"Eternal Home Again" Microchips



"Professional" microchip insertion at a clinic

 Microchip ID has been widely touted for use in recovery of lost pets and facilitating returns to owner. Since our pets can’t give a phone number or address when they are lost, no doubt microchips can be very advantageous. I choose to have my dogs microchipped.



However, the State of California wishes to remove that choice from us. Los Angeles already has a mandatory microchip law on the books, enacted based on promises from the “Found Animals Foundation” to provide the city with millions of dollars worth of microchips. Shelters in many areas routinely microchip animals prior to adoption. And now the legislature is advancing a bill (SB 702) which mandates microchipping of all animals released from shelters. The owner or prospective owner would have no choice in the matter.

Since the cost of the microchip will be borne by the owner, this will probably result in higher adoption/impound fees. For at least some pets, this will reduce the chances of being adopted or reclaimed.


A microchip can be a wonderful tool, but they are not without pitfalls. There have been rare instances of microchip insertion resulting in illness and death. Dogs have bled to death after insertion and suffered from infecton at the insertion site. Some have had the chip inserted improperly into muscle tissue or even the spinal canal, and there are even instances of lethal cancer formation at microchip sites. (See articles linked below). Chips can migrate in the body or fail, rendering them useless. Microchips also vary considerably by manufacturer and there is no universal scanner at this time.


Other forms of identification such as tattoos or tags can be immediately read by anyone who finds a stray dog, allowing rapid return to owner and reducing the burden on local shelters. Animal welfare groups such as AKC and OFA consider tattoos to be an acceptable form of permanent ID. Freeze branding is also an option worth considering.


Information on a microchip may not always be updated upon transfer of ownership. If there is increased reliance on microchip without another form of ID, the result may be the death of a beloved pet who could have survived with the use of a more visible form of ID.

Animals who are stolen will most likely never be scanned, rendering a microchip uselss in such situations. The thief can even have the microchip surgically removed. This is another instance where a more visible form of ID like a tattoo might be more useful than a microchip.


In regard to microchipping, the American Veterinary Medical association states on their website:

"As with almost anything, it's not a foolproof system. Although it's very rare, microchips can fail and become unable to be detected by a scanner. Problems with the scanners are also not common, but can occur. Human error, such as improper scanning technique or incomplete scanning of an animal, can also lead to failure to detect a microchip. Some of the animal-related factors that can make it difficult to detect a microchip include the following: animals that won't stay still or struggle too much while being scanned; the presence of long, matted hair at or near the microchip implantation site; and a metal collar (or a collar with a lot of metal on it). All of these can interfere with the scanning and detection of the microchip."


The AVMA further states on this same page:


"It looks like a simple-enough procedure to implant a microchip – after all, it's just like giving an injection, right? Well, yes and no. Although it looks like a simple injection, it is very important that the microchip is implanted properly. Using too much force, placing the needle too deeply, or placing it in the wrong location can not only make it difficult to detect or read the microchip in the future, but it can also cause life-threatening problems. Microchips should really be implanted under supervision by a veterinarian, because veterinarians know where the microchips should be placed, know how to place them, and know how to recognize the signs of a problem and treat one if it occurs."


Yet, in Rebecca May’s bill analysis for SB 702 from July 8, there are reassuring statements made regarding microchip safety. Ms. May asserts "The material is inert and biocompatible, thereby there is no health risk to the animal from the insertion of the microchip. Also, implanting the device is similar to that of a vaccination, resulting in minimal pain for the animal - and can be implanted by veterinary techs and other personnel."



The statement that "there is no health risk to the animal from the insertion of the microchip" is patently false. And the AVMA seems to feel that veterinarians should be there to at least supervise the insertion, in light of the complications that may occur.


Here are two documented cases of the microchip being implanted in the spinal canal. One is dated 2009 and the other case is dated 2010.


Who is responsible if the microchip is placed in the spinal canal? Will it now be the State?

Case 1:


http://www.ncbi.nlm.nih.gov/pubmed/19151873

Vet Comp Orthop Traumatol. 2009;22(1):63-5.

Surgical removal of a microchip from a puppy's spinal canal.


"A 1.6 kg, six-week-old Tibetan Terrier was admitted with a 12-hours
history of acute onset of progressive tetraparesis following insertion of
a microchip to the dorsal cervical region. Neurological examination
indicated a lesion to the Ce(1) to Ce(5) spinal cord segments.
Radiographic examination confirmed the intra-spinal location of a
microchip foreign body at the level of the second cervical vertebra.
Microchip removal was achieved following dorsal hemi-laminectomy;
significant intra-operative haemorrhage was encountered. The puppy was
ambulatory at day seven. Follow-up telephone interview 18 months
postoperatively confirmed that the patient had made a good recovery
although it had a mild residual right- sided torticollis."



Case 2:



http://www.ncbi.nlm.nih.gov/pubmed/20422127

Vet Comp Orthop Traumatol. 2010;23(3):213-7. Epub 2010 Apr 26.


Delayed spinal cord injury following microchip placement in a dog.

"A three-year-old female, entire Yorkshire Terrier dog was examined because 
it had progressive non-weight-bearing left forelimb lameness and
tetraparesis of two weeks duration. Clinical signs were first observed
following mating. Examination confirmed non-weight-bearing left forelimb
lameness and tetraparesis. Left forelimb muscle atrophy was also noticed.
Survey radiography revealed a metallic foreign body consistent with a
microchip in close proximity to the left articular facets between the
fifth and sixth cervical vertebrae. Computed tomography identified the
exact location of the foreign body encroaching on the left dorsolateral
vertebral canal, and osteolysis of the lamina of the sixth cervical
vertebra. Surgical removal of the foreign body was performed via a dorsal
approach to the caudal cervical vertebral column. Two weeks following
surgery the dog showed return of left forelimb function and resolving
tetraparesis. Microchip implantation had been performed three years
previously."

Risks from microchips are rare, but problems do occur. Microchip insertion should be a personal choice and an individual decision, based upon weighing the risk vs benefit. Such a procedure should not be mandated by the state.

For further information: 

"Implants Linked to Animal Tumors"
Todd Lewan, A.P.
September 8, 2007
http://www.washingtonpost.com/wp-dyn/content/article/2007/09/08/AR2007090800997_pf.html


"Chipped Pets Develop Fast-Growing, Lethal Tumors
http://www.antichips.com/press-releases/chipped-pets.html


The Scientific Evidence
http://www.chipmenot.org/scientificevidence.htm


Case Histories
http://www.chipmenot.org/casehistories.htm


CASPIAN Releases Microchip Cancer Report
http://www.chroniclewatch.com/2011/05/18/caspian-releases-microchip-cancer-report/