Thank you for the additional information.
I am very sorry to hear that she has been vomiting and has yellow gums at this time. Yellow gums and vomiting are suggestive of liver disease or a disorder that has affected her liver. Vomiting is also a common symptom of a liver disorder. Most of the chemicals that are sprayed on the grass are actually fairly safe for dogs and have been studied quite extensively. For a lab to develop a toxicity from a chemical on the grass, she would have needed to ingest quite a bit of the chemical or actually almost drank the chemical straight.
She still could have been poisoned by the chemical though this is unlikely. With dark urine and yellow gums, I would be concerned that she has a very high bilirubin level in her blood stream. The bilirubin level in her blood stream indicates that her liver is not functioning correctly or she could have a disorder where her red blood cells are being destroyed in her body. EIther one of these disorders can be quite serious therefore she really should be taken to a vet as soon as you can get her there. If you do have an emergency hospital nearby, it would be worth while to even consider taking her there tonight.
Possible liver diseases would be hepatitis, a blocked or inflamed gall bladder, an infection in her liver, or unfortunately cancer needs to be considered though this is not something I like to bring up. A blood panel would be recommended first to determine if her liver or her red blood cells are the main problem. If her liver does seem affected then your vet will most likely suggest an abdominal ultrasound of her liver to help narrow down the exact diagnosis.
Almost all of the above diseases can be treated with prescription medications and liver supplements.
At this time, I can understand that taking her to a vet right away is not always possible therefore if this is not possible, you can try some home care treatment. Honestly I do worry that this will not help though, but here are some suggestions to try with her.
I would try to use a oral syringe to give her some pedialyte or even some low sodium chicken
broth. You can give her about 5-10 cc every 30-60 minutes to try to rehydrate her. Giving her smaller amounts more frequently can help her keep some of the liquids down better
You can also give some pepcid AC to help with the stomach
discomfort. This is very safe and virtually has no side effects. I would give her 5 mg for every 25 pounds of weight every 24 hours. This medication usually comes in 10 mg per tablet. You can get this medication from a local drug or grocery store over the counter.
Activated charcoal can be given also since a toxicity is suspected. The dose is about 500 mg for every pound of weight therefore as you can tell she will need quite a bit to give the full dose. This can be given orally every 12 hours. You could always start with a lower dose first to see if she will hold the charcoal down.
If she starts to hold down liquids then you can feed her 8 hours after the last vomit. My recommendation would be to feed some boiled ground beef or boiled chicken breasts with cooked rice. Two parts rice to one part meat. Feed this until she is back to normal. This is very easy for her to digest and should help reduce inflammation in the stomach/intestines.
Overall if she cannot hold down liquids at all then she really should be taken to the vet as she will need fluids to prevent her from getting seriously dehydrated. She also sounds like her liver or red blood cells counts are serious affected which is causing her gums to be yellow therefore if possible definitely get her to a vet soon.
Hope this helps to answer your question - if not or if you have any more questions please feel free to reply by clicking on the "reply to" button. Thank you for your question!