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.

Foreign bodies

The last few weeks at work has been madness. We've done quite a few enterotomies which are always a challenge. This is a radiograph of a medium sized dog which had ingested a rubber bone (see arrows). She began vomiting. To cut a long story short we took her to surgery (you can see the enterotomy site) and removed the offending object (pictured). Another lesson in why choosing indestructible, dog-size appropriate toys is critical.

Cleaning wounds

If you are going to clean a pet's wound at home, please, please, please do not use phenol-based antiseptics (eg Dettol) as these cause a chemical burn locally - and orally when the animal licks them! The dog above presented for sore feet. It had been running on rocks covered in oyster shells, and its well-meaning owner's bathed the sore feet in Dettol - making them a lot more sore. If you use anything, a gentle saline solution is best (you can make it yourself or grab some from the chemist) or povidone-iodine (the most popular brand here is Betadine, its the stuff that goes on red and dries yellow). Don't apply any human creams or lotions from your first-aid kit. They may be non-toxic on humans but remember animals groom themselves. One of my colleagues had a cat who developed fatal toxicity after grooming anti-inflammatory ointment (diclofenac sodium) off itself. Different species metabolise drugs completely differently: remember that dogs, cats, rabbits, guinea pigs and the rest are not small humans (and thank goodness, really, how boring life would be if they were!).

Hair loss in guinea pigs

This one's for Soccergirl and any other fan of guinea pigs. Hair loss can be associated with a number of disease processes in guinea pigs. My major differentials would be ectoparasites (eg mites), dermatophytosis (aka ringworm) or dietary deficiency (guinea pigs, like humans, require exogenous vitamin C as they don't produce their own, and a diet deficient in vitamin C can lead to "scurvy"). My rule of thumb with a sick guinea pig is always supplement vitamin C. This is found in highest levels in fresh foods like parsley. One of my gps suffered from hair loss due to scurvy when I rescued him and I simply treated him with an excellent plane of nutrition: timothy hay, fresh pellets (the vitamin C content in dry food depletes over time) and fresh vegies (parsley, corn on the cob, bok choy, dutch carrots, beans etc). Aim to give 100mg/kg vitamin C until the condition resolves. My colleague David Vella (see link on this site) has a great gp care sheet which discusses dietary requirements.

Ringworm can be treated with medication but often washing in a medicated shampoo helps. Remember this is a "zoonotic" disease so can be transmitted to humans.

GPs are prone to mites (hay mites, sarcoptes or scabies mites and demodex mites) and these should be treated by a veterinarian as most products (at least here in Australia) are not registered for use in gps so all use is considered "off label" and determining the accurate dose can be tricky. Female gps may have symmetrical areas of alopaecia (hair loss) over their flanks if they have ovarian cysts - treatment involves ovariohysterectomy. Diffuse hair loss may be a sign of liver disease.

Barbering or fur-biting can occur where cage mates chew on each other.

Tip - Medicating Pets

One of my clients shared a very simple, obvious but cool tip for medicating animals (and hers is a very lovely but timid cat). When medication is dispensed for her guy, she puts a few dry biscuits (as in, dry cat biscuits - not Tim Tams) in the jar or bag with the pills, so the meds take up the scent of the biccies. I tried it and it works brilliantly for dogs and pretty well for cats. If anyone else has tips for medicating pets post away. Embedding tablets or capsules in cheese seems extremely popular but isn't always the best option as this may trigger abdominal pain, or vomiting and/or diarrhoea in some animals (esp those which are overweight or suffer from inflammatory bowel disease or pancreatitis).