"brusing" on belly

Our boy dog had surgery 2 years ago on his knee. I noticed "brusing" on his belly and the vet said it was from the knee surgery. When I wouldn't take that as an answer he took blood and told me that it was a tick illness (put on meds for 2 wks) and that he would always have the discoloring. Now our most recent dog (german shepard mix had for little over year and a 1/2) started having them about 3 wks ago. Took her to the vet and he said it was a german shepard zinc deficiency. No blood was taken from her. It looks to be the same discoloring on each of them. What is wrong? I think it may be more than a coincidence that they both have it. They are 4 years old. Please Help.

I'd be at a different vet.  Bruising on the stomach when there has been no trauma can be a HUGE indiator of auto-immune blood disease like thrombocytopenia (where the body attacks the platets and the dog may be bleeding internally.  The FIRST thing the vet should do is bloodwork. 

 Tick disease is almost **never** "cure" in 2 weeks.  It often requires a long long time on antibiotics. 

I'd be at a different vet.  This is most suspicious.

For me, I'd get the second opinion.

To add to what Callie said, my dog had Lyme disease which could have triggered the thrombocytopenia.  I'd definately get a CBC blood test done to make sure.  It was a huge ordeal for my dog lasting 5 months.  So, you want to catch it early if it is.

My first thot was that you need a different vet.  The current one seems less than thorough.

 I second what Orange said. This sounds to me like a vet who doesn't know (at least in the case of the first dog) and is guessing. One question, what breed is the first dog? Is it close enough to a Shepherd that the same diagnosis might apply, i.e. zinc deficiency? But yes, take both dogs to another vet. And I would add, don't go back to that one.

  Hi Dottie and welcome to the forum; I agree with the other posters that you should look for a different vet. We've been with our current vet for about six years, but he was the third vet I took Jessie to. Sometimes it takes awhile to find a good vet, but it's worth the trouble.

   Do your dogs have allergies? This summer has been brutal for both people and dogs with allergies, and last month Jessie was scratching her sides. The scratching caused some small red marks, about the size of a nickel, on her abdomen. I keep Jessie's nails short; if they weren't trimmed, the marks would have been worse.

he is a lab/chow mix

I'll be making an appointment (at a different vet) tomorrow for both of them to be looked at.

Good for you -- pretty please let us know what happens??