Hi Jaime,

I have experience with wild animals haematology, but mainly with mammals, reptiles and birds. For me, seems that you are dealing with viral inclusions.

See images attached (They are available in the book "Infectious diseases and pathology of reptiles" - Jacobson E, 2007, CRC Press).

Kind regards

Carolina

I regret to "ask" for pointing me by arrows to a location of    "light blue vacuoles/granules"    within the images uploaded by Jaime. By no means convincing.

As of his information, he is looking into drained, peripheral blood (?) from Cane Toads = Rhinella marina (former Bufo marinus) for "detection of parasites (protozoa....)".

RBC's of that toad are nucleated and as of my understanding are these "light blue vacuoles/granules" which are seen in the uploaded micrographs (and their color excellently compatible with GIEMSA Staining). 

So I can see no vacuoles, no parasites, no virus inclusions proper  (anticipating that the big, pale textures -kind of balloons) are the erythrocytes (unfortunately no scale bar attached to the images).

Sources:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3507160/ (CR Tracy et al, ‎2012 find in text/Methods: centrifugation of nucleated erythrocytes) 

https://www.ncbi.nlm.nih.gov/pubmed/11510993 (2001)

https://micro.magnet.fsu.edu/primer/techniques/phasegallery/frogblood.html

http://www.gettyimages.at/detail/foto/frog-blood-nucleated-red-blood-cells-250x-at-35mm-stock-fotografie/139820139

http://www.gettyimages.at/detail/foto/leopard-frog-blood-showing-nucleated-red-blood-cells-stock-fotografie/106452702

http://www.gettyimages.at/detail/foto/microscopic-image-at-100x-of-frog-blood-cells-stock-fotografie/575142975

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0018871

https://pdfs.semanticscholar.org/6f8e/d375e3571386ae59f0230b30f97209a2ccc5.pdf =  http://jcb.rupress.org/content/jcb/20/3/521.full.pdf  (O'Brien 1964) 

https://researchonline.jcu.edu.au/24098/2/02whole.pdf (Thesis, 1995:   p. 176: "Amphibian red blood cells are nucleated and largerelative to other vertebrates" )

https://link.springer.com/article/10.1007/s004360100414

@Jaime Manzano Alvarez:

hola, dear Jaime, you're welcome. 

I gladly should appreciate your information on the procedure of blood collection, and further protocol(s), especially naturally the reference/bibiographic data/"recipe" of your Giemsa stain. If you have doubts on my trustworthiness or seriousness:  I am no competitor (any more), just only interested to provide and relay knowledge to others (I know: sometimes my knowledge fails / could fail too...(;-)(  ).

So willingly I am learning / want to learn - also from my colleagues out there - at hard work.... (if you won't /don't want to send an  information publicly in this thread -e. g. by adding/attaching a .doc or a .pdf - you naturally feel free to communicate by the RG-messaging system as well as by private e-mail to [email protected]. Thank you!