CASE DESCRIPTION 2 female red-necked wallabies (Macropus rufogriseus) were evaluated because of sudden-onset mandibular swelling, ptyalism, and hyporexia.
CLINICAL FINDINGS Physical examination revealed a mandibular swelling with a fluctuant center in both wallabies. Hematologic analysis revealed leukocytosis with a mature neutrophilia and monocytosis in one wallaby (case 1) and a slight neutrophilia, hyperglobulinemia, and high serum alanine aminotransferase activity in the other (case 2). Cytologic examination of the swelling revealed a uniform population of gram-negative rods in case 1 and neutrophilic inflammation in case 2. Radiography revealed a soft tissue mandibular swelling with osteolucency around mandibular incisor roots in both wallabies. Computed tomography revealed changes consistent with chronic active mandibular osteomyelitis and reactive bone formation, but also sequestra formation not appreciable via radiography.
TREATMENT AND OUTCOME Long-term antimicrobial treatment was initiated with clindamycin (17 to 21 mg/kg [7.7 to 9.5 mg/lb], IV, q 12 h for 40 to 55 days) and high-dose benzathine penicillin G (80,000 U/kg [36,364 U/lb], SC, q 12 h for 150 days). Serial CT was performed to evaluate response to treatment and resolution of disease. A CT scan 18 months after the initial evaluation revealed complete resolution of osteomyelitis and sequestra.
CLINICAL RELEVANCE Advanced imaging and long-term treatment and management were integral to the successful outcome for these wallabies, given that the osseous changes visible on CT images were not visible on standard radiographs, guiding therapeutic decision-making. This report provides new therapeutic and diagnostic monitoring information to assist clinicians with similar cases.
To characterize induction and recovery characteristics of 3 commonly used inhalant anesthetics in prairie rattlesnakes (Crotalus viridis): isoflurane, sevoflurane, and desflurane.
12 healthy adult prairie rattlesnakes.
In a randomized crossover design, snakes underwent anesthetic induction with 5% isoflurane, 8% sevoflurane, or 18% desflurane, with a washout period of ≥ 7 days between anesthetic events. Anesthetic depth parameters were recorded throughout induction and recovery, including time to loss and return of righting reflex, muscle tone, ability to intubate, response to pressure, and time to return to spontaneous respiration. Every 5 minutes throughout the anesthetic procedures, heart rate, respiratory rate, and percentage expired anesthetic gas were recorded.
No snakes died during the study. Sevoflurane anesthesia resulted in anesthetic gas avoidance behavior in snakes during induction and had the significantly longest recovery time to extubation and time to return of pressure response, compared with the other inhalant anesthetics. Anesthesia with isoflurane resulted in a significantly longer time to return of righting reflex, compared with sevoflurane or desflurane. No significant difference was noted in time to loss of pressure response among the 3 anesthetic gases. Desflurane anesthesia resulted in the significantly quickest loss of righting reflex among the anesthetic protocols; despite this, 4 of 12 desflurane anesthetized snakes did not achieve an anesthetic plane deep enough for intubation.
CONCLUSIONS AND CLINICAL RELEVANCE
Isoflurane and sevoflurane, but not desflurane, inhalation anesthesia resulted in consistent and predictable loss of righting reflex and induction of anesthesia deep enough to allow intubation in snakes.
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.
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.
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.