Common Conditions - Reptiles

Question 1

What happens when ectotherms live outside their preferred body temperature?

Answer 1

They will have reduced immunity and metabolism

Question 2

What are some clinical signs we may see in sick reptiles?

Answer 2

• Reduced flight distance/predator avoidance response
• Lack of ‘normal’ behaviours
• Reluctance to feed, move (care with species that brumate/hibernate, or during ecdysis/shed in snakes)
• Neurological signs: star gazing, writhing, paralysis

Question 3

What is metabolic bone disease of reptiles?

Answer 3

Group of diseases characterised by a failure to regulate calcium and vitamin D.
-> results in secondary changes in bones, body condition, and activity levels/physiology

-> Primarily a disease of captive reptiles - husbandry factors: inadequate UV-B, unsuitable temperature, prolonged Ca or Vit D3 deficiency.

Question 4

What are the clinical signs of metabolic bone disease in reptiles?

Answer 4

• Fractures, soft bones, rubbery jaw
• Long bone and spinal deformities
• Lethargy, weakness, abnormal stance
• Paralysis
• Inappetence or anorexia
• Tremors
• Dystocia

Question 5

What is the hormonal response of the body if the reptile is hypo calcaemic?

Answer 5

When the circulating calcium is low, the parathyroid gland will increase PTH which in turn increases the synthesis of Calcitriol (active vitamin D3).
Calcitriol increases calcium levels by increasing the absorption of calcium in the GI tract, increases tubular resorption of calcium from the kidneys and increases resorption of calcium from bones.

Question 6

What is the hormonal response of the body if a reptile is hyper calcaemic?

Answer 6

When the circulating levels of calcium are adequate, the thyroid gland will increase calcitonin which opposes the action of PTH.

Question 7

How do we diagnose metabolic bone disease in reptiles?

Answer 7

• Ante-mortem: history, clinical signs, radiographs most useful. Can check the serum Vit D and calcium/phosphorus (biochemistry) but risks may outweigh benefits in unwell animals
• Post-mortem: sections of affected bone, liver for vit D analysis, radiographs

Question 8

How do we treat metabolic bone disease in reptiles?

Answer 8

Mild-moderate:
- 1ml/kg PO bid for 1-3 months of either Ca glubionate o calcium gluconate
- continue until eating okay on own and clinically improved (weight and movement)

Severe (tetany):
- 100mg/kg 10% Ca gluconate IM or intracoelomically q 6 hours until tetany ceases

Euthanasia can be an appropriate treatment for severe cases, the pathological fractures and bone issues will not resolve even with treatment

Don’t forget: nutritional support, analgesia, rectify husbandry issues - temperature, UVB, diet

Hypocalcaemia/radiolucency of bone, and/or paresis, paralysis = poor prognosis

Question 9

What are the causes for dysecdysis (abnormal shedding)?

Answer 9

Usually husbandry related:
- low humidity
- lack of appropriate substrate/structures in enclosure - abrasive assist shedding
- ectoparasites (mites)
- scars (old injuries)
- systemic disease
- dermatitis

Question 10

How do we treat dysecdysis?

Answer 10

• soak in warm water for 1-2 hours
• gently remove slough with moist towel
  when soaking: use shallow water, ensure there are structures for the snake to rest head out of water, never leave soaking reptile unattended

retained spectacles: do not pull off! eye lubricant can soften and assist shedding

Question 11

How do we treat thermal burns in reptiles?

Answer 11

• healing can take months
• clean wounds with mild antiseptic
• consider systemic ABs for widespread or severe burns
• correct fluid and protein loss
• analgesia

Question 12

How do we treat necrotic stomatitis?

Answer 12

• dilute antiseptic flush e.g. chlorhexidine
• topical antimicrobials e.g. silvazine
• severe cases: anaesthesia and debride affected area, systemic AB (after C&S)

-> Need to identify and treat underlying cause e.g. poor husbandry, other diseases

Question 13

Nidovirus affects snakes, lizards, and turtles - which organ system does it affect? (except in turtles)

Answer 13

Think respiratory! (except in turtles)

Transmitted through direct contact with respiratory secretions and aerosols.
Dx: swab eye/mouth for PCR, histopathology

Question 14

What are the clinical signs of nidovirus in lizards, turtles and snakes?

Answer 14

Shingleback lizard: oral/ocular discharge, often mucoid, and stomatitis

Bellinger river turtle: sudden death, more systemic effects with kidney involvement

Snakes: lower respiratory, more common

Question 15

If we submit a sample for PCR testing from a snake with respiratory signs which differential disease are we asking the lab to test for?

Answer 15

Nidovirus
Ferlavirus
Inclusion body disease (Reptarenavirus)
Sunshine virus

Question 16

A snake/reptile with thick crusty raised nodules and ulceration on its skin - what are the DDx?

Answer 16

Dermatomycosis (yellow fungus disease)

Ophidiomycosis - snake fungal disease (although exotic to Australia - seen in Europe and north America in wild animals)

Question 17

You want to submit samples to confirm what the crusty raised nodules and ulcerations on the skin are of a snake/reptile - which samples do you submit?

Answer 17

-> Section of affected and unaffected skin (multiple samples, include underlying tissue/muscle to see if deeper spread)

-> Place in 10% neutral buffered formalin, freeze representative sections for PCR analysis and fungal culture

-> Submit fresh piece of affected skin collected aseptically for fungal and bacterial culture (care with false negatives on fungal culture!!!)

Labs will not necessarily use the right conditions to grow the fungus unless you tell them you suspect it!!!