Killed (inactivated) virus vaccines containing adjuvants, like those for the rabies virus (mercury), can trigger both immediate and delayed adverse vaccine reactions. These neurological effects can result in various clinical signs including muscular atrophy, inhibition or interruption of neuronal control of tissue and organ function, muscular excitation, uncoordination and weakness, as well as seizures, and unprovoked aggressive behavior. Post-vaccinal polyneuropathy is a recognized entity occasionally associated with the use of canine distemper and rabies vaccines, although any vaccine could presumably be implicated.Vaccinating dogs with polyvalent vaccines containing rabies virus or rabies vaccine alone can induce the production of anti-thyroglobulin autoantibodies, which has implications for the subsequent development of canine hypothyroidism.The investigators stated that their “study identified distinct similarities between canine fibrosarcomas from presumed injection sites and feline post-vaccinal fibrosarcomas, suggesting the possibility of the development of post-injection sarcomas not only in cats, but also in dogs.” Other cancers such as leukemia have also been associated with vaccines. Additionally, a more recent study from Italy reported similar tumors in dogs at vaccine injection sites.
In cats, aggressive tumors ( fibrosarcomas) can occasionally arise at the site of vaccination.Hepatic enzymes may be markedly elevated, and liver or kidney failure may occur by itself or accompany bone marrow suppression. Clinical signs associated with these reactions typically include fever, stiffness, sore joints, abdominal tenderness, susceptibility to infections, neurological disorders and encephalitis, collapse with auto-agglutinated red blood cells and icterus (immune-mediated hemolytic anemia, IMHA), or generalized petechiae and ecchymotic hemorrhages (immune-mediated thrombocytopenia, IMTP). These effects can occur within minutes to hours of vaccination they can also be biphasic and appear again in several days.ĭelayed vaccine reactions can occur anywhere between five to 45 days. Clinical signs can include rapid swelling of the eyelids, lips and face, itching, vomiting, weals and hives, and difficulty breathing. Immediate and short-termĪdverse effects occur immediately or can occur within several days, and manifest as anaphylaxis (allergic shock) or even death, although rapid intervention and therapy are usually successful. Reactions may be immediate or delayedĪdverse vaccinal events can be classified as immediate/short-term, or delayed/longer-term. In this article, we’ll look at vaccinosis in detail, and offer some tips for protecting your own dog or cat from this scary situation. This phenomenon is termed vaccinosis, and reactions can range from mild lethargy or a temporary loss of appetite, to severe conditions such as anaphylactic shock, ataxia, or even death. Defined as an adverse reaction to a shot, vaccinosis can affect dogs and cats in various ways, from mild to severe.ĭogs and cats sometimes react negatively to vaccination, just as we humans do.