Veterinary Medicine: Muscle Disorders Quiz

Ruminant Muscular System Disorders

• Clostridium spp.: Gram-positive bacteria; infection routes include ingestion (botulinum, perfringens) and wound contamination (chauvoei, septicum, tetani); diagnosis involves enzyme tests (CK and AST) and smear analysis; treatment includes antibiotics and surgery; vaccination is available.

Clostridium Chauvoei (Blackleg)

• Effects: Upper leg, diaphragm, tongue, heart, neck, and jaw; no penetrating trauma required.
• Clinical Signs: Initially, muscles are hot, tight, and painful, progressing to painless and cold emphysema; infected muscles are dark and dry; localized post-mortem emphysema is significant.

Clostridium septicum / novyi (Malignant edema)

• Effects: Any muscle; penetrating trauma is required.
• Clinical Signs: Soft doughy muscles (edema); infected muscles are red and wet.

Selenium and Vitamin E Deficiencies

• Clinical Signs (Cardiac Form): Acute onset, frothy or bloody discharge, normal temperature, and increased or normal heart rate, dyspnea.
• Clinical Signs (Skeletal Muscle Form): More common; animals lie down and struggle to stand, show stiffness/trembling, and have stiff shoulders, backs, or hips; normal temperature, myoglobinuria.
• Clinical Signs (Smooth Muscle Form): Dystocia, retained placentas, chronic bloat, left displaced abomasum.
• Diagnosis: Bloodwork (increased CK and AST) – muscle damage; increased creatinine; myoglobinuria. Subclinical – test milk or blood for selenium. Post-mortem – liver analysis, light muscles.
• Treatment: Parental selenium and vitamin E.

Horse Tendon Damage

• Thoroughpin: Swelling above the hock; not associated with lameness.
• Bog Spavin: Swelling in the hock; not associated with lameness.
• Bowed Tendon: Injury to superficial digital flexor tendon (SDFT) or deep digital flexor tendon (DDFT).
• Curb: Inflammation of the plantar tarsal ligament of the hock.
• Tendonitis: Inflammation of the tendon, but not the tendon sheath.
• Tenosynovitis: Inflammation of the tendon and sheath.
• Tendon rupture: Fiber rupture.
• Accessory check ligament bows: Appear in the upper third of the leg.

Sole Bruises

• Cause: Damage to blood vessels in the lamina between the sole and P3; often due to hard surfaces, improper shoeing, or genetics.
• Clinical Signs: Lameness, bruising, infection.

Exertional Rhabdomyolysis

• Sporadic (SER): Over-exertion, dietary issues, inadequate warm-up.
• Chronic (CER): Recurrent. Abnormal intracellular Ca regulation from stress causing disrupted muscle contractions.
• Breeds at risk: Thoroughbreds, standardbreds, and Arabians.
• Increased heart rate (HR) and respiratory rate (RR).
• Diagnosis: Clinical signs (cramping, stiffness); chemical analysis for increased CK and AST levels; muscle biopsy.
• Treatment: Acepromazine, intravenous fluids, rest.

Polysaccharide Storage Myopathy (PSSM)

• Type 1: Excess carbohydrate storage in muscle; common in Quarter Horses, Morgans, and draft horses.

• Type 2: Similar clinical signs and often younger horses show symptoms.

Tetanus

• Cause: Clostridium tetani
• Clinical signs: Muscular rigidity, spasms, prolapse of third eyelid, hyperesthesia, puncture wound.
• Diagnosis: Culture, Gram stain, smear from site.
• Treatment: Antitoxin, antibiotics.
• Prevention: Vaccination.

Neonatal Encephalitis

• Cause: Bovine Herpes Virus (IBR) or E. coli.
• Clinical signs: Salivation, nasal and oral mucosa inflammation, respiratory distress, opisthotonus.
• Diagnosis: CSF analysis (increased WBCs, protein).
• Prevention: Vaccination.

Histophilus Somni (Histophilosis)

• Cause: bacteria, septicemia -> vasculitis
• Clinical signs: Pre-acute (dead animals), acute (Neurological involvement, pneumonia/pleural involvement, myocardial necrosis, and synovial involvement; laryngitis; apparent blindness; depressed animals).
• Diagnosis: Microscopic evaluation of cerebrospinal fluid (CSF) with neutrophils, and bacterial culture.
• Prevention: Vaccination.

