Microchip side effects in a cat

A microchip is a small encoded piece of silicone that is implanted into the soft tissue of your pet's neck. It can be scanned by animal welfare organisations if your is found. In 2010, microchips in cats and dogs has become a common practice for pet owners.

While there are generally little to no side effects with microchips, a mild, short-term skin irritation and soreness can occur. Also, the more serious problem of fibrosarcoma can be a problem.

Reactions to the Procedure

The process of microchip placement is as simple and routine as a vaccination. A large needle is used to insert a silicone chip into the loose skin between a cat's shoulder blades. Most cats will have no reaction to this procedure, though a few may experience side effects similar to a vaccination injection. In rare cases, there may be a small amount of itchiness or tenderness at the injection site, but most cats will be unaffected. Since cats do not need to be sedated for this procedure, the recovery time is almost immediate.

Reactions to Placement

Early types of microchips had the propensity of sliding around in an animal's soft tissue once injected. Recent developments have led to the creation of a safer, more inert microchip that stays comfortably at the injection site. In most cases, the tissue surrounding the injection will grow around the chip, assuring that it will stay in place. Migration of the microchip is mostly a concern due to the possibility that it will not be scanned properly by animal welfare agencies. However, the migration of the chip can also cause discomfort and rejection in cats. Because microchips are now made of a biocompatible material, they are more likely to bond to the soft tissue and stay in place, preventing infection and rejection.


Fibrosarcoma is a rare cancer that can occur in a pet's soft tissue at any injection site. Due to their size and the types of vaccines they require, cats are more likely to develop injection-site-related fibrosarcoma than larger pets. Research has indicated that injection-site-related fibrosarcoma is linked mostly to the use of certain rabies and feline leukaemia vaccines, though the site of any injection can become a source of cancer. Most cats who develop fibrosarcoma have a genetic predisposition to cancer, and many vaccines have been corrected to allow for the lowest possible occurrence of cancer.