Check cbc, liver profile tests and kidney profile tests. Try giving syrup aptiquik for 7 days, 5 ml upto 20 kg bwt, check rectal temperature to rule out fever.

There can be an underlying infection or other non infectious causes so need more information better to book a consultation for the same

It nay be due to behavior issue or some infection. We need to check her before prescribing medications

Hi dear, Appetite loss is ur main concern about ur dog. (Here is my small video link on this topic- https://youtu.be/1Q3rnQapZME?si=c_vun3DH2L8XhGmM ) So, Loss of appetite and lethargy persisting for 11d is a matter that requires urgent vety attention, especially in a normally active breed like a Golden Retriever. While it's good that she is drinking water and occasionally eating eggs or dog biscuits, this pattern is not sustainabl especially for a dog her size (40 kg). Vaccinations given 12 d ago are unlikely to cause such prolonged symptoms, so it’s important we don’t overlook other potential cause,,such as GIT issues, infections, organ dysfunctionor pain. I strongly recomend a thorough clinical examination at the earliest. Blood tests, abdominal palpation, and possibly imaging (like X-ray orultrasound) may be needed to identify the root cause. Please don't delay any further — early diagnosis leads to better outcomes. Wishing her a speedy recovery, 🙏