Six signals, read around the clock by one device on your dog's existing collar.
Dogs are built to hide pain. The Ruff is built to read the signals they can't hide, and to make sense of them.
Pain shows up as small changes long before a limp or a whimper. The Ruff catches those changes in three steps.
Six signals, read around the clock by one device on your dog's existing collar.
Every reading is weighed against your dog's own normal, identifying what is unique about your dog.
The result is the Pain Probability Index, a pain score from 0 to 100, and the Tether app explains what it means and what to do.
The Ruff learns your dog. It tracks each animal against their own baseline and flags change over time, which is what makes an early shift visible. It is not a clinical measuring instrument and it is not trying to replace one.
It ships with breed reference ranges, so it has a starting point from day one and can tell you when a new dog is likely already in pain.
The Ruff learns your dog's normal, how he moves, rests, and settles, while starting from breed reference ranges so it is useful from day one.
The score is tuned to him rather than to an average, so a small change stands out instead of getting lost in the noise.
You can see the long trend, which is where slow problems like arthritis first show, and hand your vet a real history instead of a guess.
The Ruff started with a clinical question, not a feature list. Everything it measures traces back to a paper, and both papers are open here for you to read.
Why dogs mask discomfort, the early signs owners miss, and how watching your own dog over time catches pain sooner.
Read the paperHow The Ruff reads five sensor streams continuously and scores pain against each dog's own baseline rather than population averages.
Read the paperPapers publish here as they clear Tether's clinical review with Dr. Pollack and Dr. Pachtinger.
Dogs rarely announce pain. They keep moving, keep wagging, and keep participating until discomfort has been present for weeks. This guide explains why that happens, which early signs owners miss, and how to tell your veterinarian what changed.
Your dog tells you a lot. They tell you when they are hungry, when they want to play, when someone is at the door, and when the cheese drawer has been opened from three rooms away.
But pain is different. Dogs often do not announce pain clearly. Many keep moving, keep wagging, and keep participating until discomfort has been present for weeks or months. That silence can fool even highly attentive dog owners.
The key idea: pain in dogs usually shows up as a pattern of small changes, not one dramatic sign.
This guide explains why dogs hide pain, what early signs owners commonly miss, why pain can be difficult to catch during a veterinary visit, and how watching your dog over time can help you and your veterinary team act earlier.
Dogs often mask pain because vulnerability is risky. That instinct does not disappear just because a dog sleeps on a memory-foam bed and has a toy basket larger than most human closets. The drive to keep moving and avoid looking weak is deeply rooted behavior, not a conscious decision to be difficult.
That is why a painful dog may still greet you, wag their tail, chase a ball, or finish a walk. Those behaviors do not prove comfort. They only prove the dog is still trying.
It also helps to separate two related ideas: nociception and pain. Nociception is the body detecting a potentially harmful stimulus, such as pressure, inflammation, heat, or tissue damage. Pain is the unpleasant sensory and emotional experience the brain creates from those signals. In plain English: nociception is the alarm system; pain is the experience of hearing the alarm.
This matters because a dog does not need to cry, limp, or refuse food to be experiencing pain. The International Association for the Study of Pain emphasizes that an inability to communicate does not rule out pain or the need for pain relief. For dogs, that communication gap is exactly where careful observation becomes essential.
A quiet dog is not automatically a comfortable dog.
Pain in dogs often appears as a cluster of behavioral and movement changes. No single sign proves pain by itself, but several small changes together should raise concern, especially when they are new for your dog.
, Morning stiffness during the first few minutes after waking, followed by gradual loosening as the day goes on.
, Slower or more hesitant rising from rest. A healthy dog may stand quickly; a dog with joint or back pain may pause before committing to the movement.
, Avoiding activities they previously did without hesitation, such as stairs, jumping onto furniture, getting into the car, or playing on slippery floors.
, Shorter walks, slower walks, or stopping more often without an obvious reason.
, Panting at rest when heat, exercise, or excitement do not explain it.
