Head lice are one of the most common parasites in humans, but they are not exclusive to us, they can also appear on our pets or wild animals, causing a lot of itching and, in some cases, certain pathologies and diseases.
In this article on our site we will talk about the life cycle of lice solving doubts such as “how long does a louse live? " or "How long does it take for a louse to lay nits?"
Characteristics and types of lice
Lice are small insects, less than one centimeter in length. They have hemimetabolousmetamorphosis, that is, since they hatch they look very similar to the adult. They are ectoparasites of mammals and birds.
There are two types of lice, the chewers (suborder mallopahga) and the suckers (suborder anoplura). They all have a flattened body, six legs that end in claws with a diameter according to the hair of the species they parasitize, and a pair of antennae. Sucking lice have heads smaller than the thorax and mouthparts with which they pierce and suck blood from their hosts. Chewing lice have broad heads and strong jaws for chewing. The eyes are greatly reduced or absent in both groups. The entire body of the lice is covered by setae or setae (sensitive skin structures).
sucking lice are obligate hematophagous ectoparasites (feed on blood) of placental mammals. Chewing lice have a more diverse diet, from blood to hair, feathers, or fur from mammals or birds. They can only go without eating for 2 days
Biological cycle of lice
Each species of louse has a specific but very similar life cycle among them with respect to breeding times, life expectancy and way of life. Thus, female louse stick their eggs or nits on the hairs of mammals. These eggs have a different shape depending on the species, but they shine when the light hits them and are easy to spot, even easier than the adults. Lice eggs remain permanently attached to the hair and spend several days gestating. After about 7 days of gestation, the first nymph hatches from the egg. This will go through two morenymph stages, each lasting between 2 and 8 days, depending on the species and the environmental conditions. After each nymph stage, a moult occurs. We can distinguish a nymph from an adult because it will have fewer setae, its body is not as sclerotized (hardened), and it will be smaller
An adult louse can live for around 30 days if it doesn't die first from other causes, such as grooming or other reasons. So every 45 days a completely new generation appears, thus restarting the lice life cycle.
How long does it take for a louse to lay nits?
Mating occurs when the lice have reached the adult stage, approximately two weeks after hatching the egg At that time, the male enters under the female and bends his abdomen upwards to initiate copulation. A single louse can reproduce more than 10 times a day
Is it possible to spread lice from cats and dogs to humans?
Head lice infestation is known as pediculosis Each species of lice normally infects only one group of animals. For example, dogs are infested by two different species of lice, Trichodectes canis (biting lice) and Linognathus setosus (sucking lice), while cats are only infested by one species (Felicola subrostratus, sucking lice). Humans times three, all suckers: (Pediculus humanus capitis, Pediculus humanus humanus and Pthirus pubis), for this reason, we cannot get feline or canine lice, nor are they affected by our lice.
The diagnosis of pediculosis is made by taking samples of the animal's skin and hair using adhesive tape. Sometimes they can be seen with the naked eye. Infection occurs when two animals, one he althy and the other with pediculosis, come into direct contact. For more information, don't miss these articles: "Lice in dogs" and "Lice in cats".
Lice are not difficult parasites to eradicate from our pets. There are several chemical and natural solutions on the market for its control, but you must observe that it attacks both lice and nits, otherwise there will be no nits without lice and the lice's life cycle will begin again. Although it is best to go to your veterinarian, as he can show you the most effective methods to fight lice and the different ways to prevent them, since they can transmit other diseases our pets or cause anemia, lack of appetite or skin damage.
Diseases transmitted by lice
The most common disease transmitted by lice is rickettsiosis, specifically type epidemic typhusand is produced by the bacterium Rickettsia rickettsii.
Illness begins with headaches and fever, continues with vomiting, loss of appetite, abdominal pain, or photophobia, and ends with severe respiratory failure, jaundice, and central nervous system involvement, which is often the cause of the illness. death and that, without treatment, occurs two weeks after infection. It is a zoonosis, so it can be infected to humans, not by a louse (because each species infests a group of animals, as we said) but by fleas or ticks. For more details, don't miss the article "Rickettsia in dogs - Symptoms and treatment".
