Created by Alinta Kalns
over 6 years ago
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Question | Answer |
What is the most common syndrome of Listeria monocytogenes in Australia? What are the other syndromes? | Meningoencephalitis Abortion, septicaemia/uveitis, mastitis |
What is the incidence of listerial meningoencephalitis in cattle? | 2-3 year olds - tooth eruptions allow bacteria to invade Travels via trigeminal nerve to brain |
What lesions occur with Listerial meningoencephalitis? | Focal necrosis and micro-abscesses of nerves, brain, and meninges |
Which route of transmission is more important in Listeria zoonosis? | Food contamination |
What are common signs of Listerial meningoencephalitis? | Unilateral facial paralysis + secondary keratitis Head tilt + circling +/- recumbency and opisthotonus Propulsive tendency Pyrexia (first 96 hours) Depression, weight loss, milk drop |
What are uncommon signs of listeria meningoencephalitis? | Stertor Dysphagia |
Which 3 nerves does listeria most commonly affect? | Facial vestibulocochlear Glossopharyngeal |
How would you diagnose listeria infection? | CS Post-mortem + histopathology Cold enrichment culture |
What are differentials for listerial meningoencephalitis? | Brain stem abscess Pituitary abscess syndrome Otitis media Trauma TEME Lead poisoning Nervous ketosis |
How would you treat listeriosis? | High dose penicillin or tetracyclines 7 days NSAIDs IV fluids + electrolytes Rumen support |
How could you prevent listeria meningoencephalitis? | Proper silage collection and storage - Anaerobia - Allow 24 hours to wilt prior - Early growth grass = more sugars - Cover + seal tightly |
What clostridium botulinum types affect cattle? | Types C and D (maybe B) |
What is the lethal dose of botulinum toxin? | 10 ug |
What is botulinum intoxication associated with? | Phosphorous deficiency Contaminated food (carcasses, decaying vegetation) = outbreaks |
What are the forms of botulinum intoxication and what are the CS? | Peracute - death Subacute - ascending flaccid paralysis (dysphagia + tongue protrusion early sign) Toxico-infectious - chronic toxin absorption due to vegetative GIT growth |
What is a distinguishing feature of botulinum paralysis? | Cattle remain conscious and have sensation |
How would you diagnose botulinum intoxication? | Relapse after calcium treatment History of P deficiency or poor nutrition No vaccination history No other disease evidence ELISA Abs Rumen content toxicology |
How would you treat and prevent botulinum intoxication? | Antitoxin + supportive P supplementation Vaccination annually Remove carcasses Assess risk in feed |
What pathogen causes thromboembolic meningoencephalitis (TEME)? | Histophilus somni |
Which form of histophilus somni infection is TEME? | Septicaemic form - Infarction of the CNS |
CS of TEME? | Rapidly progressing: Pyrexia Ataxia --> stupor Muscle tremors Retinal haemorrhage/hypopyon Mortality |
How do you diagnose TEME?
Image:
Teme (binary/octet-stream)
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Post-mortem Fibrinopurulent meningitis + hyperaemia Focal infarcts + haemorrhages |
When and how would you treat TEME? | Before recumbency - penicillin - florfenicol - Oxytetracycline |
What could help prevent TEME? | Manage against the respiratory syndrome - Reduce stress - Avoid overcrowding - Good nutrition - Biosecurity |
How does Clostridium tetani infect cattle? | Via deep, anaerobic wounds - E.g. castration, dehorning, tail docking, omphalophlebitis Travels up local motor neurons to spinal cord OR idiopathic multiplication in rumen |
What are the CS of tetanus? | 10-14 days post-infection - stiffness - Hyperaesthesia, anxiety, erect ears, bulging eyes - Lockjaw, slight bloat, rigid stance + tail Tetany + convulsions --> recumbency + opisthotonus |
How would you treat tetanus? | 1. Anti-toxin in early stages 2. Wound debridement + penicillin 3. Relax muscle tetany - acetylpromazine Quiet, dark area + relieve bloat |
Tetanus prevention? | Toxoid or multi-valent clostridial vaccine 2 doses 4-6 weeks apart |
What is the aetiology of pituitary abscess syndrome (basilar empyema)? | Haematogenous bacteria invade rete mirabile or cavernous sinus of pituitary Bull nose rings |
What are the CS of pituitary abscess syndrome? | Salivation and inability to swallow Tongue protrusion Head extended Wide-base stance, ataxia, depression Recumbency + opisthotonus |
Diagnosis of pituitary abscess syndrome? | Neuro exam - absent pupillary light reflex, exophthalmos, strabismus, nystagmus, dysphagia + flaccid tongue, facial paralysis + head tilt, bradycardia PM - abscess of pituitary |
What are main differentials for pituitary abscess syndrome? | Listeriosis Otitis media |
What are CS of nervous coccidiosis? | Tenesmus and dysentery 1st Depression, incoordination, hyperaesthesia --> Recumbency, tremors, frothing, paddling --> ventroflexion of head or opisthotonus |