, Uncharacteristic growling, snapping, flinching, or guarding when touched. A dog reacting to handling may be protecting a painful area rather than acting out.
, Becoming unusually clingy, withdrawn, restless, or attention-seeking.
, Sleeping more, sleeping less, changing sleep locations, or repeatedly repositioning at night.
, Facial changes such as flattened ears, a tense expression, glazed eyes, or showing more of the whites of the eyes.
The most important question is not whether your dog matches a textbook description. The better question is: Is this different from MY dog's normal?
Early pain gets missed because the first clues are usually explainable. Slow in the morning becomes just sleepy. Hesitating before a jump becomes being dramatic. A shorter walk becomes not in the mood today. None of those interpretations are unreasonable on their own. The problem is that pain often hides in the pattern.
, An awkward sitting position, especially one or both hind legs splayed to the side instead of tucked under the body.
, Stiffness that improves after a few minutes of movement. This is common with arthritis and easy to miss once the dog has warmed up.
, Out-of-context lip licking, yawning, or looking away during position changes, such as rising, sitting, lying down, or being handled.
, A subtle head bob while trotting. With forelimb discomfort, the head often rises when the painful limb contacts the ground and drops when the sound limb lands.
, Choosing hard or cool surfaces instead of a soft bed, especially if that is new behavior.
, Nighttime restlessness, repeated repositioning, or trouble settling.
, New behavior changes after puppyhood, including leash pulling, irritability, resource guarding, reactivity, or excessive barking when those behaviors were not previously part of the dog's pattern.
Pain is not always loud. Sometimes it looks like a dog quietly changing the way they live.
Pain often gets caught late because the veterinary visit is a brief snapshot of a problem that usually develops slowly at home. Even a careful examination may not reproduce the movements or situations that trigger discomfort.
The clinic itself can also mask pain. Many dogs are nervous, excited, or highly focused in the exam room. Stress hormones like adrenaline can temporarily make a painful dog look more mobile than they are during a normal morning at home. A dog that struggles to rise from bed every day may still move fairly well during a ten-minute visit.
There is another problem: gradual change becomes the new normal. If a dog's walk gets shorter over three months, the owner may adapt without realizing it. The dog is still walking, so the change does not feel urgent. Meanwhile, the pain may be progressing.
Chronic pain also shows up in context. Stairs, slippery floors, jumping into the car, getting up after sleep, and settling at night are home-life moments. They are hard to recreate in an exam room.
A clinic visit can provide excellent medicine and still be a poor surveillance system for subtle pain.
Breed, age, and size matter, but averages can mislead. A Greyhound, a Chihuahua, a French Bulldog, and a Labrador do not move, breathe, rest, or recover in the same way. Even within a breed, dogs vary widely.
That is why the most useful baseline is your dog's own baseline. What does YOUR dog look like when they are comfortable? How quickly do they rise? How far do they usually walk? How often do they reposition at night? How much panting is normal for them?
Comparing your dog to other dogs can create false alarms in some cases and miss real problems in others. Comparing your dog to yesterday, last week, and last month is often more meaningful.
Start by building a simple mental baseline. You do not need a medical degree, a spreadsheet, or a detective board covered in red string. You need a consistent way to notice change.
, Watch your dog rise from rest first thing in the morning before they have warmed up. Count how long it takes and note any hesitation.
, Watch the first few steps. Are they fluid, stiff, uneven, or cautious?
, Watch your dog sit. Are the hind legs tucked underneath, or does one leg drift out to the side?
, Watch your dog trot, if possible. Look for symmetry, head bobbing, or one limb landing differently than the others.
, Track walks. Are they getting shorter, slower, or more stop-and-start without a clear reason?
, Pay attention overnight. Repositioning once or twice may be normal. Repeated waking, pacing, or resettling can matter.
, Before a veterinary appointment, take short videos at home: rising from rest, walking, stairs, jumping into the car, or the specific movement that concerns you.
