Do Dogs Cry? The Science Behind Dogs Crying and What It Really Means
Do dogs cry tears of emotion? Explore the science behind dogs crying, including tear production, vocalization, and what your dog's behavior really signals.
The Direct Answer: Do Dogs Cry?
No, dogs do not cry emotional tears the way humans do. While dogs produce tears for physiological reasons — lubricating the eyes, flushing irritants, and fighting infection — research published in Current Biology (2022) found that dogs may produce increased tear volume when reuniting with their owners, possibly linked to oxytocin release. However, this is not "crying" in the human emotional sense. When people talk about dogs crying, they're usually describing vocalizations (whining, whimpering, howling) or excessive tear production (epiphora), both of which have specific medical and behavioral causes you need to understand.
The Science of Tear Production in Dogs
How Canine Lacrimal Systems Work
Dogs have a lacrimal (tear) system remarkably similar to humans in structure but different in function. The system includes:
- Lacrimal glands: Located above the outer corner of each eye, producing the aqueous (watery) layer of the tear film
- Meibomian glands: Located along the eyelid margins, producing the oily outer layer that prevents evaporation
- Goblet cells: Found in the conjunctiva, producing the mucin layer that helps tears adhere to the cornea
- Nasolacrimal ducts: Drainage channels running from the inner corner of the eye into the nasal cavity
According to the Merck Veterinary Manual, the normal canine tear film is approximately 3 micrometers thick and completely renews itself every 5-7 minutes. Healthy dogs produce tears at a rate measured by the Schirmer Tear Test (STT) — normal values fall between 15-25 mm of wetting per minute.
The key distinction: in humans, the parasympathetic nervous system triggers emotional tearing through complex pathways involving the limbic system (specifically the anterior cingulate cortex and hypothalamus). In dogs, tear production is primarily reflexive — triggered by physical irritation, dryness, allergens, or corneal damage — rather than emotional states.
The 2022 Reunion Tears Study: What It Actually Found
In August 2022, researchers at Azabu University in Japan published a study in Current Biology that generated significant media attention. The study, led by Takefumi Kikusui, examined 18 dogs and measured tear volume using the Schirmer Tear Test before and after reuniting with their owners following a 5-7 hour separation.
Key Findings from Peer-Reviewed Research
- Tear volume increased by approximately 10-20% during owner reunions compared to reunions with familiar non-owner humans
- Oxytocin connection: Applying oxytocin drops to dogs' eyes increased tear production, suggesting the hormone may play a role in lacrimal secretion
- Sample size limitation: Only 18 dogs were studied — far too small to draw definitive conclusions about all dogs
- Not "crying": Researchers specifically noted this was increased tear volume, not the emotional crying seen in humans. Dogs did not display tear-streaming behavior
- Evolutionary hypothesis: Researchers proposed this may facilitate bonding by triggering caregiving responses in humans — dogs with moist, "puppy-dog" eyes may elicit more nurturing behavior
Source: Nagasawa et al., "Dogs shed tears of joy when reunited with their owners," Current Biology, Volume 32, Issue 16, August 2022.
This study is frequently misrepresented online. The dogs were not streaming tears down their faces. The increase was measurable only through clinical testing. If your dog's eyes are visibly watering or tearing is running down their face, this is almost certainly a medical issue — not an emotional response.
Why Dogs Produce Excess Tears: Medical Causes
Excessive tearing in dogs is called epiphora, and it's one of the most common reasons owners think their dogs are "crying." The Merck Veterinary Manual identifies several underlying mechanisms:
| Cause Category | Specific Conditions | Typical Signs | Vet Visit Cost Range |
|---|---|---|---|
| Overproduction | Conjunctivitis, corneal ulcers, uveitis, foreign bodies, allergies, entropion | Redness, squinting, pawing at eye, mucoid discharge | $75-$250 (exam + STT + fluorescein stain) |
| Drainage obstruction | Nasolacrimal duct blockage, punctal aplasia, dacryocystitis | Tear staining on face, overflow from inner corner, no other eye signs | $150-$500 (exam + duct flushing + possible imaging) |
| Conformational | Shallow orbits, medial lower lid entropion, trichiasis, facial fold pyoderma | Chronic tear staining, hair contacting cornea, skin fold redness | $100-$800+ (exam, possible surgical correction $500-$2,500) |
| Breed-specific anatomy | Punctal aplasia (missing drainage openings), narrow puncta | Present from puppyhood, chronic tearing without irritation signs | $200-$600 (surgical punctal opening) |
Breed Predispositions to Excessive Tearing
Brachycephalic (flat-faced) breeds are disproportionately affected by epiphora due to their skull conformation. Breeds with the highest prevalence include:
- Shih Tzu, Pekingese, Lhasa Apso: Extremely shallow eye sockets, prominent globes, medial lower lid entropion common
- Pugs, French Bulldogs, Boston Terriers: Large protruding eyes with inadequate eyelid coverage, prone to exposure keratitis triggering reflex tearing
- Poodles, Bichon Frisés, Maltese: Narrow nasolacrimal ducts and punctal aplasia; tear staining on white coats is particularly visible
- Cocker Spaniels, Basset Hounds: Loose facial skin and pendulous eyelids create wicking of tears onto the face
If your dog belongs to one of these breeds and has chronic tear staining, this is an anatomical issue requiring veterinary management — not emotional distress.
