Neural tube defects in four Shetland sheepdog puppies: clinical characterisation and computed tomography investigation

Exencephaly-Anencephaly Sequence Associated with Maxillary Brachygnathia, Spinal Defects, and Palatoschisis in a Male Domestic Cat

Anencephaly, a severe neural tube defect characterized by the absence of major parts of the brain and skull, is a rare congenital disorder that has been observed in various species, including cats. Considering the uncommon appearance of anencephaly, this paper aims to present anencephaly in a stillborn male kitten from an accidental inbreeding using various paraclinical methods. Histological examination of tissue samples from the cranial region, where parts of the skull were absent, revealed the presence of atypical nerve tissue with neurons and glial cells organized in clusters, surrounded by an extracellular matrix and with an abundance of blood vessels, which are large, dilated, and filled with blood, not characteristic of nerve tissue structure. In CT scans, the caudal part of the frontal bone, the fronto-temporal limits, and the parietal bone were observed to be missing. CT also revealed that the dorsal tubercle of the atlas, the dorsal neural arch, and the spinal process of the C2-C7 bones were missing. In conclusion, the kitten was affected by multiple congenital malformations, a combination of exencephaly-anencephaly, maxillary brachygnathism, closed cranial spina bifida at the level of cervical vertebrae, kyphoscoliosis, palatoschisis, and partial intestinal atresia. The importance of employing imaging techniques cannot be overstated when it comes to the accurate diagnosis of neural tube defects.

Pentalogy of Cantrell in Two Neonate Littermate Puppies: A Spontaneous Animal Model Suggesting Familial Inheritance

Developmental anomalies are an important cause of stillbirth and early perinatal death in companion animals. Many of these disorders remain poorly understood and provide an opportunity as a spontaneous animal model for human disease. Pentalogy of Cantrell is a rare congenital syndrome described in human neonates. It is a ventral midline closure defect with a proposed familial inheritance in humans. This syndrome involves five defects, including the thoracoabdominal wall, sternal, diaphragmatic, pericardial and cardiac malformations. Diverse expressions of these defects have been described in humans and sporadically in domestic animals. This severe syndrome commonly harbors a poor prognosis, posing an ethical and surgical dilemma. To better understand this syndrome and its presentation in dogs, we describe two rare cases of Pentalogy of Cantrell in a litter of papillon dogs. The affected puppies had anomalies compatible with the Pentalogy of Cantrell, including thoracoabdominal schisis, ectopia cordis, sternal cleft, pericardial agenesis, and diaphragmatic defects. The diagnosis was confirmed by advanced imaging (computed tomography) and postmortem examinations. The family history of this litter was explored and other cases in domestic animals were reviewed. This is the first report of the complete Pentalogy of Cantrell with ectopia cordis in the dog and the only report on papillons. Similar to human cases, possible familial inheritance and suspected male gender bias were observed. Further research on this novel animal model, its pathogenesis and its hereditary basis, may be helpful in better understanding this rare developmental disorder.

Neurogenic Bladder in Dogs, Cats and Humans: A Comparative Review of Neurological Diseases

Lower urinary tract disease (LUTD) includes abnormalities in the structure and function of the bladder and the urethra. LUTD caused by neurological disease is defined neurogenic bladder (NB). The integrity of the central nervous system (CNS) and peripheral nervous system (PNS) is required to explicate normal micturition, maintaining the proper function of bladder and urethra. The location and type of neurological lesions influence the pattern of clinical manifestations, potential treatment, and prognosis. Though, in dogs and cats, spinal cord injury is considered mainly responsible for bladder and/or urethra incompetence, other disorders, congenital or acquired, involving CNS or PNS, could play a role in NB. In veterinary medicine, the information about the epidemiology, prevalence, etiopathogenesis, diagnosis and treatment of NB are scattered. The aim of this study is to provide an overview of the epidemiology, prevalence, clinical findings, diagnosis and prognosis for NB in dogs and cats compared with humans.

Anencephaly, Bifid Tongue, and Cleft Palate in a Pomeranian Dog: GFAP and NeuN Immunoreactivities

Anencephaly is a congenital disease manifesting with the absence of the brain due to the failure of the cranial part of the neural tube to close during the embryonic stage. The disease may be accompanied by other anomalies and usually results in premature death. A stillborn puppy of a 2-year-old female Pomeranian dog is examined in this case. The lack of brain tissue and accompanying abnormal skull formation was noted macroscopically. The eyes were protruding out of their normal position (exophthalmos), and a bifid tongue together with a secondary cleft palate was present. On serial sections stained with Haematoxylin-Eosin, only the medulla spinalis among the central nervous system structures could be inspected microscopically. Immunohistochemistry staining revealed GFAP immunoreactivity in the astrocytic glial cells. NeuN immunoreactivity was detected in the neurons in the medulla spinalis and spinal ganglions. Incomplete retinal layers were observed on the eye sections stained with Haematoxylin-Eosin and NeuN. The case was concluded to be coherent with skull and nervous system congenital malformations rarely observed in dogs. To the best of our knowledge, this represents the first description of a dog with anencephaly, bifid tongue and cleft palate.

Comparison of inherited neural tube defects in companion animals and livestock

Neural tube defects (NTDs) are congenital malformations resulting from the improper or incomplete closure of the neural tube during embryonic development. A number of similar malformations of the protective coverings surrounding the central nervous system are also often included under this umbrella term, which may not strictly fit this definition. A range of NTD phenotypes exist and have been reported in humans and a wide range of domestic and livestock species. In the veterinary literature, these include cases of anencephaly, encephalocele, dermoid sinus, spina bifida, and craniorachischisis. While environmental factors have a role, genetic predisposition may account for a significant part of the risk of NTDs in these animal cases. Studies of laboratory model species (fish, birds, amphibians, and rodents) have been instrumental in improving our understanding of the neurulation process. In mice, over 200 genes that may be involved in this process have been identified and variant phenotypes investigated. Like laboratory mouse models, domestic animals and livestock species display a wide range of NTD phenotypes. They remain, however, a largely underutilized population and could complement already established laboratory models. Here we review reports of NTDs in companion animals and livestock, and compare these to other animal species and human cases. We aim to highlight the potential of nonlaboratory animal models for mutation discovery as well as general insights into the mechanisms of neurulation and the development of NTDs.