Those baseline moments can be extremely helpful because they show your veterinarian what your dog looks like in the environment where the problem actually happens.
Human observation is powerful, but it is intermittent. You sleep. You work. You leave the house. You cannot reliably count every nighttime repositioning, every hesitation before movement, or every subtle change in resting respiratory rate.
That is the gap continuous monitoring is designed to close. Tether's collar-mounted device, The Ruff, collects multiple streams of information over time, including movement, radar-derived heart rate and respiratory rate, surface temperature, acoustic signals such as vocalization and panting, and a dedicated vibration channel for micro-tremor detection.
Tether's Individualized Longitudinal Baseline Engine (ILBE) is designed to learn what normal looks like for an individual dog over time. Instead of relying only on breed averages, it compares new signals against that dog's own established pattern.
When several signals change together, reduced activity, altered movement, increased nighttime restlessness, changes in respiratory patterns, or more vocalization, the system can help surface a structured picture of what changed, when it changed, and why it may matter.
This does not replace your veterinarian, and it should not be treated as a diagnosis. The value is earlier visibility. By the time your dog reaches the exam room, your veterinarian can have more than a one-day snapshot. They can have a longitudinal story.
The goal is not to make owners anxious. The goal is to make subtle change visible before pain becomes a crisis.
Call your veterinarian if your dog has a new limp, repeated stiffness, reluctance to rise, sudden behavior change, reduced appetite, unexplained panting at rest, crying out, guarding when touched, difficulty using stairs, or any pattern that feels meaningfully different from their normal.
Seek urgent veterinary care if your dog cannot walk, collapses, has severe weakness, cries out in pain, has a swollen abdomen, has trouble breathing, is pale, is unable to urinate, or has sudden neurologic signs such as dragging limbs, severe imbalance, or inability to stand.
When in doubt, assume discomfort is possible and ask. That is not overreacting. That is good advocacy.
Dogs are experts at hiding pain. Owners are experts at knowing their own dogs. The earlier those two realities meet, the better.
Pain is most often caught by patterns: slower rising, changed movement, altered sleep, new behavior, reduced activity, and subtle shifts away from normal. A veterinary exam remains essential, but the strongest signal often begins at home, in the small daily moments that show who your dog really is when no one is watching.
If you can see the pattern sooner, you can ask better questions sooner. And sooner is exactly where quality of life is protected.
Dr. Zachary L. Pollack, DVM, MRCVS
1. International Association for the Study of Pain Task Force on Taxonomy. In: Merskey H, Bogduk N, eds. Classification of Pain. 2nd ed. Seattle: IASP Press; 1994:209-214.
2. Merck Veterinary Manual. Recognition and Assessment of Pain in Animals. Reviewed/Revised March 2023.
3. Walsh S. Understanding the link between canine pain and problem behaviours. Veterinary Ireland Journal. February 2025.
4. Mills DS, Demontigny-Bedard I, Gruen M, et al. Pain and Problem Behavior in Cats and Dogs. Animals (Basel). 2020;10(2):318. doi:10.3390/ani10020318.
5. Barcelos A-M, Mills DS, Zulch H. Clinical indicators of occult musculoskeletal pain in aggressive dogs. Veterinary Record. 2015;176(18):465. doi:10.1136/vr.102830.
6. Mills D, Zulch H. Veterinary assessment of behavior cases in cats and dogs. In Practice. 2023;45:444-458. doi:10.1002/inpr.322.
7. Landsberg G, Hunthausen W, Ackerman L. Behavior problems of the dog and cat. Vet Clin Small Anim Pract. 2013;43(5):975-1003.
8. Cornell Richard P. Riney Canine Health Center. Cohen A. Recognizing Pain in Dogs. Updated October 2025.
9. Mota-Rojas D, et al. Current Advances in Assessment of Dog's Emotions, Facial Expressions, and Their Use for Clinical Recognition of Pain. Animals. 2021;11(11):3334.
