Standard radiographic lymphangiograms and computed tomography (CT) lymphangiograms were performed on 10 female dogs without intrathoracic disease. Positive contrast lymphagiography was performed by injection into a catheterized mesenteric lymphatic vessel, and lateral thoracic radiographs, ventrodorsal thoracic radiographs, and thoracic CTs were obtained. The number of visible ducts was recorded for each image at the midbody of the ninth thoracic vertebra (T9) through the first lumbar vertebra (L1). Data were combined for all dogs at each data acquisition point. Data were analyzed by comparing data from all three images independently, and then by combining data for the radiographs and comparing the study with the highest number of visible duct branches to the CT. Significant differences in numbers of branches were found at T11 and L1. This study suggests that CT may be able to quantify branches of the thoracic duct more accurately than standard radiographic lymphangiography.

Summary The middle and inner ears of 16 dogs, from 1.5 to 17 years of age, with differing degrees of suspected hearing loss were examined. Auditory function was assessed subjectively, and electrophysiologically by recording brainstem auditory‐evoked responses (BAER) to click stimuli. Ossicular chains and stapediovestibular articulations were evaluated macroscopically and by light microscopy for evidence of bony ankylosis; no abnormalities were found. A determination of spiral ganglion packing density revealed a loss of spiral ganglion cells in all areas of the cochlea in dogs of the deaf group and in the upper and lower basal region of dogs from the hearing impaired group. The largest losses of spiral ganglion cells in the deaf group were located in the upper and lower basal region. The deaf group's density was reduced to 44 % (upper basal) and 15 % (lower basal) of the normal hearing group. The largest spiral ganglion cell loss for dogs in the hearing impaired group occurred in the lower basal region where the density was reduced to 40 % of the normal hearing group. These morphological findings in the aging canine are consistent with a peripheral nerve hearing loss. Zusammenfassung Verminderung der Neuronen des Ganglion spirale bei alternden Hunden mit Hörschaden Bei 16 Hunden im Alter von 1,5 bis 17 Jahren mit offenbar unterschiedlich ausgeprägten Hörschäden wurde das Mittel‐ und Innenohr untersucht. Die Hörfunktion wurde subjektiv sowie elektrophysiologisch mittels Registrierung der Reaktion des Hirnstamms auf kurze Schallreize beurteilt. Die Anordnung der Gehörknöchelchen sowie der Kontakt des Steigbügels mit dem ovalen Fenster wurden makroskopisch untersucht. Für den Nachweis knöcherner Ankylosen wurden lichtmikroskopische Untersuchungen durchgeführt. In beiden Fällen ergaben sich keine Veränderungen. Die Bestimmung der Populationsdichte von Nervenzellen im Ganglion spirale ergab bei den tauben Hunden in allen Abschnitten der Cochlea einen Verlust an Ganglienzellen, während dies bei Hunden mit verringertem Hörvermögen im Bereich der oberen und unteren Basalregion der Fall war. Die größten Verluste an Ganglienzellen waren bei den tauben Hunden in der oberen und unteren Basalregion zu verzeichnen. Die Zelldichte war bei der Gruppe der tauben Hunde auf 44 % (obere Basalregion) bzw. 15 % (untere Basalregion) der Gruppe der normal hörenden Hunde reduziert. Der größte Verlust an Ganglienzellen war bei den Hunden mit beeinträchtigtem Hörvermögen im Bereich der unteren Basalregion festzustellen, wo die Zelldichte auf 40% der normal hörenden Hunde vermindert war. Diese morphologischen Befunde beim alternden Hund sprechen für einen peripheren nervalen Hörschaden.

Formalin was injected into an ethmoidal hematoma in an 18-year-old Arabian gelding. Abnormal neurologic signs were observed within minutes of the injection. The horse did not respond favorably to medical treatment of the neurologic signs and was euthanatized. Postmortem examination revealed erosion and necrosis of the ventral cribriform plate, which appeared to have allowed the injected formalin to reach the rostral portion of the frontal lobe of the brain. Endoscopy and radiography had been performed prior to euthanasia, but neither delineated the cribriform lesion. Before treating large progressive ethmoidal hematomas with formalin, it may be beneficial to perform computed tomography to assess the extent of damage caused by the lesion.

A 5-month-old female Border Collie was evaluated because of progressive hind limb ataxia. The predominant clinical findings suggested a sensory neuropathy. Sensory nerve conduction velocity was absent in the tibial, common peroneal, and radial nerves and was decreased in the ulnar nerve; motor nerve conduction velocity was decreased in the tibial, common peroneal, and ulnar nerves. Histologic examination of nerve biopsy specimens revealed considerable nerve fiber depletion; some tissue sections had myelin ovoids, foamy macrophages, and axonal degeneration in remaining fibers. Marked depletion of most myelinated fibers within the peroneal nerve (a mixed sensory and motor nerve) supported the electrodiagnostic findings indicative of sensorimotor neuropathy. Progressive deterioration in motor function occurred over the following 19 months until the dog was euthanatized. A hereditary link was not established, but a littermate was similarly affected. The hereditary characteristic of this disease requires further investigation.

SummaryThe purpose of this study was to evaluate the blood supply to the humeral condyle of dogs and compare the blood supply of Cocker Spaniel dogs to non- Cocker Spaniel dogs. We hypothesize that there is a congenitally altered blood supply of the humeral condyle in some Cocker Spaniels when compared to the blood supply of the humeral condyle in other breeds of dogs, which leads to abnormal ossification between the medial and lateral aspects of the humeral condyle, and predisposes them to fracture and delayed healing.Microangiography was performed on four Cocker Spaniel and four non- Cocker Spaniel dogs of similar size and weight. Qualitative and quantitative evaluation of the microangiographs of the humeral condyles revealed a decreased vascular density in the medial, midcondylar and lateral aspects of the condyle in the Cocker Spaniel dogs compared to the non-Cocker Spaniel dogs. This decreased vascular density may play a role in the increased incidence of humeral condylar fractures in the adult Cocker Spaniel dog without any or only minor trauma, and in the delayed healing seen in association with these fractures.A microradiographic comparison was made between the blood supply of the humeral condyles of Cocker Spaniel and other breeds of dogs. A decreased vascular density was documented in Cocker Spaniel dogs.