Animal Welfare Professionals

Most people know that it is recommended to vaccinate only healthy animals. There are several definitions as to what is considered “healthy” or to what degree is “unhealthy”. I am trying to convince the cat coordinator of our shelter why it is a bad idea to vaccinate sick TNR'd cats with RCP that appear to be unwell or present with URI at the time of surgery.    Unfortunately, most community cats arrive at the shelter with parasitic infections, are often malnourished, and stressed.  They are vaccinated for rabies (required), distemper, given selamectin and treated with antibiotics for any infections (some cats could be sick and we don't know it yet and they are not treated with any antibiotics). Upon returning to their colony, I have personally noticed that many cats’ clinical signs become more severe if they originally presented with a URI and they received the RCP vaccine.    Also, if a cat is not healthy their immune system most likely will not be able to build the proper antibodies necessary to fight the disease after being vaccinated.   Could you please provide me with your opinion or any documentation indicating why it is not always recommended to vaccinate unhealthy cats?    Thank you!
#CommunityCatManagement

Hope this helps:

"Some of the factors that negatively affect an individual animal’s ability to respond to vaccination include interference from maternally derived antibodies (MDA), congenital or acquired immunodeficiency, concurrent disease or infection, inadequate nutrition, immunosuppressive medications, chronic stress and an aging immune response."https://journals.sagepub.com/doi/pdf/10.1177/1098612X13500429

Zoetis (vaccine manufacturer) also states: "Vaccinating a sick animal is not going to help and in fact is not advised. A healthy pet and healthy immune system is required in order to build these protective antibodies in response to a vaccine."

The situation you describe is actually a challenging one, as there doesn't appear to be a lot of definitive "evidence" to support an always vaccinate vs. an absolutely don't vaccinate position. I think common sense needs must prevail, as it appears that vaccinating a sick animal may very well compromise the efficacy of the vaccine.

#CommunityCatManagement

Attached is a vaccination guideline for shelters from the ASPCA which you might find helpful. In a shelter setting it is always recommended to vaccinate at intake even if they are experiencing mild URI. It would be different in a home setting where you are not exposed to other cats or a variety of cats who might be shedding virus.

With our TNR/SNR program here in Jacksonville, FL we also vaccinate cats with mild URI if they are otherwise healthy enough for surgery. It is unlikely you're going to get your hands on these cats again so if they are healthy enough for surgery they should receive their vaccines. In our program we recorded a lot of data on each cat including general health status, weight and body score. We found that less than 1% were too sick, ill or injured to be returned to their outdoor home. We've had over 30,000 cats come through this program since 2008 and this doesn't include all of the TNR cats that also come through the clinic from the general public. Best Friends Animal Society also did a study that included over 100,000 community cats with the same results. Your comment that most of the cats you see are infested with parasites and malnourished is not what we found to be true. 

#CommunityCatManagement

I think your mention of vaccinating with a "mild" URI is an important point to note. More significantly compromised animals are a tough call, even in a shelter setting.

#CommunityCatManagement