Working our way down the horse, next up is the breast collar. There are several styles and we will discuss a good fit as well as the best collar to use with the different vehicles.
The Straight Breast Collar
The straight style of breast collar is most commonly seen in the show ring. Show harnesses are often made to be as fine as possible to better show off the horse. The straight breast collar works for this type of driving because you are in a groomed, level show ring without hills and lumps and bumps. The collar fit will still be important.
You don’t want the collar to press on the bundle of nerves at the point of shoulder. So it needs to be high enough to miss that and low enough to not interfere with the wind pipe.

This style of breast collar is only appropriate to use with a horizontal line of draft. This is when the single tree is above the hocks of the horse.
It’s important to use a neck connector strap with this style of breast collar. This will help distribute the weight from the top of the neck strap to the saddle.
The Deluxe Breast Collar
This style of breast collar is my favorite for miniature horses or those types of horses that have a low neck set. If their neck ties in low on their chest the Deluxe style breast collar has a deep V shape that allows the collar to clear the point of shoulder and leaves room for the wind pipe.

The photo collage below shows this style of breast collar properly adjusted, then adjusted too low and then too high.
It can take some adjusting to get things just right!
With this style of breast collar you need to use a neck connector strap AND a martingale. The neck connector strap will help distribute the weight from the top of the neck strap to the saddle.
The martingale will keep the v part of the collar in the middle and balanced. You can see the martingale in the front shot photo above.
This style of breast collar should be used with a horizontal line of draft.
The SuperFlex Collar
The SuperFlex collar is similar to the Eurostyle collar. People love this collar for marathon driving. You still need to work with the adjustments when fitting this collar. It will easily clear the point of shoulder but can push up into the wind pipe if it’s not fitted correctly.
To measure for this collar you will need two carpenter squares or a collar measuring tool. Then measure exactly as you would measure for a collar and hames. I made a video showing how to measure:
When using this collar you will want to use a martingale but NOT a neck connector strap. The neck connector strap causes the top of the collar to tip and with this style of collar we want that part to lay flat.
One of the fun things about the SuperFlex collar is that it comes in COLORS!
This collar is most appropriate for a horizontal line of draft just as the other two above. All three of these collar are soft so when used with a low line of draft they tend to literally fold up. The bottom of the collar will press up into the wind pipe while the top of the collar presses down on the top of the horse’s neck. At times all the weight from the vehicle can be on that neck strap if the line of draft isn’t correct.
Collar and Hames
Okay now we are going to get into the interesting stuff!!! Breast collars were designed with a certain line of draft in mind. When using your typical breast collar, as shown above, you need to have a line of draft that goes from the breast collar relatively straight back to the front of the cart – with the single tree in line behind the horses rear end.
If you are using a cart that has a low line of draft, with the single tree below the horse’s hocks, then you need to use a different collar, the collar and hames. There is a reason they use these collars for hard working horses that are dragging logs, farm machinery, harrows, and/or fore carts. The collar and hames helps the horse manage the lower line of draft by allowing the horse to pull from the chest and shoulders and NOT the neck strap. When you use a regular collar for a low line of draft most of the weight from behind (the weight of you and your vehicle) ends up on that neck strap. Just flip through some photos online and you’ll see the pressure that ends up on that neck strap!
I set up an experiment with my mare Sky using a breast collar and a low line of draft versus the collar and hames with the low line of draft. It’s absolutely astounding how much weight ends up in that neck strap when driving with the low line of draft.
You can see how hard it is for my mare to pull the sled with the wrong breast collar. Then when I switch to the collar and hames she can pull so much easier.
When we sled in the winter time she wears her collar and hames! If I ever had a vehicle with a low line of draft my minis and ponies would wear a collar and hames.

This was very informative! I am going to go back and look at my pictures as I have a low line of draft on my favorite carts. Also I just started using a gullet strap for safety and need to add my martingale strap. I am doing most of the other fitting advice you gave but found a few holes in my fitting. Thanks for all the info!