Feeling Bloated?

Hydrops and Hydrocoelom in a Green Frog

Amanda Igeta, Colorado State University, DVM Candidate 2016

Signalment

Green Frog (Rana clamitans), male, approximately 2 years old

History

An approximately 2 year old wild-caught Green Frog was presented for a 1 week history of generalized swelling and a 1 day history of anorexia. He is housed alone in a half aquatic 20 gallon tank with a stone substrate, a hide box, and fake branches. The temperature is maintained at 75 degrees F with a room humidifier and heater. A canister is used to filter the water, and the water is changed monthly with tap water. The daily diet consists of crickets and a multivitamin. 

Physical exam

On physical exam, he was quiet, alert, and responsive. The coelom and hind limbs were swollen and edematous, and transillumination of the coelom revealed no abnormalities. The eyes were clear, though there were red abrasions ventral to both eyes and a bloody discharge from the left naris. Oral examination revealed swelling of the dorsal aspect of the mouth, located ventrally to the eyes. He was able to ambulate on all four limbs, though there were noticeable musculoskeletal deformities of the long bones, which were softened and mildly rubbery on palpation. A 1 cm diameter, dark red swelling was present on the caudal aspect of the dorsum in the region of the cloaca.

 

Differential diagnoses

Initial differential diagnoses for hydrocoelom and hydrops include renal failure, lymph heart failure, and liver disease. The underlying etiologies of these organ failures vary and may include bacterial (Mycobacterium) or fungal infections (Batrachochytrium dendrobatidis) that are often secondary due to poor husbandry, malnutrition leading to immunosuppression or hypoproteinemia, osmotic imbalances, and hypocalcemia which can lead to decreased function of the lymph hearts. Differential diagnoses for the musculoskeletal abnormalities and the mass in the region of the cloaca include metabolic bone disease and cloacal prolapse, respectively.

Diagnostics

It was decided that we would drain the subcutaneous and intracoelomic fluid and analyze it via cytology and refractometry. On presentation, the frog was 145 g. Celiocentesis was performed with a 25 gauge butterfly needle attached to a 6 cc syringe. Prior to puncturing the skin, the coelom was transilluminated in order to identify and avoid any organs or blood vessels, and 29 mL were aspirated. The same procedure was repeated for the right and left hind limbs, which yielded a total of 27 mL. A total of 56 mL of a serosanguinous fluid were removed from the frog to yield a new body weight of 89 g. The total protein of the fluid was 0.2 g/dL. Direct microscopic examination and a diff-quick stain of the coelomic fluid revealed 3+ erythrocytes. A gram stain did not reveal any bacteria, though there was a moderate amount of proteinaceous debris.   

VD whole body radiographs were taken after the 56 mL were aspirated from the frog. The radiograph revealed an increased soft tissue/fluid opacity of the thorax and hind limbs. The lung fields appear to be clear, though perhaps mildly decreased in size. There is generalized decreased bone density of the long bones, and both humeri are bowed. There is no foreign body or mass appreciated on evaluation of the coelom.

  

Treatment

He was hospitalized and provided with earthworms overnight after receiving one subcutaneous injection of 8.9 mg calcium gluconate. Treatments during hospitalization included 8.9 mg calcium glubionate PO once daily, 1-2 drops of tobramycin ophthalmic solution applied topically to the skin once daily, and a 10 minute soak in amphibian ringer’s solution once daily (1 part LRS to 2 parts 0.45% saline + 2.5% dextrose). He was sent home the next day with instructions to continue applying 1-2 drops of tobramycin ophthalmic solution once daily topically to the skin for 21 days, 0.09 mL calcium glubionate (2.07 mg elemental calcium) PO once daily for 21 days, 8 mg piperacillin IM once daily for 14 days, and to return for a recheck in 21 days. Recommendations for husbandry were also made and included 10 minutes of supervised exposure to sunlight when temperature permits, using dechlorinated tap water for 25% water changes, removal of pebbles from the tank to decrease bacterial load and the possibility of ingestion, wearing gloves during handling, adding a 10.0 UVB light bulb, and improving his diet by adding earthworms with three times weekly calcium powder dusted on top and a weekly multivitamin.

Follow up

A week after initial presentation, the Green Frog returned for a recheck appointment. Over the week, the generalized edema improved, although the hind limbs continued to remain more swollen than normal. Several days after the frog was sent home, aquarium salt was added to his water, but when a color change of the ventral surface of the frog was noticed, the water was switched to distilled water. In addition, the owners were syringe feeding the frog because he still had a decreased appetite. On examination, the 61 g frog was much improved with regards to the cloacal swelling, the abrasion ventral to his left eye was healing, his left naris was no longer bleeding, and there was only moderate edema of the hind limbs. However, there were multiple areas of the skin that had a gray discoloration with petechiation (ventral abdomen, ventral thighs, lateral carpi) suggestive of chemical burns that were likely due to being soaked in salt water and distilled water. The owners were warned that while the skin may heal with care, it could also potentially become necrotic and slough off. The frog was then sent home with instructions to soak 10-15 minutes once daily in amphibian ringer’s solution for the next two weeks, to syringe feed an insectivore supportive diet as needed, to continue administering the previously prescribed medications, and to return for a recheck in 14 days.  

 

References

Mader, DR. Reptile Medicine and Surgery. 2nd ed. St. Louis: Saunders Elsevier, 2006.

Wright, Kevin M. and Brent R. Whitaker. Amphibian Medicine and Captive Husbandry. Malabar: Krieger Publishing Company, 2001.