R. José-López

Presumed brain infarctions in two dogs with systemic leishmaniasis

Clinical signs and magnetic resonance imaging findings of multiple brain infarcts in two dogs infected with Leishmania spp. are reported. Clinical signs of intracranial dysfunction were peracute and there was no further deterioration. Magnetic resonance images of the brain were consistent with multifocal, non-haemorrhagic, ischaemic lesions. Routine serum biochemistry revealed hyperproteinaemia and hyperglobulinaemia. Serum antibody titres were highly positive for Leishmania infantum and Leishmania amastigotes were seen within bone marrow macrophages in both cases. Canine leishmaniasis can cause cerebrovascular alterations, such as vasculitis, that might predispose dogs to brain infarcts.

Evaluation of radiography as a screening method for detection and characterisation of congenital vertebral malformations in dogs

Congenital vertebral malformations (CVM) are common in brachycephalic ‘screw-tailed’ dogs; they can be associated with neurological deficits and a genetic predisposition has been suggested. The purpose of this study was to evaluate radiography as a screening method for congenital thoracic vertebral malformations in brachycephalic ‘screw-tailed’ dogs by comparing it with CT. Forty-nine dogs that had both radiographic and CT evaluations of the thoracic vertebral column were included. Three observers retrospectively reviewed the images independently to detect CVMs. When identified, they were classified according to a previously published radiographic classification scheme. A CT consensus was then reached. All observers identified significantly more affected vertebrae when evaluating orthogonal radiographic views compared with lateral views alone; and more affected vertebrae with the CT consensus compared with orthogonal radiographic views. Given the high number of CVMs per dog, the number of dogs classified as being CVM free was not significantly different between CT and radiography. Significantly more midline closure defects were also identified with CT compared with radiography. Malformations classified as symmetrical or ventral hypoplasias on radiography were frequently classified as ventral and medial aplasias on CT images. Our results support that CT is better than radiography for the classification of CVMs and this will be important when further evidence of which are the most clinically relevant CVMs is identified. These findings are of particular importance for designing screening schemes of CVMs that could help selective breeding programmes based on phenotype and future studies.

Clinical Features, Imaging Characteristics, and Long-term Outcome of Dogs with Cranial Meningocele or Meningoencephalocele

Background The term meningoencephalocele (MEC) describes a herniation of cerebral tissue and meninges through a defect in the cranium, whereas a meningocele (MC) is a herniation of the meninges alone. Hypothesis/Objectives To describe the clinical features, magnetic resonance imaging (MRI) characteristics, and outcomes of dogs with cranial MC and MEC. Animals Twenty‐two client‐owned dogs diagnosed with cranial MC or MEC. Methods Multicentric retrospective descriptive study. Clinical records of 13 institutions were reviewed. Signalment, clinical history, neurologic findings and MRI characteristics as well as treatment and outcome were recorded and evaluated. Results Most affected dogs were presented at a young age (median, 6.5 months; range, 1 month – 8 years). The most common presenting complaints were seizures and behavioral abnormalities. Intranasal MEC was more common than parietal MC. Magnetic resonance imaging identified meningeal enhancement of the protruded tissue in 77% of the cases. Porencephaly was seen in all cases with parietal MC. Cerebrospinal fluid (CSF) analysis identified mild abnormalities in 4 of 11 cases. Surgery was not performed in any affected dog. Seventeen patients were treated medically, and seizures were adequately controlled with anti‐epileptic drugs in 10 dogs. Dogs with intranasal MEC and mild neurologic signs had a fair prognosis with medical treatment. Conclusion and clinical importance Although uncommon, MC and MEC should be considered as a differential diagnosis in young dogs presenting with seizures or alterations in behavior. Medical treatment is a valid option with a fair prognosis when the neurologic signs are mild.

Two mixed breed dogs with sensory neuropathy are homozygous for an inversion disrupting FAM134B previously identified in Border Collies: Two mixed breed dogs with sensory neuropathy are homozygous for an inversion disrupting FAM134B previously identified in Border Collies

Two unrelated 8‐month‐old male mixed breed dogs were presented for evaluation of progressive ataxia, knuckling, and lack of pain perception in the distal limbs. Because of the similarity in age of onset, progression, and clinical findings with previously described sensory neuropathy in Border Collies, the affected dogs were screened for an FAM134B mutation and were determined to be homozygous for the mutation. Despite few phenotypic similarities with other breeds, genetic testing for specific diseases should be considered in mixed breed dogs with compatible clinical signs, especially if ancestry is unknown.

C7 vertebra homeotic transformation in domestic dogs – are Pug dogs breaking mammalian evolutionary constraints?

