Some hematological changes in chickens infected with ectoparasites in Mosul

The study was conducted to identify different ectoparasites infesting 280 chicken (native breed out door house reared layers, 6 months – 2 years old), from various regions of Mosul city (poultry market, Hadba' Flock, and six flocks at Kogialli village), for one year. Total percentage of ectoparasites in chickens were 19.3 % of which (54 positive case out of 280 chicken) 81% were single infections and 19 % mixed infections. Lice infestation (12.5 %) and four types of chewing lice were classified (Menacanthus stramineus, Cuclotogaster hetrographus, Goniocoteus gallinae, and Columbicola columbae). One species of flies (1.4%) (Pseudolynchia canariensis). One species of mites (4.3%) (Dermanyssus gallinae) were seen. One species of soft ticks (6.8%) (Argas persicus) were seen. Parasitological findings of skin and feathers examination for all types of ectoparasites on chicken showed three degrees of infestation depending on the number of these ectoparasites on each bird (low degree 1–50/ bird, moderate degree 51–100/ bird, and heavy degree more than 100/ bird). Clinical signs of the infected chicken with ectoparasites especially severe infection were itching, annoyance, loss of sleep, general weakness, loss of appetite, restless, allergy, drop of egg production in layers and anemia. It clear from results of blood examinations the presence of anemia in infected birds blood sucking ectoparasites with significant decrease in PCV % , TRBC and Hb concentration in chicken especially in severe (heavily) infestation with soft ticks and mites. Results also showed increase in total white blood cells (Leucocytosis) with increase in heterophils, and eosinophils in infected chicken with ticks, mites and lice, with bad nutrition and unhygienic management as compared with non-infected chicken control group.

. They cause discomfort, irritation, loss of plumage, stunted growth, decrease egg production in layers and anemia (3).External parasites may also serve as carriers of bacterial, viral or protozoal diseases from one bird to another (4).Biting or chewing lice are probably the most common and widespread avain ectoparasites (5,6,7), these are Menacanthus stramineus, common body louse of chicken, Goniocotes gallinae (fluff louse), Cucloto-gaster heterographes, (head louse) and Columbicola columbae (wing louse), they spend their entire life cycle on the host and cause irritation by feeding on skin and feathers and in heavy infestation can be injurious especially in cold weather (3,4,6).
Deremanyssus gallinae, red mite of poultry and one species of flies Pseudolynchia canariensis were frequently infesting chicken (3,7).Soft ticks Argas persicus was found to be the most ectoparasite infecting chicken and is widely distributed in tropical and subtropical areas (3,7,8).Soft ticks Argas Persicus cause anemia, anorexia, weight loss, depressed egg output (2,4,5).This ectoparasite feeds on blood for a short period at night hidden in cracks and surfaces (3,4).Deremanyssus gallinae is widely distributed throughout the world infest chicken and other birds it is non-burrowing mite and can be serious pests due to their blood sucking habits (7,8).
The extent of damage caused by ectoparasite depends on the numbers of parasites, nutritional status of the host and intercurrent disease (3,4,5).House-reared chicken are particularly exposed to ectoparasitic infestation as they are kept for longer periods thus allowing the parasite to complete its life cycle (7,8), whether on the host or in its environment.The most common cause of anemia in birds is blood sucking ectoparasites (8,9).Heavy infestation with blood sucking ectoparasites such as soft ticks or mites can lead to blood loss anemia in birds (9,10), PCV is the quickest and most practical method for evaluation the red cell mass of birds (10).Leucocytosis refers to an absolute increase in the total number of white blood cells in circulation, caused by inflammation, resulting from parasitic infections (9,10).

Materials and Methods
Collection of ectoparasites: Individual examination of each bird (280 chickens) samples were taken randomly from each bird from vent, head, neck, breast, back, comb, and wing, by using eye lense 4X, comb, brush and fine forceps with good light source.Any suspected parasites or material are kept in small Petri-dish and 70% alcohol were added and sent for examination in the lab microscopically and classified according to (4,11,12).Number of ectoparasites and degree of infestation was estimated as mentioned before (1).
Collection of blood: Blood samples for hematological test were collected by venipuncture of wing vein kept in EDTA tubes and processed in the lab for the following tests: Hb using Drabkin solution (by using spectro-photometer) and Digital blood cell counter (8,9).PCV microhematocrite method (Capillary tube) RBC Digital blood counter and hemocytometer using Haymes' solution (9,10).WBC Digital blood cell counter and hemo-cytometer using Turks solution (9,10).Differential leucocyte count by staining blood films using leishman stain or Giemsa' stain (9,10).