Listeriosis

• Cause: Listeria monocytogenes. Zoonotic.
• Cause: Bacteria enters through oral mucosal abrasions and travels up cranial nerves to the brain.
• Clinical signs: Encephalitis, unilateral brain stem infection; unilateral facial hypoplasia, facial nerve paralysis, ataxia/circling, head tilt, abortion, septicemia, ophthalmitis.
• Diagnosis: Cerebrospinal fluid (CSF) analysis; post mortem (PM) histology.
• Treatment: Broad-spectrum antibiotics.
• Prevention: No vaccine available.

Transmissible Spongiform Encephalopathies (TSE)

• Types: Scrapie (sheep), Chronic Wasting Disease (cervids), Bovine Spongiform Encephalopathy (BSE, mad cow).
• Cause: Abnormal isoform protein (PrPsc) replication in the central nervous system (CNS).
• Source of PrPsc: Genetic mutation, iatrogenic, ingestion.
• Clinical signs vary; weight loss, neurological issues, behavioral changes. (Sheep; Scrapie: rubbing/biting at wool, weeks between episodes, behavioral, incoordination, tremors). Cattle (BSE): long incubation period, weight loss, neurological signs, behavior changes, specific risk materials include (Skull, brain, trigeminal ganglia, eyes, tonsils, spinal cord).
• Diagnosis: Confirmatory tests performed by CFIA on brain tissue (ELISA).
• Prevention: Removal of specific risk materials.

Polioencephalomalacia (PEM)

• Cause: Thiamine deficiency; sporadic in feedlot cattle; softening of gray matter in the brain.
• Other causes: Lead poisoning, nitrate/sulfate poisoning, salt poisoning.

Equine Encephalomyelitis

• Cause: Virus spread by mosquitoes. Birds are reservoir hosts.
• Clinical signs: Lethargy, fever, circling, head pressing, blindness, seizures, permanent CNS damage.
• Diagnosis: CBC (lymphopenia, neutropenia) and CSF (increased total protein and WBCs).
• Prevention: Vaccinations starting at the beginning of mosquito season.

West Nile Virus (WNV)

• Cause: Virus spread by mosquitoes.. Birds (crows, magpies) are the main hosts.
• Clinical signs: May be asymptomatic, or ataxia/head tilt, hypermetria, seizures, fever, behavioral changes.
• Humans: 3-15 day incubation, flu-like symptoms.
• Diagnosis: Antibody testing.
• Prevention: Vaccinations.

Squamous Cell Carcinoma (Cancer Eye)

• Cause: UV exposure, light pigmented animals.
• Stages: Epithelial dysplasia, carcinoma in situ, squamous cell carcinoma.

###Infectious Bovine Keratitis (Pinkeye)

• Cause: Moraxella bovis.
• Clinical signs: Infection, edema of conjunctiva, epiphora, blepharospasm; opacity of cornea; ulceration, purulent discharge
• Treatment: Subconjunctival injections, eye patches, antibiotics.
• Prevention: Vaccination.

Entropion

• Cause: Eyelid rolls inward; cilia rubs on cornea; inherited condition in lambs.
• Clinical signs: Epiphora, corneal edema, blepharospasm.
• Treatment: May self-correct; eyelid eversion with sutures; injection of penicillin.

Equine Recurrent Uveitis

• Cause: Bacteria, parasites, and trauma. Common in specific horse breeds.
• Effects: Uvea, iris, ciliary body, choroid.
• Clinical signs: Stages; Active, Quiescent, and End stage.
• Diagnosis: Fluorescein dye, tonometry, CBC/chemistry tests, leptospirosis tests.
• Treatment: NSAIDs, steriods, atropine, antibiotics.
• Ophthalmic procedures: Fluorescein dye (orange/green/yellow), subpalpebral lavage (SPL), subconjunctival/palpebral injection.

Test your knowledge on various muscle disorders in veterinary medicine, focusing on Clostridium infections and nutritional deficiencies. This quiz covers significant clinical signs, diagnostic indicators, and symptoms related to muscle diseases in animals.