Cutaneous and Pulmonary Mucormycosis in Rag1- and Il2rg-deficient Rats.

Immunodeficient rats are valuable in transplantation studies, but are vulnerable to infection from opportunistic organisms such as fungi. Immunodeficient Rag1- and Il2rg-deficient (RRG) rats housed at our institution presented with dark, proliferative, keratinized dermal growths. Histologic and PCR results indicated that the predominant organism associated with these lesions was fungus from the family Mucoraceae, mostly of the genus Rhizopus. The Mucoraceae family of fungi are environmental saprophytes and are often found in rodent bedding. These fungi can cause invasive opportunistic infections in immunosuppressed humans and animals. We discuss husbandry practices for immunosuppressed rodents with a focus on controlling fungal contaminants.

Umbilical cord hypercoiling in two rhesus macaques (Macaca mulatta).

Obstruction of umbilical blood flow is a common cause of death in fetal nonhuman primates, but cord accidents have not been reported in the macaque. We describe two cases of cord accident in rhesus macaques (Macaca mulatta) resulting in fetal death at approximately 110 and 50 days of gestation, respectively.

Transverse myelitis following measles vaccination in a rhesus macaque (Macaca mulatta).

A 16-year-old rhesus macaque presented with progressive, ascending quadriparesis following measles vaccination. He was diagnosed with transverse myelitis following MRI, gross necropsy, and histopathology. This is the first report of transverse myelitis in a rhesus macaque following measles vaccination.

Concentration-dependent Toxicity after Subcutaneous Administration of Meloxicam to C57BL/6N Mice (Mus musculus).

Studies using the Mouse Grimace Scale have shown that for many NSAID, including meloxicam, minimal doses of at least 20 mg/kg may be necessary to achieve adequate peri- and post-operative analgesia in mice. However, more data are needed to determine whether such NSAID doses exceed the threshold for gastrointestinal ulceration or induce other relevant pathology. We administered equal volumes of saline or injectable meloxicam (1 or 5 mg/mL) at a dose of 20 mg/kg SC to 20 young adult male and female C57BL/6N mice daily for 6 d and performed necropsies on all mice on the seventh day. Mice given 5 mg/mL meloxicam subcutaneously developed significantly more severe pathology at the injection site than saline controls. Pathology was characterized by full-thickness epidermal necrosis; cavitary lesions within subcutis, muscle, or fat; steatitis; and myositis. Mice that received 1 mg/mL meloxicam subcutaneously developed lesions that were qualitatively similar but far less severe than those after 5 mg/mL. However, no pathologic lesions typically associated with NSAID toxicity, such as gastric ulceration and liver and kidney lesions, were seen. These results demonstrate that although meloxicam injected subcutaneously causes concentration-dependent skin pathology at the injection site, a dose of 20 mg/kg can be safely administered subcutaneously at a concentration of 1 mg/mL for as long as 6 d.