10. Demirtas A, et al. Dog owners' recognition of pain-related behavioral changes in their dogs. Journal of Veterinary Behavior. 2023;62:12-17.
11. American Animal Hospital Association. AAHA 2022 Pain Management Guidelines for Dogs and Cats.
12. Caddiell RM, et al. Pain sensitivity differs between dog breeds but not in the way veterinarians believe. Frontiers in Pain Research. 2023;4:1165340.
13. Brown DC, et al. The use of the Canine Brief Pain Inventory to characterize osteoarthritis-associated chronic pain in dogs. J Vet Intern Med. 2007;21(2):248-255.
14. Reid J, et al. Development of the short-form Glasgow Composite Measure Pain Scale (CMPS-SF). Vet Anaesth Analg. 2007;34(2):97-104.
15. Downing R, Della Rocca G. Pain in Pets: Beyond Physiology. Animals (Basel). 2023;13(3):355.
By the time pain becomes visible, the window for early intervention has often closed. This paper sets out what The Ruff measures, how the Individualized Longitudinal Baseline Engine models each dog against its own history, what the Pain Probability Index produces, and what the system does not claim to do.
Dogs are stoic by nature. Hardwired over millennia to suppress outward expressions of pain as a survival mechanism, companion dogs routinely mask discomfort long past the point where a condition has meaningfully progressed. Owners miss it. Veterinarians, seeing a patient for minutes at a time, weeks or months apart, miss it too. By the time pain becomes visible, the window for early, less invasive intervention has often already closed.
Tether has built a system designed to operate inside that window. The Ruff is a collar-mounted wearable device that continuously captures five streams of physiological and behavioral data from a dog during its ordinary daily life. That data flows to the Tether cloud platform, where an Individualized Longitudinal Baseline Engine (ILBE) compares real-time sensor outputs against a behavioral model built from that specific animal's own history, not population averages, not breed norms. When meaningful deviation is detected, the system generates a Pain Probability Index (PPI), classifies the probable character and anatomical locus of the pain, ranks candidate conditions, and delivers urgency-stratified guidance to both owners and veterinarians.
This document describes what the system measures, how it works, what it produces, and, critically, what it does not claim to do. The system does not diagnose. It does not replace physical examination, imaging, or clinical judgment. It identifies the probability of a pain state and supports the humans responsible for acting on that information.
The goal is not to replace veterinary care. The goal is to ensure that by the time a dog reaches the clinic, the veterinarian has weeks of objective, continuous behavioral data, not a five-minute observation window.
Pain concealment in dogs is not a behavioral quirk. It is an evolutionary adaptation rooted in predator avoidance: an animal that visibly limps or vocalizes distress advertises vulnerability. The instinct to suppress outward pain expression is deeply hardwired, and it operates regardless of the severity of the underlying condition. A dog with moderate osteoarthritis may move normally enough during a clinic visit, adrenaline, changed environment, and the instinct to appear capable all contribute, while spending the other 23 hours of its day struggling to rise from rest, hesitating before stairs, waking repeatedly through the night.
The validated clinical pain scales used in veterinary practice, the Canine Brief Pain Inventory (CBPI), the Glasgow Composite Measure Pain Scale Short Form (CMPS-SF), the Helsinki Chronic Pain Index (HCPI), are well-constructed instruments. They are also episodic, observer-dependent, and administered at intervals of weeks to months. They were designed for the clinic visit, which means they are structurally blind to the vast majority of a dog's lived experience with pain.
Veterinary costs have increased by 55.5% since 2019, while clinic visit volume has declined for four consecutive years. Owners are paying more per visit and attending fewer of them. The result is a growing population of dogs whose pain conditions are either undetected between visits or detected late, at the point of emergency presentation, when intervention is more intensive, more expensive, and less likely to fully restore function. Early detection moves diagnosis upstream toward a point where conservative management, targeted physiotherapy, or timely pharmaceutical intervention can meaningfully alter the course of the condition.
