Understanding prolapse in reptiles
Prolapse in reptiles can involve the cloaca, a common receiving chamber for the reproductive, urinary, and gastrointestinal tracts (Fig 1). Prolapses can also originate from the distal gastrointestinal tract, reproductive organ, or urinary bladder—in those species with a bladder like the green iguana (Iguana iguana) and leopard gecko (Eublepharis macularius).
The underlying cause of prolapse is often related to straining or tenesmus and dyschezia caused by infection, inflammation, or trauma (Box 1).Prolapse can also develop secondary to constipation or fecal impaction caused by ingestion of a foreign body such as sand, bark chips, or gravel. Prolapse can also be associated with neurologic dysfunction or general debilitation in all reptiles (Martinez-Jiminez 2007, Innis 2002).
Box 1. Possible underlying causes of cloacal prolapse
|N||Neoplasia (Kik 2011)|
|Nutritional||Nutritional secondary hyperparathyroidism|
|I||Infection, inflammation (Roe 2002)||Endoparasitism
|T||Traumatic||Aggressive sex probing
Cloacal urate concretions
Oviductal prolapse is a common sequela to dystocia, particularly in snakes.
Prolapse of the phallus in chelonians or hemipenis in squamates, or snakes and lizards, is usually the result of infection and inflammation secondary to trauma, chronic sexual activity, or excessive straining caused by disease of the lower urogenital or gastrointestinal tract. Copulatory organ prolapse is most common in chelonians but also occurs in snakes and lizards. A normal chelonian penis can become turgid during cloacal manipulation, handling of the caudal shell or other causes of excitement, but the phallus should retract within a few hours (Innis 2002).
Urgent care tips
Keep prolapsed tissues moist until they can be gently cleaned. Liberally and gently apply water-soluble lubricant. Reduce tissue edema with cold compresses or hypertonic solutions like 50% dextrose, glycerin, or hypertonic saline. In some cases of penile or hemipenis prolapse, irrigation, lubrication and occlusive bandaging can be applied overnight while the patient is stabilized for surgery and anesthesia the next day (Martinez-Jiminez 2007).
While the swelling is going down, carefully evaluate the entire patient:
- Verify signalment since gender will affect your differential diagnosis list.
- Is the patient alert, responsive, and in good body condition?
- Is there evidence of concurrent or underlying disease?
The next task, identifying the prolapsed tissue, is sometimes easier said than done. Prolapses are often chronic in nature by the time the reptile is presented for medical care.
- In a mild prolapse, only cloacal tissue may bulge through the vent or the opening through which droppings and reproductive products are expelled from the cloaca. Cloacal mucosa normally appears smooth and shiny although prolapsed tissue will become swollen over time.
- The distal gastrointestinal tract has a smooth, tubular appearance. In some instances feces are also observed.
- The hemipenes in squamates or phallus in chelonians is a relatively solid tissue that originates from the lateral portion of the cloacal wall (Fig 2).
- The lumen of the oviduct gives this tissue a “donut-like” appearance. Longitudinal folds can also be observed on the oviductal wall.
- Of course the urinary bladder is a thin walled, often fluid filled, structure.
Seminal or hemipenal plugs consist of keratinized material that fills one or both hemipenes. These plugs can protrude from the cloaca and can be mistaken for a prolapse in squamates. Visit Anapsid.org for a color photograph of seminal plugs.
The diagnosis of prolapse relies on physical examination, however additional testing is often required to identify the underlying cause. The tests performed will vary with the tissue prolapsed but can include:
- Survey whole body or abdominal radiographs
- Fecal parasite testing
- Complete blood count/biochemistry panel
Management of the prolapse
Management of prolapsed tissue should almost always be performed under sedation or general anesthesia. Use a local anesthetic when general anesthesia s not used for reduction of a mild cloacal prolapse. Clean the exposed tissue with saline or dilute chlorhexidine solution. Removing superficial crust and debris as needed. Administer fluids and begin analgesic therapy such as an anti-inflammatory agent. Synthetic absorbable suture such as polyglyconate or polydioxanone is often selected.
Once the swelling is down and the tissue is clean, carefully and gently Invert and return prolapsed tissue using a relatively large diameter, blunt instrument like a rubber catheter, syringe case, or sexing probe. NEVER simply “stuff” tissues back into the cloaca. Tissues should invert back inside in an anatomically correct orientation, like a sock being turned inside out. Devitalized tissue may require resection.
Place stay sutures after the prolapse is reduced. A purse-string suture is often placed in chelonians or larger squamates, while transverse cloacal sutures such as horizontal mattress serve well in many snakes and lizards. Stay sutures decrease the size of the opening to prevent recurrent tissue prolapse, but should remain loose enough to allow droppings to pass. Stay sutures are typically left in place for 3 to 5 days.
Visit Herp Center Network for images illustrating gastrointestinal tract reduction in a bearded dragon (Pogona vitticeps).
Mild oviductal prolapses can be reduced transcloacally. More severe prolapses require a surgical approach performed by a reptile veterinarian. Traumatized tissue may need to be removed intraoperatively, however if this is necessary then ovariectomy on the same side should also be recommended to reduce to risk of yolk coelomitis.
Prolapsed copulatory organs quickly become traumatized and swollen, making reduction near impossible in many cases. Recurrent prolapses or when prolapsed tissue is nonviable or cannot be reduced, the phallus or hemipenis can be amputated. Fortunately the urinary system is separate from phallus since the ureters empty into the cloaca so this will not compromise the reptile’s ability to urinate. Additionally, when one hemipenis is retained in squamates, future reproduction is still possible.
Make sure the prolapsed copulatory organ is fully everted. In small chelonians, place a ligature proximal to damaged tissue. Ligate tissues with transfixing, circumferential, or vertical mattress patterns. The phallus is then transected and removed (Innis 2002). In larger chelonians, the lateral vessels as well as each corpus cavernosum should be ligated separately. Transect and remove the prolapsed tissue, then replace the stump into the tail base. Afterwards a stay suture like a purse string suture is left in place for up to 2 to 3 weeks (Sykes 2010, Barten 2006, Denardo 2006).
After the prolapse has been reduced…
After the prolapse has been reduced, begin systemic antibiotics if infection is present and the keep the patient well hydrated. A stool softener can also be useful in lizards.
Prognosis and follow-up
Prognosis depends on the patient’s overall condition, viability and duration of the prolapsed tissue, as well as the cause of prolapse. If the underlying cause of prolapse has not been identified and resolved, there is a good chance that prolapse will recur. Refer “mystery” prolapse patients to a reptile veterinarian for additional diagnostics.