Drooling

by Mike
(Saint Lazare Québec Canada)

Reader Question: My dog started to drool profusely, has a hard time to chew and swallow with inside sores in his mouth that bleed.

Answer from our Publisher on Excessive Dog Drooling

Hi Mike,

I want to be direct with you up front: this combination — sudden profuse drooling, trouble chewing or swallowing, and bleeding sores inside the mouth — is one I'd treat as urgent, not a "wait and see how he does over the next few days" situation. I'd try to get him seen today or tomorrow, and if your regular vet can't fit him in quickly, an emergency vet is a reasonable option. I'm not a vet myself, just someone who researches dog health closely, but here's the reasoning behind that recommendation and what's likely going on.

Possible causes

A caustic or chemical burn. If he chewed on something like a leaking alkaline battery, a cleaning product, or another corrosive substance, it can burn and ulcerate the tissue in the mouth within one to two hours, and the resulting sores often bleed and are quite painful, which fits everything you're describing. If there's any chance he got into a battery, cleaner, or similar item, this jumps to the top of the list and is treated as a true emergency.

Stomatitis. This is a broader term for painful, ulcerated, bleeding inflammation of the mouth tissue. It can happen on its own, or be triggered by contact with something corrosive, an electric shock (like biting a cord), or as a secondary effect of another illness such as diabetes.

Uremic ulcers from kidney disease. When kidneys aren't filtering properly, toxins build up in the blood and can cause painful ulcers on the gums, tongue, or inner lips, along with drooling and reluctance to eat. This is more common in older dogs, and it's often accompanied by other clues like bad "ammonia" smelling breath, increased thirst and urination, or lethargy — worth mentioning to your vet if you've noticed any of those too.

Dental disease or a tooth root abscess. Advanced gum disease or an infected tooth can cause enough pain that a dog drools, chews carefully or on one side, and has bleeding, inflamed tissue nearby.
Trauma or a foreign object. A sharp stick, bone fragment, or something lodged between teeth or in the soft tissue can cause exactly this kind of bleeding sore and sudden reluctance to chew.
An oral tumor. Less common, but tumors in the mouth can ulcerate and bleed, and if they're toward the back of the mouth or throat, they can also make swallowing difficult. This is more of a concern in older dogs and is part of why an in-person exam matters rather than guessing from a description.

What I'd do

Don't try to force a look in his mouth if he's resisting or seems painful — you could get bitten, and you likely won't be able to see everything that matters anyway (the back of the mouth and throat need a proper exam, sometimes under light sedation).
Think back on what he's had access to recently — batteries, cleaning supplies, electrical cords, plants, bones, sticks, or anything he could have chewed on. Mention anything you can think of to your vet, since it changes how urgently they'll want to act and what they'll check for.
Skip food and water if he's struggling to swallow, or offer only a small amount of water, until he's been seen — you don't want him aspirating anything into his lungs.

Call your vet now and describe exactly what you told us — the drooling, the difficulty chewing and swallowing, and the bleeding sores. Most clinics will want to see a dog with this presentation same-day.
If it's after hours, or your vet can't get him in quickly, go to an emergency vet, especially if the bleeding is significant, he seems weak or lethargic, or he's refusing water entirely.

I know that's a lot to take in, but this really is one of those situations where a same-day exam is the right call rather than home care — figuring out which of these is actually happening (and how to treat it) needs a hands-on look, and some of the possibilities above get worse quickly if left untreated.

I hope he's okay, Mike. Please let us know how he's doing.

— The Dog Health Guide Team

This response is intended to provide general information and perspective for pet owners and is not a substitute for veterinary diagnosis or care.