Eimeria oocyst count
There are few studies that show a relationship between parasite load and blood and biochemical parameters in baby alpacas. Is is very important to understand the effects that these parasites have on biochemical parameters and weight because thee newborns are the most susceptible.
Table 1 shows that the mean OPG at time 1 (T1) ranged from 1111.9 to 7373.8 OPG, with a minimum load of 0 OPG and a maximum load of 36,700 OPG for
E. lamae, a total average of 14,511.9 OPG and a maximum of 69,800 for all
Eimeria. For time 2 (T2) the average parasite load was between 2390.5 and 19.1 with a minimum of 0 and a maximum of 27,600 OPG for
E. lamae having a total average of 5,769
Eimeria and a maximum of 44,700 OPG.
The prevalence of
Eimeria shown in Table 1 are similar what was reported by
Rodriguez et al. (2012), who found a high load of
E. lamae in Boli
via. Our results are also similar to
Camareno (2014), who found a higher load for
E. punoensis and
E. alpacae.
Quina (2015) repored 21,977 OPG in alpaca babies.
Merzenich (2022) showed that the OPG in alpaca babies were higher than those of adults in Quimsachata. The results of this and other research differ due to differences in the climate, sanitary conditions and the different locations studied. The presence of
Eimeria in young animals is related to a very poor immune response (
Pérez et al., 2014).
Weight and hematological parameters
In Table 2, the average weight of the alpacas at T1 was 11.52 kg and at T2 15.04 kg (p<0.05). The parasitic load at T1 was 8484.71 OPG. At T2 the parasitic load decreased to 2400.00 OPG (p<0.05). The average hematocrit value at T1 was 31.86%. at T2 the hematocrit decreased to 13.47% (p<0.05). The average number of erythrocytes was 9.39 x 106/μL at T1 and 3.27 x 106/μL at T2 (p < 0.05). The total leukocyte count at T1 was 11.47 x10³/μL. At T2 the average value of white blood cells decreased to 9.38 ´ 103/μL, as did the parasitic load (p<0.05). There was no significant differences in cell differentiation.
In Table 2, the result of the average hematocrit value at T1 was similar to values recorded by Barrios
et al. (2016), who measured an average hematocrit value of 29.36% in calves under 1 month old. The average hematocrit value found at T2 was lower than T1. The difference could be due to alpaca calves experiencing anemia due to the parasitic infection.
Watson (2015) mentioned that iron deficiency is linked to blood loss due to parasitic infestation, hemostatic deficiencies and bleeding lesions in the digestive system: all of which lead to anemia. The erythrocyte values shown in Table 3 are slightly below the normal values reported by
Barrios et al. (2016) who mention reference levels of 9.75 to 16.4 ´106/μL in healthy alpaca calves. It could be deduced that the average values of erythrocytes in alpaca babies are lower because South American Camelids (CS) are partially anemic until they reach 3 to 4 months of age. This results from a process in which the fetal Hemoglobin cells are replaced by large adult Hemoglobin cells. This exchange ends at 3 months of age (
Abaigar, 1993). Eimeriosis cause animals to have diarrhea due to poor absorption by destroyed intestinal villi, chlorine secretion and increased intestinal permeability, giving rise to dehydration (
García and Rivera, 2017). This accompanied by anemia can cause a false increase in total erythrocyte volume, resulting in the erythrocyte levels being slightly lower than normal for this species (
Weiss and Wardrop, 2010).
Table 3 shows that, the parasite load did not influence the weight of alpacas (p>0.05). The hematocrit results did not change with differing parasitic loads (p>0.05). There were fewer red blood cells at T1 (9.10 x10
6 /μL and 9.39 x10
6/μL) in alpaca with moderate and high OPG loads (p>0.05). Samples taken at T2 showed below normal RBC indicating an anemic process. Red blood cell values in animals with a high parasite load were slightly elevated (3.26 x 10
6/μL) compared to animals with a moderate parasite load (3.20 x 10
6/μL) (p<0.05). White blood cell values at T1 were higher with increased parasite load (9.15, 10.32 and 11.88 x 10³/ìL). At T2 the amount of white blood cells in offspring with a high parasite load decreased (8.97 x 10³/μL) (p>0.05).
According to
Vale (1999) and
Martínez (2009), iron is essential and vital in cellular activity, so an iron deficiency (iron deficiency anemia) exhibits a reduction in lymphocyte DNA synthesis and decreases the number of T cells. These results were documented in laboratory animals.