Consumer pet wearables have advanced meaningfully over the past decade. GPS tracking, step counting, and basic activity monitoring are now widely available. A smaller number of products have extended into vital sign monitoring. These systems represent real progress. They also share four structural limitations that prevent them from serving as reliable early pain detection tools.
POPULATION THRESHOLDS CANNOT ACCOUNT FOR INDIVIDUAL VARIATION
Dogs vary enormously in their baseline physiological signatures. A healthy adult Greyhound has a naturally lower resting heart rate than a healthy adult Chihuahua. A brachycephalic breed has respiratory patterns that would be flagged as abnormal in a mesocephalic dog. Systems that compare sensor outputs against population averages generate false positives in some animals and miss genuine signals in others. The appropriate comparison is not against the breed or population, it is against that individual dog's own established normal.
Pain-associated vocalizations, whimpering, groaning, yelping, are among the most specific behavioral indicators of pain in dogs. Yet prior wearable systems have not treated acoustic data as a primary pain biomarker stream. This leaves a significant dimension of pain-related behavioral expression unmeasured.
Fine muscle micro-tremors, the involuntary neuromuscular tension associated with pain-induced muscle guarding, are not detectable by motion sensors or temperature sensors. They require a sensor capable of detecting sub-millimeter displacement: millimeter-wave radar. This capability has not, prior to this platform, been incorporated into a collar-mounted wearable for continuous pain monitoring.
A pain score, on its own, is not enough. An owner who receives a score of 71 out of 100 needs to know what kind of pain is likely present, what is probably causing it, how urgent the situation is, and what to do next. Without a contextualization layer, a detection system produces anxiety without guidance.
The Ruff is a collar-mounted device housing five sensor components selected for their complementary, non-redundant coverage of the physiological and behavioral dimensions most relevant to canine pain. The device generates in excess of 10,000 data points per animal per day, transmitting continuously to the Tether cloud platform via encrypted wireless protocols. It is waterproofed to IPX7 standard and designed for continuous wear. GPS-based location tracking is not included in the initial hardware release and is planned for inclusion in future device updates as part of Tether's ongoing hardware investment.
| Sensor / Component | What It Captures | Clinical Relevance |
|---|---|---|
| 60 GHz Radar (Acconeer A121) | Respiration rate, heart rate, micro-tremor index, contactless | Primary non-contact physiological channel. Works through the enclosure and through fur. Micro-tremor index detects muscle guarding, neuromuscular tension, and pain-related tremor, a capability with no equivalent in prior wearable systems. Values interpreted as trends against the dog's own baseline. |
| 6-Axis IMU, Primary (LSM6DSV16X, U1) | Gait symmetry, head-bob, activity level, postural transitions, restlessness | Always-on sentinel in the firmware architecture. Drives activity level, gait symmetry, posture transitions. Gait asymmetry and head-bob are primary lameness indicators. Slow postural transitions are a hallmark of arthritis and spinal pain. |
| Dedicated Vibration Channel (LSM6DSV16X, U10) | High-rate vibration on an isolated signal path | A second IMU on its own SPI interface, providing fine vibration-domain features independent of the primary motion stream. Captures physiological information that standard motion sampling at lower rates cannot. |
| MEMS Microphones ×2 (SPH0641LU4H-1, MK1 & MK2) | Vocalizations, panting, coughing, classified on-device. Raw audio never transmitted. | Paired placement supports robust capture on a moving animal. On-device firmware converts digital streams into audio features. Vocalization contextualization that helps distinguish fear, anxiety, and pain is available from launch. |
| Temperature (TMP117, U2) | Surface temperature via dedicated thermal path through enclosure | Accuracy in the 0.1°C class, sufficient to distinguish genuine physiological shifts from sensor noise. Temperature shifts accompany inflammation, infection, and stress responses. Signal value comes from trend deviation against the individual animal's own baseline. |
| GPS, planned | Not in v1 hardware | Roaming radius, daily distance, planned for future hardware updates. These GPS-derived metrics will contribute to the behavioral sub-score when introduced. |
The Individualized Longitudinal Baseline Engine is the core technical innovation of the Tether platform. Rather than comparing a dog's sensor outputs against breed averages or population reference ranges, the ILBE constructs and maintains a continuously updated behavioral model built from that specific dog's own historical data. Every dog receives a baseline that is uniquely theirs. Every deviation is measured against the version of themselves the system has learned over weeks and months of continuous wear.
