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Maples in the fall.


The Law in Canada has confirmed that pet owners must receive enough information to provide informed consent and that the content of that information must be similar to that received by patients in the field of human medicine before any consent they provide can be considered "informed." The noted Canadian lawyer, Doug Jack traced the history of "informed consent" in the 2009, DVM 360 magazine article entitled, "Another Primer on Informed Consent." In that article he outlined what must be disclosed to a pet owner as follows,


"The person obtaining the informed consent must disclose the following to the person giving the consent: 

1. The diagnosis or nature of the patient's ailment. 
2. The general nature of the proposed treatment and the purpose or reason for the treatment. 
3. The risks or dangers involved in the proposed treatment. 
4. The probability or prospects of success. 
5. Alternative treatments or procedures along with the risks associated with those alternatives. 
6. The prognosis or risk if no treatment or procedure is performed. 
7. In veterinary medicine, discussion of costs of the various alternative treatments.


He then went on to say, " Many "practice development" speakers and writers today advocate recommending to the client the highest level of treatment for any condition found in an animal presented for treatment. Such recommendations are justified as providing "quality medical care". Although such recommendations may increase the income of the practitioner, this practice does not provide the client with proper informed consent. A client cannot provide proper consent for a particular treatment when they have not been informed of alternative treatments, as well as the risks and probable outcomes of those alternative treatments."

Some Veterinary Regulatory bodies in Canada have codified policies on "informed consent" available for both the public and veterinarians to review, while others have not.


So what may be the consequences for pet owners and their animals if they are deprived of appropriate information before giving the go ahead for recommended tests and procedures?

a) Unnecessary or inappropriate tests and procedures may be performed. 

i) Some seemingly benign investigations for pets, such as blood work, can result in "overdiagnosis" on the basis of minor and often clinically insignificant results. If owners are not made aware of this fact and invasive tests such as CT or MRI scans are subsequently recommended to evaluate those initial "abnormal" results, the animal involved may suffer unwanted consequences, as these type of tests frequently involve the use of sedation or general anesthesia.


ii) If cancer is suspected, (it accounts for 50% of deaths in animals over the age of ten), the detection of its spread (metastases) beyond the primary site is a game changer for the prognosis of the animal concerned. The tests commonly used to discover cancers, beyond a primary site, include ultrasounds, lymph node aspirations, chest x-rays, CT and MRI scans. The commonest test used in veterinary medicine to detect lung metastases is a three view digital chest x-ray. Those x-rays have an 81% chance of detecting metastases compared to a CT scan of the chest and generally avoid the need for sedation or a general anesthetic. A chest x-ray costs around $150-200 compared to the $1500-2000 needed for a CT scan. Both a chest x-ray or a CT scan can provide a radiological diagnosis of cancer. Biopsies are needed to confirm a histological diagnosis but are only indicated if treatment will occur. If an animal is suspected of cancer or other serious conditions, the owner needs to be provided with information about the pros and cons of the relevant tests, staging or otherwise, before any investigations occur. Failure to provide such information, I suggest, is denying a pet owner proper informed consent and at least one Canadian Court of Appeal has agreed with this principle.     


b) Animals may be subjected to unnecessary side effects.

If an animal ends up having an investigation that needs a general anesthetic, because their owner was denied informed consent, then adverse effects, including death, can occur, especially in cats and other smaller CAs. The majority of anesthetic related deaths in CAs occur within seven days of receiving their anesthetic and not during the time the test or surgery was being done. Numerous factors increase the risks associated with general anesthetics and sedation in CAs and these include the pet's age, the urgency of the procedure, the general condition of the CA, the presence of anemia, the presence of metastases, the degree of procedural monitoring, the performance of a pre-anesthetic full physical and the taking of a complete pre-anesthetic history. Obviously, it is best to avoid these potential problems, however small, if a diagnosis can be obtained in another way that avoids a general anesthetic and pet owners need to be given these other options before proceeding. 

c) Owners may be subjected to unnecessary increased costs.

Owners may want the best for their animals but the "best" doesn't have to entail doing the most invasive or the most costly procedures to obtain a diagnosis. Numerous studies have shown that taking a detailed history and performing a complete physical can be the most useful thing a physician or a veterinarian can do for their patient. Once a provisional diagnosis is made on the basis of a detailed history, a full physical examination and basic laboratory work, it is imperative that the clinician explain to the owner what the most likely diagnosis is and what the likely prognosis for that diagnosis is, if confirmed. The veterinarian then needs to thoroughly discuss how to best clarify that diagnosis and whether in fact the owner evens wants that suspected diagnosis validated, before they recommend expensive and often invasive testing and procedures. All reasonable alternatives need to be discussed with the owner and not just the Gold Standard test the veterinarian may believe is in the best interest for the animal. This is especially relevant when dealing with geriatric animals with limited life expectancies. Without doing that, a veterinarian is depriving the owner of the ability to provide informed consent. The end result is that an animal may be subjected to inappropriate tests and procedures which may be far more expensive than needed and which may potentially harm the animal in question.


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