1. Clostridium tetani: The Veterinary Technicians Role
Tiffany Bartlett, LVT

2. Clostridium Species Large Spore forming Gram-positive Rods
Obligate anaerobic
Catalase negative
Oxidase negative
Over 200 species- less than 20 are pathogenic
Pathogenic species produce potent exotoxins
4 groups
Neurotoxic, histotoxic, enteropathogenic & enterotoxaemia producing, and atypical
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3. Clostridium tetani Neurotoxic clostridia
T. botulinum
Endospores live in soil and feces
Affects
Humans, domestic, and wild animals
Dogs & cats have high resistance *not immunity
Less prevalent in developed countries due to vaccines for humans and farm animals
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4. Pathogenesis
Wounds
Proliferation only occurs when tissue necrosis is present
Not all patients wounds with c. tetani contamination develop tetanus
C. tetani autolyse in the anaerobic necrotic tissue
Bacterial cell walls autolysis- neurotoxin is released
Neurotoxin is zinc-binding protease
Cleaves synaptobrevin (purple circle)
Toxin absorbed locally by motor nerves
Ascends to spinal cord- ascending tetanus
synaptobrevin, a vesicle-associated membrane protein
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5. Incubation typically 10-14 days
Dogs & cats tend to have a longer incubation due to high resistance
Site of infection affected 1st
Localized stiffness- most common
Masseter muscles
Neck
Pelvic limbs
Generalized stiffness- less common
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6. Tetanospasmin Neurotoxin
The 2nd deadliest substance
Flaccid paralysis *identical to botulism
Localized → General stiffness
Prehension and mastication difficulty *AKA Lockjaw
“Smiling”- ears pulled back, lips drawn back
Increased reflexes
Tonic spasms
Worsened when excited/startled

7. Sawhorse stance Hyperesthesia
Muscle spasms of the neck, back, and limbs
Opisthotonos- muscle spasms causing backward arching of head, neck and spine (see picture)
Hyperesthesia
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8. Diagnosis History Clinical signs Gram stained slides from lesions
Recent trauma/ wounds
Clinical signs
Gram stained slides from lesions
Anaerobic culture of wound
Tetanus toxin detection in serum analysis
Injecting mice with animal serum to see if tetanus occurs
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9. Treatment in Dogs Sedatives Anticonvulsants
Benzodiazepines, barbiturates, etc.
Anticonvulsants
Phenobarbital, Keppra, etc.
Tetanus antitoxin 1,500-3,000 IU IV q12h
May induce anaphylaxis
Debride and treat wounds-
Oxygen kills C. tetani bacteria
Penicillin 20,000-30,000u/kg IV q6-q8h X10d
Metronidazole 15mg/kg PO q12h X10d
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10. Nursing care is critical to good patient outcome
Patient rotation q4 to prevent decubital ulcers
Clean, padded, safe kennel
IVF to prevent dehydration
Hand feeding
PT- PROM on all joints, on all limbs QID
Reduce noise, light, and other sensory inputs that could startle the patient
Walk, with support, if able
24hr nursing care

11. Case Study

12. Punkin 6 y/o FS Pit Bull Mix HX:
Dropping food, weak, lethargy, ataxia, stiffness, no known trauma or wounds
Diagnostics
MRI- WNL
CSF- WNL
BW- WNL
Tick panel- WNL
Neospora- negative
Toxoplasma- negative

13. CT- WNL, no wounds or other abnormalities found
On Clindamycin, Prednisone, Gabapentin, Tramadol, and Clonazepam
DX over 2 weeks- continual decline
Falling, difficulty walking, progressive prehensile difficulty, progressive stiffness
Additional DX:
CT- WNL, no wounds or other abnormalities found
After ruling all other causes out, diagnosis was Tetanus even though no wound could be found
On day of hospitalization, patient presented
Tonic spasms, worsened when excited
Lock jaw
Saw horse stance
“Smiling”

14. Punkin’s Treatment Covered cage Antitoxin 3,000 UI IV q12 PT
PROM, all joints all limbs QID
Recumbency care q4
Acepromazine 0.01mg/kg IV q6 PRN
Hand fed meatballs q6
Hand offered water q6
Antitoxin 3,000 UI IV q12
60mL/kg/hr
Ear plugs
Penicillin 20,000-30,000u/kg IV q6- q8h X10d
Metronidazole 15mg/kg PO q12h X10d
Diazepam 0.25mg/kg IV PRN for seizures *had 1 seizure on day 3 of treatment

15. Conclusion
After initially deteriorating for the first 72 hours in spite of treatment, Punkin started to improve on day 4
By day 5 she was walking well with a sling
Day 8- after a fall, she was able to get back up unassisted
Day 10- Punkin was discharged from the hospital

16. References