Reptile diagnostics part 2

Endoscopy in Reptiles

  • Historical Background

    • Reports of endoscopy use in reptiles and small exotics date back to the 1960s.

    • Most previous reports focus on:

    • Visualization of the gastrointestinal (GI) tract.

    • The removal of foreign bodies (FB) from the GI tract.

    • Additional procedures include:

    • Laparoscopy.

    • Bronchoscopy.

    • Internal examination techniques include:

    • Sex determination.

    • Evaluation of the urogenital system.

Types of Endoscopy

  • Flexible Endoscopy

    • Allows for the removal of foreign bodies located in:

    • The esophagus.

    • The stomach.

    • Airway structures.

  • Rigid Endoscopy

    • Used for:

    • Internal examination.

    • Collection of biopsy samples without major surgical intervention.

Tracheobronchoscopy in Reptiles

  • Examples of Tracheobronchoscopy

    • Greek Tortoise (Testudo graeca):

    • Visualization of trachea exhibiting complete tracheal rings.

    • Ball Python (Python regius):

    • Observations of trachea with a distinct dorsal ligament.

    • Green Iguana (Iguana iguana):

    • Visualization of tracheal bifurcation and primary bronchi.

    • Compartmentalized Lung in Panther Chameleon (Furcifer pardalis):

    • Unique lung structures observed.

    • Granulomatous Pneumonia:

    • Caused by Mycobacterium spp. in a ball python.

Endoscopic Procedures and Pathology in Reptiles

  • Glenoscopy

    • Stomatoscopy, Esophagoscopy, and Gastroscopy Examples:

    • Radiated Tortoise (Astrochelys radiata):

      • Demonstration of choana, hard palate, fleshy tongue, and glottis.

    • Burmese Python (Python bivittatus):

      • Air-distended esophagus.

    • Green Iguana (Iguana iguana):

      • Saline-infusion view of the esophagus.

    • Savannah Monitor (Varanus exanthematicus):

      • Normal ruggal folds in the stomach.

    • Corn Snake (Pantherophis guttatus):

      • Gastric hypertrophy due to cryptosporidiosis.

      • Leiomyoma obstructing pyloric outflow leading to chronic regurgitation.

  • Endoscopic Pathology and Kidney Biopsy Examples:

    • Green Iguana (Iguana iguana):

    • Enlarged kidney with related renal cyst. Symptoms of anorexia and cachexia.

    • Radiographic and ultrasonographic findings confirmed renomegaly with plasma biochemistry revealing reversed calcium:phosphorus ratio and increased uric acid.

    • Biopsy confirmed glomerulonephrosis with renal gout and mineralization via left lateral coelioscopy.

    • Greek Tortoise (Testudo graeca):

    • Abnormal kidney with fibrous bands. Symptoms included anorexia, lethargy, and polyuria.

    • Unremarkable diagnostic imaging and clinicopathology, renal biopsy confirmed diagnosis of severe tubulonephrosis.

    • Biopsy of Iguidid Kidney:

    • Conducted using 1.7-mm biopsy forceps via right lateral coelioscopy.

    • Yellow-bellied Slider (Trachemys scripta scripta):

    • Incision of the caudodorsal coelomic membrane for access to retrocoelomic kidney using 1.7-mm endoscopy scissors.

    • Collection of Kidney Biopsy:

    • Biopsy forceps employed to collect samples.

Therapeutic Interventions in Reptiles

  • Fluid Therapy:

    • Choice of fluid based on:

    • Clinician's preference.

    • Presenting clinical problem.

    • Clinical pathology considerations.

    • Acid-base abnormalities.

    • Fluid Types:

    • Reptile Ringers Solution:

      • Combination of one part Lactated Ringers, two parts 2.5% dextrose, and 0.45% sodium chloride.

    • Normasol-R, Lactated Ringers Solution, 0.9% Sodium Chloride.

  • Routes of Fluid Administration:

    • For severely compromised reptiles, the following routes enable rapid rehydration and emergency care:

    • Intravenous (IV) or Intraosseous (IO).

    • Intravenous or IO routes: Required for administration of:

      • Whole blood.

      • Artificial blood.

      • Colloidal fluids.

      • Fluids with >5% dextrose.

    • IO:

      • Not suitable for snakes; applicable sites include:

      • Bridge or gular scute in chelonians.

      • Tibial crest in lizards.

    • IV:

      • Accessible vessels include:

      • Jugular vein.

      • Cervical sinus in sea turtles.

      • Advantages:

      • Easy vessel accessibility.

      • Minimal stress to the patient.

      • Allows repeated vascular access.

    • Intracoelomic (ICe):

      • Used for maintenance therapy.

      • Injection locations:

      • Inguinal fossa in chelonians.

