Hi again and thanks for the additional information. It is helpful.
A dog adopts a hunched back appearance for a few different reasons including abdominal pain and disc issues. Some breeds like dachshunds, chihuahuas, terriers, etc are more prone to disc issues than other breeds so you might investigate this if she is also avoiding stairs and jumping as well.
There are several causes for abdominal pain such as pancreatitis, extreme gas and swallowed foreign objects or issues from items such pig's ear, rawhide boens, etc
Pancreatitis is an inflammation of the pancreas. The pancreas is a gland that produces and releases enzymes into the digestive track that aid in the digestion of food. When these same enzymes are activated while they are still in the pancreas, inflammation occurs and the enzyme start "digesting" the pancreas itself. Some common causes of pancreatitis are eating a lot of very fatty foods, obesity, steroid use and other diseases and conditions. Symptoms of pancreatitis vary but include vomiting, diarrhea, anorexia, weakness or collapse, dehydration, shock, fever, depression, and upper abdominal pain. A dog may indicate abdominal pain by acting restless, panting, crying or wincing when picked up, shaking, standing with an arched back, or lying with the front end down and the rear end elevated. You can read about it in detail here:
Now she is at the right age to be going into heat. A female in heat for the first time sometimes does have difficult heat cycles and it can seem like they are very uncomfortable. You can let your female curl up with a warm water bottle or warm towel on her belly. Many dogs in heat exhibit behavioral changes and cry but the crying is due to the urge to mate and not being able to. So if her vulva is swollen or starting to swell, she may be experiencing her first heat cycle and is uncomfortable.
If she has eaten a non food item or pig ear/rawhide item, it might be causing pain in the gastrointestinal tract. If she stops eating, starts vomiting or has a lot of diarrhea or unable to defecate, you will want to have her seen to rule out an obstruction.
Now check her rectum as well. Swelling around the rectal area can cause anal gland issues and if they are swollen a dog might walk a little weird. So you might investigate that possibility as well. The anal glands are 2 sacs on either side of the anus at about the 4' o'clock and 8 o'clock positions. If your dog is continually licking their anus and dragging it, it could also indicate that they are full. This problem can usually be resolved by emptying out the glands. To empty them or express them, you will want to cover the area with a tissue and press your finger on the dog's anal glands with an upward motion. A foul smelling liquid should come out. If nothing comes out and your dog appears to be in pain, you should take him to the Vet. Your vet can do this easily, as he is experienced at it.
Excellent site on anal glands
Hopefully it is just her coming into heat and not something more serious.
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