What are differential diagnoses for nervous coccidiosis? | Polioencephalomalacia Lead poisoning Salt intoxication Acute meningitis Hypovitaminosis A C. perfringens enterotoxaemia |
What is the aetiology and CS of cerebral babesiosis? | Babesia bovis Hyperaesthesia, aggression Nystagmus, convulsions, circling + head pressing Paralysis +/- fever, anaemia, haemoglobinuria |
What pathology is associated with polioencephalomalacia (PEM) | Necrosis of the cerebral cortical grey matter |
What can cause PEM? | Salt toxicity Lead poisoning Thiamine deficiency (high sulphur diets or high concentrate diets) |
What are CS of PEM? | Well-fed young cattle Transient diarrhoea + self-isolation Depression, ataxia, high head carriage Central mediated blindness Hyperaesthesia head pressing + bruxism Recumbency, opisthotonus, rigidity, seizures |
What is central mediated blindness? | Absent menace response but present palpebral and pupillary light reflexes |
How can you diagnosis PEM? | CS + normal rumen function Response to TX PM - cerebral pallor + oedema, grey matter vacuolation, UV fluorescence |
What are differentials of PEM | Lead poisoning Salt toxicity Listeria Bacterial meningitis Vitamin A or magnesium deficiency TEME |
How would you treat PEM? | Thiamine IV for 3 days |
How long does it take for adult cattle to develop vitamin A deficiency CS? | 180 days |
What are risk factors for hypovitaminosis A? | Drought Poor quality preserved feed High grain diet Repeat bloat oil admin |
What are CS of hypovitaminosis A in calves? | Anorexia, ill-thrift, diarrhoea Blindness Lacrimation Head-pressing, convulsions, paralysis, recumbency |
What are CS of hypovitaminosis A in adult cattle? | Night blindness Weight loss Infertility |
How to managed hypovitaminosis A? | Vitamin A IV Culling if blind |
What are CS of lead poisoning? | Peracute sudden death Acute - depression, ataxia, hyperaesthesia + aggression, blindness, head-pressing, rumen atony Subacute - depression, anorexia, blindness, incoordination, constipation --> diarrhoea, death in a few days |
How do you diagnose lead poisoning in cattle? | Whole blood lead concentrations Renal cortex lead concentration |
How would you treat lead poisoning? | Chelation - calcium compounds Magnesium sulphate PO Thiamine HCl IV Pentobarbitone (convulsions) |
What is the pathogenesis of water intoxication? | Restricted water access = fluid drawn out of CNS Rapid rehydration --> rapid fluid movement into CNS --> oedema and PEM |
What are clinical signs of water intoxication? | Opisthotonus, nystagmus, tremors, weakness, head-pressing Central blindness Polyuria and haemoglobinuria due to intravascular haemolysis |
How would you treat water intoxication? | Sedation IV NaCl 0.9% slowly over 24 hours |
What is the pathogenesis of urea poisoning? | Normally bacteria in rumen capture ammonia made from urea Overwhelming amounts = overwhelmed bacteria and liver --> ammonia in blood |
What are CS of urea poisoning? | 20 minutes post-ingestion Muscle twitching, hypersalivation, bruxism, abdominal pain, PU --> tremors, tachypnoea, ataxia, convulsions and collapse |
How can you diagnose urea poisoning? | History Rapid decomposition of carcass PM - bloat, congestion/oedema, cardiac haemorrhage Rumenocentesis alkaline |
How could you treat urea poisoning? | Rumenotomy + content evac 50 L cold water + vinegar/acetic acid PO |
What is the aetiology of ryegrass staggers? | Endophytic fungus grows on perennial ryegrass - Neotyphodium lolii Lolitrem B toxin |
What are CS for ryegrass staggers | When disturbed: - Tremors/muscle fasciculations Jerky stiff gait Head nodding Ataxia + sternal recumbency and splayed hind limbs |
How can you treat ryegrass staggers? | Remove from pasture Takes 1-2 weeks |
What is the aetiology of annual ryegrass toxicity? | Lolium rigidum (annual ryegrass) Rathayibacter toxicus neurotoxin Bacterial invasion via Anguina nematode |
What are CS of annual ryegrass toxicity? | Sudden death Cerebellar dysfunction - wide-base stance - ataxia - Hypermetria Collapse, convulsions, opisthotonus |
Diagnosis of annual ryegrass toxicity? | Presence of all 3 predisposing factors |
Treatment of annual ryegrass toxicity? | Remove from infected pasture and supplementary feed Biological control of nematode |
What is the aetiology of sporadic bovine encephalomyelitis? | Chlamydia pecorum Cattle <3 years |
What are CS of sporadic bovine encephalomyelitis? | Fever, depression, hypersalivation Diarrhoea, anorexia, weight loss Stiffness, ataxia, head tilt, hyperaesthesia, recumbency, opisthotonus |
What pathology does chlamydia pecorum cause? | Vasculitis and serositis Meningoencephalitis Fibrinous peritonitis, pleuritis, pericarditis |
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