Pain in dogs does not present as a single threshold violation. It presents as correlated drift across multiple subtle signals over time, gait symmetry shifts by a few percent, resting respiratory rate creeps upward, vocalization frequency moves into pain-associated bands, morning activity onset slows. No individual signal is diagnostic. The multi-signal deviation pattern, measured against an individualized baseline, is.
, The 24-hour baseline detects acute changes, sudden activity drops, gait symmetry collapses, fever spikes, and vocalization bursts consistent with acute injury or acute illness.
, The 7-day baseline identifies sub-acute trends developing over days, such as a progressing soft-tissue injury or the early stages of an infectious process.
, The 30-day baseline represents the dog's established normal and is the primary reference for chronic pain detection, the gradual, insidious drift that characterizes osteoarthritis, degenerative joint disease, and progressive neurological conditions.
Baselines require approximately 14 days before they are considered reliable. Confidence scores, present on every assessment, reflect baseline maturity explicitly. Breed, age, and morphological context are incorporated into what the ILBE considers normal for each individual, preventing false positives from breed-normal physiology while remaining sensitive to genuine deviations.
The ILBE's output feeds a scoring engine that computes a composite pain score on a 0, 100 scale, derived from three weighted sub-scores:
, Behavioral score (40% weight)
Nighttime restlessness, activity trend slope, vocalization rate and intensity, and activity reduction. Behavioral changes are the broadest indicator across pain types and receive the highest weight.
, Mobility score (35% weight)
Activity level, gait symmetry, peak angular velocity, head-bob asymmetry (forelimb lameness indicator), postural transition rate and duration, and morning stiffness index.
, Cardiorespiratory score (25% weight)
Heart rate elevation (radar-derived), respiratory rate elevation (radar-derived), micro-tremor index, circadian HR pattern disruption, resting panting rate, coughing rate, and skin temperature deviation.
Each sub-score is driven by the single worst indicator within its category, not an average. The composite score is classified into a Pain Probability Index (PPI) tier: Green (no significant indicators), Amber (monitoring or veterinary consultation recommended), and Red (veterinary attention recommended).
Each assessment classifies the detected pain state across four clinical dimensions simultaneously. Pain acuity describes the temporal character, acute, subacute, chronic, or episodic. Anatomical locus uses kinematic signature patterns to estimate the probable body region involved. Pain character classifies the probable pathophysiological mechanism, nociceptive, inflammatory, neuropathic, visceral, or mixed. Environmental and activity context is integrated explicitly to prevent false-positive classifications.
The causal attribution model produces a ranked differential list of probable conditions weighted by breed-specific condition prevalence, age-adjusted risk, sensor signal pattern matching, and the individual animal's known health history. This is not a clinical conclusion. It is a data-backed starting hypothesis intended to direct clinical attention toward the most likely diagnoses before the examination begins.
The recommendation engine maps the pain classification and differential output to an urgency tier, each with a distinct recommended response protocol. Recommendations are voiced separately for owners in plain language and for veterinarians in clinical language, including examination focus areas, imaging modalities to consider, and treatment response benchmarks.
Every assessment generates a SOAP-formatted veterinary report structured to align with the format used in veterinary medical records. This transforms the clinic visit from a single-point snapshot into a longitudinal consultation. The veterinarian arrives having seen not just today's presentation but the behavioral arc of the preceding weeks.
