Quantitative electroencephalographic findings in beagles anaesthetized with propofol

The purpose of this study was to assess quantitative electroencephalography (q-EEG) in 10 healthy beagle dogs under propofol anaesthesia in order to determine objective guidelines for diagnostic electroencephalographic (EEG) recordings and interpretation. The basic pattern after preliminary visual examination of EEG recordings was characterized by spindles, k-complexes, vertex sharp transients, and positive occipital transients that were superimposed on the slow background activity. The results of the q-EEG were characterized by the prevalence of slow rhythms delta and theta, both in absolute and relative power spectrum analysis, while fast rhythms (alpha and beta) were poorly represented. The distribution of single frequency bands was widespread for delta, focal for frontal and central for theta, as well as for most alpha and beta patterns. The present study has shown that the use of quantitative EEG gives information on the frequency content of the bio-electrical activity and defines the distribution of the single frequency bands under a standardized anaesthetic protocol.

[Anesthesia and analgesia of small mammals. Part 1: Preparation, premedication and general anesthesia]

In today's society small rodents and rabbits are increasingly kept as pets. Anaesthesia is necessary for numerous reasons and proves to be a challenge for many veterinarians. Following surgical intervention analgesia is frequently neglected. This article reviews the preparation of small mammals for anaesthesia, the choice of anaesthetics and the possibilities of perioperative care including monitoring, complications, fluid therapy and analgesia.

[Llamas--sedation and anesthesia (review article)]

Increasing is the number of Llamas (Llama glama) referred to veterinarians for diagnostic or therapeutic procedures which frequently require sedation or anaesthesia. Much of the knowledge concerning sedation and anaesthesia of domesticated ruminants and horses can be applied to sedate or anaesthetise a llama. A variety of considerations remain special for the llama. The article reviews all aspects of today's knowledge about sedation and anaesthesia of llamas.

Is carbon dioxide (CO2) a useful short acting anaesthetic for small laboratory animals?

The anaesthetic effect of carbon dioxide (CO2) was investigated under predetermined exposure times in rats, mice and guinea pigs with admixture of 20% of oxygen (O2), and with 20% of ambient air in rats. In rats first symptoms (median) were detectable between 7 and 9.5 s, the induction time (median) varied between 16 and 20.5 s and the surgical tolerance (median) was 40 s (after 60 s of exposure) and 53.5 s (after 120 s of exposure) to 80% CO2/20% O2. When O2 was replaced by ambient air, a surgical tolerance of 53.5 s (after 60 s of exposure) and 77 s (after 120 s of exposure) was measured. In mice the induction time to 80% CO2/20% O2 was 10 s and the surgical tolerance 19.5 s (after 120 s of exposure). Guinea pigs showed an induction period of 20 s and a surgical tolerance of 50 s (after 30 s of exposure) to 80% CO2/O2. Recovery was short and smooth in all species. This method of general anaesthesia seems to be suitable for short and painful interventions, mainly in rats, but also in guinea pigs.

Dental health status and endodontic treatment of captive brown bears (Ursus arctos ssp.) living in the Bernese bear pit

The teeth of five adult captive brown bears (Ursus arctos ssp.) were examined and radiographed for occlusion, loss of teeth, dental plaque and calculus, and attrition under general anesthesia. Deposits of dental calculus were found in various locations with an overall prevalence of 8% to 15% of all tooth surfaces. In all five animals, severe enamel and dentinal attrition defects were observed in canine teeth with exposed pulp. Cage-chewing behavior is probably the main cause for the dental attrition. The composition of the food and feeding management are most likely responsible for the lack of natural cleaning and the resulting plaque and calculus formation. All affected canine teeth were treated with endodontic procedures using several materials and techniques, and evaluated one- to two-and-a-half years later by clinical examination, radiography, and scanning electron microscopy of silicone casts of the treated teeth. All coronal fillings were tight. The apices were not completely sealed in two teeth. We conclude that the use of adequate and specialized instrumentation and techniques for the treatment of these long, curved, large diameter root canals is more important than the particular endodontic and restorative materials used. The dental health status of zoo animals is an indicator of their general well-being. Preventive measures should be taken in their environment and management to minimize the risk of dental conditions.

Lethal peracute rhabdomyolysis associated with stress and general anesthesia in three dystrophin-deficient cats

Three cats affected with dystrophin deficiency and hypertrophic muscular dystrophy developed peracute rhabdomyolysis with a fatal outcome. Two cats were anesthetized with isoflurane for routine procedures and did not recover properly from the anesthetic procedure. One cat was manually restrained for an echographic examination and started staggering after a short struggle; its condition worsened, and it died. Blood chemistry findings included severe hyperkalemia, hyperphosphatemia, hypocalcemia, massive increases in creatine kinase, aspartate aminotransferase, and alanine aminotransferase concentrations, and high ion gap metabolic acidosis. Light microscopic evaluation of skeletal muscle revealed severe acute rhabdomyolysis with marked extensive necrosis of large groups of fibers and endomysial edema. These lesions were observed in many skeletal muscles but particularly in the masseter and supraspinatus muscles and in the diaphragm. Typical changes associated with dystrophin deficiency in cats were also noted. Histochemical analysis revealed that the dystrophin deficiency was associated with a decrease in the percentage of type 1 myofibers in all three cats. This change was marked in the 20-month-old cat and milder in the younger cats (6.5 and 8.5 months of age). Percentages of type 2A fibers were markedly decreased and percentages of type 2X fibers were markedly increased in the younger cats. Rhabdomyolysis has been reported in dystrophinopathic humans but not in other animal models of dystrophin deficiency. An increased sensitivity of the dystrophin-deficient sarcolemmal membrane to volatile anesthetic agents, stress, or intense muscular activity is suspected.