Complications associated with total hip arthroplasty in four large nondomestic felids.

CASE DESCRIPTION: A 9-year-old 37-kg sexually intact male snow leopard (Panthera uncia) with no history of lameness but radiographic evidence of right femoral subluxation and flattening of both femoral heads, 2 juvenile (< 1 year old) 25-kg sexually intact male cheetahs (Acinoynx jubatus) with unilateral hind limb lameness resulting from trauma, and an 11-year-old 110-kg sexually intact female Amur tiger (Panthera tigris altaica) with a 2-year history of left hip joint osteoarthritis were examined. CLINICAL FINDINGS: No clinically relevant clinical findings other than hip joint problems were identified. All 4 felids underwent staged bilateral (snow leopard) or unilateral (cheetahs and tiger [Panthera tigris]) total hip arthroplasty (THA). TREATMENT AND OUTCOME: In the snow leopard, both femoral THA components were found to be luxated 1 year after surgery. Treatment consisted of autogenous corticocancellous rib graft augmentation of the dorsal acetabular rims and synthetic suture capsulorrhaphies. The snow leopard lived for an additional 4 years with no additional THA-related complications. In the other 3 animals, catastrophic complications (luxation in the cheetahs and femoral fracture in the tiger) occurred shortly after THA. The THA implants were removed, and excision arthroplasty was performed. Long-term outcomes were good in all 3. CLINICAL RELEVANCE: Findings underscore the challenges associated with THA in large nondomestic felids. Given the high risk for early catastrophic failure as a result of luxation or fracture, plans must be made and resources must be available in case revision surgery or implant removal with excision arthroplasty becomes necessary.

Effect of Multiradiance Low-Level Laser Therapy and Topical Silver Sulfadiazine on Healing Characteristics of Dermal Wounds in Marine Toads (Rhinella marina).

Current recommendations for wound management in amphibians are based primarily on clinical experience and on extrapolation from other taxa, whereas controlled clinical studies are lacking. Low-level laser therapy, also termed photobiomodulation, has gained popularity in veterinary medicine and may represent a valuable adjunct therapy for wound care in amphibians, though dosing and safety evaluations have not been previously reported. Silver sulfadiazine (SSD), a topical antimicrobial, is commonly utilized in amphibian medicine but little is known about its effects on wound healing in this class of animals. This pilot study evaluated the effects of repeated treatments of low-level laser therapy or topical SSD on second-intention healing characteristics of surgically induced full-thickness dermal wounds in 33 adult wild-caught marine toads. Toads were anesthetized, and a 6 mm cutaneous biopsy was performed over the right dorsum. They were then randomly assigned to one of three groups: laser therapy (LT) at 5 Hz (905 nm wavelength on a super pulsed sequence), topical SSD (SD), or control sham treatment (CT). Treatments were administered at 24 hrs after biopsy and then every 72 hrs thereafter, concurrent with a visual assessment of the wound. Toads were euthanized at one of five timepoints (day 4, 7, 13, 19, or 28) to permit scoring of histologic criteria, including lymphocytic inflammation, granulomatous inflammation, heterophilic inflammation, granulation tissue, fibrosis, and reepithelialization. Visual assessments and histologic scoring did not identify a benefit of laser therapy or SSD as compared to controls. Laser therapy and SSD, at the doses and dosing schedule utilized in this pilot study, appear to be safe and well-tolerated treatments in marine toads, but may not be warranted for uncomplicated skin wounds in this species.

The Use of Self-Inflating Hygroscopic Tissue Expanders to Facilitate Osteosarcoma Removal in a Massasauga Rattlesnake (Sistrurus catenatus).

A 0.34 kg adult female Massasauga rattlesnake (Sistrurus catenatus) was presented for evaluation of a subcutaneous mass affecting the ventral scales. The mass was diagnosed as a sarcoma via punch biopsy with no evidence of metastasis on diagnostic imaging. Surgical margins of 1-2 cm were planned to achieve complete excision of the neoplasm. A technique for tissue expansion was employed due to concerns regarding the ability to close the surgical site without excess tension or dehiscence. Two 27 mm diameter × 5 mm hygroscopic self-inflating tissue expanders were placed subcutaneously under the lateral scales adjacent to the mass. Maximum skin expansion occurred over a four-week period, and no direct negative effects were noted. Excision of the primary mass was performed routinely five weeks after implant placement. Primary closure of the defect was achieved with minimal tension by incorporating the expanded skin. While the surgery was successful with no evidence of metastasis, the snake died of sepsis two weeks postoperatively. This is the first report of the use of self-inflating hygroscopic tissue expanders to help close a surgical defect in a reptile.

2-PHENOXYETHANOL (2-PE) AND TRICAINE METHANESULFONATE (MS-222) IMMERSION ANESTHESIA OF AMERICAN HORSESHOE CRABS (LIMULUS POLYPHEMUS).

