Herp Husbandry & Enrichment

Question 1

Describe the general husbandry of reptiles.

What is the most important biological factor to consider in their care?

Describe ideal temperature and lighting (what wavelenght of UV).

What substrates should be avoided?

What disinfectants should be used for cleaning?

What considerations should be made when housing more than one species together?

Answer 1

MARMS – 16. General Husbandry and Management of Reptiles

Incorrect husbandry and diet are the number one reason for illness in captive reptiles.

Biology

• The most important factor is that most reptiles are ectothermic
• Exception: leatherbacks are extremely stenothermal, and primarily endothermic.
  
  • Derive the majority of body heat from metabolic functions and conserve heat
• POTZ: preferred optimal temperature zone
• Generally reptiles from dry environments are uricotelic in an effort to conserve water
  
  • Reptiles from aquatic environments generally produce the smaller, more soluble urea, or in some cases ammonia
• Three major categories of behavioral changes in captivity. Seasonal/hormonal, learned, and medical/pathological.
  
  • Seasonal/hormonal changes may make medical problems more difficult to detect.
• Immune status varies seasonally
  
  • Clinicians should recommend exams, fecals, and parasite control before and after hibernation

Basic Husbandry Requirements

Temporary Housing in Hospital

• Consider rack or drawer systems in hospitals

Temperature

• Provide thermal gradient. Underwater heater for aquatic species. Radiant heat for arboreal species.
• Most diurnal reptiles: 80° to 90°F (27°–32°C) with a basking area of 90° to 100°F (32°–38°C).
• Nighttime air temperatures for most reptiles should not drop below a temperature of 21°C (70°F)
• Brumation (hibernation) temperatures generally maintained between 35° to 59°F (3.8°–15°C)

Lighting

• Photoperiod guideline, about 14 hours of light in the summer and 12 hours of light in the winter.
• Animals may respond to seasonal changes, esp if access to natural light
• ultraviolet
• UVB (290–320 nm) light is necessary for most reptiles to manufacture vitamin D3.
  
  • Vitamin D3 is necessary for the absorption of calcium from the intestinal tract.
• UVA (320-400 nm) does not assist in converting vitamin D. May have beneficial behavior effects
• Too much light can be detrimental to nocturnal or other low light adapted species.
• Variety of different lights and intensities exist. Natural light preferred if it can be provided.

Humidity and Ventilation

• Remember that the higher humidity must not be created at the expense of total cage ventilation
  
  • Confined spaces/boxes or areas or moistened substrate.

Substrate

• Avoid substrates that contain irritating aromatic compounds (cedar, eucalyptus, or pine shavings).
  
  • May also result in skin or respiratory irritation and possible secondary infection.
• Natural substrates that maintain moisture may lead to bacteria or fungal overgrowth
• Careful with small ingestible substrates
• Tap water is inappropriate for more aquatic species. Neutral pH and no beneficial bacteria. Leads to skin disease.

Caging

• Size is important to consider. There are minimum size guidelines to consider.
  
  • There are formulas for calculating this in different reptiles in the book, but it doesn’t feel testable to me and would be long to summarize. See book if interested.
• Remember that smaller may be better for young animals who may have trouble finding food or thermoregulating in a large enclosure.
• Cage materials should be smooth, nonabrasive, non-porous

Quarantine

• 3 months advisable for most reptiles.
• Service healthy before new arrivals or sick animals.

Cleaning/Disinfection

• Halogens and quaternary ammonium compounds are generally the most effective and safe
• Household bleach (sodium hypochlorite), can be diluted to one part bleach to 30 parts water.
• 5% ammonia solution is effective against coccidia and cryptosporidia,
  
  • remember that bleach and ammonia when mixed produce toxic fumes.
• Organic debris must be cleaned before disinfection

Parasite Control

• Many reptiles have symbiotic flora, esp herbivorous species.
• Evaluate overall health of the reptile
• A moderate amount of protozoans in a healthy herbivorous reptile may be normal
  
  • protozoans in an anorectic carnivorous reptile should be considered potential pathogens
• Quarantine to identify and prevent snake mites (Ophionyssus) and lizard mites (Hirtstiella)

Multi-individual/Multispecies enclosures

• chelonians and crocodilians carry commensal protozoans that may be pathogenic for snakes and
• lizards (e.g., Entamoeba).
• Chelonians and terrestrial snakes should not be housed together in small enclosures.
• Ensure there is enough resources for each animal (lighting, heat, food, etc.) and they will not harm eat each other.

Question 2

Describe the environmental lighting needs of reptiles.

What are the various parts of the UV spectrum - how do reptiles use each part?

Why is UVB so important?

