04/21/2025
Myth-busting Monday: Canine Connection LLC breaks down the comparison between TENS units and E-Collars (often compared to TENS units.). Spoiler alert - they aren’t the same.
ARE SHOCK COLLARS (E-COLLARS) COMPARABLE TO TENS UNITS?
The use of electronic collars (e-collars) in dog training and Transcutaneous Electrical Nerve Stimulation (TENS) units for medical purposes may appear superficially similar due to their use of electrical stimulation. However, they are fundamentally different in purpose, design, electrical parameters, and physiological impact. Following is a comparison supported by scientific references.
1. Purpose and Design Differences
TENS units are designed for pain relief and muscle stimulation in humans. They work by stimulating sensory nerves to block pain signals or increase endorphin production.
E-collars are designed for behavior modification in dogs, typically using aversive stimuli to suppress or redirect undesired behaviors. Although some trainers use them at low levels for attention-getting or communication, their primary mechanism remains aversive.
References:
Johnson, M. I., & Paley, C. A. (2021). "How does transcutaneous electrical nerve stimulation (TENS) work? A narrative review." Pain, 162(3), e41–e56.
China, L., Mills, D. S., & Cooper, J. J. (2020). "Immediate and long-term effects of an electronic training collar (e-collar) on the behavior of dogs in a controlled training environment." Frontiers in Veterinary Science, 7, 508.
2. Electrical Parameters (Intensity, Frequency, Duration)
TENS units typically operate at low voltage (10–50 V) and low-frequency (1–200 Hz), with adjustable pulse duration. They are designed to avoid discomfort and provide therapeutic effects.
E-collars can deliver much higher voltages (up to 1500 V or more) in very short pulses. High-end models allow for fine control, but cheaper or older models often lack precision. Even low-level stimulation is designed to be uncomfortable enough to alter behavior.
References:
Johnson, M. I., & Paley, C. A. (2021). "How does transcutaneous electrical nerve stimulation (TENS) work? A narrative review." Pain, 162(3), e41–e56.
Vieira de Castro, A. C., Barrett, J., de Sousa, L., & Mills, D. S. (2020). "Electronic training devices: Can they be used for training and is there evidence for welfare concerns?" Journal of Veterinary Behavior, 37, 25–34.
3. Nerve Fiber Activation
TENS units selectively stimulate Aβ fibers, which are large-diameter, myelinated fibers responsible for non-painful sensations like touch and pressure. These fibers play a key role in inhibiting pain signals by outcompeting nociceptive signals in the spinal cord (Gate Control Theory).
High-frequency (50–100 Hz), low-intensity TENS selectively activates Aβ fibers, producing a comfortable paresthesia without activating pain pathways.
Low-frequency (1–5 Hz), high-intensity TENS may recruit Aδ fibers, leading to endogenous opioid release and modulation of pain at spinal and supraspinal levels.
E-collars, depending on the intensity used, can activate Aδ fibers (small-diameter, thinly myelinated) and C fibers (unmyelinated). These fibers are responsible for transmitting sharp and dull pain, respectively, and their activation is associated with pain, stress, and emotional distress.
E-collars, even at low settings, have been shown to produce stress-related behaviors in dogs, such as lip licking, yawning, avoidance, and vocalization. These can indicate discomfort, confusion, or anxiety. Cortisol level increases and long-term emotional effects have also been documented.
References:
Johnson, M. I., & Paley, C. A. (2021). How does transcutaneous electrical nerve stimulation (TENS) work? A narrative review. Pain, 162(3), e41–e56.
China L, Mills DS and Cooper JJ (2020) Efficacy of Dog Training With and Without Remote Electronic Collars vs. a Focus on Positive Reinforcement. Front. Vet. Sci. 7:508.
4. Ethical Considerations and Regulations
TENS units are regulated medical devices, approved for use in pain management. Their effects are well-studied and generally positive.
Shock collars/e-collars are increasingly banned or restricted in many countries (e.g., Germany, Austria, the Netherlands, Wales, and parts of Australia) due to welfare concerns. Many veterinary and animal training and behavior organizations discourage or oppose their use.
References:
AVSAB (2021). "Position statement on humane dog training." https://avsab.org/resources/position-statements/
Masson, S., de la Vega, S., Gazzano, A., Mariti, C., Pereira, G. D. G., Halsberghe, C., Muser Leyvraz, A., McPeake, K., & Schoening, B. (2018). Electronic training devices: Discussion on the pros and cons of their use in dogs as a basis for the position statement of the European Society of Veterinary Clinical Ethology. Journal of Veterinary Behavior, 25, 71-75.
While both TENS units and e-collars use electrical stimulation, their design intentions, regulatory oversight, physiological impact, and ethical implications differ dramatically. The use of e-collars — even at low levels — can result in significant stress and welfare concerns in dogs and is not comparable in safety or purpose to the therapeutic use of TENS in humans.
Key Differences in Nerve Stimulation
TENS Unit
Nerve Types: Affects mainly Aβ fibers
Goal: Pain relief, sensory modulation
Perception: Tingling, mild pulsing (non-painful)
Output: Low-voltage, high-frequency (~1–200 Hz)
Control: User
Shock Collar
Nerve types: Pain (Aδ and C fibers), some motor
Goal: Behavioral deterrence through aversion
Perception: Pain, discomfort, or startle reaction
Output: High-voltage, short pulse, variable frequency
Control: Trainer
Summary
Both TENS units and shock collars stimulate nerves — but TENS targets non-painful sensory nerves for therapeutic reasons, while shock collars target pain pathways to create aversive stimuli to control behavior. The effects on the nervous system are not equivalent, and they are not interchangeable in terms of safety, function, or outcome.
Cindy Ludwig, M.A., B.S., R.N., KPA-CTP, CPDT-KA
Owner, Canine Connection LLC
Voted Best Springfield, Missouri Dog Trainer
Positive training solutions for today’s pet parent. 