The number of cervical vertebrae in mammals is almost constant at seven, regardless of their neck length, implying that there is selection against variation in this number. Homebox (Hox) genes are involved in this evolutionary mammalian conservation, and homeotic transformation of cervical into thoracic vertebrae (cervical ribs) is a common phenotypic abnormality when Hox gene expression is altered. This relatively benign phenotypic change can be associated with fatal traits in humans. Mutations in genes upstream of Hox, inbreeding and stressors during organogenesis can also cause cervical ribs. The aim of this study was to describe the prevalence of cervical ribs in a large group of domestic dogs of different breeds, and explore a possible relation with other congenital vertebral malformations (CVMs) in the breed with the highest prevalence of cervical ribs. By phenotyping we hoped to give clues as to the underlying genetic causes. Twenty computed tomography studies from at least two breeds belonging to each of the nine groups recognized by the Federation Cynologique Internationale, including all the brachycephalic ‘screw‐tailed’ breeds that are known to be overrepresented for CVMs, were reviewed. The Pug dog was more affected by cervical ribs than any other breed (46%; P < 0.001), and was selected for further analysis. No association was found between the presence of cervical ribs and vertebral body formation defect, bifid spinous process, caudal articular process hypoplasia/aplasia and an abnormal sacrum, which may infer they have a different aetiopathogenesis. However, Pug dogs with cervical ribs were more likely to have a transitional thoraco‐lumbar vertebra (P = 0.041) and a pre‐sacral vertebral count of 26 (P < 0.001). Higher C7/T1 dorsal spinous processes ratios were associated with the presence of cervical ribs (P < 0.001), supporting this is a true homeotic transformation. Relaxation of the stabilizing selection has likely occurred, and the Pug dog appears to be a good naturally occurring model to further investigate the aetiology of cervical ribs, other congenital vertebral anomalies and numerical alterations.

Spinal extradural T-cell lymphoma with paraneoplastic hypereosinophilia in a dog: clinicopathological features, treatment, and outcome

Spinal lymphoma is a rare manifestation of a common canine hematopoietic neoplasia. Description of treatment, outcome, and MRI features are scarce. The latter can be heterogeneous, stressing the importance of lesion excision and analysis. Clinicians should also be aware of hypereosinophilia as accompanying paraneoplastic syndrome and its potential prognostic implications.

Successful medical management of an epidural abscess in a dog

A seven-month-old entire male dobermann presented with acute onset neck pain and left thoracic limb lameness. The dog had a similar episode eight weeks before presentation that responded to meloxicam. A cervical spinal epidural abscess secondary to Staphylococcus pseudintermedius bacteraemia was diagnosed following investigations, including MRI of the cervical vertebral column and blood cultures. Treatment with cephalexin, gabapentin and meloxicam was started. The dog was doing clinically well one month later. A control MRI and radiographs of the cervical vertebral column showed evidence of discospondylitis and resolution of the primary lesion, therefore the treatment course with cephalexin was continued. Three months after initial presentation the clinical signs had resolved, radiographs showed improvement of the discospondylitis and antibiotics were stopped. Seven months later the dog continued doing well with no relapse.

Vertebral venous system abnormalities identified with magnetic resonance imaging in sighthounds

In humans, abnormalities of the vertebral venous system are considered rare but significant causes of radiculopathy and myelopathy. Published information on abnormalities of the canine vertebral venous system is currently lacking. Aims of this retrospective descriptive study were to characterize magnetic resonance imaging (MRI) abnormalities of the vertebral venous system in a population of sighthounds, report prevalence of vertebral venous system abnormalities within that population and explore possible clinical significance. Our hospital database was searched over the period of 2002-2013 for sighthounds with MRI studies of the vertebral column. Medical records and MRI studies for included dogs were retrieved and findings were recorded by a single observer. A total of 92 sighthounds were sampled. Eleven cases (prevalence 12%) showed abnormal enlargement of the internal vertebral venous plexus (10/11 unilaterally, 1/11 bilaterally), external vertebral venous plexus (7/11 cases unilaterally), and/or intervertebral veins (8/11 unilaterally, 2/11 bilaterally, and 1/11 unilaterally and bilaterally at different sites). The majority of the abnormalities were right sided and the most common location for abnormalities was C6/7. Of the 11 cases, nine did not have a definitive diagnosis. Seven of those nine cases had an abnormality in a neuroanatomical localization that could wholly or partly explain the clinical signs. Findings indicated that, while the prevalence of vertebral venous system abnormalities was low in this sample of sighthounds, the majority of dogs with these abnormalities had clinical signs that matched the location of the abnormalities. Further prospective research is needed to investigate potential underlying aetiologies for vertebral venous system abnormalities in dogs and clarify their clinical significance.