Physical examination of the animal/herd: Size, shape, symmetry, mobility score, abnormal gait, weakness, stiffness & pain, palpation (tone of muscle, consistency, tenderness)  Diagnostic tests: Radiographic exams e.g. X-ray, MRI, CT-scan Arthrocentesis and arthroscopy Muscle biopsy Clinical pathology e.g. CK, AST, LDH  Lameness in farm animals  An animal is said to be lame when its normal stance or gait is changed by a problem in one or more of the limbs, usually accompanied with pain in the MSK system.  Lameness is not a specific disease but may indicate a disorder in the musculoskeletal system.  Can exhibit mechanical lameness- developing abnormal gait as a result of scarred and thickened connective tissues or an abnormality in normal anatomy (such as a kneecap that is stuck in an abnormal position).  Disorders caused by nerve dysfunction (neuromuscular disorders) can also cause lameness.  Economic importance of lameness  Lameness in animals (horse, cow, pig, cat etc.) are a major animal welfare issue.  result in intense pain  causes stress, which debilitates and reduces productivity.  Loss of productivity  1.7–3 L/day reduction in milk production for up to 1 mo before and 1 mo after treatment (because of pain) + milk discarded because of antibiotic therapy  Racehorses  Lame cows are more reluctant to use automatic milking systems and show visible signs of stress when forced to do so.  Economic Importance of lameness  Reproductive failure: Inability to maintain breeding schedule, overworking of sound sires; increased pre-weaning mortality in lame sows;  Increased culling rate: at least 10% of cows in a herd are culled for reasons related to lameness.  cost of treatment  Difficult clinical management  Increase condemnation at slaughterhouse How can MSK diseases be a drawback to livestock sustainability goals?  Signs and Symptoms of Musculoskeletal disorders 1. Abnormal gait Lameness Stiffness (as in Rhabdomyolysis) Stumbling (as in Arthritis) 2. Abnormal Posture Shifting from limb to another (as in laminitis) Sticking out limb & dragging (as in sciatic nerve paralysis or unilateral hip dislocation) Extended hind limb (as in Spastic paresis) Persistent recumbency (e.g Myopathy) 3. Crackling sound while walking 4. Pain in standing, movement and on palpation 5. Deformity 6. Ease of fracture/Brittle bone  Nutrition and lameness: Case Study of Body Condition Score Mobility score (MS) and Body condition score (BCS) assessment of 731 cows with 6889 observations across 4 herds in the UK midlands Observation  Greater loss of BCS leads to a higher risk of lameness possibly due to the thinning effects on the digital cushion. BCS loss decreases an animal’s chance of recovery.  Wide change in BCS could influence the risk of becoming lame and the chance of recovery from lameness. Cows that have been lame for longer are less likely to recover.  Lame cows Source: have Word Microsoft shorter feeding times and - PVM_BCS_01_10_14 JK suffer reduced (core.ac.uk) feed intakes Diseases/disorders of the MSK system  Myopathy Non-inflammatory degeneration of skeletal muscle characterized clinically by: 1. Muscle weakness 2. Hyaline degeneration of the muscle fibres. 3. Elevated levels of muscle enzymes in serum 4. Myoglobinuria  Dystrophy-like Myopathies Muscular dystrophy-general term encompassing variety of inherited diseases that affect muscles of mammals.  Affected muscles have degenerative and atrophic changes: over time healthy muscle fibres are lost, replaced by fibrosis and fat  Muscle tissues are less able to generate force for everyday activity. -Duchenne muscular Dystrophy DMD in humans & dogs -Weaver syndrome in Brown Swiss cattle -Hyperplasia (Double muscling) in cattle -Pietran creeper syndrome- Pietran pigs https://doi.org/10.3892/ijmm.2017.3082  Disorder of joint-Arthritis A joint is classified as immovable (synarthrodial), slightly movable (amphiarthrodial), or freely movable (diarthrodial). Osteoarthritis-degenerative, progressive disease affecting the articular cartilage of diarthrodial joints. -Multifactorial- ageing, trauma, abnormal or excessive mechanical forces, poor conformation, hormones, genetic factors, and sepsis. Radiographic observation: soft tissue swelling, narrowing and/or unevenness of the joint space, subchondral bone lysis, subchondral bone sclerosis, osteophyte formation, joint remodelling, and periarticular new bone formation. Advanced stage: clinically observable cartilage damage causing synovitis or lameness. Treatment: Corticosteroids and NSAIDs symptomatic relief; glycosaminoglycans, pentosan polysulfate, hyaluronic acids;  Arthritis