Rectal itching is an expected symptom of candida die-off.
Rectal itching for a dog is almost always worms. That's easily checked, diagnosed and treated, though. It is possible your dog has an intestinal candida infection, however she would not be having die-off symptoms of rectal itching unless she is currently on an anti-fungal drug, which I'm guessing she's not.
To have such a strong positive blood sample for candida is fairly serious.
Candida species live happily in our intestines and metabolize vitamins for us. They bloom only when our normal gut flora is kicked out of whack. This can happen due to stress, extended use of Antibiotics
or the introduction into our gut of a nasty pathogen (bacterial or parasitic).
It is always a good idea to have an ova and parasite
test done on a stool sample to rule out an underlying parasite.
One of the problems with having an intestinal candida bloom is that it will not show up reliably in blood tests. It can be cultured from stool samples, but this says more about the ability to culture the sample than it does about what is really happening in the gut. The most reliable test is saliva antibody testing and that is not readily available in most labs (not the same as the saliva in a glass test). Which leaves most patients who have candida blooms using the anti-candida diet as the best measure of whether they do have a candida bloom or not (trial and error).
When it does show up in a blood sample, then that likely indicates an invasive or systemic fungal infection (IFI). What this means is that candida has now entered your system, rather than remaining in the gut. And IFI requires significant medical care.
Do your circulatory problems include low body temperature, cold hands and feet? If so, this may be more a sign that the adrenals are struggling to keep up with powering your immune system to fight what might be IFI.
I am not sure how you determine you have a swollen liver -- did this show up on a CT scan? If that's the case then that also indicates a body working too hard to fight off infection.
Interestingly, naturopathic and complementary doctors are much better suited to supporting the suppression of intestinal candida blooms than medical doctors. Most medical doctors do not 'believe' in intestinal candida blooms. In fact any organism that is part of our normal flora or seems to be harmless is categorized as comensal and therefore unable to produce illness in a human being. It's an easily debunked theory, but not one they will usually spend the time to listen to.
However, medical doctors *are* best suited to IFI. IFI is something a medical doctor does know because it happens to many HIV positive and AIDS patients as a result of their long term need of Antibiotics
I urge you to go to a medical doctor with your blood test result and discuss what will probably need to be more intervention with anti-fungals and closer monitoring of your progress.
Best wishes to you and your dog for health and comfort soon.