Inherited Sensory and Autonomic Neuropathy in a Border Collie, Interest of Oclacitinib for the Control of Self-Mutilation

Sensory and autonomic neuropathy was diagnosed in a five-month-old Border Collie puppy, who presented with progressive self-mutilation, proprioceptive ataxia and urinary incontinence. In the Border Collie, sensory neuropathy is different from what is observed in acral mutilation syndrome, as the genetic mutation is linked to an inversion disrupting the FAM134B gene. Diagnosis was based on history, clinical signs and genetic testing. The prognosis of sensory neuropathies is poor and no curative treatment is available. In the present case, oclacitinib was started for symptomatic treatment of the self-mutilation. A good control of the self-mutilation was quickly observed with an improvement in quality of life for five months. Unfortunately, progression of neurological signs with severe proprioceptive deficits, ataxia, muscular atrophy and urinary/fecal incontinence was observed. Five months after diagnosis, the owner elected for euthanasia.

Neurogenic keratoconjunctivitis sicca in 34 dogs: A case series

OBJECTIVE

To describe the clinical findings, imaging features, underlying conditions, treatment, and progression of dogs presented between 2010 and 2019 with neurogenic keratoconjunctivitis sicca (NKCS).

METHODS

Dogs diagnosed with NKCS were searched in the clinical database. Inclusion criteria were STT-1 readings <15 mm/min, clinical signs of KCS with concurrent ipsilateral xeromycteria.

RESULTS

Thirty-four cases were identified. Mean age at presentation was 8.2 years, median 8.9 years (0.3-14.7). Twenty dogs were male, and 14 dogs were female. Concurrent neurological deficits included facial neuropathy (n = 13, 38%), peripheral vestibular syndrome (n = 10, 29%), and Horner's syndrome (n = 5, 15%). Advanced imaging was acquired in 53% of cases (n = 18). Etiologies included idiopathic (n = 18, 53%), endocrinopathy (n = 6, 18%), otitis interna (n = 4, 12%), head trauma (n = 3, 9%), iatrogenic (post-TECA-LBO, n = 1, 3%), brainstem mass (n = 1, 3%), and an area of inflammation in the pterygopalatine fossa (n = 1, 3%). Treatment for NKCS was initiated in most cases (n = 30, 88%) including: oral pilocarpine 2% and lacrimostimulant (n = 19), oral pilocarpine 2% only (n = 3), or lacrimostimulant only (n = 8). A mean time follow-up of 3.7 months, median 3 months (1-14) was available in 23 cases (68%). Eleven cases with follow-up were responsive (48%) with resolution of the clinical signs in a median time 4 months (1-10), and all of them were treated with oral pilocarpine (±lacrimostimulant).

CONCLUSIONS

Most cases presented as idiopathic NKCS; in others, an underlying cause of facial neuropathy was identified. All responsive cases were treated with oral pilocarpine 2%.

The diagnostic yield of advanced imaging in dogs with Horner's syndrome presenting with and without additional clinical signs: A retrospective study of 120 cases (2000-2018)

PURPOSE

To evaluate the diagnostic yield of advanced imaging in dogs with Horner's syndrome (HS) both with and without additional clinical signs.

METHODS

Retrospective review of clinical records from a UK referral hospital (2000-2018). Cases were excluded if HS was trauma- or surgery-related and if no advanced imaging with MRI or CT was performed. Imaging findings were assessed as well as any additional investigations performed.

RESULTS

One hundred twenty cases met the inclusion criteria; 88 with additional clinical signs and 32 with isolated HS. MRI or CT of head and neck was performed in 115 cases and/or thoracic CT in eight cases. Causative lesions were identified in 98% (86/88) of cases with additional clinical signs and 3% (1/32) of cases with isolated HS. This was statistically significant (p < .001). Pharmacological localization using phenylephrine (0.1%-10%) was accurate in predicting the site of a causative lesion in 79% (19/24) of tested cases. Overall, 28% (33/120) of cases were idiopathic, of which 49% (16/33) were golden retrievers. When compared to the overall hospital population, and UK Kennel Club records, this confirmed a significant predisposition in this breed (p < .001). No associations between idiopathic HS and concurrent systemic disease were identified.

CONCLUSION

This is the first study to evaluate the diagnostic yield of advanced imaging in dogs with HS. Isolated HS is significantly more likely to be idiopathic than cases presenting with additional clinical signs; this could guide decision-making regarding further investigations performed in a clinical setting. Idiopathic HS is over-represented in the golden retriever.

Canine neuropathies: powerful spontaneous models for human hereditary sensory neuropathies

In humans, hereditary sensory neuropathies (HSN), also known as hereditary sensory and autonomic neuropathies (HSAN), constitute a clinically and genetically heterogeneous group of disorders characterized by progressive sensory loss, often accompanied by chronic skin ulcerations and nail dystrophic changes. To date, although around 20 genes have already been discovered, they do not explain the genetic causes of all patients. In dogs, similar neuropathies are also diagnosed, several breeds being predisposed to specific forms of the disease. Indeed, the breed specificity of most canine genetic diseases is due to the small numbers of founders and high levels of inbreeding. Recent knowledge and tools developed to study the canine genome efficiently allows deciphering the genetic bases of such diseases. To date, a dozen breeds are recognized to develop specific HSN. For the Border collie and hunting dog breeds, the genes involved have recently been discovered. Other affected breeds thus constitute potential genetic models, with new genes to be found in dogs that can be considered as candidate genes for human HSAN/HSN. Here, we review the different forms of human and canine HSAN/HSN and we present a novel form in Fox terrier cases, highlighting the advantages of the dog model for such rare human diseases.

Pathology of the Aging Brain in Domestic and Laboratory Animals, and Animal Models of Human Neurodegenerative Diseases

According to the WHO, the proportion of people over 60 years is increasing and expected to reach 22% of total world’s population in 2050. In parallel, recent animal demographic studies have shown that the life expectancy of pet dogs and cats is increasing. Brain aging is associated not only with molecular and morphological changes but also leads to different degrees of behavioral and cognitive dysfunction. Common age-related brain lesions in humans include brain atrophy, neuronal loss, amyloid plaques, cerebrovascular amyloid angiopathy, vascular mineralization, neurofibrillary tangles, meningeal osseous metaplasia, and accumulation of lipofuscin. In aging humans, the most common neurodegenerative disorder is Alzheimer’s disease (AD), which progressively impairs cognition, behavior, and quality of life. Pathologic changes comparable to the lesions of AD are described in several other animal species, although their clinical significance and effect on cognitive function are poorly documented. This review describes the commonly reported age-associated neurologic lesions in domestic and laboratory animals and the relationship of these lesions to cognitive dysfunction. Also described are the comparative interspecies similarities and differences to AD and other human neurodegenerative diseases including Parkinson’s disease and progressive supranuclear palsy, and the spontaneous and transgenic animal models of these diseases.