FOREIGN BODY REMOVAL BY GASTROTOMY IN A BUDGETT'S ( laevis)

Shawn Messonnier, DVM Paws and Claws Hospital 2145 West Park Boulevard Plano, TX 75075 USA

Key words: foreign body, gastrotomy, Budgett's frog,

CASE REPORT

A young captive bred Budgett's frog (Lepidobatrachus laevis) was seen for a second opinion. The frog had recently ingested a large amount of aquarium gravel from its cage. The referring veterinarian had tried to remove the gravel by gastric lavage with no success. Examination showed a 148 g frog with an enlarged abdomen. Many firm objects were easily palpable. Radiographs confirmed the presence of gravel in the gastrointestinal tract.

The frog was induced with 50 mg ketamine i.m. (Ketaset, Ft. Dodge Laboratories, Ft. Dodge, lA, 50501, USA). Within 20 min the righting and withdrawal reflexes were absent. Anesthesia was maintained with 1-2% isoflurane (Aerrane, Ohmeda, Liberty Comer, NJ, 07938, USA) via face mask made from a syringe case. The dorsum of the frog was coated with sterile lubricant prior to surgery. The frog was placed in dorsal recumbency; the skin was kept wet during the procedure by wetting it with a 3 ml syringe filled with tap water. A ventral left paramedian incision was made; the abdominal musculature was then incised. The stomach was isolated and held by two stay sutures of 2-0 Vicryl (Ethicon, Johnson & Johnson, Somerville, NJ, 08876-0151, USA). A gastrotomy was made in an avascular portion of the stomach, and 35 pieces of gravel were removed. Prior to closing, an intraoperative radiograph revealed two remaining stones, only the larger of which could be located and removed. The stomach was closed - first mucosa with an interrupted pattern, then serosa and muscularis with an interrupted Lembert pattern using 4-0 PDS-II (Ethicon, Johnson & Johnson, Somerville, NJ, 08876-0151). The skin was closed with a continuous intradermal pattern of 4-0 Vicryl and Nexaband (Veterinary Products Laboratories, Phoenix, AZ., 85013, USA) glue. Enrofloxacin (Baytril, Bayer, Shawnee Mission, KS, 66201, USA) at 5 mg/kg Lm. q 24 hr for 7 d was dispensed. The owner was instructed to keep the frog on moist paper towels for 2 wk and then returned to its tank (without gravel). Three days post-operatively the frog passed the remaining small piece of gravel and has made a full recovery. The frog was normal at follow-up 3 mo later.

There are several routes of anesthesia administration in including gas, injectable, and cutaneous (or topical)'. Cutaneous agents include tricaine methanesulphonate or benzocaine administered through the water. Ketamine hydrochloride can be used as an injectable drug but its response in amphibians in somewhat unpredictable. Some species may be extremely sensitive or resistant. Gas anesthetics including isoflurane can be used as well although amphibians may develop epidermal damage if kept in contact with the gas for prolonged periods of time. Since amphibians may exhibit cutaneous respiration, maintaining anesthetic control with inhalants may be more difficult than in mammals.

1997 PROCEEDINGS ASSOCIATION OF REPTILIAN AND VETERINARIANS 135 Anesthetic monitoring is challenging in amphibians. Surgery can generally be performed once the withdrawal reflex is lost. Withdrawal to deep pain is absent at the appropriate level of ketamine anesthesia and can be distinguished from random movement. As with other pets, respiratory efforts decrease with increased anesthetic depth. The withdrawal reflex is often the last one to disappear. With ketamine, spontaneous movement may occur even after the withdrawal reflex is lost. Additionally, amphibians should be kept moist during the surgical period.

Although nonabsorbable, non-wick-type suture material has been recommended to prevent infection 2 and dehiscence, this frog recovered without incidence •

LITERATURE CITED

1. Wright, K. 1996. Amphibian Husbandry and Medicine in Mader, D. (Ed.): Reptile Medicine and Surgery. W.B. Saunders, Philadelphia. p 436459. 2. Stetter, M. 1995. Noninfectious Medical Disorders ofAmphibians in Seminars in Avian/Exotic Pet Medicine. Vol 4(1 ):49-55.

136 1997 PROCEEDINGS ASSOCIATION OF REPTILIAN AND AMPHIBIAN VETERINARIANS