Herp Preventative Medicine

Question 1

What is the difference between cleaning, disinfection, and sterilization?

Discuss some of the common disinfectants used in reptile enclosures.

Iodophore solution - how does it work and what contact time is needed?

What about bleach?

What about chlorhexidine?

What about quaternary ammonium compounds?

What about alcohols?

What about lysol?

What about peroxide?

What about aldehydes?

Answer 1

MARMS – 18. Disinfection

• Cleaning- physical removal of organic matter
• Disinfection- reduces pathogen load, but not eliminate it
• Sterilization- kills all life

Techniques and Products

• Ammonia & bleach are excellent, inexpensive, and readily available disinfectants
• Bleach- diluted to 1% or 5% (1:50 to 1:10 dilution)
• Contact time is important (5-30 mins)
• Iodophore Solutions (Betadine, prov idodine, pevidine…), Inactivated by organic debris & alcohol
  
  • 1-5 mins contact time, denatures proteins and disrupts nucleic acids
• Chlorines (Sodium hypochlorite, bleach), must be rinsed well
  
  • 10 min contact time, denatures proteins
• Chlorhexidine (Novasan, Hibitane, Savlon,…), not inhib by organc matter or alcohol
  
  • 10 mins, alters cell membrane permeability
  • NOT effective against pseudomonas
• Quaternary ammonium compounds (Roccal-d, Parvosol,….), Inhib by organic matter, inacti by soaps, poor in hard water
  
  • 5-10 mins, Denatures proteins, disrupts cell membrane, inactivates enzymes
• Alcohols (Ethyl, Isopropyl), good antiseptic, inactivated by organic matter
  
  • 20 mins, cell lysis
• Phenolic Compounds (Lysol)- not inactivated by organic material, corrosive to skin, rinse well
  
  • 10 mins, alters cell membrane permeability and denatures proteins
• Aldehydes (Formula h), not inactivated by organic matter, toxic, corrosive, must be rinsed well
  
  • 20 mins, denatures proteins and alkylate nucleic acids
  • *Great against fungi & spores (all other compounds say that they are only partially effective)
• Peroxide- Toic gases when in contact with chlorine, dilute always by adding acid to water
  
  • 10-30 mins, denature protein and lipids

Question 2

What are the goals and steps of an adequate disease risk assessment for quarantined herps?

How do you determine whether a parasite needs to be treated in quarantine?

What are important pathogens of concern for the various herp groups undergoing a quarantine period?

Answer 2

MARMS – 19. Quarantine

• Quarantine: Period in which a new arrival to a collection is kept isolated for observation, habituation to its new environment, disease testing, and subsequent treatment or relocation if required.
  
  • Goals – optimize resources available to properly isolate new animals while minimizing risk to established collection.
  • Can combine with disease risk assessment approach/modify based on medical records.
• Disease risk assessment
  
  • Goals – estimate presence, exposure, and consequences of introducing an infectious disease of concern.
    
    • Review current knowledge about disease of concern
    • Review medical records from sending institution
    • Review pertinent historical data of animal and collections
    • Review important natural history information
  • Four interconnected steps:
    
    • Hazard identification
    • Risk assessment
    • Risk management
    • Risk communication
  • Hazard identification – identification of diseases of concern.
    
    • List of important diseases per taxa that should be considered – Table 19.1.
    • Review animal’s history – temperament, nutrition, enclosure requirements.
  • Risk management – develop and implement policies and procedures.
    
    • Refusal to accept an animal
    • Extending quarantine time period
    • Additional disease testing
    • Euthanasia based on results or necessity
    • Acceptance of animal if the disease is already present in collection
    • Risk management integrates identification of pathogen with actions needed to minimize introduction into naïve collection.
  • Risk communication – keeping individuals and departments informed.
• Quarantine duration: dependent on place.
  
  • Reptiles of unknown source or wild caught, minimum 90 days.
  • Known institutions with health history and without hazards identified – 14 days.
  • Principles to follow:
    
    • Space for quarantine separate from collection.
    • Quarantine care and husbandry must be completed to minimize cross-contamination with collection.
    • Animals housed in enclosure that meets their needs.
      
      • Paper is ideal substrate.
    • Dedication of tools and equipment for quarantine use only and disinfected.
• Quarantine evaluation.
  
  • Physical examination – entry weight, BCS, permanent ID established.
  • Note behavior, demeanor, appetite, defecation frequency and consistency.
  • Intestinal parasites.
    
    • Some i.e. oxyurids and Nyctotherus spp can be commensals.
    • Direct life-cycle ascarids and strongyles can be pathogenic, eliminate or decrease loads.
    • Cryptosporidiosis, intranuclear coccidiosis, amoebiasis must be kept out.
      
      • Screening with PCR for cryptosporidium and intranuclear coccidiosis or fecal exams and special stains for amoeba.
    • Serology screening – assays available.
      
      • Ophidian paramyxovirus in snakes.
      • Mycoplasma agassizzii and Mycoplasma testudineum in chelonians.
      • If positive, indicative of infection.
      • If negative, does not exclude early infection, may need to repeat.
  • Ectoparasites.
    
    • Snake mites (Ophionyssus natricis).
    • Ticks, especially wild-caught animals.
      
      • i.e. African tortoise tick (Amblyomma marmoreum).
        
        • Vector of heartwater, acute rickettsial dz of ruminants.
  • Once an animal enters quarantine, no other animals should be allowed in until those animals leave. All in/all out policy.