Infestations of Trichodectes canis most commonly occur among poorly nourished animals, but may also occasionally plague healthy individuals as well. The typical signs of the presence of these annoying pests are incessant itching and sleep loss. Rendering the insects an even greater nuisance is their ability to cause anemia and to act as an intermediate host for Dipylidium caninum, the common tapeworm that infects dogs and cats. Animals that are suffering from the presence of the parasitic lice can usually be successfully treated with two applications of an insecticidal shampoo. The second of these applications should be applied 14 days after the first in order to eradicate the lice that emerge from newly hatched eggs.