Which Types of Collars and Harnesses are Safe for Your Dog? by Dr. Sophia Yin is a fairly thorough look at your options. However, it addresses safety more than effectiveness; this is an issue where you will find more opinions than facts outside of the behavioral-research literature, so I think your best bet is to:
- weigh the pros and cons of each method,
- be honest about your own skills and experience, and
- consult a vet or professional trainer before embarking on a corrections-based training program.
Reasons to Avoid Choke Chains
There are a lot of reasons to avoid choke chains, but from a tooling perspective the main reason to avoid them is that they are difficult to use properly. Issues include:
- Improper fit, where the collar remains too tight at all times.
- Improper placement, resulting in a failure to release after a correction.
- Poor trainer timing, resulting in positive or negative punishment that reinforces the wrong behavior.
- An unlimited choke diameter, potentially resulting in nerve or tracheal damage.
When used correctly by a professional trainer, the P-shape of a choke is used to deliver a well-timed "leash pop" that should be informational rather than punitive. This is extremely hard to do, is almost never what happens with at-home training, and doesn't provide "control." There are simply better tools for this.
If you accept the need for aversive collars (not everyone does), then you might consider using a limited-choke collar that avoids the possibility of actual choking as a hazard. Options in this category include:
As one example, the Herm Sprenger Quick Release can't over-tighten if properly sized. While the collar certainly looks medieval, it is actually more humane than a choke collar. However, one can still use it improperly in a variety of ways, so please do additional research before choosing a prong collar.
Martingale or slip collars.
These are very similar to flat-buckle collars, but have a short chain section (or other material) that can provide a limited tightening when the live ring is pulled. This is most often used with dogs who can back out of a collar, or who might benefit from an extremely-limited tightening as a well-timed correction. In general, these collars don't provide "power steering," but are best used as safety tools for racing breeds or mild training tools for very soft dogs.
Head Guides and Harnesses
Other alternatives that provide feedback and control include:
Halti or Gentle Leader head collars.
Like any tool, improper use can cause damage. A good fit and gentle use will prevent eye damage, nasal damage, and neck damage, but should still be used with skill, care, and proper preparation.
This is another broad category, and includes harnesses that provide no control but a great deal of safety by distributing pressure across the chest, as well as other harnesses that are designed to give dogs tactile feedback through chest-mounted rings (e.g. the Har-Vest).
For optimal results I currently recommend clicker training, with or without no-reward markers. However, when safety is the primary consideration, head harnesses or prong collars might give you the extra control needed to keep you and your dog safe during walks.