and Bursitis in Calves Case presentation and consultation findings -respiratory problems and cases of purulent arthritis in the calves -impaired fertility with high rates of retained fetal membranes & mastitis cases among dairy cows -several calves with pneumonia and swollen carpal and tarsal joints. -haematogenous spread of bacteria suspected rather than localised infection via skin -Radiography, X-ray, -Synovial fluid Sonography sampling exam? & exam Contrast to traumatic arthritis https://doi.org/10.1186/s12917-021-02996-6  Multifactorial causes of lameness in farm animals-1 Exertional rhabdomyolysis Nerve damage – Large Animal Surgery – Supplemental Notes (um n.edu) https://www.msdvetmanual.com/musculoskeletal- system/myopathies-in-horses/exertional- myopathies-in-horses  Exertional rhabdomyolysis-1 There is enhanced glycolysis with depletion of muscle glycogen, the accumulation of large amounts of lactate in muscle and blood and the development of hyaline degeneration of myofibers  Exertional rhabdomyolysis Three stages of rhabdomyolysis 1. Muscular dystrophy Degeneration of skeletal muscle Muscular weakness and stiff gait 2.Myoglobinurea Liberation of Myoglobin Elevation of Muscle Enzymes-creatine kinase (CK), aldolase, and lactate dehydrogenase, 3.Myoglobinuric nephrosis Release of intracellular muscle components, as well as electrolytes, into the bloodstream and extracellular space. tea-coloured urine  Myositis 1. Myositis arises from direct or indirect trauma to muscle. 2. Abnormal immune reaction of the body directed against the muscle- (Immune-mediated Myositis) 2. Occurs as part of a syndrome in a some diseases e.g. blackleg, foot and mouth disease, bluetongue, ephemeral fever, sarcosporidiosis and trichinosis. 3. Sporadic cases of a localized infectious myositis of skeletal muscles, associated with Escherichia coli, may occur in calves. 4. An asymptomatic eosinophilic myositis occurs  Acute myositis of limb muscles Acute myositis of limb muscles: This disease is accompanied by severe lameness, swelling, heat and pain on palpation. There may be accompanying toxemia and fever. In chronic myositis There is much wasting of the affected muscles and this is difficult to differentiate clinically from atrophy due to other causes. So, biopsy of the muscles may be necessary to confirm the diagnosis. 3. Traumatic myositis of the posterior thigh muscles may be followed by the formation of fibrous adhesions between the muscles (fibrotic myopathy) and by subsequent calcification of the adhesions (ossifying myopathy). 4. External trauma can result in fibrotic myopathy but it may also be associated with excessive exercise or secondary to intramuscular injections.  Laminitis -Laminitis = “inflammation of the laminae,” -either a short-term inflammation or the disease caused by long-term or repeated attacks of inflammation. -The sensitive laminae is attached to the pedal bone. -The insensitive laminae- layers of tissue just inside the hard exterior of the hoof. -Can develop in the forefeet, in all 4 feet, or in the hindfeet only. -Acute: 1-3 days; before any displacement of the pedal bone; Subacute: > 3 days but no displacement of the pedal bone; Chronic: pedal bone displacement, regardless of duration. Hoof Structure  Laminitis- Causal factors - Excessive soluble carbohydrate intake-lush pasture, grains etc. -Inflammatory-inducing diseases causing inflammatory responses- sepsis or toxin (endotoxaemia) Spread -Endocrinopathies such as -equine metabolic syndrome, -ingestion of black walnut heartwood shavings, -retained placenta after delivery of a foal, -treatment with corticosteroids and certain other medications. -higher risk in ponies and in overweight horses  Laminitis-Treatment & Control -Acute state: medical emergency because pedal displacement can occur quickly. Contact a vet. -Cooling the affected foot by placing it directly in ice water (called digital hypothermia) may protect the laminae early & and attempt to restore the normal alignment of the rotated coffin bone. Cryotherapy -Anti-inflammatory therapy for sepsis-related acute laminitis. E.g. parenteral antibiotics (when bacterial infection is documented), -Pain management- nonsteroidal anti-inflammatory drugs (NSAIDs) and hyperimmune serum or plasma. -Corrective hoof trimming and shoeing with an appropriate shoe https:// may be implemented. www.researchgate.net/ publication/ -Surgical options include severing of the deep digital flexor tendon 321224490_The_potential (tenotomy) and removal of a section of the separated hoof wall. _of_the_bare_hoof_after_d amage_due_to_laminitis  Pathogenesis of