Two Common Diseases of Captive Chelonians

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Two Common Diseases of Captive Chelonians

• Trevor Zachariah
• Mizue Ambo

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• Terminology
• Anatomy Physiology
• Hypovitaminosis A
• Pneumonia

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• Terminology
• Turtles - generally aquatic
• Tortoises - terrestrials

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

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• 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

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• 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!!)

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• 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

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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

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• 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

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Clinical Symptoms (contd)

• 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)

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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

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• 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

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Left post-treatment day 16
Right post-treatment day 18
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• 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

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Pneumonia in Chelonians
Eastern box turtle
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Normal Respiratory Anatomy

• dorsal and ventral attachments
• no true diaphragm
• internal ridging
• large volume
• small respiratory surface area

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Normal Respiratory Anatomy

• muscle pairs control visceral, and thus lung
  volume
• head and limb movements
• no reliance on negative thoracic pressure

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Pneumonia

• serious problem in cheloniansvery difficult to
  remove secretions/foreign material out of lungs
• -entrance of bronchi
• -compartmentalization
• -large potential space
• -no diaphragm
• -mucociliary elevator

Common map turtle
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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
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Diagnostic Plan--Physical Exam

• dyspnea
• -inspiratory /- expiratory
• -open mouth breathing, head and neck extended
• RR increased
• rales during auscultation
• cyanotic mucous membranes
• lethargic, depressed

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Diagnostic Plan--Physical Exam

• less time in water
• asymmetrical swimming

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Diagnostic Plan--Radiology

• lateral view

• craniocaudal view

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Diagnostic Plan--Radiology

• compare R and L lung fields in craniocaudal view
• know what normal looks like
• pneumonia is diffuse or regionalized opacity

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Diagnostic Plan--Radiology
pneumonia
normal
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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

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Diagnostic Plan--Sampling

• sample uses
• -wet mount
• -exfoliative cytology and special stains
• -microbiologic evaluation

Desert tortoise
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Diagnostic Plan--Systemic

• critical illness
• secondary effects on other systems
• -eg evaluate renal and hepatic function prior to
  antimicrobial administration

Hermann tortoise
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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

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Differential Diagnoses--Bacterial

• Escherichia coli
• Klebsiella
• Pseudomonas
• Proteus
• Aeromonas
• Salmonella
• Pasteurella

• Bacteroides
• Peptostreptococcus
• Fusobacterium
• Clostridium
• mycoplasma
• chlamydia
• mycobacteria

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Differential Diagnoses--Viral

• herpesvirus
• -severe necrotizing bronchitis, pneumonitis, and
  hepatitis

Red-eared slider
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Differential Diagnoses--Fungal

• Aspergillus
• Candida
• Mucor
• Geotrichum

• Penicillium
• Cladosporium
• Rhizopus
• Beauveria

-most treatments are unsuccessful
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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)

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Differential Diagnoses--Other

• noninfectious causes
• -aspiration
• -inhalation

Aldabra tortoise
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Treatment

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

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Treatment

• 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

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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

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Treatment

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

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Treatment
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Treatment

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

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Treatment

• supportive care
• -fluid therapy
• -preferred optimal temperature
• -feeding
• -vitamin A

Gopher tortoise
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Treatment

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

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Thank You!
Common snapping turtle
Alligator snapping turtle
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References

• Aiello, SE, ed. The Merck Veterinary Manual,
  Eighth Edition. 1998. Merck Co., Inc.
• Bartlett, RD Bartlett, PP. Turtles
  Tortoises. 1996. Barrons 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.

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Questions?