26 Secretions INCREASED TEAR PRODUCTION: EPIPHORA Presenting signs Overflowing tears, tear staining of the medial canthus. Cause Reflex lacrimation occurs in response to eye pain which should be evident on examination. Owners sometimes report epiphora occurring a few days before ipsilateral facial paralysis develops. Parasympathetic stimulation from organophosphate toxicity results in SLUD (salivation, lacrimation, urination, defecation). Obstruction of the tear duct is a common cause of tear staining. Paradoxical (‘crocodile’) tears occur in the human during and immediately after eating as a rare phenomenon secondary to aberrant reinnervation of CN VII when the fibres innervating the salivary glands are redirected to the lacrimal gland. This may be tested with 1% tropicamide placed on the tongue as a sialogogue. Excess tearing is seen in the ipsilateral eye after approximately 1 minute. WET NOSE Presenting signs Clear watery (serous) nasal discharge from one or both nostrils may be normal. It is an unreliable indicator of general wellbeing hence the thermometer’s supremacy. Systemic causes are usually bilateral. Causes • Early sign of nasal irritation by fungi, parasites, foreign bodies or neoplasia • Viral or allergic • Rhinorrhoea: CSF leaking from the nose caused by Congenital fistula or head trauma • Over-hydration. SALIVATION The parotid, mandibular, sublingual and zygomatic glands secrete saliva into the oral cavity under the influence of the parasympathetic nervous system. The parotid and zygomatic glands are innervated by CN IX. The facial nerve (CN VII) innervates the mandibular and sublingual glands. In both cases, the post-ganglionic fibres travel in association with the mandibular branch of the trigeminal nerve (CN V). Salivation is a reflex which is stimulated by taste (CNN VII, IX) and tactile sensation in the mouth (CN V) and gastric end of the oesophagus (CN X). Higher centres initiate salivation, as demonstrated by anticipation of a food reward, or as part of an anxiety response. EXCESSIVE SALIVATION Presenting sign Drooling, dribbling, strings of saliva hanging from mouth, frequent swallowing. Excessive salivation is more commonly due to an inability to swallow (pseudoptyalism) than an excessive production (ptyalism, hypersalivation, sialism, sialismus, sialorrhoea, sialosis). Drooling is one of the first signs of facial paralysis noticed by the owner. Finding their pet with wet fur under the chin is often the first evidence of seizure activity. Conditions causing oropharyngeal irritation or pain are far more common than neurological lesions as the cause of excessive salivation. Excessive production • Nausea Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Related posts: Metabolic encephalopathy: hepatic encephalopathy Meningioma Idiopathic epilepsy LMN paresis and paralysis: Brachial plexus avulsion Stay updated, free articles. Join our Telegram channel Join Tags: Saunders Solutions in Veterinary Practice Small Animal Neurology Sep 3, 2016 | Posted by admin in SMALL ANIMAL | Comments Off on Secretions Full access? Get Clinical Tree Get Clinical Tree app for offline access Get Clinical Tree app for offline access
26 Secretions INCREASED TEAR PRODUCTION: EPIPHORA Presenting signs Overflowing tears, tear staining of the medial canthus. Cause Reflex lacrimation occurs in response to eye pain which should be evident on examination. Owners sometimes report epiphora occurring a few days before ipsilateral facial paralysis develops. Parasympathetic stimulation from organophosphate toxicity results in SLUD (salivation, lacrimation, urination, defecation). Obstruction of the tear duct is a common cause of tear staining. Paradoxical (‘crocodile’) tears occur in the human during and immediately after eating as a rare phenomenon secondary to aberrant reinnervation of CN VII when the fibres innervating the salivary glands are redirected to the lacrimal gland. This may be tested with 1% tropicamide placed on the tongue as a sialogogue. Excess tearing is seen in the ipsilateral eye after approximately 1 minute. WET NOSE Presenting signs Clear watery (serous) nasal discharge from one or both nostrils may be normal. It is an unreliable indicator of general wellbeing hence the thermometer’s supremacy. Systemic causes are usually bilateral. Causes • Early sign of nasal irritation by fungi, parasites, foreign bodies or neoplasia • Viral or allergic • Rhinorrhoea: CSF leaking from the nose caused by Congenital fistula or head trauma • Over-hydration. SALIVATION The parotid, mandibular, sublingual and zygomatic glands secrete saliva into the oral cavity under the influence of the parasympathetic nervous system. The parotid and zygomatic glands are innervated by CN IX. The facial nerve (CN VII) innervates the mandibular and sublingual glands. In both cases, the post-ganglionic fibres travel in association with the mandibular branch of the trigeminal nerve (CN V). Salivation is a reflex which is stimulated by taste (CNN VII, IX) and tactile sensation in the mouth (CN V) and gastric end of the oesophagus (CN X). Higher centres initiate salivation, as demonstrated by anticipation of a food reward, or as part of an anxiety response. EXCESSIVE SALIVATION Presenting sign Drooling, dribbling, strings of saliva hanging from mouth, frequent swallowing. Excessive salivation is more commonly due to an inability to swallow (pseudoptyalism) than an excessive production (ptyalism, hypersalivation, sialism, sialismus, sialorrhoea, sialosis). Drooling is one of the first signs of facial paralysis noticed by the owner. Finding their pet with wet fur under the chin is often the first evidence of seizure activity. Conditions causing oropharyngeal irritation or pain are far more common than neurological lesions as the cause of excessive salivation. Excessive production • Nausea Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Related posts: Metabolic encephalopathy: hepatic encephalopathy Meningioma Idiopathic epilepsy LMN paresis and paralysis: Brachial plexus avulsion Stay updated, free articles. Join our Telegram channel Join Tags: Saunders Solutions in Veterinary Practice Small Animal Neurology Sep 3, 2016 | Posted by admin in SMALL ANIMAL | Comments Off on Secretions Full access? Get Clinical Tree
