Two Common Diseases of Captive Chelonians

1. Two Common Diseases of Captive Chelonians Trevor Zachariah & Mizue Ambo

2. Terminology • Anatomy & Physiology • Hypovitaminosis A • Pneumonia

3. Terminology • Turtles - generally aquatic • Tortoises - terrestrials

4. Anatomy & Physiology • Shell • Upper shell = carapace • Lower shell = platron • Scutes = superficial layer of keratin shield over • bony shell

5. Respiratory System • Breath in and out of nares • Trachea has complete cartilaginous ring • Short trachea bifurcates directly into the paired • lungs • The lung is dorsally attached to the ventral surface • the carapace • No true diaphgram separates the lungs from • the other internal organs • Less surface lung area • Large lung volume which provide buoyancy for • the aquatic turtles

7. GI System • Terrestrial species = hervivors • Aquatic species = carnivors or omnivors • No teeth with large fleshy tongue • Shorter small intestine compare to the mammals • Food digestion time = 3-28 days • Circulatory System • 3 chambered heart like typical reptiles • Renal portal system (watch out!!)

8. Renal System • No Loop of Henle • Aquatic = soluable urinary, nitrogenous wastes • need large amount of water for excretion • Terrestrials = insoluable urinary waste, uric acid, urate • salts

9. Hypovitaminosis A • Lack of vitamin A in the diet • Multifocal squamous metaplasia of epithelium • Respiratory, ocular, endocrine, GI, and genitourinary • system are often involved • Normal columnar, cuboidal epithelium is replaced by • flattened cells • Granulocyte and desquamated material fill multiple • cysts • Cellular debris accumulates underneath the eyelids • in the conjunctival sac, fuse eyelids if severe

10. Clinical Symptoms • “Swollen eyelids” - most commonly blepharoedema with or • without whitish-yellowish cellular debris underneath the • eyelids • Lethargy • Anorexia & weight loss • Nasal, ocular discharge • In chronic cases - irregularly thickened integument that • cracks and abonormal keratin growth in the seams • between scutes

11. Clinical Symptoms (cont’d) • Pneumonia and hypovitaminosis A are concurrent in • desert turtles • Middle ear and respiratory tract infection and egg • retention are common in Box turtles • Inguinal, axillary edema can be a sign of kidney failure • secondary to hypovitaminosis A (poor prognosis)

12. Diagnosis • Vitamin A assay of liver, or large quantities of blood • are needed for definitive diagnosis • Normal liver vitamin A level is over 1000 IU/gm • Mean plasma retinol values can be measured • Dietary history, clinical signs, and response to • treatment are crucial

13. Treatment • SQ injection of 1500-2000 IU Vitamin A /kg weekly • for 2-6 weeks • Not to give high dose of Vitamin A • - can result in Hypervitaminosis A • Symptoms can resolve between 2-6 weeks • Carefully remove cellular debris • Ophthalmic antibiotic ointment can be useful

14. Left: post-treatment day 16 Right: post-treatment day 18

15. Prevention / Long term treatment • Client education • Expanding diet - food rich in beta carotin • Yellow-orange colored vegetable or fruit, steamed winter • squash, carrots, sweet potatoes, and cantaloupes • For aquatic turtles - liver from mice or fish • Commercial diets suitable for reptiles are good, too • - Purina Trout Chow • - Tera Reponin • - Floating food sticks

16. Pneumonia in Chelonians Eastern box turtle

17. Normal Respiratory Anatomy • dorsal and ventral attachments • no true diaphragm • internal ridging • large volume • small respiratory surface area

18. Normal Respiratory Anatomy • muscle pairs control visceral, and thus lung volume • head and limb movements • no reliance on negative thoracic pressure

19. Pneumonia • serious problem in chelonians—very difficult to remove secretions/foreign material out of lungs -entrance of bronchi -compartmentalization -large potential space -no diaphragm -mucociliary elevator Common map turtle

20. Diagnostic Plan--History • complete and thorough • important points -origin -quarantine procedures -other reptile species in the collection -environmental disinfection -progression of clinical signs Midland painted turtle

21. Diagnostic Plan--Physical Exam • dyspnea -inspiratory +/- expiratory -open mouth breathing, head and neck extended • RR increased • rales during auscultation • cyanotic mucous membranes • lethargic, depressed

