WILDLIFE MED - Reptiles and Amphibians

• Chelonian


  Any of various reptiles of the order Chelonia (or Testudines), which includes the turtles and tortoises

  
• Chelonians lack teeth and usually have a hard shell that protects the body and consists of bony plates fused to the vertebrae and ribs
• Chelonians are toothless, oviparous, quadrupedal, pentadactyl reptiles with a shell and a unique trochlear system for the common tendon of the jaw adductor muscles
• Chelonian shell


  • Made up of keratinized epidermis covering fused live dermal bone
  • It should never be used to attach chelonians to ropes or chains as they can experience pain and other emotions
• Turtles


  Aquatic or semi-aquatic reptiles with streamlined bodies and webbed feet, typically living in water bodies
• Turtles species

  • Sea turtles
  • Painted turtles
  • Snapping turtles
• Tortoises


  Land-dwelling reptiles adapted for terrestrial life, with stout, dome-shaped shells and sturdy, elephant-like legs, herbivorous
• Terrapins


  Semi-aquatic turtles that live in freshwater or brackish habitats, with features intermediate between turtles and tortoises, capable of swimming and well-adapted for terrestrial life, omnivorous
• Transmission of TINC


  1. Fecal-oral route

  2. Environmental contamination

  3. Stress and immunosuppression
• Clinical signs of TINC

  • Renal dysfunction (increased water intake, increased urine output, dehydration, lethargy, anorexia, weight loss)
  • Shell damage due to weakened immune system function and secondary infections
  • General signs of illness (lethargy, decreased appetite, weakness)
• Fibropapillomatosis (FP)


  A tumor-causing disease that affects some sea turtles, characterized by the development of benign but often extensive fibroepithelial tumors (fibropapillomas) on the skin, mucous membranes, and internal organs

  
• Clinical signs of Fibropapillomatosis (FP)

  • Tumor growth (fibroepithelial tumors on the skin, particularly around the eyes, neck, flippers, and soft tissues)
  • Lesion severity (ranging from small, solitary growths to extensive, multiple tumors)
  • Secondary infections (ulcerated tumors leading to systemic illness)
  • Ocular lesions (vision impairment or blindness in sea turtles)
• Metabolic bone disease (MBD)


  A common condition affecting chelonians, characterized by a disruption in the normal metabolism of calcium, phosphorus, and other minerals, leading to skeletal abnormalities and systemic health issues
• Contributing factors to Metabolic bone disease (MBD)

  • Inadequate diet (lacking in essential nutrients, particularly calcium and vitamin D3)
  • Inadequate UVB exposure (essential for chelonians to synthesize vitamin D3)
  • Incorrect environmental conditions (improper temperature, humidity, housing)
• Clinical signs of Metabolic bone disease (MBD)

  • Soft shell (deformities, pyramiding, or shell fractures)
  • Skeletal abnormalities (bowed limbs, swelling or bending of the limbs, abnormal growth patterns)
  • Weakness and lethargy
  • Decreased appetite
  • Respiratory and digestive issues
• Respiratory infections


  Common in chelonians, often caused by bacteria such as Mycoplasma and various other pathogens, with clinical signs including nasal discharge, wheezing, open-mouth breathing, and lethargy
• Shell rot


  Typically caused by a variety of bacterial and fungal pathogens, which can infect the shell due to trauma, poor environmental conditions, or compromised immune function
• Parasitic infections


  Can be caused by various internal and external parasites, including nematodes, cestodes, protozoa, ticks, mites, and leeches
• Ranavirus


  A double stranded DNA virus that can cause severe infections in a number of cold-blooded taxa, including amphibians, reptiles, and fish
• Rana

  Derived from the Latin for "frog", reflecting the first isolation of a Ranavirus in 1960s from the Northern leopard frog (Lithobates pipiens)
• Ranavirus


  • Large icosahedral DNA viruses measuring approximately 150 nm in diameter with a large single linear dsDNA genome of roughly 105 kbp which codes for around 100 gene products
  • The main structural component of the protein capsid is the major capsid protein (MCP)
• Ranavirus can infect at least 175 species across 52 families of ectothermic vertebrates
• Ranavirus can affect animals at all life stages, though in general, mortality rates are highest if the animal contracts the virus during a juvenal or larval stage (hatchlings and metamorphs)
• Transmission of Ranavirus


  • Occurs via exposure to contaminated water or soil, contact with infected individuals, and consumption of infected tissues
  • Fish and reptiles (especially turtles) are reservoirs for ranaviruses
• Ranaviruses are highly persistent and can remain infectious in the environment for an extended period, likely surviving for months in water under favorable conditions
• Ranaviral diseases in amphibians

  • Midwife toad virus
  • Bohle virus
  • Frog virus 3 (FV3)
  • Ambystoma tigrinum virus
• Midwife toad virus, Bohle virus, Frog virus 3 (FV3)


  Ranaviral diseases that results in edema, hemorrhage, and necrosis of lymphoid tissue, hematopoietic tissue, liver, spleen, and renal tubules (3)
• Ambystoma tigrinum virus


  First detected in the oral cavity and upper respiratory mucosa, with infections spreading to the connective tissues and vasculature of the gastrointestinal tract
• Ranaviral diseases in fish


  • European Catfish Virus
  • Epizootic Haematopoietic Necrosis Virus
• European Catfish Virus


  The most important ranavirus that causes disease of fish in Europe. It has triggered epizootics in cultivated sheatfish in Germany
• Epizootic Haematopoietic Necrosis Virus


  Identified as the cause of epizootic mortality of redfin perch (Perca fluviatilis) and rainbow trout (Oncorhynchus mykiss) in Australia in 1985
• The first cases of ranavirus infections in reptiles from which data were available on the viral genome were from a box turtle (Terrapene c. carolina) and a tortoise (Testudo horsfieldii) from North America. Both appeared to be FV3-like based on partial MCP gene sequences and restriction endonuclease analysis
• Clinical signs of Ranavirus


  • Frequently, the first sign of an outbreak is the sudden onset of illness and death in large numbers of amphibians and/ or reptiles over a 1-5 day period
  • In amphibians, include mild to severe hemorrhages in the skin, especially near the base of the hind limbs and the vent opening. At necropsy, there may be fluid accumulation in the body cavity and hemorrhages on the surfaces of the heart, stomach, and liver. Occasionally, the liver or spleen are affected and ulcers in the skin and palate may be observed
  • In turtles, include weakness, swollen eyelids, discharge from the nose and mouth, ulcers on the feet, and dull white or thick yellow plaque on the tongue, palate, pharynx
• Diagnostic methods for Ranavirus

  • Electron microscopy
  • Molecular identification (PCR)
  • Virus isolation
• Management of Ranavirus


  • Quarantine infected animals to prevent spread
  • Apply disinfectants like Virkon®, Nolvasan®, bleach, and ethanol to inactivate ranavirus
  • Perform complete drawdown of water bodies to allow soil desiccation and inactivate ranavirus
• Ophidiomycosis


  Also referred to as snake fungal disease (SFD), caused by the fungus Ophidiomyces ophiodiicola
• Ophidiomyces ophiodiicola


  • Keratinophilic fungus belonging to the Onygenales order's Onygenaceae family
  • Newly discovered pathogen that affects both captive and wild snakes in North America and Europe
• Ophidiomycosis clinical symptoms

  Skin nodules, crusts, and edema
• Fibropapillomatosis


  Commonly referred to as "FP", is a tumor-causing disease that usually affects some sea turtles

  
• There is no known treatment for Ophidiomyces ophiodiicola