You could try any of these:
1. Barberry Root
Generally speaking, barberry root is good for kidney problems. Dogs with bladder stones tend to demonstrate pain while urinating. For this issue, barberry root is the best home remedy. To use it, just add a teaspoon of barberry root in one cup of hot water. Let it steep for five minutes or so and then strain. It should be administered three times a day. For small dogs, give it in doses of one tablespoon each. Larger dogs require two tablespoons and three tablespoons for even bigger dogs.
2. Sarsaparilla root
Sarsaparilla root is great for dogs with smaller bladder stones. If you see that there's gravel in your dog's urine, then just prepare sarsaparilla root in the same way the barberry root is prepared. Just double the amount of herbs to be added to the cup of water.
Goldenseal is a popular herbal antibiotic that you can also give your pet. However, this one is only prescribed for dogs that are suffering from bladder infection rather than those that have mineral crystals present in the urine. Other than goldenseal, other herbal antiseptics such as Echinacea and pau d'arco are helpful as well.
4. Thalaspi Bursa Pastoris
Thalaspi Bursa Pastoris is the best first aid for dog suffering from urinary obstructions. Give one dose to your pet every 30 minutes or so until it can urinate again. This remedy is perfect for instances wherein you can't bring your dog to the vet given the circumstances.
Other than the ones listed above, you can also give aconite to your pet. Not only would it relieve the pain caused by the stones - it could also address the fear and distress that your dog suffers. Just a few doses of aconite could put your whining pet at bat.