Tungiasis-associated morbidity in pigs and dogs in endemic villages of Uganda

Background: Tunga penetrans (Insecta, Siphonaptera, Tungidae) causes severe morbidity among heavily infected humans and animals in Latin America and sub-Saharan Africa. The clinical pathology of tungiasis in animals has never been studied systematically. Methods: This was a cross-sectional study conducted between January to March 2015, aimed at describing tungiasis-associated clinical pathology in 121 and 20 T. penetrans-infected pigs and dogs, living in nine and five endemic rural villages respectively located in Bugiri District, Busoga, Uganda. Results: The parasite load of infected animals ranged from one to 246 (median 8) and one to eight (median 2) in pigs and dogs, respectively. In pigs 99.3 % and in dogs 100 % of the lesions were located on feet. In pigs, hind legs were significantly more affected than front legs (90.9 % vs. 57.9 %; p = 0.002) and also had more lesions than the front legs (median 5 vs. 1; p = 0.0001). However, in dogs localization of lesions between front and hind legs never differed significantly (front, 50 % vs. hind, 65 %; p = 0.51) and so were the number of lesions (median front = 0.5 vs. median hind = 2; p = 0.7). Acute and chronic clinical pathology coexisted. The most common disease manifestations in pigs were hoof wall erosions (68.6 %), tissue necrosis of hoof wall and skin (66.1), pain at infection sites (47.9 %), hoof deformity (45.5 %), fissures (44.6 %) and edema (44.6 %). In dogs, tungiasis mainly presented with pain at attachment site (80 %), ulcers (55 %), necrosis (30 %) as well as hyperemia and edema (both 15 %). One pig had lost dew claws while two had loose detaching claws. Despite a lower number of sand fleas, a higher proportion of infected dogs (20 %) than pigs (5.8 %) exhibited functional limb use difficulties (p = 0.05). Conclusions: The pattern of clinical manifestations in pigs and dogs were very similar to those reported from affected humans and rats. The important morbidity associated with animal tungiasis makes the disease a serious veterinary health problem in sub-Saharan Africa warranting treatment and control for optimal animal production.