Specialerapporter og -abstracts

Development of Anaesthesia in Reptiles

Iversen, Sofie Hahn, 23.02.2018

Objective 1. To Identify an effective dose of medetomidine and ketamine in combination, and to investigate the suitability of these anaesthetics for induction and/or anaesthesia in snakes. 2. To investigate the isolated and combined physiological and cardiovascular effects of a clinically relevant dose, and to study the effect of a dose too low for visible sedative effects, yet still elicit physiological responses.
Animals 1. Six healthy juvenile ball pythons (Python regius). 2. Eleven healthy adult ball pythons.
Methods 1. Four combinations of medetomidine and ketamine (0.2, 0.2, 0.3, and 0.3 mg kg-1 medetomidine combined with 5, 10, 5, and 10 mg kg-1 ketamine, respectively) was injected, and anaesthetic depth was based on the following parameters: spontaneous movement, head support, jaw tone, body tone, and righting reflex. 2. Two doses of anaesthetics (0.1 and 0.3 mg kg-1 medetomidine both combined with 5 mg kg-1 ketamine) were administered IM to pythons, and HR and MAP were obtained from a catheter placed in the vertebral artery. Furthermore, blood samples were taken at different time points to measure PaCO2 and PaO2 along with pH and lactate levels. Lastly, influence of handling was investigated by IM injections of saline, mimicking the administration of anaesthetics.
Results 1. The effects were clearly dose-dependent, but there was considerable variation amongst individuals. 2. Tachycardia and hypertension resulted from of both dosages of medetomidine and ketamine. After 20-30 min, bradycardia occurred. MAP remained above base-line. Furthermore, hand­ling caused significant tachycardia and hypertension.
Conclusions The combinations of medetomidine and ketamine administered in the present study only provided sedation adequate for immobilisation and minor manipulations and was not suited for surgical procedures. Caution is needed for this combination due to individual variation and the physiological disturbances.

The effect of long-term hypercapnia on the metabolism and growth in striped catfish (Pangasianodon hypophthalmus)

Nielsen, Tine Haslam, 19.02.2018

Hypercapnia in aquacultures have been associated with negative effects such as a reduced food consumption, reduced aerobic scope, and reduced growth in several water-breathing species. Though, the effects of hypercapnia on air-breathing fish is limited. In the present study, standard metabolic rate, maximum metabolic rate, and the partitioning of air-breathing in P. hypophthalmus long-term exposure to 3% CO2 and an acute exposure to 3% CO2, were estimated using intermittent closed respirometry combined with a chase protocol. Further, two growth experiments were conducted and blood samples were collected to determine the effects of hypercapnia on haematocrit, plasma pH, and pH regulation. Standard metabolic rate, routine metabolic rate, maximum metabolic rate, and aerobic scope remained unchanged when exposed to hypercapnia. Likewise, no difference in growth was found. The air-breathing was significantly higher for the hypercapnic group measured in hypercapnia with 18.608 ± 2.820%, compared to the normocapnic group measured in normocapnia and the hypercapnic group measured in normocapnia which was 8.902 ± 2.410% and 8.670 ± 2.311% respectively. The bicarbonate level in the hypercapnic group was significantly higher than in the normocapnic group (33.462 mM difference, p: <0.01) and the chloride concentration was equivalent smaller (38.200 mM difference, p: <0.01). There was no difference in pH nor in haematocrit. This suggests that P. hypophthalmus is able to fully compensate the decrease in pH that hypercapnia would cause without any consequences for growth or metabolism, which makes it an excellent fish for aquaculture.

Udholdenhedspræstationsevne og okklusionstræning

Bartholomæussen, Jeppe, 24.01.2018, speciale

Ilttransport i blodet hos hvirveldyr med fokus på krybdyr

Ravn Malling, Martin, 22.01.2018, speciale

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