Hello, my name is***** and I have over 20 years of experience as a veterinarian. I am sorry to hear that Sally has labored breathing, large, irregular lumps on her throat and abdomen, is lethargic and refusing to eat.
I understand that her breathing changes and loss of appetite and lethargy were sudden changes but have the lumps come up suddenly too or have these slowly gotten larger?
Any fever (rectal temperature greater than 103F)?
Any history of ticks on her?
Does she have dental disease and/or gum disease?
There are a few structures in those areas that may be causing her problem.
The submandibular lymph nodes as well as salivary glands are on her throat.
Both can be swollen secondary to oral infections. Salivary glands can swell secondary to a blocked salivary gland duct.
The inguinal lymph nodes are located on the rear of her abdomen near her rear legs. Or it may be that she has mammary gland masses.
If she has swelling of her lymph nodes in multiple areas of her body then a systemic infection (like tick borne infections such as Lyme disease or Rocky Mountain Spotted Fever) is possible as well as a cancer called lymphoma. Here is a link to a picture depicting the location of a dog's lymph nodes which may help you to identify if her other lymph nodes are swollen:
With an infection I would expect her to run a fever (temperature more than 103.5F rectally), be eating poorly and be lethargic.
Dogs with lymphoma often seem fine until the disease is quite far along. If she has multiple large lymph nodes that may be the case with her now.
I doubt that an aspirin will be helpful for her now, and giving an aspirin to a dog that is already eating poorly may lead to gastric ulcers and could further suppress her appetite.
I highly recommend she see her veterinarian for an examination and aspirate of these swellings as well as testing for tick borne diseases. Lymphoma is a cancer that is responsive to chemotherapy, especially if caught early on, and if this is infection related she needs to get on antibiotics.
Please let me know if you have any further questions.