In T 19/90 (OJ 1990, 476) the board confirmed the general principle that the exception to patentability under Art. 53(b) EPC 1973 applies to certain categories of animals, but not to animals as such. In interpreting the term "animal varieties" the board emphasised the narrow interpretation to be given to the provisions of Art. 53(b) EPC 1973. It is not a bar to patentability for subject-matter which is not covered by any of the terms "animal varieties", "races animales" or "Tierarten".

Concerning the patentability of animals, it was held in T 315/03 (OJ 2006, 15) that, in an assessment under Art. 53(b) EPC 1973, the principle enunciated in G 1/98 (OJ 2000, 111) concerning plants and "plant varieties" should also be followed in the case of animals. This meant that a patent could not be granted for a single animal variety (or species or race, depending on which language text of the EPC 1973 was used) but could be granted if varieties might fall within the scope of its claims.

The bar on patenting under Art. 53(b) EPC 1973, first part of sentence, EPC 1973 did not extend to the products of a micro-biological process, which were patentable under Art. 53(b) EPC 1973, second part of sentence, EPC 1973. Thus patents were held to be grantable for animals produced by a microbiological process. However, particularly in cases of genetic manipulation of animals involving, as in the case at issue, the insertion of an activated oncogene, there are compelling reasons to consider the provisions of Art. 53(a) EPC when assessing patentability (T 19/90).

In T 315/03 the board did not agree with the assertion of some of the opponent appellants that the claimed transgenic mice were a new species because they inherited one particular characteristic, namely an increased probability of developing tumours. This was not enough to create a new species when the possible "starting material" might be any of a whole genus of animals, namely all mice. The board held that Art. 53(b) EPC 1973 did not exclude the patentability of the claims amended to encompass only mice and maintained the patent on that basis.