Papale et al. (2008) show that iron is associated with the immune response against parasites, for this reason iron deficiency anemia impacts parasitic infestation. The results found at T2 indicate that the response of white blood cells against parasitic infection by a high load of
Eimeria is deficient.
Barrios et al. (2016) shows an average WBC of 18.02±7.7 x 10³/μL, with ranges of 7.2 to 43.6 x10³/μL in alpaca calves with diarrhea. According to
Barrios et al. (2016) and
Bautista (2009) a significant decrease in leukocytes could be associated with parasitic factors that manage to evade and/or adapt to the leukocyte response.
Arece et al. (2015) reported that parasitized sheep with greater amounts of eggs per gram, had lower WBC counts (6.51 x 10³/ μL), than animals with lower HPG (10.57 x 10³/μL).
The values of neutrophils, monocytes, eosinophils and basophils did not show variations with respect to the level of parasitic load at T1; implying that the level of parasitic infection in alpaca calves does not significantly alter the level of white blood cells. However, the values of lymphocytes in calves with a high level of parasitic load decreased to 30.15%. The level of neutrophils, lymphocytes, monocytes and eosinophils was not different at T2. However, the level of basophils decreased to 0.37%.
Morales and Vargas (2018) reported that in cattle infected with gastrointestinal parasites, many with
Eimeria sp. 41.46% of animals presented with monocytosis and 40.24% neutropenia. According to
SUISA VET (2018) neutropenia could be due to the acute increase in tissue demand, as occurs in over-acute infections, such as gastrointestinal parasitosis since perforations and/or ruptures of the intestinal walls occur.
Rodríguez (2017) mentions that monocytosis is the product of hemolysis as a result of parasitic proliferation, cellular debris, dead cells and hemoparasites. It is also known that infection in the body, nature of the causative agents, resistance by the animal and the localization of the inflammatory response might be possible causes of lower biochemical parameters and hematological parameters, except total leukocyte count
(Sarkar et al., 2016).
Albumins, globulins and total proteins
Table 4 shows the average total protein was 4.44 g/ dL at T1. At T2 the average value was higher, 4.80 g/dl (p<0.05). The average value found for albumin at T1 was 3.57 g/dl, lower than T2 which was 4.00 g/dl (p<0.05). The average globulin values at T1 were 0.87 g/ dL, similar to the average value of 0.80 g/ dL recorded at T2 (p>0.05). Table 5 shows that the level of parasite load did not influence the parameters of albumin, protein and globulins at T1 or T2 (p>0.05).
The level of parasite load did not influence the parameters of albumin, protein and globulins. However, it should be noted that the levels of total protein, albumin and globulin at both time points were below the normal reference values.
Woodward (2015) points out that various gastrointestinal diseases, including parasitic infections, cause changes in the mucosa, as well as lesions in the intestinal epithelial cells and cause the rupture of lymphatic vessels in the intestinal lumen; leading to the loss of proteins through the vessels and the interstitial space of the intestinal mucosa. Total protein is affected by other infections
(Ekisi et al., 2021).
The decrease in normal albumin values is related to hypoproteinemia due to diarrheal intestinal processes, lack of appetite and malabsorption of nutrients, which can give rise to cases of ascites and edema
(Gyles et al., 2010). Globulins increase as an immune response against parasites. However, the average value of globulins found in this research is outside the range of values reported by other authors. This hypoglobulinemia is related to enteropathies in which proteins are lost due to parasitic infestations, hemorrhages and malabsorption syndromes.
Correlation between the burden of Eimeria and some hematological parameters
Table 6 shows the significant negative correlation (-0.42) between the level of red blood cells and the level of oocysts at T1and the positive correlation (0.31) between neutrophils and OPG levels. At T1 and T2 there was a moderate, highly significant inverse correlation (-0.39 and -0.43) between OPG level and monocytes.
A similar result was reported by
Arece et al. (2015), who found a high negative evaluation of -0.63 with significance (p<0.01) between the egg count per gram of feces and the RBC values in sheep. As the eggs per gram level increased the red blood cell count values decreased. Although they are not eimeria but the influence on the RBC count is similar in the month of T1, At T2 neutrophils were increasing with the OPG levels, presenting a positive pressure of 0.31. This increase in neutrophils occurs because they are the main cells recruited in the submucosa during the infection process with the aim of fighting and resolving the infection. According to
Barrios et al. (2016) and
Bautista (2009) the levels of leukocytes are increased due to the invasion of foreign agents, such as parasites.
