Tetanus is bacterial disease which mostly occur in horse. But other animal also susceptible. 

In tetanus, animal body is stretched and unable to walk, stand and other activities.


Cause

Tetanus is caused by Clostridium tetani. In soil clostridium tetani present from month, year or decades. 

Mechanism of action

Clostridium is anaerobic bacteria thus it not require oxygen to reproduction. 

Tetanus occur while favorable condition is there to grow bacteria.

Deep wound and contaminated material is lead to infect animals.

After favorable condition, bacteria grow and produce neurotoxin. Which is cause of death.

This neurotoxin block the neurotransmitter at neuromuscular junction.

GABA(gamma-Aminobutyric acid) is inhibited by Clostridial neurotoxin. And thus muscle not get relaxed.

Why in tetanus muscle is stretched?

In muscle contraction, Ca+2 is required to contract the muscle by ACh(Acetylcholine). After contraction it's time to relax.

And relax mechanism is done by GABA. When GABA release, inhibitory responce from brain and muscle get relaxed. 

But Tetanus neurotoxin Block the GABA action receptor and inhibitory responce absent.

Diagnosis

Diagnosis is done by visual after infection to animal. But when animal is normal and want to diagnose then laboratory finding of sample is use.

During incubation period animal is normal but when neurotoxin bind with receptor at neuromuscular junction, animal show symptoms and we diagnose.

Animal show symptoms like
  • Powerfull muscle twitching
  • Lockjaw (Advance)
  • Arch back body
  • Stiff joint
  • Stiff tail (goat)
  • In horse third eyelid get prolapsed

Treatment

If neurotoxin is not bind with receptor at neuromuscular junction, treatment may work.

But if toxin is bind then not any treatment work. This process is irreversible.

May this treatment work before toxin attachment.
  • TT(tetanus toxoid)
  • Flunixin/meloxicam
  • Fluid therapy

Case discussion

A 9 day old kid having stiff joint with lockjaw condition. Infection may spread throgh naval junction at the time of parturition by rupture junction by history.