Trigeminal nerve-evoked potentials in the dog

Brain stem and cerebrocortical potentials were evoked by electrical stimulation of the infraorbital nerve of dogs and recorded through needle electrodes placed adjacent to the contralateral parietal bone. Five individual, short latency peaks were recorded in each averaged trigeminal nerve-evoked potential and were identified as I, II (A and B), III (A and B), PI (A, B, and C), and NI. Mean peak latencies +/- 1 SD were as follows: I = 0.9 +/- 0.1 ms, IIA = 1.7 +/- 0.1 ms, IIB = 2.5 +/- 0.1 ms, IIIA = 3.6 +/- 0.15 ms, IIIB = 4.1 +/- 0.2 ms, PIA = 5.2 +/- 0.15 ms, PIB = 6.4 +/- 0.2 ms, PIC = 7.3 +/- 0.3 ms, and NI = 11.0 +/- 0.6 ms. Trigeminal nerve-evoked potentials recorded through needle electrodes were essentially the same as potentials evoked by direct stimulation of the infraorbital nerve and recorded directly from the dura mater overlying the contralateral rostral suprasylvian gyrus. The specificity of the stimulating site was verified by recording before and after the infraorbital nerve was cut proximal to the stimulating site.     

Medetomidine-butorphanol combination anesthesia in the dog]

The combination of Medetomidine and Butorphanol leads to a sufficient sedation with good analgesia and is thus superior to the application of Medetomidine only. By reducing the dosage of Medetomidine, reduced cardio-respiratory side-effects are to be expected. The comparative application of the two Butorphanol preparations Torbugesic (group T) and Morphasol (group M) did not show any differences concerning effect and tolerance. No statistically significant and clinically relevant differences between the two groups were observed for any of the parameters.     

3 gastrointestinal neoplasms in the dog]

In the last five years, 3 carcinomas of the intestine were found in a total of 1961 necropsies of dogs. One proved to be a primary gastric carcinoma situated in the area of the Curvatura minor, another a primary carcinoma of the ileocaecal valve and the third one a signet-cell carcinoma in the end of the jejunum. The morphological characteristics of the carcinomas are discussed.     

Tube cystostomy in the dog and cat]

Prepubic tube cystostomy was performed in 10 dogs and one cat. Indications include urinary bypass following urethral trauma or surgery (six cases), following surgery for prostatic abscesses or cysts (four cases) and bladder atony secondary to urethral obstruction (one case). Tubes were left in situ for a minimum of seven days. All patients returned to normal micturition following tube removal. Urine leakage occurred for up to four days after tube removal by which time the stoma was granulating. Nosocomial infection was a consistent finding, but was controlled with antibiotic treatment following tube removal. Tube cystostomy was considered an effective means for diverting irritant urine from healing epithelium and thereby minimising the risk of urethral cicatrisation. It may also be indicated in the management of urinary retention as an alternative to repeated urethral catheterisation. This study indicates that tube cystostomy is readily performed, with few unexpected or serious complications.     

Clinical electroretinography in the dog. Part 3]

In this last part the preparation of the patient for the ERG is shown. Anesthesia, positioning, and retrobulbar injection technique are discussed. The protocol for recording the ERG is presented. The dog is dark adapted for 30 minutes. The level of adaptation is examined using a single flash of dim red light at various times. Rods and cones are stimulated separately by scotopically balanced red and blue flashes. After a single flash of bright white light the rods and cones are studied with flicker trains at 5, 12.5, 15 and 30 Hz. During dark adaptation the maximum b-wave amplitude increased from 13.8 +/- 8.4 microV to 49.3 +/- 16.3 microV. Bright white light stimuli resulted in b-wave amplitudes of 167.7 +/- 75.3 microV. There were always 6 oscillatory potentials visible on the b-wave. Scotopically balanced stimuli produced b-waves of 104 microV (red) and 116 microV (blue). It was found that older dogs had reduced b-wave amplitudes and longer peak times than younger dogs. The most common artefacts in electroretinography are discussed.     

Serious reactions after the TSH-stimulation test in the dog]

The thyrotropin response test is the most common test for the diagnosis of hypothyroidism. Here we report serious adverse effects in two dogs after intravenous administration of bovine TSH. The clinical signs were consistent with an anaphylactoid or anaphylactic reaction. In both cases a previous sensibilization with bovine TSH can be excluded. We discuss the etiology and emphasize the most probable cause to be an anaphylactoid reaction. Preventive measures are discussed.     

Values of acido-basic balance in the blood of the beagle breed dog in comparison with the German shepherd dog]

The values of acidobasic balance were examined in 101 dogs of the Beagle breed and in 20 German Sheep-Dogs. The Beagle dogs were divided into five age groups. A difference was found between the values obtained in the group of the youngest dogs and those in older age groups. In comparison with Beagle dogs, the values were higher in German Sheep-Dogs (pH, base excess). A figure is attached representing the deviations of the values of acidobasic balance of blood in the two breeds.     

Compound-action potentials of myelinated fibers in the saphenous nerve of the dog: in situ electrophysiologic and behavioral studies

Compound-action potentials (CAP) were recorded directly from the surface of fascicles of the distal portion of the saphenous nerve (SN) of dogs in situ. Potentials were evoked through needle electrodes and were recorded through bipolar stainless steel electrodes. Stimuli of 10-microseconds duration and of 0.4 +/- 0.15-mA amplitude evoked a monophasic CAP. Sensory conduction velocities of afferent fibers, the action potentials of which contributed to this evoked compound potential, ranged from 62.4 +/- 2.8 m/s for the most rapidly conducting fibers to 30.5 +/- 2.4 m/s for the least rapidly conducting fibers. Stimuli of 25-microseconds duration and of 2.2 +/- 0.8-mA amplitude evoked a second, longer latency CAP in addition to the first CAP. Sensory conduction velocities of afferent fibers, the action potentials of which contributed to this evoked compound potential, ranged from 20.4 +/- 2.9 m/s for the most rapidly conducting fibers to 13.7 +/- 1.0 m/s for the least rapidly conducting fibers. Low-amplitude, negative peaks were recorded between the first and second major potentials elicited by the longer duration stimuli. Stimuli of still longer duration and higher currents induced contractions of the caudal part of the sartorius muscle by current spread in 9 of 12 dogs. In 3 dogs, a third monophasic CAP was evoked, having a maximal conduction velocity of 1.7 +/- 0.2 m/s. After section of the distal portion of the SN on one side in each of 2 dogs, an absence of signs of sensory deficit was found on clinical neurologic examination. The area of cutaneous innervation of the cranial branch of the distal portion of the SN was determined electrophysiologically.