Hello, I'm Dr. Kara. I have over 20 years of experience as a veterinarian and I'd like to help with your concerns about Kora's yellow color to her eyes and gums (jaundice), dark urine color and little production and lethargy.
A white blood cell count points toward inflammation. If she is running a fever as well then that can indicate an infection. Given her dark urine and decreased urine production it is likely that she has an infection in her urinary tract, and as sick as she is a kidney infection (pyelonephritis) seems to be a possibility.
However pyelonephritis doesn't usually cause jaundice. Jaundice is caused by increased amounts of bilirubin in the blood and can be secondary to liver disease or red blood cell destruction in large numbers overwhelming the liver's ability to clear the pigments.
So I would be concerned about tick borne diseases which can affect multiple organ systems, lead to red cell destruction but I would also be concerned about a bacterial infection called leptospirosis which can affect the kidneys and liver.
Doxycycline is an excellent antibiotic for many tick borne diseases and is effective against leptospirosis as well but if she is vomiting it then it cannot be absorbed to help her. Unfortunately Doxycyline often causes nausea, especially when give on an empty stomach. She needs to be on intravenous fluids, injectable antibiotics, and antinausea drugs like Cerenia. My concern is that if she doesn't get help soon her organ damage could be irreversible.
If you absolutely cannot have her seen today then I would try to control her nausea as best you can and give lots of fluids.
To try and settle her stomach today you can try either:
1) Pepcid-ac (famotidine) at one 10mg tablet per 20 to 40 pounds of body weight
every 12 hours.
2) Prilosec (omeprazole) at one 10mg tablet per 20 to 40 pounds of body weight
every 24 hours.
These will reduce stomach acid and should help settle her stomach.
An hour after the acid reducer is given offer small amounts of water or ice cubes frequently as she needs fluids. You can give her pedialyte or low salt clear broths to replace electrolytes and fluids too.
I would not give her doxycycline today unless she stops vomiting and you can get her to eat.
Offer her a bland diet mix of 1/3 boiled hamburger (or white skinless chicken), all fats and juices drained off mixed with 2/3 boiled, plain white rice or plain boiled pasta. Feed several small meals a day. You can add low salt broths or warm water and warm it in the microwave to increase her fluid intake and improve its palatability.
If she eats well then you can restart her antibiotic.
Even if she eats well for you, but especially if she does not I would have her rechecked by her veterinarian in the morning given her worsening condition.
Please let me know if you have any further questions.