EQST301 Topic #14 Tetanus

Clostridium tetani

Etiology of tetanus

1) anaerobic

2) gram positive

3) spore-forming

3 characteristics of Clostridium tetani bacteria

A few days to up to 6 weeks

Incubation period of tetanus

puncture wounds

Most common way of horses contracting tetanus

binds to & blocks the inhibitory neurons in the spinal cord, causing spastic movement of the skeletal muscle

C. tetani toxin mechanism of action

asphyxiation due to paralysis of respiratory muscles

Case of death due to tetanus

50-80%

mortality rate of tetanus

1) Penicillin (IV)
2) Metronidizole (rectally or IV)

Antibiotics used to treat tetanus & route of administration

1) Toxoid vaccine

2) Tetanus antitoxin

3) Debridement

4) Antibiotics

5) Sedation

6) I.V. fluids

7) Stomach tube (for nutrition)

8) Hyperbaric chamber

8 treatments of tetanus

1) 3rd eyelid prolapse

2) Exaggerated response to stimuli (hyperexciteability & hyperreflexia)

3) “Saw-horse” stance

4) “Lock-jaw”

4 main clinical signs of tetanus

1) Assess clinical sings

2) Micrscopic examination

3) Laboratory testing

3 ways to diagnose tetanus

gram positive, rod-shaped bacteria

What bacteria are we looking for on a micrscopic examination for tetanus?

anaerobic culture

What type of culture is taken for laboratory testing of tetanus?

tetanus toxoid vaccine

used only for prevention of tetanus & prevides good lasting immunity

2 weeks

How long does it take the tetanus toxoid vaccine to produce antibodies?

1 cc IM then booster in 2-4 weeks

booster yearly

tetanus vaccine series

binds to and neutralizes unbound toxin

tetanus antitoxin mechanism of action

3-4 weeks

How long does the tetanus antitoxin protect for?

tetanus antitoxin

used for treatment or prevention of tetanus & used for immediate protection

1) Newborn foals

2) Treatment of all wounds in poorly vaccinated horses

3) Treatment of tetanus

3 indications for tetanus antitoxin use