Clinical credibility requires clarity about limitations. These are accurate characterizations of a system in active development, described here so that veterinary professionals, owners, and all others evaluating this platform can form an accurate understanding of what it can and cannot tell them.
, It does not diagnose. Differential rankings are probabilistic suggestions to guide examination, not clinical conclusions. Veterinary examination is always recommended for elevated scores.
, It does not replace physical examination. Palpation, manipulation, response to touch, gait assessment, and imaging provide information no wearable sensor can supply.
, It requires a maturation period. Reliable baselines require approximately 14 days of continuous wear. First-week results carry reduced confidence, clearly indicated in the output.
, It is strongest for musculoskeletal and behavioral pain. Dental and oral pain, and some visceral pain presentations, may have subtler sensor signatures.
, Audio classification has known limitations. On-device vocalization classification may occasionally confuse environmental sounds with pain-associated vocalizations. Multi-dog households present attribution challenges.
, Skin temperature is surface temperature, not core body temperature. The TMP117 measures neck surface temperature through the collar's thermal path. Clinical value comes from trend deviation against the individual animal's own baseline.
, Clinical scale mappings are estimated, not validated. CBPI, CMPS-SF and other clinical metrology instrument equivalents are sensor-derived estimates requiring prospective calibration studies before carrying clinical authority.
, GPS-derived mobility metrics are not available in the initial hardware release. Roaming radius and daily distance will be introduced in future hardware updates.
The system described in this document is a clinically reasoned design grounded in established veterinary pain biology. It is not yet a clinically validated system. Specific open questions requiring prospective clinical data include: scoring weight validation across pain types; threshold calibration for mild, significant, and severe deviation categories; brachycephalic respiratory rate multiplier calibration; and CCD versus nocturnal pain discrimination in geriatric dogs.
Tether is actively seeking veterinary partners, individual practitioners, academic clinical programs, and specialist referral centers, to participate in the prospective validation studies needed to answer these questions. If you are a veterinary professional with relevant clinical experience, we invite your engagement.
| Sensor | Hardware | Sample Rate | Derived Outputs |
|---|---|---|---|
| Radar, physiological | Acconeer A121 (60 GHz) | Every 10s | Respiration rate, heart rate, micro-tremor index |
| Movement, primary | LSM6DSV16X IMU (U1) | Every 1s | Gait symmetry, activity level, head-bob, morning stiffness, restlessness, postural transitions |
| Movement, vibration channel | LSM6DSV16X (U10), isolated SPI | High-rate | Fine vibration signatures, physiological features in development |
| Vocalization (×2 microphones) | SPH0641LU4H-1 (MK1 & MK2) | Every 2s | Vocalization rate, panting rate, coughing rate, vocal intensity |
| Temperature | TMP117 (U2) | Every 2s | Surface temperature deviation from individual baseline |
| GPS, planned | Not in v1 hardware | Roaming radius, daily distance, planned for future updates |
| Parameter | Value | Purpose |
|---|---|---|
| Behavioral sub-score weight | 0.40 | Composite score |
| Mobility sub-score weight | 0.35 | Composite score |
| Cardiorespiratory sub-score weight | 0.25 | Composite score |
| Acute floor, 1 flag | 55 | Acute pathway |
| Acute floor, 2+ flags | 75 | Acute pathway |
| EWMA alpha: short-term (24h) | 0.30 | Baseline update |
| EWMA alpha: medium-term (7d) | 0.10 | Baseline update |
| EWMA alpha: long-term (30d) | 0.03 | Baseline update |
| PPI Green threshold | < 0.30 | PPI tier |
| PPI Amber threshold | 0.30, 0.65 | PPI tier |
| PPI Red threshold | ≥ 0.66 | PPI tier |
| Baseline maturity (full confidence) | 14 days | Confidence scoring |
| Minimum confidence floor | 0.10 | Confidence clamp |
CBPI (Canine Brief Pain Inventory): A validated owner-reported clinical pain scale for dogs, producing a Pain Severity Score and a Pain Interference Score on a 0, 10 scale.