Results
Table (1) shows different species of ectoparasites isolated from native chicken in Mosul.Total infestation rate was 19.3 %, of which 81% were single and 19 % were mixed infestations.Four species of chewing or biting lice were diagnosed from chicken under study (12.5%), (Fig. 2,  3, 4).
Menacanthus stramineus (chicken yellow body louse) were isolated from skin on breast, thigh and near cloaca.Cuclotogaster heterographes found on feathers of the head (head louse) it is dark grey colour.Goniotoes gallinae mainly was seen on down feather (fluff louse) and Columbicola columbae (wing louse).These lice are not blood sucking ectoparasites, but have cutting or biting mouth parts and feed on feathers or scales from skin and cause considerable irritation and annoyance to the chicken on which they live.One species of flies Pseudolynchia canariensis 1.4% was detected, (Fig. 4).
One species of non-burrowing mite Dermanyssus gallinae the red mite of chicken, was isolated (4.3 %), (Fig. 5), it feeds mainly at night with blood sucking habits.One species of soft ticks Argas periscus was seen (6.8 %), Fig. ( 6), which is commonly distributed on tropical and sub-tropical areas, was the most important parasite seen from infested birds.Meanwhile, concerning the severity and number of ectoparasites on each bird three degrees of infestation were noticed (low number 1-50, moderate 51-100, and large number more than 100/ bird) in case of heavy infestation (1).
Infestations with mites 4.3% Dermanyssus gallinae (Red mites of poultry), were detected these mites feed on hosts during the night, and hide during the day.The mites suck blood, which result in restless, poor egg production and anemia (3,8,13).
Clinical signs of chickens seriously infested with these ectoparasites exhibit irritation, scratching, rubbing, restless, weakness, anorexia, decrease egg production and anemia.Most of these ectoparasites live on the skin or in the feather, some penetrate the skin, others sucking blood.
Table (2) shows that a significant decrease in (PCV %), erythrocyte and/or HB values (P<0.05) in infested group as compared with normal chickens.
It is clear from table (2) that a significant (P<0.05)decrease in PCV, and erythrocyte values, HB values in chickens infested with blood sucking ectoparasites (soft ticks and mites) as compared with control non-infected group of birds.Significant hetrophilia and eosinophilia (P<0.01) as compared with control groups of birds, also seen in table (2).

Discussion
Many kinds and species of ectoparasites are known to infest chicken (flies, lice, mite, and ticks).The total loss for which they are responsible is numerous, and they present an important practical problem wherever chicken are kept (13,14).During the present study an attempt was made to find the ectoparasitices infesting native chicken in Mosul from different farms, houses and markets (280) birds, and also to determine some haematological changes caused by those ectoparasites.
The majority of the ectoparasites reported in this study were similar to those described by other workers in chicken (3,6,7,13,15).Infestation rate with lice was 14.2 % approximately to that reported in Mosul (6,15) and the body louse of chicken Menacanthus stramineus is one of the most common parasites of poultry and this is in agreement with (16).It is mostly located in the region of vent, breast, back, and under the wings.Cuclotogaster heterographis chicken head louse is found chiefly on head and neck, Gonicotoes gallinae.Columbicola columbae all were belong to order Mallophaga chewing lice of birds.
Hoogstraal (17) stated that A. Persicus were found in every flock of chicken in several parts of Egypt.The results from Table (1) indicated that 81 % of infected chicken were single (one type of ectoparasite) 19 % were mixed (two type or more).This is similar to that of (6, 11).It appears from our results that there was three degrees of ectoparasitic infestations, (low No. 1-50 / bird, moderate No. 51-100/ bird, and large No. more than 100/ bird)(1), depending on hygienic measures size of houses or cages, and malnutrition as reported by (16).
Hemotological findings of the present study (Table 2) revealed decrease values of PCV%, total erythrocytes and / or HB values of the infested chicken as compared with control group.The cause of anemia of infected chicken in this study is due to blood sucking parasites (blood loss anemia), those results were also recorded by (5,10,18).Birds with PCV % of less than 35% are generally considered anemic (9,10,18), in which ticks and mites were responsible for these haemorrhagical changes, while lice or flies cause no-anemia in birds (not blood sucking ectoparasites).
Leuckocytosis and hetrophilia (34%) were seen in diseased birds heavily infested with ectoparasites (more than 35000/ cmm).Eosinophilia 6% was predominant and very characteristic feature seen in Rowmnowsky stained blood smears taken from birds infested with lice, mites, and / or ticks, in addition hetrophilia was common among infested chicken in stained blood film (colorless cytoplasm and rod shaped cytoplasm granules).It was evident that Eosinophilia is common in blood examined smears of infested birds specially moderate or heavy degree of infestation (chronic parasitic disease).Eosinophils look pale blue cytoplasm and round red Eosinophilic granules bright and lobed nuclei, this is similar to that reported by (9,10,18).
From this table significant increase of Heterophils and Eosinophils of infested chickens as compared with control group (normal birds).

Table ( 2
): Hematological changes in chickens infested with different ectoparasites in Mosul * Significant difference from other values at P < 0.01 Values of HB, P.C.V., Total red cell count are presented as mean µ standard deviation Values under control group are normal ranges. *