Gasterophilosis in horses in Sardinia (Italy): effect of meteorological variables on adult egg-laying activity and presence of larvae in the digestive tract, and update of species

Abstract

Gasterophilus larvae are common obligate parasites of the digestive tract of the equids. Horses become infected with this parasite by ingesting the larvae hatched from eggs laid by the female flies. In this study carried out monthly, we (i) counted the Gasterophilus eggs deposited by female flies on the coat of 30 grazing horses, (ii) counted and identified the Gasterophilus larvae retrieved from the digestive tract of 128 slaughtered horses, and (iii) compared these results to meteorological data. Eggs were deposited on all monitored horses, and were present from October to January and from May to September, whereas they were absent from February to April. The number of laid eggs was significantly different between the months, body regions, genders, and age classes (p < 0.05). Larvae were recovered in 112 (87.5%) horses, and 6 species of Gasterophilus were identified. The prevailing species were Gasterophilus intestinalis (recovered in 110 horses; 85.9%) and Gasterophilus nasalis (69 horses; 53.9 %), recovered in all months. Gasterophilus inermis (5 horses; 3.9%), Gasterophilus pecorum (3 horses; 2.3%), Gasterophilus haemorrhoidalis (3 horses; 2.3%)¸ and Gasterophilus meridionalis (2 horses; 1.6%) larvae were also found. Significant differences were found among monthly larval burdens for both Gasterophilus spp. and G. intestinalis (p < 0.05), but not for G. nasalis (p > 0.05). Larval burdens and prevalences did not differed significantly between both genders and age classes (p > 0.05). Monthly eggs and larvae trends were not significantly correlated (p > 0.05). With regard to the meteorological variables, minimum air temperature was significantly correlated with the eggs trend (rho = 1.000; p < 0.001) and maximum air temperature with the Gasterophilus spp. (rho = 0.972; p < 0.001) and G. intestinalis (rho = 0.972; p < 0.001) larvae trends. In addition, the number of hours with a temperature below +10 °C was significantly correlated with G. intestinalis larvae trend (rho = 0.602; p < 0.05). Our findings confirmed that in Sardinia, Gasterophilosis is an important parasitosis in the horses, and it needs more attention and extensive and/or correct treatment to reduce its prevalence.

Report on Gasterophilus spp. (Diptera, Gasterophilidae) of Horses in Algeria: Prevalence, Intensity, and Monthly Variations

“…These results suggest that both G. intestinalis and G. nasalis are the predominant species in Algeria. Similar results were reported in other countries in the Mediterranean zone, such as in Morocco [24], in Italy [23,27], and in Jordan [21].…”

“…larvae. Similar observations were recorded by Otranto et al [23], Pilo et al [27] in Italy, and Niedźwiedź et al [22] in Poland. However, Ibrayev et al [15] and Pandey et al [24] found in Kazakhstan and Morocco respectively that older animals have fewer larvae than younger ones.…”

Ocurrencia de miasis cavitaria equina (Gasterophilus Spp) y su relación con las úlceras gástricas secundarias en la mucosa escamosa en Temuco, Chile

“…Después de la ingestión, el primer estadio larval (L1) pasa a través del tracto digestivo, donde permanecerán unidos a la mucosa gástrica hasta por 10 a 12 meses y evolucionar hasta el tercer estadio (L3). Las especies de Gasterophilus difieren también en su color y en la localización final de la larva en el tracto digestivo; es así como larvas (L3) de G. intestinalis son de color rojo y se adhieren a la mucosa escamosa del estómago, mientras que larvas (L3) de G. nasalis son de color amarillo y se ubican en la mucosa de la región antropilórica y porción proximal del duodeno 7,32,33,39 .…”

Gasterophilus flavipes (Oestridae: Gasterophilinae): A horse stomach bot fly brought back from oblivion with morphological and molecular evidence

“…donkeys) and the highly effective and widespread use of anti-parasitic drugs for domestic animals [15,19]. Nevertheless, all the seven Palaearctic Gasterophilus species have been recorded in Xinjiang [17,20,21], which represents the highest species diversity of this genus worldwide [3,4,6,15,52,53]. Even more, at least six of these seven species (data unavailable for G .…”