Flea Related Dermatitis
Directly and indirectly, the flea is probably the cause of more dermatological disorders in small animals than all other etiological agents together (Keep, 1983).
Concerning the pathogenic effect of flea infestation, differentiations between the direct consequences of a flea bite, the allergic reactions of the host and the effect of blood consumption by the fleas have to be made (Kalvelage and Münster, 1991).
On the one hand, there is flea bite dermatitis and on the other hand, there is flea bite hypersensitivity which according to Halliwell (1985), can also be defined as flea allergy dermatitis (FAD). Meanwhile further research and diagnostic techniques suggest that most of the cases of dermatitis without the presence of allergic hypersensitivity reaction do have hypersensitivities and that dermatitis without allergy is a rare phenomenon (Halliwell, 1983, 1986). Nevertheless several authors still differ between the two clinical situations of flea bite dermatitis and flea bite hypersensitivity (FAD).
Once the flea has found a host for the uptake of blood, a few test bites have to be performed until a blood leading capillary vessel has been found (Karandikar and Munshi, 1950). The direct contact with the host’s skin as well as these bites cause an irritation of the skin, pruritus and an insignificant, transient invasion of lymphocytes in the direct proximity of the biting site (Gothe, 1985). These local reactions are suggested to be principally similar in all hosts, whereas in the so far examined animal species differences exist concerning allergic reactions (Kalvelage and Münster, 1991).
- Gothe R: [Pathogenesis of arthropod infestations.] Berl Münch Tierärztl Wochenschr. 1985, 98, 274-9 [in German]
- Halliwell REW: Flea allergy dermatitis. In: Kirk RW (ed.): Current veterinary therapy VIII. Small animal practice. 1983, WB Saunders Co., Philadelphia, pp 496-499
- Halliwell REW: Flea allergy: Pathogenesis, therapy, and flea control. In: Proc Am An Hosp Assoc. 1985, 52nd Meeting, pp 145-149
- Halliwell REW: Managing canine flea allergy. Solvay Vet Dermatol Rep. 1986, 5, 7-8
- Kalvelage H, Münster M: [Ctenocephalides canis and Ctenocephalides felis infestation of dog and cat. Biology of the agent, epizootiology, pathogenesis, clinical signs, diagnosis and methods of control.] Tierärztl Praxis. 1991, 19, 200-6 [in German]
- Karandikar KR, Munshi DM: Life history and bionomics of the cat flea, Ctenocephalides felis felis (Bouché). J Bombay Nat His Soc. 1950, 49, 169-77
- Keep KM: Flea allergy dermatitis. New South Wales Vet Proc. 1983, 19, 24-7