Fish and amphibian anesthesia.

This article is designed to provide the veterinary practitioner with some basic information on how to anesthetize fish and amphibians. General guidelines regarding working with these aquatic animals are covered. Specific topics include methods of anesthetic delivery, anesthetic monitoring, and recovery. Various anesthetic regimes and dosages are presented both in the text and in table form.     

Fish, amphibian, and reptile analgesia.

Pain perception and appropriate behavioral responses are important for survival. The conservation of the opioid ligand and receptor suggests evolution of opioid receptors mediating antinociception throughout vertebrate phylogeny. Fish, amphibians, and reptiles have appropriate neurologic components, display the appropriate behavior in response to a painful stimulus, and possess antinociceptive mechanisms to modulate pain. Because pain perception in these species is therefore likely to be analogous to that of mammals, invasive and painful procedures should always be accompanied by appropriate analgesia and anesthesia. Although specific doses have not been established in clinical trials, clinicians should attempt to provide lower vertebrates with appropriate analgesia during painful procedures. Further experimental and clinical investigations are necessary to expand the current veterinary literature in the area of pain and analgesia in lower vertebrates such as fish, amphibians, and reptiles.     

The eye and orbit

Computed tomography (CT) and magnetic resonance imaging (MRI) provide excellent morphological detail of the eye and its associated structures. In veterinary medicine, these imaging modalities are most often used to diagnose and determine the extent of ocular or periocular tumors. They may also be used to diagnose inflammatory conditions of the orbital region and to determine the severity and extent of ocular trauma. This article reviews the applications of CT and MRI for ocular and orbital diseases, discusses normal findings, and presents representative case examples.     

Basic husbandry and clinical assessment of the amphibian patient.

The veterinarian presented with an amphibian patient must be prepared to assess both the animal's medical condition and its husbandry record; good health is inextricably linked to proper care and diet. This article provides the clinician with guidelines for maintaining amphibians in captivity, including information on climate control and lighting, housing and cage enrichment, and nutrition. The article also covers questions to ask when taking a history, methods of restraint, and practical advice on the equipment and techniques used to conduct a complete physical examination of the amphibian patient.     

Oxidative stress and the eye.

Oxidative and particularly photo-oxidative processes are critical factors many ocular conditions but are often poorly recognized by those investigating ocular disease. The author discusses oxidative stress in inflammatory processes of the conjunctiva, cornea, and uvea; in cataract formation in the lens; in retinal degeneration; and in optic nerve pathologic conditions, inflammatory in optic neuritis and degenerative in glaucoma.     

Ultrasonographic anatomy of the bovine eye.

The purposes of the study were to describe the ultrasonographic appearance and measurements of the normal bovine eye, to compare the measurements to those reported previously for cadaveric eyes and to describe differences between ocular dimensions of Holstein Friesian and Jersey cattle. Sixty transpalpebral ocular ultrasonographic examinations were performed on 30 adult Holstein Friesian cows, and 16 examinations were performed on 8 adult Jersey cows. Transpalpebral ultrasonographic images were obtained with a 10 MHz linear transducer in both horizontal and vertical imaging planes. The ultrasonographic appearance of structures within the bovine eye is similar to that in other species, although the ciliary artery was frequently identified, appearing as a 0.33 +/- 0.04 cm diameter hypoechoic area. The axial length of the globe was significantly greater in Holstein Friesian cattle (3.46 +/- 0.09 cm) compared with Jersey cattle (3.27 +/- 0.19 cm; P = 0.001), although the vitreous depth was smaller in Holstein Friesian cattle (1.46 +/- 0.09 cm) (P = 0.0009). The anterioposterior depth of the lens was significantly greater in Jersey cattle (1.92 +/- 0.11 cm) and the cornea was thinner in Jersey cattle (0.17 +/- 0.02 cm). The appearance and ocular distances for live animals were similar to those reported previously for cadaveric specimens. The knowledge of normal ocular dimensions facilitates the use of ultrasonography in the evaluation of ocular disease in cattle.     

Multiple cranial nerve deficits after eye injury and eye enucleation. A case report]

A 12-year old Simmental x Red Holstein cow was admitted to the clinic eight months after an eye laceration followed by eye extirpation. The region of the excised eye had healed, however, the cow had additional trigeminal and facial nerve palsy. Nevertheless, the cow was in good general condition, and therefore, was sent home without therapy. After delivering a sound calf, her physical condition deteriorated and she was slaughtered. Histologic examination of the brain revealed degeneration of the right optic nerve and right half of the chiasma opticum as well as left tractus opticus (opposite side); furthermore, degenerative changes with slight inflammation of the right vestibular nuclei were observed. Possible pathogenesis is discussed.