For cancer patients, pets have a positive effect on wellbeing that probably outweighs any risk even in immunocompromised patients, a new review suggests.
That’s probably just as well given the majority (63%) of Australian households report having a pet – mostly dogs (40%) and cats (30%) – and the increasing popularity of animal-assisted therapy, according to Mei Mei Chan and Dr Gonzalo Tapia Rico of the Department of Medical Oncology at the Royal Adelaide Hospital.
Their narrative review of the literature on human-pet interaction in the context of cancer found no significant relationship between pet ownership and the incidence of cancer overall.
The best and most recent data came from a 2016 observational study of 123,560 participants in the Women’s Health Initiative study.
There is also little evidence that zoonotic infections from dogs and cats are a risk to immunocompromised patients however the risk is not uniform.
“The pet species that pose the greatest zoonotic risk include amphibians, reptiles, exotic animals, rodents, and young poultry, known to be carriers of Salmonella which in patients at high risk (i.e. patients with haematological malignancies) may result in severe bacteraemia,” the study authors said.
“Although having pets is not a contraindication for high-risk individuals, it is essential to take additional precautions to reduce pathogen transmission.”
“Guidelines for pet contact in high-risk individuals exist although they are minimally evidence-based and largely focus on common sense practices such as washing hands after touching animals, avoiding pet-derived secretions and avoiding contact with ill pets.”
The authors said vets could play a part by screening animals in contact with cancer patients for common infections such as Salmonella, Campylobacter, Giardia, and Cryptosporidium spp.
Doctors should also advise their patients about avoiding potential opportunities for infection such as handling animal faeces or sleeping in the same bed.
The few studies on therapy dog programs in cancer patients have suggested they can help alleviate distress, normalise the hospital environment, and distract patients from pain, treatment toxicities or worry.
However guidelines on the use of animals in healthcare facilities was warranted especially for infection control purposes.
“On balance, we conclude that pets bring more benefits to the oncology areas explored in this review than potential negative effects.”