CMPS-SF (Glasgow Composite Measure Pain Scale Short Form): A validated clinician-administered acute pain scale for dogs with an intervention threshold at a score of 6 or above.
EWMA (Exponentially Weighted Moving Average): A statistical method for updating a running average that gives more weight to recent observations, used to maintain rolling baselines for each sensor metric.
HRV (Heart Rate Variability): The variation in time between successive heartbeats, measured as RMSSD. Lower HRV is associated with pain, stress, and autonomic nervous system activation.
ILBE (Individualized Longitudinal Baseline Engine): Tether's core detection system, which builds and maintains a behavioral baseline model specific to each individual dog.
IVDD (Intervertebral Disc Disease): A common canine spinal condition involving disc herniation, particularly prevalent in chondrodystrophic breeds.
Micro-tremor index: A measure of fine involuntary muscle oscillations detected by the 60 GHz radar, associated with pain-induced muscle guarding and neuromuscular conditions.
PPI (Pain Probability Index): The composite output of the ILBE scoring engine, expressed as a value from 0 to 1 and classified into three tiers: Green, Amber, and Red.
SOAP (Subjective, Objective, Assessment, Plan): A standard format for clinical documentation in veterinary and human medicine.
TMP117: Texas Instruments digital temperature sensor (0.1°C accuracy class) used in The Ruff to measure surface temperature through a gold-plated thermal path in the collar enclosure.
1. International Association for the Study of Pain Task Force on Taxonomy. In: Merskey H, Bogduk N, eds. Classification of Pain. 2nd ed. Seattle: IASP Press, 1994:209, 214.
2. Merck Veterinary Manual. Recognition and Assessment of Pain in Animals. Reviewed/Revised March 2023.
3. Walsh S. Understanding the link between canine pain and problem behaviours. Veterinary Ireland Journal. February 2025.
4. Mills DS, Demontigny-Bedard I, Gruen M, et al. Pain and Problem Behavior in Cats and Dogs. Animals (Basel). 2020;10(2):318.
5. Barcelos A-M, Mills DS, Zulch H. Clinical indicators of occult musculoskeletal pain in aggressive dogs. Veterinary Record. 2015;176(18):465.
6. Mills D, Zulch H. Veterinary assessment of behavior cases in cats and dogs. In Practice. 2023;45:444-458.
7. Landsberg G, Hunthausen W, Ackerman L. Behavior problems of the dog and cat. Vet Clin Small Anim Pract. 2013;43(5):975-1003.
8. Cornell Richard P. Riney Canine Health Center. Cohen A. Recognizing Pain in Dogs. vet.cornell.edu. Updated October 2025.
9. Mota-Rojas D et al. Current Advances in Assessment of Dog's Emotions, Facial Expressions, and Their Use for Clinical Recognition of Pain. Animals. 2021;11(11):3334.
10. Demirtas A et al. Dog owners' recognition of pain-related behavioral changes in their dogs. Journal of Veterinary Behavior. 2023;62:12-17.
11. American Animal Hospital Association. AAHA 2022 Pain Management Guidelines for Dogs and Cats. aaha.org.
12. Caddiell RM et al. Pain sensitivity differs between dog breeds but not in the way veterinarians believe. Frontiers in Pain Research. 2023;4:1165340.
13. Brown DC et al. The use of the Canine Brief Pain Inventory to characterize osteoarthritis-associated chronic pain in dogs. J Vet Intern Med. 2007;21(2):248-255.
14. Reid J et al. Development of the short-form Glasgow Composite Measure Pain Scale (CMPS-SF). Vet Anaesth Analg. 2007;34(2):97-104.
15. Downing R, Della Rocca G. Pain in Pets: Beyond Physiology. Animals (Basel). 2023;13(3):355.
16. Gibbons J. Petflation 2026, March Update: All Pet Prices Reach Record Highs. Pet Business Professor. April 20, 2026.
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