Blackwell's Five-Minute Veterinary Consult: Reptile and Amphibian. Javier G. Nevarez

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Blackwell's Five-Minute Veterinary Consult: Reptile and Amphibian - Javier G. Nevarez

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and appearance of the eggs based on imaging or coelioscopy, and the ability to provide a suitable environment for egg laying.

       All chelonians will benefit from medical treatment even if surgery is ultimately required.

       Medical therapy consists of correcting the husbandry, providing an appropriate nesting area, and supportive therapy with emphasis on correcting calcium deficiencies.

       Oxytocin or arginine vasotocin can be administered as long as an obstructive process is not suspected.

       Some recommend the use of beta‐adrenergic blockers such as propranolol or atenolol before administration of oxytocin, as these drugs have been shown to potentiate the effects of oxytocin in humans due to their ability to increase uterine activity.

       It is critical to provide an appropriate nesting box. A plastic container with a mixture of equal parts sand and soil can be used.

       The depth of the nesting material should be at least equivalent to the length of the carapace.

       If the chelonian appears to be stable, medical therapy alone can be attempted and the animal monitored for evidence of egg laying.

       There are no specific timelines as to how quickly egg laying should occur once medical therapy is initiated.

       The majority of cases in which there are broken or malformed eggs require surgical intervention.

       Surgery is best performed before dystocia progresses while the animal is metabolically stable.

       Surgery should be an immediate consideration for chelonians with documented chronic dystocia, metabolic derangements, and when egg yolk coelomitis is suspected.

       The goal of surgery is to remove the eggs and perform an ovariosalpingectomy in order to avoid reoccurrence.

       Extreme care must be taken to not rupture the eggs in the coelomic cavity, as the yolk is extremely antigenic and will cause a severe inflammatory response.

       If leakage occurs, the coelomic cavity should be thoroughly lavaged before closure.

      NUTRITIONAL SUPPORT

      Dietary deficiencies must be corrected with special emphasis on UVB light and oral Ca supplementation.

      CLIENT EDUCATION/HUSBANDRY RECOMMENDATIONS

       Clients should be encouraged to seek veterinary care of chelonians early on to establish individual baseline values and to confirm the sex of the animal.

       Dystocia likely has a multifactorial cause, so all husbandry deficiencies must be corrected with emphasis on UVB light, calcium supplementation, nutrition, temperature, humidity, and provision of adequate nesting substrate.

       Chelonians should be weighed at least weekly to document any sudden weight increases that may be indicative of egg development.

MEDICATIONS

      DRUG(S) OF CHOICE

       Propranolol 1 mg/kg PO once at least 3 hours prior to administration of oxytocin or arginine vasotocin.

       Atenolol 7 mg/kg PO once at least 3 hours prior to administration of oxytocin or arginine vasotocin.

       Arginine vasotocin 0.5–1 μg/kg IV, IO, IM, ICe q12–24 h; should be administered 30–60 minutes after IM or SC injection of calcium gluconate.

       Oxytocin 5–10 iu/kg IM, IV, IO q4–8h; IV administration may be more efficacious but must be administered slowly.

       Calcium: start with calcium gluconate (100 mg/kg IM, SC q12–24h) followed by calcium glubionate (10–100 mg/kg PO q4–24h) long term.

       Magnesium: magnesium sulfate 20 mg/kg IM, SC q24–72h or magnesium lactate (Rescue Cal+, Repashy Ventures, CA) 20 mg/kg PO q24h.

       Crystalloid fluids 20–30 ml/kg SC, IV, IO q24h.

       Meloxicam 0.5 mg/kg PO, IM, SC q24–48h.

      PRECAUTIONS/INTERACTIONS

       There is scant information about the safety and efficacy of oxytocin and arginine vasotocin when used for prolonged periods over 2–3 days.

       Intravenous administration of both these drugs should be done slowly as they can cause life‐threatening hypotension.

       Beta‐adrenergic blockers also may cause bradycardia and hypotension.

FOLLOW‐UP

      PATIENT MONITORING

       If performing medical therapy alone, especially with oxytocin or arginine vasotocin, the animals should be monitored closely to identify any signs of distress, although this is a rare occurrence.

       If an underlying disease process was diagnosed, appropriate follow‐up diagnostics should be performed to determine improvement of that condition or the need to alter therapy.

       For those undergoing surgery, a re‐evaluation within 1–2 weeks is recommended to evaluate the surgical site and overall recovery.

      EXPECTED COURSE AND PROGNOSIS

       Ultimately, the prognosis will depend on the underlying cause of dystocia and the response to therapy.

       Cases with underlying infectious or metabolic disease that respond to medical therapy have a good prognosis.

       Many cases requiring surgical therapy have a good to guarded prognosis.

MISCELLANEOUS

      COMMENTS

       The ultimate diagnosis of dystocia is based on interpretation of clinical signs, history, and results of physical exam and diagnostics.

       In all cases, it is essential to have at least one confirmatory test that there are indeed eggs present in the coelomic cavity.

       It must be mentioned that the sex of the animals must be confirmed as female before surgery is performed.

       While this may seem obvious, in some chelonians, sex determination can be quite challenging and males may present with coelomic neoplasias or GI obstructions that clinically appear very similar to dystocia.

      ZOONOTIC

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