We compared online discussion forum posts related to pet loss to those related to human bereavement. Posts ( N =  401) were analyzed using the Linguistic Inquiry and Word Count software for frequencies of word use relevant to bereavement. Words related to anger, sadness, and negative emotions were used at similar frequencies for all grief. Sibling loss was associated with using first person pronouns at higher frequencies, and positive emotion words at lower frequencies than other categories of loss. There were some similarities in partners and pets in the word use related to friends and social connectedness. Words related to religion were highest when writing about losing a child and lowest when losing a pet. Our results highlight the similarities in the vocabulary in pet and human bereavement. Findings demonstrate the importance of online discussion forums for understanding the process of grief and specific relationship types.