Five cases of canine dysautonomia in England (2004 to 2006)

Abstract

Canine dysautonomia was diagnosed definitively in five dogs by histopathology. All dogs were seen between June 2004 and July 2006 and originated from south-east England; four dogs originated from an urban area and one from a rural area. Of the urban dogs, one had recently visited Scotland and one had visited a kennel in a rural area nearby. Acute-onset but progressive vomiting, diarrhoea, depression and inappetence were the most common presenting clinical signs. Reduced or absent anal tone, dysuria, absence of pupillary light reflexes with intact vision, mydriasis, decreased corneal sensitivity and nictitating membrane protrusion were among the most frequent neurological findings. Abnormalities in pharmacological autonomic and physiological function testing (including orthostatic hypotension in two dogs) and diagnostic imaging studies were detected in some of the animals. All dogs failed to respond adequately to treatment, and given the poor prognosis, they were eventually euthanased. Histopathology identified marked chromatolysis of ganglion cell bodies. This case series emphasises that dysautonomia should be considered when a dog is presented in the UK with acute- or subacute-onset gastrointestinal signs and compatible physical and neurological abnormalities.

Imaging Evaluation of Dogs and Cats with Dysphagia

“…Megaesophagus can be congenital or acquired [23]. Acquired megaesophagus is classified as idiopathic or secondary to other diseases such as myasthenia gravis [24, 25] (with or without thymic neoplasia [26, 27]), hypoadrenocorticism [7, 28, 29], hypothyroidism [30–32], tetanus [33], and dysautonomia [34, 35] to name a few. Acquired megaesophagus can also be segmental forming oral to an obstructive process such as a stricture or vascular ring anomaly [36].…”

Mydriasis Associated with Local Dysfunction of Parasympathetic Nerves in Two Dogs

“…We confirmed normal palpebral reflex bilaterally. The results of Schirmer's tear test and the dog's intraocular pressure (15 mm Hg OD, 20 mm Hg OS) were within the normal range at the first consultation [6].…”

“…[8] Horner's syndrome is a common neurological ophthalmologic disorder associated with miosis in dogs [3]. There have also been reports of pupillotonia with miosis, and mydriasis from ophthalmoparesis and dysautonomia in dogs [2,5,6,9]. In Japan, there have been no reports of dogs with abnormal pupil size because of autonomic nervous dysfunction.…”

“…This mechanism is common to dysautonomia because the cases of canine dysautonomia also cause mydriasis and prevent miosis after administration of 0.05% or 0.1% pilocarpine [6]. Dogs affected with dysautonomia have been reported to exhibit various clinical signs, including vomiting, diarrhea, depression, inappetence, reduced or absent anal tone, dysuria, and mydriasis.…”

Investigation of diseases with an infectious aetiology

“…Papers concerning a wide range of infectious agents are presented, including a small contribution from a local veterinary practice (Barfield and others 2007). Some of the papers have a straightforward infectious origin, while other conditions are more cryptic and have a potentially infectious aetiology, such as the dog with atrial myocarditis (Tyszko and others 2007) and the five canine dysautonomia cases (Niessen and others 2007).…”