Saturday, October 25, 2008

Post mortems: It's worth looking

Yesterday I attended an excellent seminar on conducting post mortems. These are extremely rare when it comes to animals, although they are a valuable source of information and can answer questions. I had some clients bring the body of their six-year-old cat in a few weeks ago. The cat had been perfectly normal, with no clinical signs or symptoms suggesting any illness, and was found deceased that day. Understandably they were incredibly distressed. I offered a post mortem (as a vet we can conduct a PM ourselves, looking for any gross or obvious signs of pathology, or we can send the body to a pathologist. We also take tissue samples for histopathology), but they declined on the grounds that it would not make a difference to the outcome of the cat. I appreciate that. But it is also good to have answers - if it happens to be something infectious or something that another animal household might be exposed to, a post mortem can be lifesaving. The seminar I attended yesterday gave a protocol for performing a full post mortem. This is critical in cases of suspect abuse or deliberate harm, which can end up in court, as well as deaths of unknown cause. I won't beat around the bush - to perform a full PM you need to be extremely thorough and open up all body cavities, but this can be done gently and respectfully. I've not yet performed a "full" post mortem -often the answer is very obvious when I open the abdominal or thoracic cavity. For example, I have discovered large tumours attached to abdominal organs. I performed a post mortem on my obese mouse after he passed away suddenly, and discovered a mass on the liver. I sent this off to a pathologist (which costs a few hundred dollars) and they diagnosed a hepatic lymphosarcoma). I'm glad I did it because it gave me closure.

Of course not every cause of death is obvious even on post mortem. I performed a post mortem on one of my guinea pigs who died with respiratory signs and there were no lesions on the lungs, nor could the pathologists identify anything out of the ordinary.

One of the useful things I learned about sample collecting is that the samples must be stored in formalin in a volume of 1:10 to achieve adequate fixation. While it is important to try to keep samples under 1cm thick, it doesn't matter as much if you follow the 1:10 rule.