Clostridium tetani The Veterinary Technicians Role Tiffany Bartlett

Clostridium tetani: The Veterinary Technicians Role Tiffany Bartlett, LVT

Clostridium Species v v v v Large Spore forming Gram-positive Rods Obligate anaerobic Catalase negative Oxidase negative Over 200 species- less than 20 are pathogenic v Pathogenic species produce potent exotoxins v 4 groups Image from: http: //textbookofbacteriology. net/clostridia. html v Neurotoxic, histotoxic, enteropathogenic & enterotoxaemia producing, and atypical

Clostridium tetani v Neurotoxic clostridia v T. botulinum v Endospores live in soil and feces v Affects v Humans, domestic, and wild animals v Dogs & cats have high resistance *not immunity v Less prevalent in developed countries due to vaccines for humans and farm animals Picture from: http: //paraibaparadise. com/index. php/come-to-joao-pessoa/living-in-joao-pessoa/health/diseases/tetanus/

Pathogenesis v Wounds v Proliferation only occurs when tissue necrosis is present v Not all patients wounds with c. tetani contamination develop tetanus v C. tetani autolyse in the anaerobic necrotic tissue v Bacterial cell walls autolysis- neurotoxin is released v Neurotoxin is zinc-binding protease v Cleaves synaptobrevin (purple circle) v Toxin absorbed locally by motor nerves v Ascends to spinal cord- ascending tetanus Picture from: http: //www. ipsifar. rm. cnr. it/inglese/Luvisetto_1 UK. html

v Incubation typically 10 -14 days v Dogs & cats tend to have a longer incubation due to high resistance v Site of infection affected 1 st v Localized stiffness- most common v Masseter muscles v Neck v Pelvic limbs v Generalized stiffness- less common Picture from: https: //biogeekery. wordpress. com/2013/04/08/tetanospasmin-and-tetanus-the-second-deadliest-toxin/

Tetanospasmin Neurotoxin The 2 nd deadliest substance 1) Flaccid paralysis *identical to botulism 2) Localized → General stiffness 1) Prehension and mastication difficulty *AKA Lockjaw 2) “Smiling”- ears pulled back, lips drawn back 3) Increased reflexes 4) Tonic spasms 1) Worsened when excited/startled

5) Sawhorse stance 1) Muscle spasms of the neck, back, and limbs 2) Opisthotonos- muscle spasms causing backward arching of head, neck and spine (see picture) 6) Hyperesthesia Picture from: http: //fineartamerica. com/featured/opisthotonosscience-source. html

Diagnosis v History v Recent trauma/ wounds v Clinical signs v Gram stained slides from lesions v Anaerobic culture of wound v Tetanus toxin detection in serum analysis v Injecting mice with animal serum to see if tetanus occurs Picture from: https: //vetgirl. wordpress. com/2008/09/02/tetanus/

Treatment in Dogs v Sedatives v Benzodiazepines, barbiturates, etc. v Anticonvulsants v Phenobarbital, Keppra, etc. v Tetanus antitoxin 1, 500 -3, 000 IU IV q 12 h v May induce anaphylaxis v Debride and treat woundsv Oxygen kills C. tetani bacteria v Penicillin 20, 000 -30, 000 u/kg IV q 6 -q 8 h X 10 d Picture from: https: //www. valleyvet. com/ct_detail. html? pgguid=2 e 87 bedd-7 b 6 a-11 d 5 -a 192 -00 b 0 d 0204 ae 5 v Metronidazole 15 mg/kg PO q 12 h X 10 d

Nursing care is critical to good patient outcome v Patient rotation q 4 to prevent decubital ulcers v Clean, padded, safe kennel v IVF to prevent dehydration v Hand feeding v PT- PROM on all joints, on all limbs QID v Reduce noise, light, and other sensory inputs that could startle the patient v Walk, with support, if able v 24 hr nursing care

Case Study

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

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

Punkin’s Treatment v Antitoxin 3, 000 UI IV q 12 v Covered cage v IVF @ 60 m. L/kg/hr v PT v Ear plugs v Penicillin 20, 000 -30, 000 u/kg IV q 6 q 8 h X 10 d v Metronidazole 15 mg/kg PO q 12 h X 10 d v Diazepam 0. 25 mg/kg IV PRN for seizures *had 1 seizure on day 3 of treatment v PROM, all joints all limbs QID v Recumbency care q 4 v Acepromazine 0. 01 mg/kg IV q 6 PRN v Hand fed meatballs q 6 v Hand offered water q 6

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

References