Just the obvious, even it and wait until it grows back.
Regarding the sheltie summer trim question, you aren't really supposed to trim their coats, the hair protects them from overheating and getting sunburns, is my understanding.
I have used undercoat rakes with great success on my shelties though, have you tried those?
I have used this one on Amazon. I use it after I bathe my dogs, once their coat is dry. The warm water is supposed to loosen the undercoat, so the undercoat rake will take more out. One year I swear I had enough fur to make another dog, and my female with the thickest coat looked like she lost 10 pounds after I finished. Of course it took an hour.
Fellow German shepherd owner here. Do not get a furninator brush. They cut the hair. Furninator products are okay. Get an undercoat rake like this I like the self cleaning slickers just because it can be a pain to clean.
I’m getting my girl on a regular schedule with the groomer and planning on taking her every 4-6 weeks for a bath and brush to help with the shedding. I was doing it myself and she did really good on that bathing schedule.
Make sure you spend a lot of time desensitizing them to getting their feet touched. If you’re not comfortable clipping their nails yourself you have the groomer do it at least once a month. You can use a nail file at home to help keep them rounded and smooth.
Baths and blow dries are honestly the most important and will do a lot more to deshed than a brush. I like this undercoat rake, though it’s a little controversial. It’s not as bad as a furminator but don’t use it too frequently or too much in one spot.
https://www.amazon.com/dp/B00061MWJ0/ref=cm_sw_r_cp_apa_glc_fabc_8WX0PQ0QS96KNDV7JGKB?_encoding=UTF8&psc=1 I have a Kuvasz and just got this brush and it's amazing! It gets so much undercoat out but doesn't feel like it's tearing out fur and he doesn't mind it all. I found it by searching for best great pyr brushes since there similar breeds. I use burt's bees conditioning spray too and that helps with mats around his help em up harness.
Coat King and a nice metal comb works great. Oster brand makes a good coat rake sold on amazon for a decent price Oster Dog Rake and Shedding Brush, 18-Tooth Coarse, Wide (078928-300-000) https://www.amazon.com/dp/B00061MWJ0/ref=cm_sw_r_cp_api_i_GNLBDbY3WNHMG
Well I'm in no way a dog expert hah. I would seek out any local trainers/behaviorist in your area. With the shedding problem though a good weekly run down with a rake would help tremendously. I use this one:
Oster Professional Pet Grooming Undercoat Rake, 18 Teeth Wide, Coarse https://www.amazon.com/dp/B00061MWJ0/ref=cm_sw_r_cp_awd_chUBwbKD1SYTC
It does an amazing job of pulling out the thick undercoat while leaving the top coat (the guard hairs) untouched. The thick undercoat is the culprit of all the masses of hair you see around the house, while the guard coat is very important to the dogs temperature regulation. You never want to shave, trim, or use a furminator on a double coated dog. It will do more harm than good.
As for the food aggression I would google some tips or seek out a professional. Sorry I couldn't be more help!
I use a Mars Coat King on my Pyr; this Oster undercoat rake is also good, it just doesn't have replaceable blades like the Coat King does. Undercoat rakes work really well to get out that undercoat while they're blowing it, without cutting the long top guard hair. I don't care for Furminators, which tend to have tines which are far too short to really get into a Pyrenees undercoat, and will instead pull and break the guard hair. You need to comb the rake with the direction of the coat, and it will help tremendously. It's what my mobile groomer guy uses on mine, and I keep one on hand to run through her coat about mid-way between grooming sessions.
Pin/Slicker brushes are sometimes not terribly effective on Pyr coats - some dogs have a super thick undercoat, and for those cases, a greyhound comb is usually a little better for a weekly brush session.
if the furminator isn't hurting him (by getting the outter coat) a rake isn't going to do much better (probably worse by volume).
if you are getting outer coat use something like http://smile.amazon.com/Oster-Professional-Grooming-Undercoat-Coarse/dp/B00061MWJ0/ref=sr_1_2?ie=UTF8&qid=1424232895&sr=8-2&keywords=fur+rake
there are cheaper ones out there but I can't vouch for quality so I choose one similar to the one my uncle (is a vet, owns clinic) owns at said clinic.
No worries, it's this one.
The difference is night and day. I made a short A/B comparison video between the two for you: https://www.youtube.com/watch?v=SGbdNySlfQk
Here is the rake on amazon: http://www.amazon.com/Oster-Professional-Grooming-Undercoat-Coarse/dp/B00061MWJ0
This shedding tool works great as well. https://www.amazon.com/dp/B00061MWJ0/ref=cm_sw_r_apan_glt_i_57MATP85PKZSJJH2DJ0Z
Try something like this for the undercoat and a long bristled slicker like this and a greyhound comb to check your work. Look up how to line brush as well
We use this one. Works great.
I have a German Shepherd and use this rake: Oster Dog Rake and Shedding Brush, 18-Tooth Coarse, Wide (078928-300-000) https://www.amazon.com/dp/B00061MWJ0/ref=cm_sw_r_cp_api_i_V2bJFbMGSPGAN
Are dematting rakes like this one (https://www.amazon.ca/dp/B00061MWJ0/ref=cm_sw_r_cp_apa_i_03awFbX3A7QS3) designed to actually cut the hair?
Something like this?
Oster Professional Pet Grooming Undercoat Rake, 18 Teeth Wide, Coarse https://www.amazon.com/dp/B00061MWJ0/ref=cm_sw_r_cp_apa_NezuybJYSQMCD
I use this.
https://www.amazon.ca/Oster-Professional-Grooming-Undercoat-Coarse/dp/B00061MWJ0
It works well. Plus a regular brush for finish and shine.
A large part of grooming is personal preference. They have outdoorsy coats that don't require frequent maintenance. Some Aussies coats are sort of water and dirt resistant (not to say they won't get dirty but rather it flakes off easily without your personal intervention).
I primarily focus on reducing the quantity of hair balls in my house. This take brush was suggested by a fellow member of this subreddit. Aside from that I trim the excess dirt between their paws and underneath it once in a blue moon. http://www.amazon.com/Oster-Professional-Grooming-Undercoat-Coarse/dp/B00061MWJ0 http://i.imgur.com/vnw0QJ2.jpg
Plenty of resources about this out there, so I'm not going into details, but you're not supposed to shave them.
http://ekcgrooming.com/2014/02/23/8-reasons-why-not-to-shave-your-dog/
Just buy this and run it through their coat once a week.
http://www.amazon.com/Oster-Professional-Grooming-Undercoat-Coarse/dp/B00061MWJ0