1.1. Learning Objectives

• Gain an appreciation for the physiological basis of many amphibian husbandry and health issues (skin permeablility, ectothermia, etc.)
• Become familiar with the major amphibian health issues seen in a captive setting
• Know what "redleg" is
• Understand the implications of Chytridiomycosis as an emerging disease of free-ranging amphibians

1.2. Recommended anatomy review

It is recommended that you review your amphibian anatomy notes from 1st Year Comparative Anatomy prior to attending the lectures. For good overview visit: http://biog-101-104.bio.cornell.edu/Biog101_104/tutorials/frog.html

2.1. Why learn about Amphibians?

• Increasingly popular in research/science e.g. pregnancy testing, pain research
• More and more people keep them as pets

2.2. Economics

2.3. Natural history

• Amphibians have been around for > 300 million years
• Whole families survived
• amphibios means double life

2.4. Species of interest

• Malayan leaf eyed frog
• Fire belly newt
• Pixie frog
• Dendrobates sp. (Poison arrow frog)
  • Batrachotoxin - the most lethal, non-protein, naturally-produced poison; incredible pain killers
• Tree frogs
• Fire bellied toad
• Tiger Salamander
• Argentinean horned frog
• Tomato Frog

4.1. Aquatic setup

• African Small clawed frog
• Axolotl
• Same parameters apply to aquatic set up as with fish
  • pH
  • Nitrate cycle
  • Ca, Mg, Ph content
  • Filtration

African Clawed Frogs

4.2. Semi aquatic design

• Most amphibians
• High humidity
• Large surface of water
• Running water
• Sprinkler

4.3. Tree Frogs

• Need to climb
• Keep humidity high by misting
• No need for water body - just enough to soak
• Ventilation!

5.1. Anatomy and Respiration

Eye and oral cavity involved in respiration

6.1. Examination

• Get information before handling
  • Husbandry
  • Temperature + humidity, set up, lighting, nutrition, etc.
  • Exotic Pet Owner/Client Questionnaires (Document is in Supplementary Material folder)
• Test water sample - same as for fish
• Always examine with gloves
  • Protect yourself and the animal
  • Rinse off powder and lubricate with water
• Exam with a logical system - Top to bottom - Head to tail
• Most information will come from interview
• Small amphibians may not need to be handled

No gloves!

6.2. Anesthesia

• MS-222
• Clove oil
• Isoflurane
• In light anesthesia: loss of righting reflex
• In deep anesthesia:
  • gular respiration stops
  • loss of withdrawal reflex

7.1. Nutritional

• Remember all amphibians are carnivorous!
  • High protein
  • Not high fat - Lipid keratopathy
• Nutritional Secondary Hyperparathyroidism - bloat
• Larvae have different needs
• Tadpoles do fine on fish flakes
• Thiamin deficiency - Fish diet
• Steatitis
• Renal calculi - Crickets eat plants
• Obesity
• Impaction
• Scoliosis - Vit. B complex
• Starvation - Mini African clawed frog

7.2. Infectious - Bacterial

• Just as fish, amphibian are constantly surrounded by a bacterial broth
• Mostly Gram (-) organisms
• "redleg"
• Common scenario
  • Post shipping
  • Husbandry mistakes
• Hibernation is stressful
• Superficial wounds
  • SSD ointment
  • Orabase
• Systemic infections
  • Red leg
  • Septicemia
• Causes:
  • Interaction of multiple bacteria
  • Immunosuppression
  • Other agents interact
  • Small lesion gone bad
  • Physical damage

  Redleg and ulcerative lesion in a tree frog

• Mycobacteria spp.
  • Different from bird or mammal presentation
  • Ubiquitous in aquatic environment
  • Skin nodules
  • Anorexia
  • Secondary to injury

Mycobacterial infection in a Tiger salamander

7.3. Infectious - Fungal

• Usually thought to be opportunistic invaders
• Primary cause of death has been documented
• Exposure occurs through substrate
• Decimate whole collections or just an individual

Fungal dermatitis in a frog

7.4. Infectious - Parasitic

• Consider all wild caught animals to have lots of parasites!
• Can weaken animal considerably
• Put amphibians of unknown source through deworming program

7.5. Infectious - Viral

• Different viruses have been identified
• Mortalities in large numbers
• Can infect eggs, larvae and or adult.
• E.g. Lucke’s virus - Renal adenocarcinoma

7.6. Non-Infectious

• Toxins
  • Usually chronic
  • Skin is highly permeable membrane
  • Neoplastic, repro, nutritional, developmental etc.
  • Egg is highly susceptible
• Usually mistakes in husbandry
• Chronic stressor
• High mortality
  • Secondary invader
  • Anorexia etc.

9.1. Readings

9.2. Websites

Association of Reptile and Amphibian Veterinarians http://www.arav.org

North American Reporting Center for Amphibian Malformations http://frogweb.nbii.gov/

Society for the Study of Amphibians and Reptiles http://www.ssarherps.org/

Cornell University's introductory biology sequence, BioG 101-104 course onlinehttp://biog-101-104.bio.cornell.edu/Biog101_104/tutorials/frog.html