Welcome to JustAnswer! I am a licensed veterinarian and would be glad to help!
For a constipation such as this I usually recommend a temporary diet change. One option is to add fiber to the diet. Fiber is not absorbed by the intestinal tract and passes to the colon where it contributes to the stool volume. The result is a more bulky stool which provides stronger sensory stimulation to the colon than a regular stool. Fiber may be added to the regular diet in the form of:- Canned pumpkin- Bran cereal- MetamucilYou can add 1 tablespoons of any of the above options to the food twice daily.Another option is to try an over the counter hairball product such as Laxatone - products such as this or similar to this usually are petroleum based and will allow for easier passage for the feces.
If he will not eat and you can not do the diet changes, you may want to try oral remedies such mineral oil. This can be purchased at your local pharmacy. You can give 3ml by mouth every 12 hours in an attempt to relieve the discomfort.I hope this information helps!_____________________________________________________________________Please click "ACCEPT" if the information I have provided has been of help so I receive credit for my work. Bonuses are always welcome and appreciated. Thank you.The above is given for information only. Although I am a licensed veterinarian, I cannot legally prescribe medicines or diagnose your pet's condition without performing a physical exam. If you have concerns about your pet I would highly advise contacting your regular veterinarian
If this is all related to constipation, that is not serious.
If you think the lethargy and breathing changes are very severe (something that is very hard for me to evaluated over the computer) than she may need emergency care at your family veterinarian or the local ER if your vet is not open for evaluation and treatment.
While I understand your concern - if your dog is distressed, a veterinarian is going to recommend veterinary evaluation.
If you have tried at home care and it is not working and you are worried about severe discomfort - veterinary evaluation would be best!