Effects of Intravenous Pimobendan on Cardiovascular Parameters in Healthy Sedated Cats.

This study aimed to investigate the effects of intravenous pimobendan on cardiovascular function and to determine the appropriate dose for clinical usage in cats. Six purpose-bred cats received one of the following treatments: intravenous pimobendan at a single dose of 0.075 mg/kg (low dose [LD] group), 0.15 mg/kg (middle dose [MD] group), 0.3 mg/kg (high dose [HD] group), or saline at 0.1 mL/kg (placebo group). Echocardiography and blood pressure measurements were performed before and 5, 15, 30, 45, and 60 minute after drug administration for each treatment. In the MD and HD groups, the fractional shortening, peak systolic velocity, cardiac output, and heart rate increased significantly. There were no significant differences in blood pressure among the groups. Intravenous pimobendan at 0.15-0.3 mg/kg increased the fractional shortening, peak systolic velocity, cardiac output in healthy cats.

Modified Toyoda technique for total cystectomy and cutaneous ureterostomy in a cat.

OBJECTIVES: To report the technique and outcome of a cat treated with a total cystectomy and bilateral cutaneous ureterostomy. ANIMALS: A 16-year-old male castrated domestic shorthair cat. STUDY DESIGN: Case report. CASE PRESENTATION: A cat was referred after a 2-week history of pollakiuria and hematuria. Transitional cell carcinoma (TCC) was suspected based on ultrasonographic, cytologic, and contrast computed tomographic (CT) findings. A total cystectomy was combined with a modified cutaneous ureterostomy: the ureter, incised like a fish-mouth aperture, was anastomosed to the skin after the creation of a rectangular-shaped defect. Complete excision of a TCC was confirmed histologically. RESULTS: Ureteral stents were removed 7 days (left) and 28 days (right) postoperatively. The cat's incontinence was managed with an absorbent diaper surrounding the ureteral stomata. The right ureter became obstructed 14 months after surgery, and the cat died at home approximately 16 months after surgery. In spite of the urinary incontinence, the owner was satisfied with the surgery and evaluated the cat's quality of life as satisfactory. CONCLUSIONS: The total cystectomy and cutaneous ureterostomy described here allowed urinary excretion and resulted in long-term survival of a cat with bladder TCC.

Comparison of regression for blood ALP levels using methods of the Japan Society of Clinical Chemistry and the International Federation of Clinical Chemistry and Laboratory Medicine in bovine, canine, feline, and human testing.

Livestock and companion animal health have a direct impact on human health. Research on clinical laboratory technology for veterinary medicine is as important as that on human laboratory technology. Reagents and analysis equipment for human medical laboratory tests are often used in veterinary medicine. Medical laboratories in Japan utilize the Japan Society of Clinical Chemistry (JSCC) method for blood alkaline phosphatase (ALP) analysis. The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) method is used worldwide for ALP catalytic concentration measurement. When the IFCC method is used, human blood ALP activity is approximately one-third of the JSCC method's activity. The JSCC method for ALP measurement was switched to the IFCC method in medical laboratories in Japan in April 2020 for global standardization purpose. It is uncertain whether conventional JSCC method reagents will continue to be supplied. In veterinary medicine, the relationship between the JSCC and IFCC methods in terms of ALP measurement is almost unclear. This study investigated the regression between JSCC and IFCC methods measuring ALP in bovine, canine, feline, and human. The regression formulas for bovine, canine, feline, and human ALP values using the conventional JSCC (x) and IFCC (y) methods are y = 0.379x + 0.124, y = 0.289x + 8.291, y = 0.358x + 0.432, and y = 0.337x + 2.959, respectively. These results suggested that the IFCC method measurement could be estimated by approximately one-third of the JSCC method measurement in animal species such as bovine, canine, and feline. By applying the conversion factors proposed in this study, a very good correlation could be obtained between the two methods for each animal.

Regression formula to predict the International Federation of Clinical Chemistry and Laboratory Medicine measure of alkaline phosphatase activity in canine blood based on the Japan Society of Clinical Chemistry reference method.

