Lnyxacarus radovskyi Tenorio, 1974
(Figure 5-34 through 5-35)
ETYMOLOGY: Lynx = for the host from which the first species in the genus was described and acarus for mite, along with radovskyi for Dr. Radovsky of the Bishop Museum, Honolulu, Hawaii.
SYNONYMS:Felistrophorusradovskyi (Tenorio, 1974) Fox, 1977.
HISTORY: The genus Lynxacarus was originally described by Radord (1951) for specimens collected from a Lynx in Georgia, USA. The species typically collected from cats was described as a new species by Tenorio (1974) using specimens that shee examined that had been collected from cats in Hawaii.
GEOGRAPHICAL DISTRIBUTION: Infestations with Lynxacarus radovskyi have been reported in cats from southern Texas (Craig et al, 1993); southern Florida (Greve and Gerrish, 1981), the Florida Keys (Foley, 1991), and Puerto Rico (Fox, 1977). The mite has also been reported from Hawaii (Tenorio, 1974); Fiji (Munro and Munro, 1979), and Australia (Bowman and Domrow, 1978).
LOCATION IN HOST: This hair-clasping mite is found clining to the hair of the cat (Fig. 5-34). The large eggs are attached to the hair of the cat. The larvae, nymphs, and adult are equipped with sternal plates that encirlce the hair, and the first two sets of legs “mopnorail” the mites along the hair shaft (Foley, 1991).
IDENTIFICATION: The tan mites which are less than 0.5 mm in length can be identified by their typical laterally compressed shape and by being found clinging to the hairs (Fig. 5-35). The male mites have greatly enlarged fourth pair of legs. The adult mites can be specifically identified as Lynxacarusradovski by the observation of the anteriorly directed bridge on the propodosomal plate that contacts the head plat of the mite which is lacking on the other species that has been reported from felines, Lynxacarusmorlani from the bobcat (Greve and Gerrish, 1981). The species that Lynxacarusradovskyi most resembles is Lynxacarusmustelae recovered from the least weasel (Mustelanivalis), and to be distinguished from this species, a careful examination of the shape and position of the dorsal plates must be performed (Tenorio, 1974).
LIFE CYCLE: The life cycle is very poorly described. The large eggs (about 200 m in length) produce a six-legged larval stage. The next stage in the lif cycle is a nymph, which lacks the characteristic bridge on the propodosomal plate. The adult males and females are found clining to the hairs. Foley (1991a) found that the mites were most commonly found on the tail head, tail tip, and perineal area., an that heavily parasitized cats had whole body involvement with a haircot that appeared “peppered” and which felt granular. There has been no work examining the amount of time required for adult mites to develop from the egg. It is assumed that transmission occurs by direct contact.
CLINICAL SIGNS AND PATHOGENESIS: Foley (1991a) described a large number of signs associated with infestation with this parasite. Most commonly seen was a dry, dull, and rust-colored haircoat. The next most common signs were gastrointestinal disturbances, including vomiting, constipation, rectal irritation or prolapse, and hairballs, which he felt was due to the excess grooming induced by the infestation. Also noted were gingivitis, anorexia, restlessness, fever, and weight loss.
DIAGNOSIS: The mites can be visualized on the skin using a head loupe or magnifying glass. Microscopic examination will reveal the typically morphology of the mites, usually found attached to hairs.
TREATMENT: Craig et al. (1991) report that two treatments with a pyrethrin-based miticidal shampoo appeared to eliminate the infestation, but that the cat in this case was treated four times at weekly intervals. Foley (1991a) reports that pyrethrin products and lime-sulfur dips were both capable of clearing infestations. Foley (1991a) also noted that ivermectin at 300 g/kg administered subcutaneously was highly efficacious when administered to the cats for other purposes.
EPIZOOTIOLOGY: Foley (1991a) reported on a epizootic of lynxacariasis in cats in the Florida Keys where over 300 mites were treated in a single year. Most other reports have dealt with one or two cases from isolated island cat populations; Fox (1977) reported that the infestaion was common in cats in Puerto Rico. It is assumed that the parasite is transmitted between cats by direct transmission, although Craig et al. (1993) reported that the cat that they observed in sourthern Texas had been sleeping in packing material that had accompanied a package tht the owners had received from Hawaii.
HAZARDS TO OTHER ANIMALS: It is not known that the species in cats is restricted to the feline host, but as of this time Lynxacarusradovskyi has not been reported from other hosts.
HAZARDS TO HUMANS: Foley (1991b) reports that one client with a heavily parasitized cat developed a papular forearm rash that cleared after the infestation of the cat was treated.
CONTROL AND PREVENTION: It is necessary to separate infested cats in order to prevent further spread of the infestation to other cats in the household. When pets have vacationed in areas where this parasite is common, it needs to be considered as part of the differential if any dermatological problems are noted in these animals.
Bowman WL, Domrow R. 1978. The cat fur-mite (Lynxacarusradovskyi) in Australia. Austral Vet J 54:403-404.
Craig TM, Teel PD, Dubuisson LM, Dubuisson RK. 1993. Lynxacarusradovskyi infestation in a cat. J Am Vet Med Assoc 202:613-614.
Foley RH. 1991a. An epizootic of a rare fur mite in an Island’s cat population. Fel Pract 19:17-19.
Foley, RH. 1991b. Parasitic mites of dogs and cats. Comp Cont Ed Pract Vet 13:783-800.
Fox I. 1977. Felistrophorus, a new genus of mites on cats in Puerto Rico (Acarina: Listrophoridae). Proc Entomol Soc Wash 79:242-244.
Greve JH, Gerrish RR. 1981. Fur mites (Lynxacarus) from cats in Florida. Fel Pract 11:28-30.
Munro R, Munro HMC. 1979. Lynxacarus on cats in Fiji. Austral Vet J 55:90.
Radford CD. 1951. Two new genera of parasitic mites (Acarina: Laelaptidae and Listrophoridae). Parasitology 41:102-104.
Tenorio JM. 1974. A new species of Lynxacarus (Acarina: Astigmata: Listrophoridae) from Feliscatus in the Hawaiian Islands. J Med Ent 11:599-604.
Figure 5-34. Lynxacarusradovskyi. Hiars from a naturallay infested cat with many mite present (Photograph courtesy of Dr. Robert Foley).
Figure 5-35. Lynxacarusradovskyi. Adult mite clinging to the hair of a cat.