Molecular investigation on the presence of canine parvovirus in Egypt

Canine parvovirus type 2 (CPV-2) causes a highly contagious gastroenteritis disease of dogs and wild canids. To investigate the CPV-2 prevalence in Dakahlia Governorate, Egypt, a total of 50 fecal swabs were collected from suspected diseased dogs during 2016–2017. Out of 50 collected samples, 35 samples (70 %) presented positive results for CPV-2 using immuno-chromatography (IC) as a rapid test. CPV-2DNA was detected in 42 samples (84 %) by using polymerase chain reaction (PCR). The frequencies of CPV-2 were significantly higher in German shepherd breed (46 %; 23/50) and in age groups less than 6 months (76%; 38/50). We evaluated the breed, age, sex, rapid test results and clinical signs as predictors for classification of animal status into infected and not infected. The best predictors for classification process were rapid test result and clinical signs. Both CPV-2b and CPV-2c subtypes were detected by CPV2-VP2 gene sequences analysis. Deduced amino acid sequences alignment showed substitutions at 3 sites (Arg453Pro, Ala574Glu and Gln457Leu). Further investigations are needed to reveal the genetic and antigenic relation between field and vaccinal strains of CPV-2 in Egypt.     

Detection of Leishmania (L.) infantum in stray dogs by molecular techniques with sensitive species-specific primers

Background: Canine visceral leishmaniasis (CVL) is a worldwide parasitic zoonosis caused by Leishmania (Leishmania) infantum around the world. Canids are the definitive hosts and sand flies the intermediate hosts.

Objective: To test the hypothesis that a new species-specific primers (Lch14:Lch15, targeting a multiple alignment for L. infantum kDNA minicircle) is an efficient diagnostic tool for L. infantum.

Methods: The presence of L. infantum DNA was assessed in blood samples of 69 stray dogs using the conventional PCR (cPCR) and quantitative PCR (qPCR). Additional 50 lymph nodes and 50 bone marrow samples (positive and negative samples for parasitological tests) from dogs from endemic and nonendemic areas for CVL were also used.

Results: L. infantum strains, and all positive lymph node and bone marrow samples for parasitological test gave positive results for cPCR and qPCR, presenting analytical sensitivity of ～10⁰ parasite mL^?1. For the blood samples, 40/69 (58%; CI 95%; 46%–69%) resulted positive for L. infantum in both tests. All positive samples were confirmed by sequencing.

Conclusion: This study showed the importance of the specific detection of L. infantum based on species-specific primers by molecular techniques, highlighting the application as a confirmation method in epidemiological studies and to adopt the best control measures.     

Evaluation of reticulocyte hemoglobin content (RET‐He) in the diagnosis of iron‐deficient erythropoiesis in dogs

Background

Reticulocyte hemoglobin content provided by the Siemens ADVIA (CHr) is an established marker of iron deficiency. The IDEXX ProCyte Dx hematology analyzer now provides a similar variable, reticulocyte hemoglobin equivalent (RET‐He).

Objectives

The objective was to evaluate RET‐He and its diagnostic utility in dogs, and to calculate a cutoff value for diagnosing iron‐deficient erythropoiesis (IDE). Furthermore, the prevalence of RET‐He values below this cutoff value was established.

Methods

One hundred and seventy‐one CBCs of healthy dogs were used to establish a RI. Stability of RET‐He was evaluated by repeated measurements over 48 hours (n = 10). The 25‐run coefficient of variation (CV) was calculated, and correlation and bias between measurements of RET‐He and CHr were assessed (n = 190). A cutoff value for diagnosing IDE was calculated. The utility of RET‐He in the detection of IDE was evaluated in 123 dogs. The prevalence of low RET‐He values was assessed retrospectively in a multicenter study (2012–2014) under participation of 7 veterinary clinics.

Results

Reticulocyte hemoglobin equivalent with an RI of 22.2 to 28.6 pg was statistically stable over 48 hours (P = .10). The CV was 1.8%. A fair correlation (ρ = 0.74) between RET‐He and CHr with a small bias of ?0.6 pg was found. The cutoff value for diagnosing IDE was 20.9 pg (sensitivity: 85%; specificity: 99%). The prevalence of RET‐He values below 20.9 pg was 10.3% (1084/10,553 dogs).

Conclusions

RET‐He on the ProCyte Dx is a precise screening tool in dogs to detect iron‐deficient erythropoiesis.