Veterinary Medicine - November 2008 - (Page 597)

3. A dorsoventral radiograph of a green iguana with numerous shelled eggs in the abdomen. Note that the shelled eggs are more radiopaque, with more distinct outlines, than the nonshelled follicles shown in Figure 1. reproductive tract such as abscesses or urinary bladder calculi. 3 A female that has had a previous dystocia is predisposed to having it occur again as a result of scar tissue from previous salpingotomies.6 Other causes include poor physical condition (captive reptiles may not have the muscle tone needed to lay their eggs), dehydration, low environmental temperatures, low humidity, and the lack of a suitable area for nest digging. 3 Although oviductal infection is a potential cause, infectious etiologies are not well-documented or well-understood in reptiles. 4. Surgical removal of the ovaries with multiple follicles. Shelled eggs are present within the oviduct. The shelled eggs were also removed but not the oviduct. (Image courtesy of Paolo Selleri, Dr. med. Vet., Centro Veterinario Specialistico, Rome Italy.) and are arranged in a line rather than in clusters. Shelled eggs have a hypoechoic center and a hyperechoic perimeter [shell].7) Radiography can be useful in determining egg positioning, but it can be difﬁcult to detect nonshelled eggs, and if visible, it may not be possible to determine if the eggs have well-developed shells. Lizard eggs may be detected by abdominal palpation by experienced practitioners, but it is best to conﬁrm their presence by abdominal radiography or ultrasonography because other masses could be mistaken for eggs. After conﬁrming the presence of eggs, the next step is to determine whether the animal is undergoing the normal physiologic order of events that will lead to egg deposition or if it is experiencing preovulatory stasis or dystocia. Obtaining a good history, observing clinical signs, and performing supplemental diagnostic tests are fundamental to an accurate diagnosis. An extremely swollen abdomen is common in normal, gravid female lizards, and some females will not eat for several weeks before laying eggs. However, a normal, gravid female is active and alert. Acute onset of lethargy or unresponsiveness, tremors, weight loss, or a dull skin color are important abnormalities.8 Carefully question the owner about all husbandry practices to detect possible husbandryrelated problems. If the reptile has already passed several eggs and additional eggs remain in the coelomic cavity, dystocia is most likely, especially if the animal is depressed and reluctant to move. If the animal has not passed any eggs and is depressed and abdominal palpation and radiography or ultrasonography conﬁrm that nonshelled eggs are in the coelom, preovulatory stasis is most likely. In some cases, it can be difﬁcult to discern between a nonshelled and a shelled egg, so dystocia should remain on the list of differential diagnoses. Diagnosis Diagnosing preovulatory stasis or dystocia can be problematic because it can be difﬁcult to differentiate between true reproductive system pathology and the normal phases of egg development. The presence of eggs in the coelom can be easily detected by ultrasonography, which allows the distinction between shelled eggs and preovulatory follicles. (Shelled eggs are oblong rather than rounded Treatment Ovariectomy is the treatment for preovulatory follicular stasis (Figure 4).6 In rare species, follicle removal can be VETERINARY MEDICINE November 2008 597

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Veterinary Medicine - November 2008 Contents Leading Off Editors' Guest Just Ask the Expert Letters Practice Makes Perfect Clinical Exposures Practice Matters Idea Exchange Author Guidelines A Challenging Case: Esophageal Leiomyoma in a Dog Osteoarthritis in Cats: What We Now Know About Recognition and Treatment Product Preview CE Form/Advertiser Index Marketplace/Classifieds Mind Over Miller

Veterinary Medicine - November 2008

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