MS Infections Flashcards
Crepitus
Inflammation & condition of tissue that feels like bubble wrap
Category of clostridium
G+ rods, necrotizing bacteria
Clostridial diseases can cause what types of toxins
Histotoxins - gas gangrene/black leg disease
Neurotoxins - botulism tetanus
Enterotoxemia
Enteropathies
Clostridial diseases that cause myonecrosis
Gas gangrene - malignant edema
Black leg
Features of Clostridial bacteria
G+ Rods
Strict anaerobes
Motile
Gas producing
Endospore forming - leads to gassy pockets
Species of clostridium that causes gas gangrene in equine
Clostridium perfringens
Species of clostridium that causes gas gangrene in ruminants
Clostridium septicum
What species of clostridium causes black leg and in what species does it infect
Clostridium chauvoei
Cattle
Origination of clostridium
Spores & vegetative bacteria, spores in soil are important source of infections for histotoxic disease
GIT of animals & humans
Transmission of clostridium
Direct inoculation of spores to wounds
Must have anaerobic conditions in tissue (necrosis)
Could follow management procedures
Virulence factors for Clostridia
Powerful exotoxins (cytotoxins)
Gas production
Both cause immense muscle damage
Pathogenesis of clostridia
Spores enter wound or are latent in tissue
In anaerobic conditions spores germinate
Exotoxins cause muscle necrosis & destroy WBC = more bacteria growth
Gas + collagenase cause more muscle damage
Exotoxins absorb into circulation = widespread damage
Pathogenesis of black leg
Clin signs of lameness, inappetence, tachycardia, ^RR, ^ temp
Swelling in affected area
Diagnosing clostridium
Clin signs, visualize tissue
Culture
Presence of rapid/sudden death in herd
Florescent antibody test
Treating clostridia
Aggressive removal of all infected tissue
Penicillin (sensitive) or metronidazole
Some antitoxins
Oxygen therapy to disable anaerobic function
Role of metacercariae of F. Hepatica (liver fluke)
Cause damage / trauma to liver, activates latent spores in liver
Black disease in sheep can lead to what condition and is caused by what species of clostridia
Necrotising clostridial hepatitis clostridium novyi type B
Common postmortem findings with black disease
Blood stained serous fluid in cavities
Blood stained froth (mouth & nostrils)
Sub q edema & blackening of skin
Swollen liver & areas of necrosis
Mature liver flukes present
Ways to control clostridia
Vaccination for food animals against black disease / black leg - combo vax for ewes during lambing. Less effective in goats
Management - minimize predisposing factors like hygiene & control fluke populations