Dogs Crying as Vocalization: Whining, Whimpering, and Howling
Evolutionary Roots of Canine Vocalization
Wolves (Canis lupus) use vocalizations extensively — howls for long-distance communication, whines for submissive greeting, and whimpering from pups to solicit care. Domestic dogs have neotenized (retained juvenile) vocalization patterns. Adult dogs whine and whimper far more frequently than adult wolves, a trait that likely developed during the 15,000-40,000 years of domestication because humans responded to these juvenile sounds with caregiving.
Research published in Biology Letters (2019) demonstrated that dogs' whining activates the same caregiving neural circuits in humans that infant crying does — suggesting dogs have evolved vocalizations that exploit our nurturing instincts.
When owners describe their dogs as "crying," they're most often referring to these vocalizations:
Whining and Whimpering
High-pitched, sustained nasal sounds typically signaling:
- Anxiety or distress: Separation anxiety, veterinary visits, thunderstorms, fireworks
- Anticipation: Waiting for food, a walk, or a family member to arrive
- Pain: Especially when accompanied by trembling, hiding, or reluctance to move
- Attention-seeking: Learned behavior when whining has been reinforced with petting, treats, or play
- Submission/appeasement: Directed toward a more dominant dog or an upset owner
Howling
Sustained, tonal vocalizations serving different functions:
- Contact calling: Attempting to locate separated pack members (human or canine)
- Response to sounds: Sirens, musical instruments, other dogs howling
- Territorial advertisement: Announcing presence to unfamiliar dogs
Crying During Sleep
Dogs frequently vocalize during REM sleep — whimpering, yipping, or growling softly. This is normal and corresponds to dream activity. Studies using EEG monitoring show dogs enter REM sleep approximately 20 minutes after falling asleep, with REM cycles lasting 10-15 minutes. Do not wake a sleeping dog who is vocalizing — they may startle and react defensively.
How Is Dog "Crying" Different from Human Crying?
| Aspect | Human Crying | Dog "Crying" |
|---|---|---|
| Emotional tears | Yes — triggered by limbic system via parasympathetic pathways | Not confirmed — tears are primarily reflexive; 2022 study suggests possible oxytocin-linked increase during reunions, but no tear-streaming observed |
| Vocalization | Sobbing, wailing — involuntary respiratory disruption | Whining, whimpering, howling — voluntary communication signals |
| Chemical composition | Emotional tears contain higher levels of stress hormones (ACTH, leucine enkephalin) | No research has compared reflexive vs. emotional tear composition in dogs |
| Social function | Signals distress, elicits empathy and help | Vocalizations signal specific needs; possible that increased eye moisture during reunions enhances bonding through caregiving response |
| Onset | Develops around 2-4 months in infants | Puppies vocalize from birth; mature vocalization repertoire develops by 8-12 weeks |
When Dogs Crying Signals a Problem
🚨 When to Call Your Veterinarian
Contact your vet immediately if your dog's "crying" is accompanied by any of these red flags:
- Eye changes: Visible third eyelid, cloudiness, blood in the eye, or a bulging globe — these are emergencies requiring same-day care (corneal ulcers can perforate within 24-48 hours)
- Sudden behavioral change: A normally quiet dog who begins whining constantly may be in pain — common causes include dental disease, arthritis, urinary tract infection, or abdominal pain
- Crying during movement: Whining when standing, lying down, climbing stairs, or being touched suggests musculoskeletal pain (IVDD, hip dysplasia, cruciate ligament tear)
- Crying + gastrointestinal signs: Whining with vomiting, diarrhea, a distended abdomen, or unproductive retching could indicate gastric dilatation-volvulus (bloat) — a life-threatening emergency requiring immediate surgical intervention
- Unilateral eye discharge: Tearing from only one eye with squinting strongly suggests a corneal ulcer or foreign body
Emergency veterinary care typically costs $200-$500 for the visit alone, with diagnostics adding $150-$800. Pet insurance can offset 70-90% of these costs after deductible.
Distinguishing Normal from Problematic Vocalization
Not all whining requires intervention. Use this framework to assess your dog's vocalizations:
- Identify the trigger: Is there an obvious cause (doorbell, leash, food preparation)? If yes, the vocalization is likely situational and normal.
- Check duration: Brief whining (under 2-3 minutes) that resolves when the trigger passes is typically normal. Prolonged vocalization (15+ minutes) without an obvious trigger warrants investigation.
- Assess body language: Whining with a relaxed body, wagging tail, and "soft" face is communication. Whining with trembling, tucked tail, pinned ears, panting, or hiding signals genuine distress.
