Top 10 Reptile Diseases Part 1

1. Metabolic bone disease (MBD)
   

   

   • Classic case:
     • "Bent iguana" (pathologic fractures) OR
     • Progressive weakness in a young reptile OR
     • Swollen limbs from fibrous osteodystrophy
     • History of a deficient diet (unsupplemented lettuce, ground meat, mealworms, crickets)
   • Dx:
     • Physical exam: distorted, rubbery mandible
     • Radiography: poor mineralization, greenstick fractures
     • Low plasma 25-dihydroxycholecalciferol
     • Later see hyperphosphatemia and hypocalcemia
   • Tx:
     • CRITICAL: Correct diet and lighting
       • Dietary Ca:P = 1.5-2.1
       • Unfiltered sunlight or full spectrum light (UVB) needed for vitamin D3
     • "Gut-load" whole prey (prey supplemented with calcium or calcium/vit D)
     • Calcitonin: only if normocalcemic
   • Pearls:
     • Prognosis is fair to good if caught early, but poor if hypocalcemia and bone loss
     • Renal secondary hyperparathyroidism can occur in older animals with end-stage renal disease
       • Present with inability to move and muscle fasciculations


2. Salmonellosis
   

   

   • Classic case:
     • Reptiles AND amphibians are often carriers, shedding bacteria in feces
     • May see septicemia, osteomyelitis, abscesses
   • Dx:
     • Culture (abscess or blood)
     • Biopsies
     • Radiographs: vertebral infection in snakes
     • Necropsy: acute enteritis or necrotizing fibrinous enteritis
   • Tx:
     • Debridement
     • Systemic antibiotics if septicemic (may increase emergence of resistant strains)
     • Supportive care
       • Fluids
       • NSAIDs
   • Pearls: ZOONOTIC concern
     • Red-eared slider turtles illegal to sell if under 4 inches of shell length (can fit in child's mouth)
     • Practice good hygiene after handling reptiles or amphibians, enclosures, and their food
     • Children under 5, the elderly, and people with compromised immune systems are at high risk of infection
     • Etiology: Usually S. bongori or S. enterica


3. Dysecdysis (retained shed)
   

   

   • Classic case:
     • Snakes with retained or partially shed skin
     • Lizards: see over feet and toes, can constrict distal toes and tail tip
   • Dx:
     • Physical exam
     • Rule out underlying disease
   • Tx:
     • Soak animal prior to assisting shed
     • Be careful with retained spectacles, can damage cornea
     • Treat underlying disease
   • Pearls:
     • Environment may be too dry or poor nutrition
     • Subspectacular abscesses can occur between cornea and spectacle
     • Exuvium is the shedded whole skin (snakes)
     • Lizards shed in pieces


4. Gout
   

   

   • Classic case:
     • Visceral: obtunded, weak, dehydrated
       • Primary is caused by excess dietary protein
       • Secondary is due to dehydration or renal disease
     • Articular: swellings, white nodular tophi (urate-centered granulomas) around appendicular joints, PAINFUL
     • Rare to have both types in one animal
   • Dx:
     • Increased blood uric acid levels
     • Radiographs show mineralized tophi in organs or joints
     • FNA of joints: see needle-shaped crystals
   • Tx:
     • Rehydration/abundant access to water, vitamin supplementation, analgesics
     • Primary visceral: decrease dietary protein; try to approximate diet of reptile's natural habitat
     • Secondary visceral: treat underlying disease
     • Medical Rx is challenging, poorly understood & takes cues from human protocols
       • Allopurinol, may decrease uric acid production (debated)
       • Probenecid, to promote urate excretion
       • Colchicine/corticosteroids to manage acute gouty arthritis attacks
   • Pearls:
     • Prognosis is poor
     • Pseudogout occurs in turtles, with mineral deposition (not urate) in and around feet


5. Hemipenal and phallic prolapse
   

   

   • Classic case:
     • Prolapsed structure, unable to retract
     • Vulnerable to trauma during mating
   • Dx: Physical exam
   • Tx:
     • Hypertonic topicals, lubricants, and reduction
     • Surgical amputation: phallus and hemipenes have no urethra
   • Pearls:
     • Single phallus in crocodilians and chelonians
     • Paired hemipenes in lizards and snakes
     • Oviduct prolapse can occur in females when straining to pass eggs: SERIOUS

Images courtesy of Haley Luna (Kevin the tortoise), Jean A. Paré, DVM, DVSc, DACZM (MBD, snake spine, retained spectacles, prolapsed hemipenes), and Doruk Salanci (uric acid crystals).