Grouchy Dog

Dog in question is a neutered Great Dane, who will turn 4 this year. His
mom runs a petsitting facility from home, and he as well as his Dane brother

Mary Healey...

months, he has become grouchy towards

have both been okay with all dogs. Generally, they tend to be submissive,
rolling over for new dogs, and otherwise not challenging. In the past few
months, he has become grouchy towards the other dogs, even ones he's known
for a while. He's generally become non-playful, grouchy towards dogs that
approach him, and occassionally aggressive towards a new dog or even ones
that are minding their own business and playing together.

Mary Healey...

When something similar affected Sam, it seemed to be alleviated by
glucosamine/chondroitin supplementation. Sam wasn't sore enough to be in
obvious pain, but the grouchiness towards other dogs disappeared when he
got a daily dose of Liquid Health K-9 Glucosamine (I think it used to be
"Level 100" or some such). I tried the "Level 5000" because it was more
concentrated, but it didn't work as well.

http://www.liquidhealthinc.com/prodInterior.php?prodID=6

NFI, YMMV, and all that. Dogs may respond differently to the various
formulations / varieties of glucosamine, MSM, chondroitin available.

He has had a recent blood test within the last month, and is normal as far
as energy level, appetite, behavior around people, etc. goes. He has been
more clingy than normal, and is seeking out pets when other dogs are being
petted, which is unusual for him. In the last year, he had been bratty
towards her kids, and rank reduction by the loss of couch privileges seems
to have worked. Every time he earned his bed/couch privilege back (3x) ,
his brattiness towards the kids resurfaced, so he's lost it for good, for
about a year. The visiting dogs as well as the other resident dog are
allowed on the furniture, and this appears to be a selling point for the
dogsitting business, so banishing all dogs from furniture probably won't
work.

Mom has made sure that she spends alone time with her dogs and that the dogs
have a place to get away if they want to. According to her, he has become
mopey, and she's not sure what to do to make him happy again.