Rage, for no reason

Actual phone call received by our hospital:

Caller: "I just gave my dog a handful of cat treats and now he's drooling. What should I do?"

Technician: "Well, what was the brand of treat? Has your dog vomited? How is he otherwise acting? And why did you give your dog a cat treat?"

Caller: "He vomited an hour after we gave it to him; and otherwise he appears a little less active than usual.  We just thought he would like the cat's treats......(gives us the brand name)."

Technician: "It's a product that's meant to be ingested, so it's highly unlikely to be toxic; if you're concerned, you're welcome to come in and have our doctor take a look. Somtimes, too many treats can cause GI upset, especially if he hasn't had them before.  Otherwise, you can monitor at home, and if the vomiting does not continue, you may not need to rush in."

Caller: "YOU DON"T F-ING CARE ABOUT ANIMALS! YOU JUST WANT TO PAD YOUR POCKETS!" (We could also hear a second voice in the background, swearing, yelling, and carrying on)

Technician: "I'm not sure why you're upset -I've tried to be as helpful as possible. I can't see your dog from here --  and we always recommend that if you're worried, come in and have an exam.  It may provide peace of mind.  If finances are a concern, you can watch your pet at home, or try CareCredit if you want to be seen."

Caller: Hangs up.

30 minutes later: (keep in mind the volume of calls we receive in a daily basis, and that there are multiple staff members answering the phones...)

Caller: <doesn't say hello, introduce himself, or offer any back-information>  "My dog is still drooling."

Tech 2: "I'm sorry, I don't know who you are - can you tell me what's going on with your pet? Is it a cat or a dog?"

Caller: Angrily repeats the story.  Throughout the story, interjects various comments about how we are "money grubbers" and "don't give a f- about animals" that we're committing "highway robbery" and that we're "just in this business to rape the f- out of people" like him.

 Yeah, buddy.  That's why we do this job.  We LOVE being verbally abused by you after giving telephone advice at ANY HOUR OF THE DAY for NO FEE. (Oh, wait, your daytime clinic isn't open? That's because it's TWO IN THE MORNING)

Tech 2: Gives similar advice as Tech1.  Second voice in the background is going CRAZY with rage. The caller hangs up again.

Repeat this process two more times, with increasing fury coming from the other side of the phone call.  Each time we picked up the phone, the caller expected that we'd know who they were based on voice recognition alone, and were mad at us when we didn't.  I'm not sure why they were so full of rage, especially given that we didn't charge them anything for the advice, we didn't demand that their pet be seen, and told them that we expected the ingestion to be non-toxic, but potentially irritating to the GI.....

People still confuse me.