Hello, I'm Dr. Kara. I have over 20 years of experience as a veterinarian and I'd like to help with your concerns about Buddy and your younger pup.
Because both dogs are affected and your older pup Buddy is so itchy I am highly suspicious of a contagious skin parasite behind their troubles.
Fleas and ticks are the most common skin parasites and fleas could certainly be behind what you are seeing as they can cause scabby sores and very itchy skin if a dog is allergic to the bites. If your pup has an allergic reaction to flea bite saliva then one bite a month is enough to make him scratch.
Here are some flea pictures:
Effective flea control includes using a good topical on all pets every 3 weeks such as Frontline Plus or Advantage II or Advantix. Treating the environment with a premise spray such as Siphotrol Plus especially along baseboards, under furniture and carpeted areas will kill off the population more quickly.
To control the itch use fatty acids and antihistamines in combination, which will work
synergistically, much better than either one alone.
You can try:
1)Benadryl (diphenhydramine only don't use the combination products with decongestants or acetaminophen as they can be toxic) at 1mg to 2mg per pound or one 25mg capsule per 25 pounds of dog orally every 8 hours.
OR 2)Claritin (loratidine) at 5mg per 25 pound dog once or twice daily.
OR 3)Hydroxyzine at 1mg per pound orally every 8 hours.
OR 4) Chlorpheniramine at 4mg to 8mg per dog once or twice daily.
Some dogs do better on one antihistamine rather than another. Give the one you pick a week to 10 day trial and if it isn't working try another. Be aware antihistamines can cause sleepiness or hyperactivity in some dogs. These side effects do wear off with repeated use.
Omega-3 fatty acids are fish oil products. 3V by DVM or Derm Caps ES are good brand name products. Use the high end of the dosing schedule for your pup's weight.
Clip the area around the raw spots very short and use a solution mix of Betadine solution and warm water, made to look like weak tea, and clean the affected areas twice daily. This is an antibacterial and will dry the lesions out to allow them to heal. It does stain horribly though so you probably want to do this outside.
There are other skin mites and I will list them here for you with pictures.
Cheyletiella also known as walking dander is fairly common too in some areas. It tends to congregate along the back and will often create increased scale from irritating the skin. The mites themselves are quite small, almost microscopic, but you may see white flecks moving in the coat. See pictures of the scale produced and a microscopic view of the mite below:
The only effective over the counter treatment for the cheyletiella mite is Lime Sulfur dips every 5 days for at least 3 treatments. You must also treat the environment with an effective area spray, like Siphotrol Plus spray as you would for fleas or the mite will be right back. Your veterinarian can prescribe either ivermectin or selamectin (Revolution) which is much easier to use and very effective.
Scabies mites are microscopic, they resemble cheyletiella mites but are a little smaller. They live under the skin so you won't see them, but you will see severely itchy skin, especially the ears, bottom of chest and elbows and hocks
There are no effective over the counter treatments for scabies mites so your pups must be seen by a veterinarian for proper therapy.
Demodex mites are also microscopic and they live deep in the hair follicles. They don't tend to cause much itchiness unless there is a secondary bacterial infection. We see them most commonly in dogs with poor immune system function, such as young puppies and older dogs with debilitating diseases or high levels of stress. Lesions are most common on the face and legs but can be seen anywhere on the body. They are not contagious mites but I include them to be complete. It is possible, though much less likely that both pups could develop demodex at the same time. If they are present then your pups would need prescription medication.
Lice are rarely seen on dogs but I include them to be complete.
There are sucking lice (Linognathus setosus ) and chewing lice (Trichodectes canis) and they both look very similar. They are only millimeters in length so you won't see them with the naked eye
Lice respond to effective flea control products, but they must be applied weekly for 2 to 3 treatments to catch the young as they hatch out. The environment needs to be treated as well.
In most dogs with the symptoms your pups have I would be most suspicious of fleas, or cheyletiella but sarcoptic mites are possible too, and these are contagious to you as well. Ideally your pups would be seen by a veterinarian to get things diagnosed and treated properly. You can try flea treatment first but if they aren't much better in 7 to 10 days I highly recommend an examination for them.
Please let me know if you have any further questions.