What are the main types of UVB emitting bulbs?

What effect does mesh screens have on lighting?

What are the four Ferguson zones and how do they describe a species lighting needs?

Answer 2

MARMS – 17. Environmental Lighting

Natural Sunlight:

• Reptiles utilize every part of the solar spectrum from UV to infrared
• Sunlight = short-wavelength infrared (IR-A), visible light (visible to humans), and ultraviolet (UV), subdivided into UVA and UVB from around 290 to 295 nm
• Infrared
  
  • IR-A responsible for warming effect of sunlight
  • Invisible to humans and reptiles aside from some snakes
• Visible light and UVA
  
  • UVA important in color vision
    
    • Most reptiles have full color vision
  • Affects nonvisual photoreceptors in reptile retina, pineal body, and parietal eye, and deep brain photoreceptors that respond to light filtering through the skull
    
    • Important in controlling daily and seasonal behaviors
      
      • activity levels, thermoregulation, immune system, and repro cycle
• UVB
  
  • amount of UVB in sunlight depends on solar altitude - dose of UVB received depends on time of day, sun position
  • UVB + warmth  required for cutaneous vitamin D3 synthesis in reptiles
  • 7DHC converted to previtamin D3 when exposed to UVB  temperature dependent isomerization into vitamin D3  enters blood
  • UVB at skin level – disinfectant, modulates immune system, improves skin barrier functions, upregulates melanin synthesis
• Utilizing Natural Sunlight
  
  • window glass and most plastics block all UVB and some UVA

Electromagnetic Radiation:

• Single light not sufficient – need combination for full spectrum
  
  • simple incandescent bulbs (“basking lamps”), lamps emitting additional visible light, and UV light
• Infrared
  
  • Ceramic heaters, panel heaters, heat mats  emit only long-wavelength infrared (IR-B and IR-C)
    
    • Risk of burns, not suitable for basking
    • No visible light – some reptiles use light cue for basking
• Incandescent lamps
  
  • Tungsten or halogen lamps used to create basking zones
    
    • No UVB
    • Minimal blue or UVA
  • Orange and red visible light and short-wavelength infrared (IR-A) predominate
  • Emit longer-wavelength IR-B, some IR-C
  • Intense exposure may overheat skin, need to cover area at least as large as body
  • Localized heating of basking lights on tortoises may contribute to pyramiding
• Visible light
  
  • “Daylight” fluorescent tubes, compact lamps – no UVB, minimal UVA, improve visible light
  • Metal halides – high quality “daylight” metal halide lamps
    
    • Full brilliance of sunlight with UVA, infrared, no UVB
    • High intensity discharge lamps – can cause ocular damage if in line of sight of reptiles, must place overhead
  • LED lighting (2 types) – should not be primary light source, supplementary only
    
    • “white” – no UVA or UVB, deficient in cyan and red
    • Single color in very narrow band of wavelengths
  • Colored lamps – avoid use of these lamps for reptiles
    
    • Reptiles can see both red and blue lamps so should not use at night – can disrupt circadian rhythm
• Ultraviolet – 5 main types of UVB-emitting lamps
  
  • Regular T8 UVB fluorescent tubes – low well-diffused output
  • T5-high output (T5-HO) UVB fluorescent tubes - much higher output
  • Compact fluorescent UVB lamps - well-diffused but very steep UV gradient and limited range
    
    • only suitable for use in small vivaria
  • Mercury vapor UVB lamps - high UV output, but poor visible spectrum, heat for basking but cannot be controlled by dimming thermostat
  • UVB-emitting metal halides - intense visible light, UVA and UVB, heat for basking but cannot be controlled by dimming thermostat
  • UV output varies significantly between brands
  • Mesh screens can block 30-50% of visible light and UV
  • Recommend measure UVB output of lamps as diminishes over time
  • Short wavelength UVB better at stimulating vitamin D synthesis than long wavelength
• Estimating the UV Requirement
  
  • Ferguson zones – daily UV exposure of 15 reptile species recorded and divided into four sun exposure ranges
  • Knowing species habitat and basking behavior can predict average daily UV exposure
  • Methods of providing UVB
    
    • Shade method – low level UV over large area of the enclosure
      
      • Best for shade dwelling or occasional basking reptiles
    • Sunbeam method – high level UV over basking spot
      
      • Best for basking reptiles
• Excessive UV Exposure/Nonterrestrial UVB and UVC
  
  • Albino/hypomelanistic animals may be at increased risk of UV-induced skin damage and cancer, likely have lower UV requirements
  • Few brands of lamps emitted very short wavelength UVB and UVC
    
    • caused photo-kerato-conjunctivitis, severe photo-dermatitis, burns, death