Heartworm Life Cycles
April is Heartworm Awareness Month, so it's only fitting that we provide you with a little insight into the life of the heartworm. Heartworms start life as microfilariae (also known as L1 or baby heartworms). Mosquitoes pick up the microfilariae when they ingest blood from an infected animal. Inside the mosquito, the larvae molt twice until they are at the L3 stage. Upon puncturing the skin of an animal, the L3 migrate from the mosquito's mouth parts into the puncture wound. From there, they migrate through the animal's body with the goal of maturing at the heart. In the right host, the adult heartworms reproduce, and the female heartworms release microfilariae in the bloodstream.
Everyone (or at least everyone around here) knows that dogs are pretty susceptible to heartworms, but did you know that cats can get heartworms too?Heartworms are adapted to live in a dog but not so much in a cat. In cats, heartworms are usually unable to develop in the numbers necessary to successfully reproduce (they often have single sex infections or don't produce reproduce to a level that is detectable). Also, while heartworms primarily reside in a dog's heart, heartworms in a cat primarily live in the lungs.
We've posted some life cycles below so you can compare.
As Easter is fast approaching, many parents are probably thinking (or have already gotten) a baby rabbit for their kids. Here are some FYI facts about rabbits.
Oryctolagus cuniculus, also known as the European or common rabbit, is generally the species of rabbit people keep as pets. A rabbit's muscle mass is more than 50% of its body weight, with the skeleton only making up about 7-8%. They have a digestive system very similar to horses (both of which cannot vomit). Their jaws make about 120 movements a minute.
Males are called bucks, and females are called does. They are quite successful at reproducing. Baby rabbits are called kits. Do not disturb a mother and her newborns. She may end up cannibalizing the kits.
Behavior-wise, rabbits tend to be active and curious (and some can be escape artists). They move around by hopping and may stand on their hind legs sometimes. They tend to bolt or cower when frightened.
They can be messy...their feces (poop) are usually small round pellets. Their urine can be clear red or yellow or milky yellow (because they have a lot of minerals in their urine). They also produce another kind of feces, that their owners probably never see, called night feces. The rabbits eat this kind of feces to recycle protein, water, and B vitamins (appetizing, huh?).
Rabbits can be housed indoors or outdoors and can be trained to use a litter box. Where ever you house them, they need some type of hiding place so they can feel secure. They'll also need protection from predators and temperature extremes. If they get too hot, they will not increase their water intake, and they only sweat from their lips (they're pretty good at conserving water). When deprived of water, they also stop eating (one of the first signs of a sick rabbit is loss of appetite). They use their ears to help them cool off.
While rabbits can co-habit peacefully with other species (like Guinea pigs), it is not recommended because they can infect other animals (like Guinea pigs) with Bordetella bronchiseptica (one of the factors in the "kennel cough complex").
This information is from a lecture given by Lucy Senter, DVM at Missississippi State University College of Veterinary Medicine.
Animal Medical Clinic