I can't explain "aut. libro". As you suggest, it appears to stand for "autor de(l) libro", but that doesn't fit the context at all. My best guess is that it's an error arising from the use of bibliographical software, which many academic authors use these days for their references. "[Aut. libro]" looks to me like a field name in a bibliographical database associated with this sort of software that has been captured and reproduced by mistake.

At any rate, in the example you've quoted we can deduce from the context that it simply means that the first part, Soga, D., y otros. "Die Beeinflussung der linksventrikulären...", is an article which constitutes a chapter in the book specified in the second part: M. Zindler, H. Yamamura y W. Wirth. Intravenöse Narkose mit Propanidid. Berlin : Springer, 1973. And this is confirmed by the following reference (See Inhaltsverzeichnis for the list of articles in the volume):
https://www.springer.com/de/book/9783540061724

In Spanish, you would just put "en" here, and in English, "in", like this:

Soga, D., et al., "Die Beeinflussung der linksventrikulären Myokardcontractilität und Hämodynamik durch Propanidid beim Hund", in M. Zindler, H. Yamamura & W. Wirth, Intravenöse Narkose mit Propanidid, Berlin: Springer, 1973, pp. 27–39.

The precise details (punctuation, etc.) need to be adapted to the style being used (Chicago, APA, or whatever), but that's the gist of it. In some systems you won't put anything here. But whatever the system, the article title should go in quotes and not in italic in English, and the book title should go in italic and not in QMs. And the page numbers in the book should be added at the end, by the way, as I have done here. One more point: I've corrected a typo in the article title; it should be Hämodynamik, not Hëmodynamik.


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Note added at 3 hrs (2019-05-21 09:26:04 GMT)
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(It's not quite true to say that the article/chapter title should go in quote marks, though it is true that it never goes in italic. You don't use quote marks in AMA style, which is standard in the biomedical field, and that might be relevant here, since it would commonly apply in veterinary science too. Basically when you're translating an academic article/paper for publication you should ideally try to find out which journal or publisher it's intended for and conform to the style they use, and if this is not possible, use one of the standard options, here AMA, APA or Chicago. To me this is all part of the service, which justifies the fee.)

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Note added at 3 hrs (2019-05-21 09:27:28 GMT)
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And Aida could be right that it's a typo for "art. libro". But in any case it shouldn't be translated literally.