The Japan Society of Clinical Chemistry reference method (JSCC method) is used to measure alkaline phosphatase (ALP) activity only in Japan. Other countries use the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) reference method to measure ALP activity. Since April 2020, human medical institutions in Japan have been gradually switching to the IFCC method. However, it is unclear whether the supply of reagents required for the JSCC method will be steady in the future. Additionally, the comparison of the performances and accuracies of these two methods for measuring ALP values remains uncertain in several animal species. In this investigation, we measured canine ALP activity using both methods and developed a formula to interconvert the two resulting values. The regression formula for ALP values measured using the modified JSCC (x) and IFCC (y) methods was determined as log10 y=0.960 log10 x-0.395 (r=0.997). However, the correlation between values based on JSCC and IFCC methods can change depending on the composition of ALP isozymes. Therefore, the developed formula can currently serve as a provisional strategy in calculating ALP levels. Nevertheless, this formula might avoid confusion in the clinical field during the transition from the JSCC to the IFCC method when both measurement values co-exist.

Comparison of early posttreatment effects of two steroidal anti-inflammatory ophthalmic drugs on the ocular inflammatory response induced by paracentesis in healthy canine eyes.

OBJECTIVE: We investigated the early posttreatment effects of two steroidal anti-inflammatory ophthalmic drugs on blood-aqueous barrier (BAB) breakdown by paracentesis in dogs. ANIMAL STUDIES: We studied 21 healthy beagles with normal eyes. PROCEDURES: Controlled anterior chamber paracentesis (0.5 mL) was performed in one eye of each dog. Control group dogs (n = 7) received no medication, whereas those in the treatment groups received a topical anti-inflammatory medication (difluprednate [DFBA] ophthalmic emulsion 0.05% [n = 7] or betamethasone [BMZ] sodium phosphate ophthalmic solution 0.1% [n = 7]) at 0, 15, 30, and 45 minutes after initial paracentesis in the paracentesed eyes. Secondary aqueous humor (AH) was collected 60 minutes after initial paracentesis. Protein and prostaglandin E2 (PGE2 ) concentrations in AH were determined using the bicinchoninic acid assay and commercially available immunoassay kit, respectively. All mean values in the three groups were compared using analysis of variance followed by Tukey's post hoc test. RESULTS: Aqueous protein and PGE2 concentrations were markedly increased at 60 minutes following paracentesis. Both concentrations in the secondary AH of the DFBA group were significantly lower than those of the control group; however, treatment with BMZ had no significant effects. CONCLUSIONS: Early postparacentesis treatment with DFBA was more effective than that with BMZ for reducing aqueous protein and PGE2 contents in dogs with paracentesis-induced BAB breakdown. DFBA may be an appropriate treatment during the early stage of anterior uveitis caused by intraocular surgery in dogs.

The Aldosterone Receptor Antagonist Eplerenone Inhibits Isoproterenol-Induced Collagen-I and 11ß-HSD1 Expression in Rat Cardiac Fibroblasts and the Left Ventricle.

ß-Adrenergic receptor (ß-AR)-induction of collagen-I synthesis is partially mediated by the cardiac mineralocorticoid receptor (MR) system. However, it remains unclear whether the selective MR antagonist, eplerenone, inhibits collagen-I synthesis induced by ß-AR stimulation. We investigated the effects of eplerenone on the responses to a non-selective ß-AR agonist, isoproterenol, which induced collagen-I synthesis in primary cardiac fibroblasts (CFs) and the left ventricle. mRNAs encoding the MR and 11ß-hydroxysteroid dehydrogenase type I (11ß-HSD1) were evident in the left ventricle and primary CFs. mRNAs encoding the CYP family 11 subfamily B member 2 (CYP11-B2) were not detected, even after isoproterenol treatment. In vivo, isoproterenol induced collagenous fiber accumulation in the left ventricle. The phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), 11ß-HSD1 levels, and mRNA/protein levels of collagen-I increased upon exposure to isoproterenol, but these increases were inhibited by eplerenone co-treatment. In primary CFs, isoproterenol increased the phosphorylation of ERK1/2 and the expression levels of both 11ß-HSD1 and collagen-I; these isoproterenol-attributable effects were inhibited by co-treatment with eplerenone and PD98059, a specific inhibitor of mitogen-activated protein kinase/ERK kinase activity. The results suggest that 11ß-HSD1 but not CYP11-B2 is expressed in primary CFs. Eplerenone inhibited isoproterenol-induced ERK1/2 phosphorylation and expression of 11ß-HSD1 and collagen-I in primary CFs, as well as the progression of cardiac fibrosis in the left ventricle. Therefore, eplerenone inhibited the isoproterenol-induced increases in 11ß-HSD1 and collagen-I expression in primary CFs, and progression of cardiac fibrosis in the left ventricle.

