Certain capitalization rules, such as the capitalization of animal names, in English can sometimes confuse native and non-native speakers alike. Spell check programs may help but should not be trusted entirely. Working knowledge of capitalization rules can be more helpful.
The proper capitalization of animal names will depend on if the name is categorized as a regular common noun or a proper noun. A regular common noun will not be capitalized, whereas a proper noun will be capitalized.
As a refresher, a common noun refers to a generic person, place or thing within a group. In this way, you wouldn't capitalize nouns like teacher, student, city, or country. On the other hand, a proper noun refers to a unique person, place or thing. Using the same examples, you would capitalize proper nouns like Mrs. Smith, Jerry, Los Angeles, and Mexico.
When it comes to the capitalization of animal names, the difference can be tricky. The name of your pet would be capitalized, just as the name of a human would be: Fido, Snowball, or Rover. However, the category of animal generally would not be capitalized, like dog, cat, or horse. Those are always written in lower case, because they are a variety of species within that category of noun.
Similarly, "Garfield the cat" is capitalized as such, because "Garfield" is a proper noun and "cat" is a common noun. However, "Felix the Cat" is capitalized as such, because "Felix the Cat" is the character's actual name.
Individual species, breeds or varieties within a category follow the same capitalization rules surrounding proper nouns and common nouns. The part of the breed that is derived from a proper noun is capitalized, whereas a part derived from a common noun is not. That's why "German shepherd" should have a capital "G" for German, but a lowercase "s" for shepherd. The rules would be similar for a French bulldog and English foxhound, but lowercase for a cocker spaniel or golden retriever.
That being said, common usage has led to the capitalization of all terms within a breed's name: German Shepherd, French Bulldog, and English Foxhound. This goes against official standards, like those described by the MLA Style Center (Modern Language Association).
Another type of animal name that should be capitalized is the scientific name of a species. However, not all parts of the name will be capitalized. The International Code of Zoological Nomenclature breaks the scientific classification of animals into:
In this case, the generic name should be capitalized but not any other word in the name. For example, a dog would be Canis familiaris, a cat is Felis catus, and a horse is Equus caballus. Because these are considered Latin names, they follow Latin capitalization rules.