Acanthocheilonema spp

From Dog
An infective larva of Acanthocheilonema spp within the head of an Hippobosca fly[1]

Acanthocheilonema spp are a hematophagous parasite of dogs in the Indian subcontinent, southern Europe[2], Africa[3] and south-east Asia.

Microfilaria of A. reconditum

Species which are pathogenic to dogs include:

  • Acanthocheilonema viteae
  • Acanthocheilonema reconditum
  • Acanthocheilonema dracunculoides[4]

The life cycle of this parasite involves an intermediate host (A. viteae - usually Hippobosca longipennis[1]; A. reconditum - usually fleas and lice)) and transmission of infective L3 larvae to dogs during feeding. Adult Acanthocheilonema spp reside in subcutaneous tissue or in body cavities, where they form nodules and release infective L1 microfilariae that are subsequently ingested by the intermediate host while feeding on the dog.

Wolbachia spp endosymbionts are intimate to their survival in both the intermediate and definitive hosts[5].

Co-infections with Dirofilaria immitis, Brugia malayi, Cercopithifilaria spp and Dipetalonema repens are common.

Most dogs are asymptomatically infected, but heavy worm burdens may result in canine subcutaneous filariasis due to subcutaneous nodule formations[6].

Diagnosis is based on identificaiton of circulating microfilariae in blood samples or identification of larval stages in nodule biopsies[7]. Mulitplex PCR assays are now available for speciation of this parasite[8].

Treatment is relatively effective with oral doxycycline given daily for 2 - 3 months to eradicate endosymbionts.

Moxidectin, doramectin, selamectin and ivermectin are effective microfilaricidal drugs and effectively sterilize adult worms.

References

  1. 1.0 1.1 Rani PA et al (2011) Hippobosca longipennis - a potential intermediate host of a species of Acanthocheilonema in dogs in northern India. Parasit Vectors 4:143
  2. Tasić A et al (2008) Survey of canine dirofilariasis in Vojvodina, Serbia. Parasitol Res 103(6):1297-1302
  3. Schwan EV & Schröter FG (2006) First record of Acanthocheilonema dracunculoides from domestic dogs in Namibia. J S Afr Vet Assoc 77(4):220-221
  4. Albrechtová K et al (2011) Occurrence of filaria in domestic dogs of Samburu pastoralists in Northern Kenya and its associations with canine distemper. Vet Parasitol 182(2-4):230-238
  5. McNulty SN et al (2010) Endosymbiont DNA in endobacteria-free filarial nematodes indicates ancient horizontal genetic transfer. PLoS One 5(6):e11029
  6. Megat Abd Rani PA et al (2010) A survey of canine filarial diseases of veterinary and public health significance in India. Parasit Vectors 3:30
  7. Brianti E et al (2012)
  8. Latrofa MS et al (2012) A multiplex PCR for the simultaneous detection of species of filarioids infesting dogs. Acta Trop 122(1):150-154