Repeated phlebotomies decrease body iron storage in adult dogs.

The aim of the present study was to determine changes in body iron storage in adult dogs following phlebotomy. We performed repeated phlebotomies by removing 1% body weight (approximately 10% of the total blood volume) weekly for a total of 12 times using adult beagle dogs without an iron-restricted diet. After treatment, stored iron was decreased, as demonstrated by gradual reductions in serum ferritin levels and hepatic iron contents. Anemia and abnormalities in blood chemistry analysis were not observed; therefore, this method was considered safe and useful for control of stored iron levels in adult dogs.

Influence of storage conditions on in vitro stability of atrial natriuretic peptide and of anesthesia on plasma atrial natriuretic peptide concentration in cats.

OBJECTIVE To investigate the in vitro stability of atrial natriuretic peptide (ANP) in plasma samples under various storage conditions and the influence of anesthesia on plasma ANP concentration in cats. ANIMALS 1 cat with congestive heart failure and 5 healthy adult mixed-breed cats. PROCEDURES A plasma sample from the cat with heart failure was serially diluted, and dilutional parallelism of ANP concentration was evaluated. Plasma samples containing aprotinin or serum samples from the 5 healthy cats were kept at room temperature (27°C) for ≤ 12 hours. Plasma samples from the same healthy cats were stored at -70°, -20°, or 4°C for ≤ 14 days. Plasma samples were obtained from the healthy cats before and during isoflurane anesthesia. Plasma ANP concentrations were measured at a commercial laboratory by use of a human ANP chemiluminescence assay. RESULTS Intra- and interassay coefficients of variation were 1.5% and 2.5%, respectively, and dilutional parallelism was established. Although ANP concentration decreased by 82.4 ± 13.6% (mean ± SD) after sample storage for 12 hours at room temperature, this decrease was prevented by aprotinin. Plasma ANP concentrations were stable for 7 days at -20°C and for 14 days at -70°C. However, concentrations decreased markedly to 57.6 ± 6.9% at -20°C and to 18.0 ± 3.0% at 4°C after 14 days. Plasma ANP concentration decreased significantly in cats during anesthesia and was correlated with blood pressure. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that aprotinin should be added routinely in preparation of plasma samples from cats for measurement of ANP concentration, and those samples, if stored, should be frozen immediately at ≤ -20°C. General anesthesia or systemic blood pressure may affect plasma ANP concentration in cats.

Indirect arterial blood pressure measurement in healthy anesthetized cats using a device that combines oscillometry with photoplethysmography.

We investigated the basic characteristics of indirect arterial blood pressure (ABP) measurement using a device that combines oscillometry and photoplethysmography in cats. Dobutamine was infused intravenously in four anesthetized cats. Direct ABP was measured by a catheter. Indirect ABP was measured from the left forelimb. Dobutamine significantly elevated both systolic arterial pressure (SAP) and mean arterial pressure (MAP) in a dose-dependent manner. The indirect SAP, MAP and diastolic arterial pressure (DAP) values were closely correlated with the direct ABP values (r=0.88, 0.89 and 0.83, respectively). The mean bias for SAP, MAP and DAP was 3.4, 0.2 and -2.4 mmHg, respectively. The indirect ABP measured by this device may be used to reliably monitor ABP changes in anesthetized cats.

Plasma atrial natriuretic peptide and N-terminal pro B-type natriuretic peptide concentrations in dogs with right-sided congestive heart failure.