Despite extensive literature examining American horseshoe crab physiology, there are comparatively few publications addressing their medical care. Establishing anesthesia protocols for horseshoe crabs is integral to limiting the potential stress and pain associated with invasive procedures and for advancing euthanasia techniques. The objective of this study was to compare the effects of two immersion anesthetics, tricaine methanesulfonate (MS-222) at 1 g/L (buffered with sodium carbonate) and 2-phenoxyethanol (2-PE) at 2 mL/L, on horseshoe crabs. Twenty horseshoe crabs were assigned to one of two anesthetic treatment groups and individually anesthetized in natural seawater. Water quality, cardiac contractility, and hemolymph gas analytes were measured prior to anesthesia and at 30 min Animals were monitored via heart rate, gilling rate, and sedation score every 5 min until recovered. Transcarapacial ultrasonography was used to obtain heart rate, gilling rate, and percent fractional shortening. Light or surgical anesthesia was produced in 10/10 animals in the 2-PE group and 8/10 animals in the MS-222 group. There was no significant difference in sedation scores, induction time (median 15 min), or recovery time (median 20.5 min). Gilling rate and cardiac contractility decreased during anesthesia, whereas heart rate did not. Hemolymph pH and pO2 were not different among treatment groups or time points. Baseline pCO2 was higher than pCO2 at 30 min for both groups but significantly elevated only in the MS-222 group. This is attributed to increased activity during the handling of awake animals. Invasive blood pressure obtained via cardiac catheterization in two animals was markedly decreased during surgical anesthesia. In conclusion, 2-PE and MS-222 provided effective anesthesia with clinically useful induction and recovery times. 2-PE provided a subjectively more reliable and smoother anesthesia compared to MS-222.

Cystic urolithiasis in captive waxy monkey frogs (Phyllomedusa sauvagii).

The waxy monkey frog (Phyllomedusa sauvagii) is an arboreal amphibian native to arid regions of South America, and it has developed behavioral and physiologic adaptations to permit survival in dry environments. These adaptations include a uricotelic nitrogen metabolism and unique cutaneous lipid excretions to prevent evaporative water loss. Uroliths are a rare finding in amphibians. Six adult, presumed wild-caught waxy monkey frogs housed in a museum animal collection were diagnosed with cystic urolithiasis over a 7-yr period, and a single animal was diagnosed with four recurrent cases. Six cases were identified incidentally at routine physical or postmortem examination and four cases were identified during veterinary evaluation for coelomic distension, lethargy, anorexia, and increased soaking behavior. Calculi were surgically removed from three frogs via cystotomy, and a single frog underwent three cystotomies and two cloacotomies for recurrent urolithiasis. Two frogs died within the 24-hr postoperative period. Two representative calculi from a single frog were submitted for component analysis and found to consist of 100% ammonium urate. In the present report, cystic calculi are proposed to be the result of a high-protein diet based on a single invertebrate source, coupled with uricotelism, dehydration, increased cutaneous water loss, body temperature fluctuations facilitating supersaturation of urine, and subsequent accumulation and precipitation of urogenous wastes within the urinary bladder. Surgical cystotomy represents a short-term treatment strategy for this condition. Preventative measures, such as supplying a diversified and balanced diet in addition to environmental manipulation aimed at promoting adequate hydration, are anticipated to be more-rewarding management tools for cystic urolithiasis in the waxy monkey frog.

Effects of intramuscular meloxicam administration on prostaglandin E2 synthesis in the North American bullfrog (Rana catesbeiana).

Meloxicam is a commonly used nonsteroidal anti-inflammatory drug (NSAID) in veterinary medicine, but its use in amphibians has not been reported in the literature. NSAIDs are known to act by providing anti-inflammatory and analgesic actions by inhibiting the synthesis of prostaglandin E2 (PGE2). The objective of this study was to evaluate whether the intramuscular administration of meloxicam would decrease the circulating serum PGE2 levels in the North American bullfrog (Rana catesbeiana) following tissue trauma induced by a punch biopsy. Eighteen adult North American bullfrogs were randomly assigned to two treatment groups: meloxicam (0.1 mg/kg i.m.) and control (0.9% saline i.m.). Blood was obtained via cardiocentesis immediately prior to administration of the two treatment regimes and serum was frozen. A 4-mm punch biopsy was taken from the right triceps femoris muscle to induce an inflammatory response. Twenty-four hours later, a second blood sample was collected and serum was harvested and frozen. Serum PGE2 concentrations were measured using a commercial PGE2 enzyme assay (EIA) kit. Twenty-four hours following the biopsy, the mean circulating PGE2 levels of animals treated with meloxicam was 57.79 +/- 12.35 pg/ml, which did not differ significantly from animals that were treated with saline (85.63 +/- 17.55 pg/ml, P > or = 0.05). The calculated means of the absolute change between the circulating baseline PGE2 levels and the postinjury circulating PGE2 levels were significantly lower in animals treated with meloxicam (13.11 +/- 17.31 pg/ml) than in control animals treated with saline (46.14 +/- 38.02 pg/ml) (P < or = 0.05). These results suggest that the systemic administration of meloxicam at a dosage of 0.1 mg/kg once daily suppresses circulating serum PGE2 levels postinjury in the North American bullfrog.