The distribution of IVDE site in French Bulldogs within the thoracolumbar and lumbar spine was different from Dachshunds. IVDE sites were not located at the sites of vertebral anomaly. French Bulldogs appeared to have T-L IVDE at younger ages, with higher male predisposition and higher risk of developing progressive hemorrhagic myelomalacia from grade 5 compared with Dachshunds.

The criteria for brain atrophy in dogs have not yet been established, because of wide variation in the morphology of the ventricles and sulci of the brain depending on the breed and size. In this study, we examined the thickness of the interthalamic adhesion in a transverse magnetic resonance image to investigate normal, to examine the correlation with age, body weight, and breed, and to assess whether measurement would be a useful indicator of brain atrophy. The animals used in this study were of various breeds and weight, and had no identifiable intracranial lesion. They were divided into two groups: a normal group (0.6-15-year-old, n = 66) and a demented aging group (12-18-year-old, n = 12). The interthalamic adhesion thickness in both T1- and T2-weighted transverse images were measured in all dogs. The interthalamic adhesion thickness in the normal and demented groups was 6.79 +/- 0.70 and 3.82 +/- 0.79 mm, respectively. The interthalamic adhesion thickness in the demented group was significantly smaller. In an analysis of the correlation of interthalamic adhesion thickness with age and weight in normal dogs, significant negative and positive correlation was recognized, respectively. However, the strength of these correlations was low. These results suggest that interthalamic adhesion thickness may be a good parameter for evaluating brain atrophy in dogs with cognitive dysfunction.

ABSTRACT. We investigated the epidemiological characteristics of intervertebral disc herniation (IVDH) in Japan in a large population using a retrospective study. The sample population was dogs (n=297) with IVDH in Japan. Medical records were reviewed for breed, sex, age, affected interspace and neurological severity. The dogs were comprised of 132 cases of cervical IVDH (C-IVDH) and 165 cases of thoracolumbar IVDH (TL-IVDH). In Japan, the Dachshund, Beagle and Shih Tzu tended to suffer from both C-IVDH and TL-IVDH. The Shiba Inu, a characteristic Japanese dog breed, suffered from both C-IVDH and TL-IVDH, although there was little data relating to the whole breed. Male dogs tended to suffer from C-IVDH and TL-IVDH at a rate almost twice that of females in Japan. Among the three predominant dog breeds, the Dachshund, Beagle and Shih Tzu, the Dachshund tended to suffer from both C-IVDH and TL-IVDH at an earlier age than the Beagle, and the Beagle tended to suffer from both C-IVDH and TL-IVDH earlier than the Shih Tzu. Among the three predominant breeds, the Shih Tzu, in particular, tended to suffer from both C-IVDH and TL-IVDH at multiple sites. Our data from Japan were in partial agreement with previous data from the U.S.A., and epidemiological characteristics of IVDH peculiar to Japan were also identified. KEY WORDS: age at admission, canine, chondrodystrophoid dog, epidemiological study, intervertebral disc disease.J. Vet. Med. Sci. 70 (7): [701][702][703][704][705][706] 2008 Cervical and thoracolumbar intervertebral disc herniation (IVDH) is a common cause of spinal cord dysfunction in dogs seen in small animal practice [1]. Herniation of the disc causes various grades of myelopathy, including pain, paresis and sometimes permanent paralysis. The epidemiology of IVDH in dogs has been widely studied in the U.S.A., with studies investigating a variety of epidemiological factors including breed, sex, age, location of affected interspace, the time between onset of clinical signs to having a medical examination and the severity of the clinical signs. In particular, many reports have suggested that chondrodystrophoid dog breeds tend to suffer from IVDH, with a mean age at admission that differs significantly from other breeds [6,12,13,18,22]. Epidemiological data provide clinical veterinarians with an advantage prior to diagnosis or medical treatment of IVDH. However, in Japan, the epidemiological characteristics of IVDH in dogs have not been studied sufficiently [20]. Differences in the epidemiological characteristics of IVDH in dogs between the U.S.A. and Japan might exist because the characteristics of the disease may depend in part on the canine population or the living environment of the country. To establish whether this is the case, it is necessary to examine original Japanese epidemiological data for IVDH in dogs. Therefore, we investigated the epidemiological characteristics of IVDH in Japan in a large population using a retrospective study, and in particular, evaluated the association between specific br...

Hippocampal atrophy, which is a component of hippocampal sclerosis and recognized commonly in human intractable epilepsy, is controversial in canine epilepsy. We examined the hippocampal volume in 58 epileptic dogs and 35 control dogs using magnetic resonance (MR) images, and calculated the relative hippocampal volume asymmetry of the right and left hippocampus. Subjectively, there were visible MR imaging abnormalities in seven of the 58 epileptic dogs (12%). The hippocampel volume asymmetric ratio of epileptic dogs (5.84 AE 4.47%) was significantly greater than that of control dogs (1.62 AE 0.88%). Using a cutoff threshold asymmetric ratio of 6% that is indicated in human epilepsy, 28 epileptic dogs (48%) were characterized as having unilateral hippocampus atrophy. The hippocampal volume asymmetry ratio cannot be used to detect bilateral atrophy. In conclusion, although less frequent than that observed in human epilepsy patients, hippocampal atrophy may occur in canine epilepsy. r

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