Hemoglobin types, erythrocyte membrane skeleton and plasma iron concentration in calves with poikilocytosis

Re-examining poikilocytosis in goats: prevalence, type and association with age and disease

Background

Domestic goats (Capra aegagrus hircus) are a food, fiber and companion animal. Abnormal erythrocyte shapes (poikilocytes) are considered normal in young goats, but their association with disease is not well described. Likewise, there is little information on the significance of poikilocytosis in adult goats.

Objective

The objective of this study was to investigate the prevalence, severity and type of poikilocytosis in young and adult goats and its association with age, sex, breed, laboratory results, and underlying disease.

Methods

We retrospectively examined clinical and laboratory data from 1254 goats presented at the University of California-Davis Veterinary Medical Teaching Hospital from 1997 to 2019. We analyzed 313 blood smears from goats with moderate or marked (MOD-MKD) poikilocytosis on initial blood smear evaluation. Number and type of poikilocytes per 1000 red blood cells (RBCs) were enumerated. Laboratory values and primary disease categories were compared with the severity and type of poikilocytosis.

Results

Kids (<6 mos) and juveniles (>6 mos to <1 year) had a higher prevalence of MOD-MKD poikilocytosis (95/210, 45.2% kids; 27/59, 45.8% juveniles) than adult goats (≥1 year; 190/982, 19.3%) (p < 0.001). Kids had a higher percentage of elliptocytes, dacryocytes, and schistocytes and a lower percentage of polygonal and spiculated RBCs than juvenile and adult goats (p < 0.001). Of goats with MOD-MKD (vs NONE-SLIGHT) poikilocytosis, kids had lower HGB and MCH, and higher RDW (p ≤ 0.02); juveniles and adult goats had lower HCT, MCV, MCH, and albumin concentration (p ≤ 0.01), and all age groups had lower total CO2 concentration and higher PLT counts (p < 0.03). Adult goats with MOD-MKD poikilocytosis also had higher BUN:Cr ratios (p = 0.005). Gastrointestinal parasitism, Johne's disease, diarrhea/enteritis, lice, hepatic disease and renal disease (but not urolithiasis) were significantly associated with MOD-MKD poikilocytosis (p < 0.001). Goats with hepatic and renal disease had a higher prevalence and percentage of spiculated cells (p = 0.001). Goats with Johne's disease had a higher prevalence of polygonal cells (93.3%) and dacryocytes (66.7%) than other diseases, and elliptocytes predominated in a higher proportion (36.0%) of adult goats with GI parasitism vs other diseases (p < 0.05).

Conclusion

These findings suggest that iron deficiency is an important pathophysiologic mechanism of poikilocytosis in juvenile and adult goats, and possibly in kids, whether due to iron-restricted erythropoiesis, chronic hemorrhage, functional iron deficiency, or a combination of these mechanisms. Further investigation into the detection and monitoring of iron deficiency and the value of poikilocytosis as a diagnostic marker of iron status in goats is warranted.

Serum interleukin-6 as a prognostic marker in neonatal calf diarrhea

Neonatal calf diarrhea is still one of the most important diseases in calf rearing, and severe diarrhea has a marked effect on animal welfare. Furthermore, significant economic losses can result from this disease due to high mortality rates, high medical costs, and low weight gain. To avoid a fatal outcome of the disease, it is crucial that vulnerable calves are identified as early as possible. Interleukin-6 is described as an early and reliable prognostic marker in several diseases. In this study, 20 scouring calves were tested by ELISA for their IL-6 serum concentrations. Samples were collected twice, at the beginning of diarrhea and 7 to 10 d later. Regarding the clinical outcome after 7 to 10 d, calves were classified as recovered or nonrecovered. A receiver operating characteristic analysis was conducted to determine the prognostic value of IL-6 for the progress of clinical symptoms. At the beginning of diarrhea, the IL-6 concentration was significantly higher in nonrecovering calves compared with those that recover 7 to 10 d after the onset of diarrhea. Interleukin-6 proved to be a useful additional parameter in the clinical examination. High initial IL-6 values can support the decision for closer monitoring and an adapted therapeutic strategy for the respective calves. This may help to prevent unnecessary animal suffering and reduce economic losses.

Heinz Body Hemolytic Anemia With Eccentrocytosis From Ingestion of Chinese Chive (Allium tuberosum) and Garlic (Allium sativum) in a Dog

A 4-year-old, intact male miniature schnauzer was presented with anorexia. The dog had ingested some Chinese steamed dumplings 2 days before, which contained Chinese chive (Allium tuberosum) and garlic (Allium sativum). Hematological examinations revealed severe Heinz body hemolytic anemia with eccentrocytosis and an increased concentration of methemoglobin, which was thought to result from oxidative damage to erythrocytes by constituents in these Allium plants. In this case, eccentrocytosis was a hallmark finding and could be detected easily, suggesting that this hematological abnormality is useful in diagnosing Allium plant-induced hemolysis.

Molecular basis of bovine red-cell protein 4.2 polymorphism in Japanese black cattle

Cattle were divided into three groups according to the red cell-protein 4.2 (P4.2) phenotypes P4.2(76), P4.2(75) and P4. 2(76/75), whose red cells contained Mr 76000 (P4.2/76), 75000 (P4. 2/75) and both 76000 and 75000 isoforms respectively. To elucidate the molecular basis that underlies the diversity of P4.2, the gene structures of bovine P4.2/76 and P4.2/75 were investigated. Two P4.2 cDNA clones were isolated from bone-marrow cDNAs of the animal with the P4.2(76/75) phenotype. These were identical in size (2.2 kb), encoding major erythroid P4.2 with 687 amino acids, but were different in three nucleotides, resulting in changes of amino acids at the 599th, 601st and 627th residues. Analysis of genomic DNA from the three phenotypes demonstrated that these two clones were derived from gene transcripts by which P4.2/76 and/or P4.2/75 were produced. In vitro transcription and translation of P4.2/76 and P4.2/75 cDNAs indeed generated P4.2/76 and P4.2/75 identical in size to the red-cell proteins. These findings demonstrated that polymorphism of the P4.2 gene at codons 599, 601 and 627 of P4.2 cDNA was the cause of the molecular diversity of bovine red-cell P4.2. Although distinct electrophoretic mobilities suggested a structural difference in the two isoforms, this polymorphism appeared to have little effect at least on P4.2 association with band 3, since no significant difference was observed in the amount of P4.2 relative to total membrane proteins despite the phenotype difference for P4.2.