Thank you very much for your valuable question.
In my opinion, the important challenge may not be to address how dogs can smell the dog handlers, but how to change how the dogs are reacting when they are aware of the catchers. Most dog catchers have very high and aggressive energy when catching dogs. They have the predator energy of chasing and they see it as a fight to see who wins. It is hard for people to even imagine any other way.
The other way is to gather dogs with calmness and compassion. I teach that the crazier the dog gets the calmer we should be. Imagine catching a dog with a leash or net and at first there is a struggle. Imagine that when the dog stops struggling, it already finds the person calm and relaxed and not threatening at all. Imagine that while the dog is in the net, its head might be covered with a cloth and it actually has a feeling of being safe. This is possible.
During Project Vet Train in Ballabgarh, we caught many dogs, transported them to the animal welfare campus, released many dogs in an open room to train the handlers, used Y poles with the dogs and practiced physical restraint, hobbling, headcovers, and many other ways of moving and controlling dogs. We did this with the most compassion we could give. When we released the dogs back to their village, many dogs followed us for many miles. Yes, there were many dogs who barked and ran as soon as they saw us, but in many places after netting dogs we could walk past groups of dogs who were not caught and they would not run away or bark at us because they could feel a calm and caring attitude.
There will always be dogs who will be afraid of the animal handlers. But the handlers can work with calm and compassionate energy and attitudes. After netting a dog they can stop to put a cloth over its head and calm the animal. For dogs caught with a leash they can quickly show compassion and sincerely let the dog know that it is safe. With a quick leash wrap around the muzzle they can pick up the dog, relax themselves, and calm the dog. They can even cover the head as they carry it.
And for every dog they have caught and stopped to calm and give compassion, there are a dozen more dogs watching and learning. Whenever the handlers are catching dogs they are teaching many many more about who the handlers are as a person.
One dog handler who works for an ABC program in Sikkim is known for being able to catch every dog….but not right away. When he sees a dog who is barking at him while he is trying to catch dogs, he throws treats out each day and over time even that dog because less scared and will eventually be caught. His energy is calm and compassionate.
The purpose of ABC programs is to improve animal welfare and bring compassion to the animals (as well as to the people), but often the dog catching is not done with the same intention. I am sure you are teaching your staff to be as humane as possible, but maybe you can carry it a step further. Teach the dog handlers to become dog whispers, to speak the language of Dog, and to take pride in being the best in their community to interact with dogs. Create a day to honor the handlers. It is a very honorable thing.
I am an idealist, but I can assure you: If you teach your staff to be even more calm and compassionate, to give out treats, and to be aware that they teach other dogs when they work, fewer dogs will bark and react to their smell.