Low protein level?

My wife bought a 15 year old gelding about a month ago. He has a ridge that runs from his chest to his sheath area that is swollen. He also has diareaha. The vet said to worm him a few times in the next month and that horses that didnt get enough protein in there diet have this condition. He came from a lady who had him in a back yard with little to eat. He said good food and time will correct this condition. What do you all think?

I'm usualy of the mind that if one is paying for a Vet, that you should heed their advice.
But.......just going from the information in your post, this could be one of them occassions that getting a second (professional)opinion might be good.

Just from my own experience with feeding "rescue" horses.......

Buy some good feed.
I've come to like a 14% Protien/6% Fat (pelleted)feed a lot. And make certain that it has a good vitamin/mineral package blended-in.
You don't want anything that has visable oats or corn, as they are hard to digest and IMO, won't serve a usefull purpose at this point.
There's several feed-companies that make good feeds. Which-ever brand you choose, slowly work-up to whatever amount the bag recomends. I personaly do it in steps of 25% at a time, over the course of 2 weeks.
And make certain that he gets plenty of hay and CLEAN water.
You may also note that many horses can't tolerate Alfalfa hay. It'll give them diharea. You certainly don't want to chance that.
A mineral block is also a good thing to keep handy for him. Put it close to his water-source.
Try to divide his daily feed-ration into 3 servings. Two will do but 3X daily is best. Throw him a wafer of hay at the same time.

And yeah, DO de-worm the poor thing.

Give him a couple of days after the wormer and after he gets into his improved feeding program...... then locate a pile of manure and break-up a few pieces. If you see a LOT of un-digested hay in there, he MIGHT need a few doses of Probios, to restore the "good" bacteria in his digestive system.

Watch for cribbing. Rescue horses are often cribbers. If that is the case with your new guy, you'll need to address that also.

Hope this helps.
DGW

He has been on a senior feed like our old mare. He has a mineral and salt block. We thought at first that there was an infection from smegma around his penis and sheath, which we cleaned out. And he was on penicillan for about 4 days. We then called the vet. He told us about the signs of low protein, which he descibed our horse to a T. He acts fine. Eat and drinks good. What is this Probios? And what does it do?

I would definitely get a second opinion.

Probios is a probiotic that helps promote the good bacteria in a horse's gut, so they more properly digest food. It's a good idea to use after deworming or antibiotics. Some other good brands include Source and Fastrack. Most feed stores carry at least one of those brands.

What did you deworm him with and how much? What kind of hay is he getting and how much? How much of the senior feed is he getting? Did your vet float his teeth? Have the second vet look at his teeth,even if the first one floated or looked at them.

The way you decscibed your horse is kinds how my horse got this past summer..he got real ribby I didnt know what to do with him he was gettinh a half a coffee can of 10% All Grain feed!..We called the vet and got alot of opinions..Our weather was really bad this summer as it was.We were ina drought that was miserable we were behind 17inches in rain and our pasture was pick to the grown because there ws no grass grown in was almost all dirt! :(

We called the vet one more time to see and we movied him up to 14% Advantage Equine grain and he got alot better..He was gettin a Full coffee can of that! But now we have him down to A HALF a can of that

We had to cut back because he was gettin too PORKY!!

What kinds or brands of feed is sold around where you live?

Probios can be fed in either a treat an over feed dose or a gel.
http://www.probios.com/equine.htm

I feed the treats whenever we trailer just to keep their tummys in order.
You can get it thru Smartpak http://www.smartpakequine.com/
Or Dr's foster and smith http://www.drsfostersmith.com/product/shop.cfm?c=15498

Last time I got it Foster and Smith was the cheapest. Its really great stuff.

Next week we will have this horse for 2 months.He was on sweet feed for a short time. Now he is on a senior feed. He gets one coffee can in the morn. And in the eve. We had him on a few alfalfa cubes a day but stopped about 3 weeks ago. He was wormed with invermicen about 1 week ago. Before that 1/2 dose for a 700lbs. Horse of pyrental, 1 month ago. 2 weeks before that was invermicen. The first and last dose were for a 700 lbs. Horse, as it said on the plunger of the wormer. He has free access to grass hay, as does our mare. Plus two flakes a day of alfalfa/orchard grass mix. Now what. Around these parts of Indiana were I live, we only have one horse vet. Thank for your help.

I don't know what orchard grass is but I do know what Alfalfa hay is. Alfalfa is perty rich stuff and will sometimes cause diareha.
In fact, some horses can't tolerate it at all.
That may or may not be a factor in your particular horse but being's how he does have that condition and being's how he has been getting Alfalfa in one form or another since you've had him, you may want to stop giving it to him. At least untill he gets over his present troubles.
I'd also get him on some Probios (or something simular) for a couple of days. The type that I've used came in a big tube with a garduated plunger... very simular to how wormers are packaged.
It is nasty stuff though. My mare wouldn't take it right from the tube. She'd cough it back up and spit it on the ground. What I had to do instead was mix it into a half-cup of feed and stir-in some pancake syrup so's she would eat it.
Worked though.... a couple of days after her last dose, her stools were right back to normal.

Sorry I can't help with the other problem.
Personaly, I'd try the vet again.

DGW