Again with cats aren’t small dogs. Oh, it’s so true, even bugs think so.

December 6, 2016

Day MJ. Cats are not small dogs: is there an immunological explanation for why cats are less affected by arthropod-borne disease than dogs? Parasit Vectors. 2016 Sep 20;9(1):507-515.

In this review article, Dr. Day from the University of Bristol, United Kingdom, explores possible reasons why cats, when compared to dogs, seem to be less affected by vector/arthropod-borne diseases and share fewer zoonotic pathogens with humans.

He points out that dogs were domesticated before cats, ~15,000 years ago compared to ~10,000 years ago, respectively.  It’s possible that the difference in length of time of domestication partly contributes to cats and humans having an estimated ~ 1/3 the number of shared pathogens as compared to dogs and humans.

Regarding the perception that arthropod-borne diseases affect cats less than dogs, it is often suggested that cats have some form of natural immunological resistance to the pathogens or their vectors.  Dr. Day first suggests that there may be some simple explanations for this perception.  Some simple explanations for the apparent lower prevalence of arthropod-borne diseases in cats compared to dogs may included:

1. There is less research and publications in cats because of less available funding for feline health research.
2. Cat owners spend less on preventive health care than their dog counterparts; thus, less veterinary attention leads to less diagnosis of arthropod-borne diseases.  Less veterinary preventive care is likely also due to difficulty in transporting cats to the clinic, and to cats’ relatively independent nature and being masters at hiding illness.
3. Cats’ lifestyle and behavior may also be reasons.  In many countries, cats are mostly indoor or only indoor pets and thus have a lower risk of arthropod vector exposure.  Also, cats can be fastidious groomers, and remove ectoparasites before disease transmission is possible.

Most of the review article is spent on discussing feline immunology; how it is similar and different from canine immunology.  The bottom line is: although the immune systems of both cats and dogs are similar in many ways, no single simple immunological model can summarize the difference in immune function between the two species when they are exposed to arthropods and the diseases they carry.  Feline immunology studies didn’t really start picking up until about 30 years ago, so much work is still required to better characterize the true prevalence and clinical significance of arthropod-borne diseases in the cats. [GO]

See also:
Pennisi MG. Leshmaniosis of companion animals in Europe: an update. Vet Parsitol. 015 Feb 28;208(1-2):35-47.