- Rule out pain: Gently palpate your dog's body. Flinching, tensing, or increased vocalization when touching a specific area suggests a medical cause — consult your veterinarian.
- Track patterns: Keep a brief log for 5-7 days noting time, duration, trigger, and context. This data is invaluable for your vet or a certified behaviorist.
Practical Takeaways for Dog Owners
What You Can Do Today
For excessive tearing (epiphora):
- Clean the eye area daily with a sterile, vet-recommended eye wipe or a soft cloth dampened with lukewarm saline solution — wipe from the inner corner outward
- Trim hair around the eyes every 2-3 weeks to prevent wicking (use blunt-nosed scissors; have a groomer demonstrate if you're unsure)
- Avoid over-the-counter "tear stain remover" products containing tylosin (an antibiotic) — the FDA has not approved these for dogs, and chronic antibiotic exposure risks resistance
- Schedule a veterinary ophthalmology exam if staining is chronic — your vet can perform a Jones test (fluorescein dye flushing) to check nasolacrimal duct patency for $75-$150
For excessive whining/vocalization:
- Never punish vocalization — this suppresses the symptom without addressing the cause and can increase anxiety. Use only positive reinforcement and force-free methods
- Teach an incompatible behavior: Train "go to your mat" and reward quiet settling with high-value treats (freeze-dried liver, boiled chicken). Sessions should be 3-5 minutes, 2-3 times daily
- For separation anxiety: Implement systematic desensitization — practice departures starting at 5 seconds and gradually increasing duration over weeks. Products like Adaptil (DAP pheromone diffuser, $25-$40) may provide supplementary calming
- Consult a professional: If vocalization persists beyond 2 weeks of consistent training, work with a certified applied animal behaviorist (CAAB) or a veterinary behaviorist (DACVB). Sessions typically cost $150-$350
Frequently Asked Questions About Dogs Crying
Can dogs cry tears of sadness?
There is no scientific evidence that dogs produce tears specifically in response to sadness. While the 2022 Azabu University study showed increased tear volume during joyful reunions, the mechanism appears linked to oxytocin rather than emotion-driven lacrimal pathways. Dogs experiencing distress communicate through vocalizations, body language, and behavioral changes — not through tear production.
Why does my dog cry at night?
Nighttime whining has several common causes: the need to eliminate (especially in puppies who can only hold their bladder for 1 hour per month of age + 1), anxiety from sleeping alone, pain that worsens when lying still (arthritis is worse after inactivity), or cognitive dysfunction in senior dogs (canine cognitive dysfunction affects an estimated 28% of dogs over age 11). If your dog is over 8 and has recently started vocalizing at night, ask your vet about cognitive screening.
Is it normal for my dog to cry after surgery?
Some whining after anesthesia is normal — dogs often vocalize during the recovery period (first 12-24 hours) as they experience disorientation from residual sedation. This is called dysphoria and differs from pain-related crying. However, persistent crying beyond 24 hours, crying when the surgical site is touched, or crying combined with refusal to eat warrants a call to your surgeon. Post-operative pain management typically includes NSAIDs (carprofen, meloxicam) and/or gabapentin — if your dog is still vocalizing, the pain protocol may need adjustment.
Do dogs cry when their owner dies?
Dogs do grieve the loss of a companion (human or animal). A 2022 study published in Animals surveyed over 400 multi-dog households and found that 86% of surviving dogs exhibited behavioral changes after a household dog died, including increased vocalization, decreased activity, and changes in eating patterns. These changes typically lasted 2-6 months. However, this grief response manifests as behavioral changes — not tear production.
How do dogs sense and process human crying?
Dogs are remarkably attuned to human emotional signals. A 2018 study in Learning and Behavior found that dogs approached a crying person faster than a humming person, and a 2021 study in Scientific Reports confirmed dogs can distinguish between happy and angry human faces. Dogs likely process human crying through a combination of auditory processing (the tone and pitch of sobbing), visual cues (facial expressions, body posture), and possibly olfactory changes (stress hormones alter body chemistry). Many dogs respond to crying humans with proximity-seeking, licking, or leaning — behaviors that likely evolved because they strengthened the human-dog bond.
What does it mean when my dog cries while carrying a toy?
This is typically a displacement behavior or an expression of excitement/frustration rather than distress. Some dogs, particularly retrievers and terriers, vocalize when they have a valued resource. If the whining is accompanied by pacing and searching behavior, the dog may be looking for a place to "cache" the toy — a remnant of ancestral food-burying instincts. If your dog cries when holding a toy but shows no other signs of distress (normal appetite, normal play with other toys, relaxed body language), this is generally harmless.
Disclaimer: This article provides educational information based on current veterinary science and should not replace professional veterinary advice. If you are concerned about your dog's tear production, vocalizations, or behavior, please consult your veterinarian for a thorough examination and personalized guidance.
Jonas Cole
All our authors care for dogs every day — read more of their work on the authors page.
