Analgesic Activity of Tramadol and Buprenorphine after Voluntary Ingestion by Rats (Rattus norvegicus).

Effective pain management for rats and mice is crucial due to the continuing increase in the use of these species in biomedical research. Here we used a recently validated operant orofacial pain assay to determine dose-response curves for buprenorphine and tramadol when mixed in nut paste and administered to male and female rats. Statistically significant analgesic doses of tramadol in nut paste included doses of 20, 30, and 40 mg/kg for female rats but only 40 mg/kg for male rats.

Assessment of an Orofacial Operant Pain Assay as a Preclinical Tool for Evaluating Analgesic Efficacy in Rodents.

A model system capable of providing clinically relevant analgesic doses with minimal trauma has been elusive in laboratory animal medicine. Our laboratory has developed an orofacial operant pain system that effectively discriminates between non-noxious and noxious thermal stimuli in rats and mice. Male and female rats (Crl:SD) and mice (Crl:SKR-HR(hr)) were trained to perform a task (placing their face through an opening and having their cheeks stay in contact with thermodes) to receive a reward (a solution of sweetened condensed milk).

Breeding, husbandry, veterinary care, and hematology of marsh rice rats (Oryzomys palustris), a small animal model for periodontitis.

Rice rats (Oryzomys palustris) are a recognized animal model for studying periodontal disease and the photoperiodic regulation of reproduction. Here we share information regarding the breeding, husbandry, veterinary care, and hematologic findings about this animal species to facilitate its use in studies at other research institutions. Rice rats initially were quarantined and monitored for excluded pathogens by using microbiologic, parasitologic, and serologic methods with adult female Mus musculus and Rattus norvegicus sentinel animals.

Dehydration parameters and standards for laboratory mice.

Water deprivation and restriction are common features of many physiologic and behavioral studies; however, there are no data-driven humane standards regarding mice on water deprivation or restriction studies to guide IACUC, investigators, and veterinarians. Here we acutely deprived outbred CD1 mice of water for as long as 48 h or restricted them to a 75% or 50% water ration; physical and physiologic indicators of dehydration were measured. With acute water deprivation, the appearance and attitude of mice deteriorated after 24 h, and weight loss exceeded 15%.

Effect of a short-term fast on ketamine-xylazine anesthesia in rats.

Although ketamine-xylazine (KX) anesthesia is commonly used in rats, it is often reported to have an inconsistent anesthetic effect, with a prolonged induction time, an inadequate anesthetic plane, or a very short sleep time. Blood flow to the liver is known to shift after a meal in rats, perhaps explaining anesthetic variability among rats with variable prandial status. The current study tested the hypothesis that a short period of fasting (3 h) prior to induction with intraperitoneal KX anesthesia would provide a shorter time to recumbency, a longer total sleep time, and a more consistent loss of toe pinch response than would fed rats.

Oropharyngeal Necrobacillosis with Septic Thrombophlebitis and Pulmonary Embolic Abscesses: Lemierre's Syndrome in a New Zealand White Rabbit.

Lemierre's syndrome, oropharyngeal infections induced by anaerobic bacteria, leading to fatal septic thrombophlebitis of the internal jugular vein and pulmonary embolic abscesses in humans, was diagnosed in a 6-month-old, male, New Zealand White rabbit. After acute onset of anorexia, lethargy, and depression, the rabbit died suddenly despite emergency clinical care. Necropsy revealed swelling, necrosis, and abscess in the soft tissues around the left caudal mandibular ramus, oral mucosa, and molar teeth, with systemic embolic abscesses and necrosis, especially in the jugular vein, lungs, and brain.