Your Pet Cat May Be a Bit More Dangerous Than You Think

2 minute read
Originally posted here: https://mcgill.ca/oss/article/did-you-know-general-science/your-pet-cat-may-be-bit-more-dangerous-you-think

Cat scratch disease (CSD) is an infection resulting from a scratch or bite of a cat (or, in rarer cases, dogs or other animals). It is not the same thing as Cat Scratch Fever, an album by Ted Nugent, although CSD can cause a fever, as well as swollen lymph nodes, lethargy, neuroretinitis and headaches.

CSD is the result of an infection by Bartonella henselae, a bacterium commonly transmitted to cats via the cat flea (yes, cats and dogs usually have different fleas). Rarely, ticks and spiders can also carry the bacterium, and transmit it directly to humans.

Kittens are more likely to carry Bartonella henselae than adult cats due to their underdeveloped immune systems, and are much more likely to bite or scratch their owners while learning how to play gently. But anyone who is exposed to cats of any age should take care to clean any wounds well to avoid risk. Bartonella henselae can also be transmitted to humans via cats’ saliva, so as sweet as it may seem that Fluffy is licking your wounds for you, probably best to wash it and wear a Band-Aid.

For veterinarians, CSD is actually considered an occupational hazard. Vets are frequently in close proximity to many cats, oftentimes cats that are acting aggressively and are more likely to bite or scratch. One study found Bartonella DNA in 32 of the 114 veterinarian patients they tested.

CSD is diagnosed via blood test, or simply by considering the symptoms of the patient, the most obvious of which is a swollen blister or sore and red area surrounding the infected bite or cut. Those who are immunocompromised (such as patients with HIV), very young or very old are more likely to be infected, and rates of infection generally increase during spring in North America, likely due to the birth of many new kittens.

So while they may be as cute as anything, cats do still pose a risk to their owners, and not only because they may destroy your favourite furniture.

The kitty in the picture is named Jean-Charles and he is available for adoption from the Réseau Secours Animal in Monteal now!

Spaceships recycle everything… except astronaut’s poop

Originally posted here: https://mcgill.ca/oss/article/did-you-know-technology/spaceships-recycle-everything-except-astronauts-poop

Astronauts inhale oxygen and exhale carbon dioxide, just like you and me. On Earth, where exhaled air warmed by our bodies naturally rises away from us, the possibility of inhaling too much carbon dioxide isn’t usually a worry. But for astronauts, it’s a major one. Without the ventilator fans installed in shuttles and stations, carbon dioxide would accumulate around an astronaut. This is especially a concern at night,since we tend to stay still while sleeping. This would allow CO2 to collect and starve astronauts of oxygen.

So what happens to the carbon dioxide once it’s suckedaway by the fans? Like almost everything on a spacecraft, it’s recycled.

Carbon dioxide removed from the air by the aptly named ‘carbon dioxide removal system’ is combined with hydrogen (a byproduct of the oxygen generator system) to produce methane (which is vented into space) and water, which re-enters the oxygen generating system. This cycle allows astronauts to keep breathing, drinking and flying for long periods of time without having to lug to space all the oxygen they will need for the trip.

So what isn’t recycled onthe International Space Station? Human feces. But Mark Watney seems to have inspired a potential use for that

Rabbits Eat Their Own Poop

Originally posted here: https://mcgill.ca/oss/article/did-you-know/rabbits-eat-their-own-poop

Rabbits are foraging herbivores, eating mostly grass and weeds. But this fibrous, cellulose rich diet isn’t the easiest to digest, and by the time their dinner has make it through their intestines it still contains many of the nutrients the bunnies need. 

Rabbits and hares beat this problem with a special kind of digestion called hindgut fermentation. In short, they eat their own poop and digest it a second time. Bunnies actually make two different kinds of droppings: little black round ones and softer black ones known as cecotropes that are eaten. This process is known as coprophagy, and functions the same as cows chewing their cud.

It’s very important for a rabbit’s digestive system to keep moving fluidly, as they need to re-ingest their cecotropes in order to get the nutrients they need. If anything gets stuck in a bunny’s esophagus or intestines, they’re out of luck, since they’re incapable of vomiting.