The clinical utility of plasma natriuretic peptide concentrations in dogs with right-sided congestive heart failure (CHF) remains unclear. We investigated whether plasma levels of atrial natriuretic peptide (ANP) and N-terminal pro B-type natriuretic peptide (NT-proBNP) are useful for assessing the congestive signs of right-sided heart failure in dogs. This retrospective study enrolled 16 healthy dogs and 51 untreated dogs with presence (n=28) or absence (n=23) of right-sided CHF. Medical records of physical examinations, thoracic radiography and echocardiography were reviewed. The plasma concentration of canine ANP was measured with a chemiluminescent enzyme immunoassay. Plasma NT-proBNP concentrations were determined using an enzyme immunoassay. Plasma ANP and NT-proBNP concentrations in dogs with right-sided CHF were significantly higher than in healthy controls and those without right-sided CHF. The plasma NT-proBNP concentration >3,003 pmol/l used to identify right-sided CHF had a sensitivity of 88.5% and specificity of 90.3%. An area under the ROC curve (AUC) was 0.93. The AUC for NT-proBNP was significantly higher than the AUCs for the cardiothoracic ratio, vertebral heart score, ratio of right ventricular end-diastolic internal diameter to body surface area, tricuspid late diastolic flow and ratio of the velocities of tricuspid early to late diastolic flow. These results suggest that plasma ANP and NT-proBNP concentrations increase markedly in dogs with right-sided CHF. Particularly, NT-proBNP is simple and helpful biomarkers to assess the right-sided CHF.

Hyperferritinemia is associated with short survival time in dogs with multicentric lymphoma.

In the present study, we examined the relationship between serum ferritin concentration before treatment and survival time in dogs with multicentric lymphoma. Eighteen dogs with multicentric lymphoma were enrolled in the study. When the dogs were classified into high and low ferritin groups on the basis of their serum ferritin concentration (3,000 ng/ml cut-off value), the median survival time of dogs with high concentrations (≥3,000 ng/ml, n=7) was 40 days, whereas it was 360 days among dogs with low concentrations (<3,000 ng/ml, n=11). This difference was statistically significant (P=0.001). This finding suggests that the initial high level of serum ferritin indicates short survival time in dogs with multicentric lymphoma. Large-scale research is necessary to confirm this finding.

Prevalence of intestinal parasites in breeding kennel dogs in Japan.

The present study is the first to show overall prevalences of intestinal parasites among breeding kennel dogs in Japan. A total of 573 fresh fecal samples were collected from dogs at 12 breeding kennels. Giardia-specific coproantigen was examined by ELISA kit (SNAP(®) Giardia, IDEXX Laboratories, Inc., Maine, USA). Other intestinal parasites were determined microscopically using the formalin-ethyl acetate sedimentation technique. Overall prevalences of two genera of protists, Giardia spp. and Cystoisospora spp., were 25.7 and 1.2 %, respectively. The prevalence of helminthes was recorded as: Toxocara canis 0.2 %, Toxascaris leonina 0.9 %, Ancylostoma caninum 0.2 %, Trichuris vulpis 2.1 %, and Spirometra erinacei 0.4 %. According to age categories, Giardia spp., Cystoisospora spp., and T. leonina in <1-year-old dogs were significantly more prevalent than in ≥ 1-year-old dogs (61.0 vs. 19.8 %, P < 0.0001; 7.3 vs. 0.2 %, P < 0.0001; and 4.9 vs. 0.2 %, P < 0.001; respectively). With respect to fecal condition, the prevalences of T. leonina and T. vulpis were significantly higher in unformed stool dogs than in formed ones (2.4 vs. 0 %, P < 0.01, and 4.3 vs. 0.8 %, P < 0.05, respectively). In all of the breeding kennels except for one kennel, intestinal parasite infections were found at the high prevalent, ranging from 16.0 to 70.0 %.

Effect of the phosphodiesterase type 5 inhibitor tadalafil on pulmonary hemodynamics in a canine model of pulmonary hypertension.

