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Ask Dr. Michael Salkin Your Own Question
Dr. Michael Salkin
Dr. Michael Salkin, Veterinarian
Category: Vet
Satisfied Customers: 32753
Experience:  University of California at Davis graduate veterinarian with 45 years of experience.
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My Lab holds her jaw slightly open, she has trouble drinking

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My Lab holds her jaw slightly open, she has trouble drinking and chewing. Her teeth and gums are clean and look normal. She has been X-rayed and I've been given steroids and antibiotics by my vet so far no signs of improvement.

A second opinion would help.

V Worried.
Aloha! You're speaking with Dr. Michael Salkin
Can you tell me, please, if there are any other symptoms associated with Pep's jaw drop? For example, are you seeing an eyelid droop, a change in pupil size, an eye looking "sunken in", protrusion of the third eyelid, absence of a blink relfex, or an ear droop?

I need to differentiate whether Pep has a lack of resistance to opening her jaws which would indicate a trigeminal nerve disorder or whether she suffers a lip commissure paralysis which would indicate a facial nerve disorder. I also need to consider a masticatory muscle myositis - an autoimmune disease affecting the muscles of mastication in dogs which causes a painful inability to open her jaws and, initially, swelling of her masticatory muscles - and other neuromuscular diseases.

I'll await your reply.
Customer: replied 3 years ago.

her eye has drooped towards her cheek and showing red.

Customer: replied 3 years ago.

one eye has drooped and showing red in the lower corner

Thank you. That's an important finding and identifies a Horner's syndrome - a loss of sympathetic nervous innervation to the eye. This can be seen in association with a trigeminal nerve neuritis which is the likely cause of Pep's jaw drop and difficulty in drinking and chewing.

Here are the common exam findings when trigeminal neuritis is present:

  • Bilateral paralysis of the masticatory muscles
  • Affected dogs are bright and alert and do not appear as though they are in pain. They have no other detectable neurologic abnormalities.
  • In some cases, there is decreased facial sensation bilaterally, and Horner's syndrome may be observed.
  • Trismus/inability to open the mouth does not occur with trigeminal neuritis.

Here is the etiology and pathophysiology of a trigeminal neuritis:


  • Most common neurologic cause of an inability to close the mouth in the dog
  • Etiology is unknown, but extensive bilateral nonsuppurative inflammation, demyelination, and, in some cases, axonal degeneration of all portions of the trigeminal nerve and its ganglion, with no brainstem lesions, have been reported at necropsy.
  • Complete recovery is observed in 2-3 weeks (rarely, may take several months), with no drug therapy being reported as useful.
  • Facial sensation is usually preserved. Occasionally, Horner's syndrome may be observed, presumably because the postganglionic sympathetic axons course with the ophthalmic branch of the trigeminal nerve.

This is how it's treated:



  • Maintenance of hydration and alimentation is critical.
  • Percutaneous gastrostomy (a type of feeding tube) may be helpful in severe cases.
  • Feeding canned food gruel is most helpful, since tongue function is maintained.


Signs will typically resolve spontaneously in 2-3 weeks but in some cases will take months to totally normalize.


Feel free to share our conversation with Pep's vet. Referral to a specialist veterinary neurologist might be recommended because generalist vets rarely have the specialized equipment necessary to evaluate patients such as Pep.


Please continue our conversation if you wish.

Customer: replied 3 years ago.

Thank you, XXXXX XXXXX your info on to my vet

Sounds good. I'm going to check back with you in a week for an update. Feel free to return to our conversation - even after rating - prior to my contacting you if you wish.
Dr. Michael Salkin and 3 other Vet Specialists are ready to help you
Thank you for your kind accept. I appreciate it.

I'll speak to you soon.

Please disregard the info request.