Mesocestoides spp

From Dog
Adult Mesocestoides
Explorative celiotomy showing abdominal organs covered by Mesocestoides tetrathyridia in a dog[1]
gross appearance of Mesocestoides larval tetrathyridium, approximately 0.5–1 mm long[1]

Mesocestoides is a parasitic tapeworm which occasionally infects dogs and cats worldwide.

Although this family of cyclophyllidians has a cysticercoids stage of development, it has yet to be identified[2]. Dogs are usually infected with the tetrathyridium larval stages acquire from ingestion of birds and other small mammals[3].

Adults Mesocestoides develop from the tetrathyridiums within the dog's intestine and have four suckers but no hooks. The eggs accumulate within special, thick-walled parauterine organs which eventually detach from the strobila and are shed into the dog's feces. The prepatent period is about 2 months.

Peritoneal larval cestodiasis also occurs in dogs due to translocation of tetrathyridium across the intestinal mucosa.

Species which are known to infect dogs include:

  • Mesocestoides corti
  • Mesocestoides lineatus[4]
  • Mesocestoides litteratus[5]
  • Mesocestoides vogae[6]
  • Mesocestoides variabilis[7]

Most dogs infected with Mesocestoides are asymptomatic, although heavy burdens and co-infections may cause illthriftiness.

However, peritoneal migration by larval tetrathyridium can cause a serious complication of cystic tetrathyridiosis, with a significantly higher mortality rate in dogs[8]. Larval tetrathyridia migrated from the gut and proliferate within the peritoneal cavity, parasitizing abdominal organs and migrating as far as the inguinal canal, vaginal tunic and testis in some dogs[9][10].

Clinical signs of tetrathyridiosis in dogs include peritonitis (due to intestinal perforation[11]), ascites, anorexia, vomiting, diarrhea and tachypnea[12]. Some dogs are subclinically infected and only accidentally diagnosed during routine ovariohysterectomy or neuter[13].

Diagnosis is based on coprological identification of Mesocestoides eggs. Co-infections with other intestinal parasites is extremely common[14][15]. In peritoneal tetrathyridiosis, paracentesis and ultrasonography[16] help identify the small white cyst-like larval stages as well as the occasional intact acephalic pre-adults[17]. PCR assays are also available to assist speciation of the parasite[18]

Praziquantel, emodepside and fenbendazole may be used effectively for intestinal infections[19].

For peritoneal tetrathyridiosis, subcutaneous administration of injectable praziquantel at 5 mg/kg is recommended[1]. Dose is repeated every 2 weeks until paracentesis samples are clear of larval stages.

Fenbendazole appears to be effective at eliminating intraperitoneal tetrathyridium in some cases where praziquantel has failed[20].

References

  1. 1.0 1.1 1.2 Papini R et al (2010) Effectiveness of praziquantel for treatment of peritoneal larval cestodiasis in dogs: a case report. Vet Parasitol 170(1-2):158-161
  2. Padgett KA & Boyce WM (2004) Life-history studies on two molecular strains of mesocestoides (Cestoda: Mesocestoididae): identification of sylvatic hosts and infectivity of immature life stages. J Parasitol 90(1):108-113
  3. Bowman, DD (2009) Georgis' parasitology for veterinarians. 9th edn. Elsevier Saunders, Missouri. pp:151-152
  4. Eslami A et al (2010) Helminth infections of stray dogs from garmsar, semnan province, central iran. Iran J Parasitol 5(4):37-41
  5. Foronda P et al (2007) First larval record of Mesocestoides in carnivora of Tenerife (Canary Islands). J Parasitol 93(1):138-142
  6. Padgett KA et al (2005) Systematics of Mesocestoides (Cestoda: Mesocestoididae): evaluation of molecular and morphological variation among isolates. J Parasitol 91(6):1435-1443
  7. Eguía-Aguilar P et al (2005) Ecological analysis and description of the intestinal helminths present in dogs in Mexico City. Vet Parasitol 127(2):139-146
  8. Toplu N et al (2004) Massive cystic tetrathyridiosis in a dog. J Small Anim Pract 45(8):410-412
  9. Rodríguez F et al (2003) Testicular necrosis caused by Mesocestoides species in a dog. Vet Rec 153(9):275-276
  10. Zeman DH et al (1988) Scrotal cestodiasis in a dog. Cornell Vet 78(3):273-279
  11. Wirtherle N et al (2007) First case of canine peritoneal larval cestodosis caused by Mesocestoides lineatus in Germany. Parasitol Int 56(4):317-320
  12. Bonfanti U et al (2004) Clinical, cytological and molecular evidence of Mesocestoides sp. infection in a dog from Italy. J Vet Med A Physiol Pathol Clin Med 51(9-10):435-438
  13. Boyce W et al (2011) Survival analysis of dogs diagnosed with canine peritoneal larval cestodiasis (Mesocestoides spp.). Vet Parasitol 180(3-4):256-261
  14. Nonaka N et al (2011) Coprological survey of alimentary tract parasites in dogs from Zambia and evaluation of a coproantigen assay for canine echinococcosis. Ann Trop Med Parasitol 105(7):521-530
  15. Barutzki D & Schaper R (2011) Results of parasitological examinations of faecal samples from cats and dogs in Germany between 2003 and 2010. Parasitol Res 109(1):S45-S60
  16. Venco L et al (2005) Ultrasonographic features of peritoneal cestodiasis caused by Mesocestoides sp. in a dog and in a cat. Vet Radiol Ultrasound 46(5):417-422
  17. Caruso KJ et al (2003) Cytologic diagnosis of peritoneal cestodiasis in dogs caused by Mesocestoides sp. Vet Clin Pathol 32(2):50-60
  18. Wirtherle N et al (2007) First case of canine peritoneal larval cestodosis caused by Mesocestoides lineatus in Germany. Parasitol Int 56(4):317-320
  19. Altreuther G et al (2009) Field evaluation of the efficacy and safety of emodepside plus praziquantel tablets (Profender tablets for dogs) against naturally acquired nematode and cestode infections in dogs. Parasitol Res 105(1):S23-S29
  20. Crosbie PR et al (1998) Diagnostic procedures and treatment of eleven dogs with peritoneal infections caused by Mesocestoides spp. J Am Vet Med Assoc 213(11):1578-1583