I wonder they even know or understand the meaning of "rights" who tries to defend for animal rights.
Rights are ethical principles–principles that identify and empower man’s freedom of action in the social order. The authentic foundation of rights is man’s possession of a rational ability.
The capability to reason includes the option to focus consciously one’s intellect and to incorporate perceptual facts into conceptual knowledge.
The notion of human rights protects man’s liberty of action in the social order. It allows him to use to his own rational verdict to lead his life and well-being.
Rights are the power, which provides a man, to objectify is options regarding any issue. Just like right to vote, every right provides a man, to say Yes or No.
The set of rights protects the freedom of all by prohibiting the instigation of any sort of physical or mental force by one man or group of men against another person.
Children have rights because they are the developing form of adult with an increasing intellectual faculty to reason out and explain/express.
To express is a quality, which defines the rationale basis, hence helps in determining the rights and wrongs. The freedom of expression is a fundamental right, which helps in furtherance of liberty. As freedom of expression is one’s power, to safeguard and further his living and well-being, the press, the media and individual expressive liberty must be free of any corporeal force at any level.
Unless a person in coma is not fully brain-dead, he has proper set of rights, because of the likelihood of their gaining of the full-functional rational-faculty, concept of rights is futile when applied to living beings inept of reason.
Can animal rights have any moral ground?
A human must not cause harm to animals because they can feel pain and compassion is a virtuous concept, but it cannot be a basis of any moral or constitutional right. We cannot stop medical researchers from experimenting on animals on regards of any moral or legitimate right. We cannot and should not say that it will be morally illegal to experiment on an animal even though it may result in a cure of a deadly disease of human kind.
The attitude of human towards animals and other beings should be compassionate, but one must avoid creating debates over vegetarian or non-vegetarian habits of eating, or medical researches over animals.

taken from

Reason for Liberty