nutritional Muscular Dystrophy In primary nutritional muscular dystrophy Deficiency 'of vitamin E and/ selenium causes Lipo-peroxidation of the cellular membranes of muscle fibres Degeneration and necrosis  Predisposing factors to Nutrition-induce Muscular dystrophy Deficiency of vitamin E and/ selenium is a common cause of nutrition-induced muscular dystrophy in young calves, lambs, foals, and piglets. Also common in adult horses Factors Enhancing or precipitating onset include: 1. Rapid growth, 2. Highly unsaturated fatty acids in diet and 3. Unaccustomed exercise Dyschondroplasia Milk Fever  Milk fever in cows  Milk Fever: common among transition dairy cows and occurs around calving up to 24 h  Hypocalcaemia. < 2.0mM but more than 1.4mM blood calcium (acute hypocalcemia). Below 1.4mM, there is a significant risk of death.  Hypocalcemia is often accompanied by other problems, including hypomagnesemia and hypophosphatemia.  As soon as a cow has calved, its calcium requirements will increase by around 400%.  A lack of muscle function characterises milk fever. Left untreated, muscle paralysis will end up getting worse.  Cows start walking somewhat stiffly, often sit quietly and are unable to rise.   Milk Fever -2  Unless proper and urgent treatment, cows generally end up dying. Prevention:  All cases can be prevented. Avoid breeding with sires with frequent milk fever diseases. Prevent cows from getting too fat. Cows with rapid change in BCS are likely to suffer milk fever.  Feed transition diet that reduced Diet Cation-Anion Exchange difference (DCAD) Treatment  Slow and intravenous infusion of calcium borogluconate. The solution should be warmed to be similar to the cow’s body temperature to maximise absorption.  In the UK and Ireland, products that contain calcium borogluconate, often with magnesium and phosphorus added to them, are preferred. Around 85% of cows respond well after one treatment.  Cow’s legs should be massaged from time to time.  Resources AHDB guide to reducing lameness: https://projectblue.blob.core.windows.net/media/Default/Beef%20 &%20Lamb/BRP_ReduceLame3484_200323_WEB.pdf  Footrot - Pathogenesis Dichelobacter nodous is essential organism for footrot. Scald/strip/interdigital dermatitis is caused by various bacteria that invade the surface layers of the skin between the claws (interdigital skin) following damage by moisture, frost and/or mechanical damage from long Scald with interdigital space grass, thistles, etc. One common bacterium associated affected with scald is Fusobacterium necrophorum. However if D.nodosus is present on the farm, footrot develops in first stage as scald and then second stage characterised by under-running of hoof horn and a characteristic smell. Both are anaerobic bacteria. Key Point: Scald and early stages of footrot are clinically indistinguishable Footrot with under running of heel sole and hoof wall Footrot key facts-1 The bacteria that cause footrot (D. nodosus) are adapted to live and survive on the feet of sheep D. nodosus survives on pasture or bedding for up to 14 days D. nodosus survives in hoof horn clippings for long time Footrot key facts-2 Infection can spread between sheep if they walk on the same surface Lame sheep can be treated with a combination of antibiotic injections and topical antibiotic sprays In a small number of sheep the infection can be very difficult to treat. They tend to get repeat infections and are a source of infection to the rest of the flock Within-herd pathogen transfer-1 Within-herd pathogen transfer-2 Within-herd pathogen transfer-3  Recap- Learning objectives Give examples of disease conditions which affect animal MSK system Name the causative agents which are responsible for causing diseases e.g footrot in sheep Outline how and why a disease can spread within a population. Identify the risk factors for disease across livestock species Prescribe appropriate procedures to diagnose and manage some musculoskeletal disorders. Describe how nutritional deficiencies interfere with metabolic functions that result in diseases associated with the Musculo- skeletal system  Supplementary Reading List Anatomy and Physiology of Farm Animals. 7th edition by Frandson, Rowen D., Wilke, W. Lee, Fails, Anna Dee (Available online) Sherwood, L., Klandorf, H. & Yancey, P.H. (2013) Animal Physiology: From Genes to Organisms, 2nd Edition, Brooks/Cole, CENGAGE Learning, pg 291-295, 323-328 Tortora, G.J. & Derrickson, B.H. (2009) Principles of Anatomy and Physiology, 12th Edition, Wiley, Chapter 6 The Skeletal System: Bone Tissue Nerve damage – Large Animal Surgery – Supplemental Notes (umn.edu)