Fatal patent troglostrongylosis in a litter of kittens

INTRODUCTION. Troglostrongylus brevior is a snail-borne metastrongyloid nematode affecting large bronchi and bronchioles of wild and domestic felids. Its lifecycle is indirect involving gastropod intermediate and paratenic hosts. Recent reports (Brianti et al., 2013, Parasitology, 140: 821-824; Di Cesare et al., 2014, Parasitol. Res., 113: 613-618; Diakou et al., 2014, Parasitol. Res., 113: 3895-3898) have also suggested a vertical route of transmission leading to severe and fatal infections in kittens and young cats. This study describes a case of patent troglostrongylosis in three kittens belonging to the same litter. MATERIALS AND METHODS. Three kittens ageing less than two weeks belonging to the same litter were referred to a private veterinary clinic, where they were housed in separate cages. Two (cats A and B) died of sudden respiratory failure after about three weeks. At necropsy adult nematodes were found in their trachea. The third kitten (cat C) showed respiratory signs few days later and scored positive for metastrongyloid L1 at the Baermann’s test. Therefore, it was immediately treated by the veterinarian with a single dose of Profender® (Bayer Animal Health) containing emodepside 2.1%/praziquantel 8.6%. Two weeks after the cat was still positive and symptomatic and received a second dose of Profender®, becoming negative and clinically healthy after two weeks. Adult nematodes and lung flushing obtained at necropsy of cats A and B, and L1s from cat C were microscopically (Brianti et al., 2014, Vet. Parasitol, 202:104-112) and molecularly (Di Cesare et al., 2015, J. Clin. Micobiol, 53:3009-3013) examined. RESULTS AND CONCLUSIONS. Adult nematodes found in the trachea of cats A and B and larvae shed by cat C were identified as T. brevior. Animals were referred at about 2 weeks of age, thus they acquired troglostrongylosis before their arrival in the clinic. The presence of developing eggs and L1s of T. brevior in the airways of cat A indicates an already patent infection at about one month of age. These data support the hypothesis of a vertical transmission route of T. brevior although it remains to be assessed whether this occurs via placenta or the milk. Further studies are warranted to evaluate the use of Profender® in the treatment of cat troglostrongylosis.