22. Diagnostic Plan--Physical Exam • less time in water • asymmetrical swimming

23. lateral view craniocaudal view Diagnostic Plan--Radiology

24. Diagnostic Plan--Radiology • compare R and L lung fields in craniocaudal view • know what normal looks like • pneumonia is diffuse or regionalized opacity

25. Diagnostic Plan--Radiology pneumonia normal

26. Diagnostic Plan--Sampling • transtracheal wash -not great -fleshy, muscular tongue • percutaneous lung wash -sterile saline solution (0.5-1% of BW) -needle -affected side down

27. Diagnostic Plan--Sampling • sample uses -wet mount -exfoliative cytology and special stains -microbiologic evaluation Desert tortoise

28. Diagnostic Plan--Systemic • critical illness • secondary effects on other systems -eg evaluate renal and hepatic function prior to antimicrobial administration Hermann tortoise

29. Differential Diagnoses--Bacterial • majority of pneumonia cases • many are gram negative • often found in healthy individual • occurrence -primary entity -extension of another disease -normal commensal established in unusual place

30. Escherichia coli Klebsiella Pseudomonas Proteus Aeromonas Salmonella Pasteurella Bacteroides Peptostreptococcus Fusobacterium Clostridium mycoplasma chlamydia mycobacteria Differential Diagnoses--Bacterial

31. Differential Diagnoses--Viral • herpesvirus -severe necrotizing bronchitis, pneumonitis, and hepatitis Red-eared slider

32. Aspergillus Candida Mucor Geotrichum Penicillium Cladosporium Rhizopus Beauveria Differential Diagnoses--Fungal -most treatments are unsuccessful

33. Differential Diagnoses--Parasitic • live a portion of life cycle in respiratory tract • cause secondary bacterial infections • pentastomids (“tongue worms”) -annulate metazoan parasites • trematodes -renifers (eg Dasymetra, Lechriochis, Aeugochis, Ochestosoma, Stomatrema)

34. Differential Diagnoses--Other • noninfectious causes -aspiration -inhalation Aldabra tortoise

35. Treatment • clinical signs usually not noticed until advanced disease present • serious enough to mandate aggressive therapy • start right away with broad-spectrum antimicrobials

36. Amikacin Ceftazidime Ceftiofur Cefotaxime Cefuroxime Enrofloxacin Piperacillin Metronidazole Amphotericin B Ketoconazole Ampicillin Carbenicillin Ceftazidime Doxycycline Trimethoprim-sulfadiazine Gentamicin Amikacin Enrofloxacin Tylosin Ketaconazole Nystatin Acyclovir* Ganciclovir* Treatment

37. Treatment • nebulization -increase humidity -increase efficiency of mucociliary system -aid breakup of necrotic and inflammatory debris -deliver antibiotics deep into site of infection -Amikacin, Cefotaxime, Piperacillin

38. Treatment • intrapneumonic catheter -hand drill with 4mm bit -over-the-needle catheter -polymethylmethacrylate

39. Treatment

40. Treatment • other options -mucolytic agents (eg acetylcysteine)? -coupage? -furosemide? -atropine? -oxygen therapy?

41. Treatment • supportive care -fluid therapy -preferred optimal temperature -feeding -vitamin A Gopher tortoise

42. Treatment • cessation -clinical signs -serial hemograms -serial radiographs -serial transtracheal or lung washes -patient disposition -your judgement and intuition

43. Thank You! Common snapping turtle Alligator snapping turtle

44. References • Aiello, SE, ed. The Merck Veterinary Manual, Eighth Edition. 1998. Merck & Co., Inc. • Bartlett, RD & Bartlett, PP. Turtles & Tortoises. 1996. Barron’s Educational Series. • Davies, R & Davies, V. The Reptile & Amphibian Problem Solver. 1997. Tetra Press. • De Vosjoli, P. General Care & Maintenance of Popular Tortoises. 1996. The Herpeticocultural Library. • Lewis, W. How to Place Intrapneumonic Catheters in Chelonians. Exotic DVM Magazine, Vol. 3.5, Oct./Nov. 2001, pp.16-17. • Mader, D. Reptile Medicine & Surgery. 1996. W. B. Saunders Co. • Messonnier, SP. Common Reptile Diseases & Treatment. 1996. Blackwell Science, Inc. • Phalen, DN. The Veterinary Clinics of North America Exotic Animal Practice, Repiratory Medicine. 2000. W. B. Saunders Co.

45. Questions?