Below are some excerpts from Pets: a paper ©1859 by Edgerton Leigh I'm posting this because it will help those of us who write historical fiction realize pets are not new to society and to see how having pets was viewed during the mid 19th century.
The love of Pets is one of the flowers of civilization, a feeling either openly apparent or lying dormant until warmed into existence by circumstances, like the fire hid in the cold steel till it comes in contact with the flint. Many may carry this affection too far, but on the whole there is something humanizing in a Pet, which makes the heart open to the genial warmth of kindness, like the rose bud expanding its long folded leaves when kissed by the sunbeam. The word Pet is derived by some from the French word " petit," and there are similar words in Italian, Irish, Dutch, and even Persian, meaning bosom friend, idol, dear, &c. I would rather derive it from the Latin petere, to seek, as one of the characteristics (I may say one of the unamiabilities) of Pets is continually to be looking out and seeking for something for themselves. The derivation from the French "petit" may justly be preferred by others, as in many languages "diminutives" (as they are called) are peculiarly in use for fondling purposes. The French word " enfantiller, to talk affectionate nonsense to a child," is a very expressive instance of this. The other meaning of Pet is ill-temper, easily traceable to the unhappy effect of spoiling the Pet, which, whether human or animal, we are all too much inclined to do.
I shall not touch upon human Pets further than to recommend that no affectionate mamma (if she only values her own peace) should ever run the risk of deserving the toast proposed by an irritated old bachelor, upon the ladies and a batch of spoilt children leaving the dining room, viz.,
" The immortal memory of the good King Herod."
Gratitude sometimes causes the adoption of a Pet. A dog that has saved your own or child's life, or, as in the case of Lord Forbes's dog, which discovered that the castle was on fire and saved the inmates, has a right to be regarded during the rest of its life with care, gratitude, and affection. We hear of a Turkish Emperor who rewarded a horse which had carried him safely through danger by giving him a marble stable, an ivory manger, a rack of silver, shoeing him with gold, settling on him estates, appointing servants to wait on him, &c. The horror of solitude, whether natural or compulsory, is one of the greatest inducements to drive men to endeavour to relieve themselves from the monotonous oppression of the eternal self, by striving to gain the affection and extract sympathy from anything possessing life. We hear of prisoners taming the sparrows that twittered on the bars of their cell, and striking up friendship of a most ardent nature with a stray rat or mouse; and we have, I have no doubt, all felt indignant at the conduct of the heartless jailor who, to intensify misery, killed the spider, the sole friend and consolation of some political prisoner sentenced to a life imprisonment. We may many of us have read with interest the account of the pleasures, pains, hopes and fears that a chance-sown seedling, springing up between the flags of his small exercising court, gave to the poor creature cut off by prison from all communication with the outer world. He called the plant Picciola (poor little thing), and the story of the captive's flower expands into a volume.
The author goes on to name various types of pets: dogs, horse, guinea pigs, rabbits, tortoise (10k are sold in London a year), green frog, snake, hedgehog, monkeys (apparently out of date), birds of various types, squirrels, and cats to name a few the author lists.
If you'd like to read the entire paper you can at Google Books
Another book written during the 19th century that might give you further insight is History of My Pets by Grace Greenwood, also located at google books.
Later in the 19th century "Our Home Pets How to Keep Them Well and Happy" was written in 1895 by Olive Thorne Miller.