      • Right side of lower abdomen in lizards.

      • Lower third of body in snakes.

    • Advantages of ICe:

      • Technically easy to perform.

      • Effective for administering crystalloid fluids with up to 5% dextrose.

      • Disadvantages:

      • Slow fluid absorption in severely compromised reptiles.

      • Potential risk of compromising lung space, perforating lungs, urinary bladder, or ovarian follicles.

      • Hypoproteinemic patients may exhibit fluid buildup in coelomic cavity, complicating absorption issues.

    • Subcutaneous (SC):

      • Advantages:

      • Technically simple to perform at multiple skin folds.

      • Preferred sites include:

        • Inguinal fossa, medial front limb fossa, ventral neck fold in chelonians.

        • Lateral body wall in snakes.

        • Over scapulae in lizards.

      • Disadvantages:

      • Poor absorption in severely debilitated reptiles.

      • Limited to administering fluids of 2.5% dextrose or less.

    • Oral (PO) Administration:

      • Indicated for mild to moderate dehydration or maintenance.

      • Fluids can be delivered via a lubricated feeding tube.

    • Soaking:

      • Recommended for rehydration over 24 hours to reduce epibiota.

    • Intra-cloacal:

      • Alternative route available.

  • Volume of Fluids to Administer:

    • In the case of severely compromised reptiles:

    • Maintenance fluid dose:

      • Calculated at 10 to 20 ml/kg/day plus deficits.

    • Replacement of losses over 72 to 96 hours:

      • Approximately 25 to 30 ml/kg/day.

    • Maintenance should not exceed 1 to 2% of the animal's total body weight per day (10-20 ml/kg BW).

  • Blood Transfusions:

    • Indications include:

    • Life-threatening anemia with packed cell volume (PCV) < 5%.

    • Acute blood loss, trauma, or severe chronic disease-associated anemia.

    • Stabilization before surgical procedures.

    • Important considerations:

    • Both donor and recipient must be of the same species.

    • Use of acid-citrate-dextrose (ACD) solutions for blood collection.

    • Post transfusion, if PCV still exceeds 5%, continue supportive measures with fluid therapy and iron supplementation.

  • Antimicrobial Therapy:

    • Challenges:

    • Insufficient pharmacokinetic studies.

    • Extra-label drug use due to absence of specific formulations.

    • Small patient sizes complicate treatment.

    • Cost factors impacting accessibility of medications.

    • Difficulty associated with the ease and frequency of administration.

    • Safety concerns with specific drugs.

    • Drug Selection:

    • Should be based on cultures and sensitivity testing.

    • Diagnostic samples should be obtained before initiating therapy:

      • Blood culture.

      • Wound culture.

      • Gram stain and cytology.

      • Histopathology to inform diagnosis.

    • Assessment:

      • Determine if antibiotic is bactericidal or static.

      • Consult veterinary formulary and look for pharmacokinetic studies if available.

  • Intestinal Dysbiosis:

    • Occurs when indigenous intestinal flora is depleted or altered, often after an oral course of antibiotics.

    • Clinical Signs:

    • Anorexia, lethargy, diarrhea.

    • Treatment and Management:

    • Repopulation with probiotics.

    • Feces should be obtained from untreated animals of the same species, preferably passed before commencing antibiotic therapy.

    • Address issues of Candida overgrowth with nystatin.

    • Agricultural practices should avoid feces exposure from infected sources.

  • Antifungal Therapy:

    • Fungal infections can affect various systems, notably:

    • Integumentary system.

    • Respiratory system (both upper and lower).

    • Gastrointestinal tract.

    • Diagnosis of systemic mycoses is generally rare in reptiles and often discovered postmortem.

    • Mixed infections of bacteria and fungi may be opportunistic.

    • Diagnosis and Treatment:

    • Requires appropriate selection and collection of diagnostic specimens, including biopsies of infected tissues.

    • Treatment involves administering effective antifungal agents and correcting environmental conditions.

    • Common antifungals include amphotericin B, itraconazole, fluconazole, and voriconazole.

  • Antiparasitic Treatments:

    • Recommended drugs include:

    • Praziquantel: Effective against trematodes.

    • Pyrantel pamoate: Effective against ascarids and hookworms.

    • Fenbendazole: Effective for nematodes and some protozoa but uses require caution due to potential bone marrow suppression.

    • Important Note:

      • NEVER USE IVERMECTIN IN CHELONIANS (tortoises and turtles).

  • Nutritional Needs:

    • When to Initiate Feeding Interventions:

    • Acute loss of 10% of body weight (BW).

    • Chronic loss of 20% of BW.

    • Following injuries preventing oral intake, consider using an esophagostomy tube for long-term maintenance.