Phosphodiesterase type 5 (PDE5) inhibitors are used for treating pulmonary arterial hypertension (PAH) in dogs. The long-acting PDE5 inhibitor tadalafil was recently approved for treatment of PAH in humans. Basic information related to the pharmacological and hemodynamic effects of tadalafil in dogs is scarce. In this study, the hemodynamic effects of tadalafil after intravenous (IV) and oral administration were investigated in a healthy vasoconstrictive PAH Beagle dog model induced by U46619, a thromboxane A2 mimetic. Six healthy Beagle dogs were anesthetized with propofol and maintained with isoflurane. Fluid-filled catheters were placed into the descending aorta to measure systemic arterial pressure and in the pulmonary artery to measure pulmonary arterial pressure (PAP). U46619 was infused via the cephalic vein to induce PAH. IV infusion of U46619 significantly elevated PAP from baseline in a dose-dependent manner. U46619-elevated PAP and pulmonary vascular resistance was significantly attenuated by the simultaneous infusion of tadalafil at 100 and 200 µg/kg/h. Likewise, oral administration of tadalafil at 1.0, 2.0, and 4.0 mg/kg significantly attenuated U46619-elevated PAP in a dose-dependent manner. U46619-elevated systolic and mean PAP decreased significantly 1 h after oral tadalafil administration at 4.0 mg/kg, and this effect was maintained for 6 h. In conclusion, tadalafil had a pharmacological effect in dogs and IV infusion of tadalafil induced pulmonary arterial relaxation, while oral administration of tadalafil decreased PAP. These results suggest that tadalafil may offer a new therapeutic option for treating dogs with PAH.

Molecular detection and characterization of Cryptosporidium species in household dogs, pet shop puppies, and dogs kept in a school of veterinary nursing in Japan.

Members of Cryptosporidium species, which are protozoan parasites, are prevalent worldwide and can cause diarrhoea in both humans and animals, including dogs. In addition, the Cryptosporidium species harboured in dogs have the potential for zoonotic transmission. The purpose of the present study was to determine the prevalence of Cryptosporidium species infection and perform molecular characterization of isolates in household dogs, pet shop puppies, and dogs kept in a school of veterinary nursing in Japan. Fresh faecal samples were collected once from 529 household dogs (aged from 2 months to 18 years old, from 9 veterinary clinics located in 6 different regions), 471 pet shop puppies (≤ 3 months old, from 4 pet shops located in 2 different regions), and 98 dogs (aged from 2 to 11 years old) kept in a veterinary nursing school. A nested polymerase chain reaction (PCR) assay targeting the 18S rRNA gene was employed for the detection of Cryptosporidium species, and 111 random samples of PCR amplicons (approximately 500-bp) were sequenced for the molecular characterization of the isolates. The prevalences of Cryptosporidium species in household dogs, pet shop puppies, and veterinary nursing school dogs were 7.2%, 31.6%, and 18.4%, respectively. In household dogs, no significant correlation was observed between the prevalence of Cryptosporidium species and the age (≤ 6 months vs. >6 months), living conditions (indoor vs. outdoor), faecal conditions (formed vs. unformed), and location of residence. In pet shop puppies, the prevalence of Cryptosporidium species was not related to faecal condition; however, the prevalence significantly differed among the pet shops. All of the 111 sequence samples (26 from household dogs, 75 from pet shop puppies, and 10 from veterinary nursing school dogs) were identified as Cryptosporidium canis. The present study demonstrates a high prevalence of Cryptosporidium species infections in pet shop puppies and dogs of a veterinary nursing school in Japan. However, because Cryptosporidium hominis and Cryptosporidium parvum are the most common causes of human infections, it is likely that the risk of zoonotic transmission of Cryptosporidium species from dogs to humans is low.

Erythrophagocytosis enhances heme-dependent cytotoxicity of antimalarial drugs in canine histiocytic sarcoma cell line DH82.

Antimalarial drugs, dihydroartemisinin (DHA) and artesunate (ATS), exhibit iron-dependent cytotoxicity in tumor cells. We hypothesized that erythrophagocytic uptake of heme-iron enhances the cytotoxicity of DHA and ATS. Erythrophagocytic (EP) treatment of the canine histiocytic sarcoma cell line DH82 markedly increased the cytotoxicity of DHA and ATS compared to controls. Succinyl acetone, an inhibitor of intracellular heme synthesis, decreased the cytotoxicity of DHA and ATS in normal cells, but this change was not observed in EP cells. These results suggest that exogenous heme derived from erythrocytes can enhance the cytotoxicity of DHA and ATS. Furthermore, our study suggests that heme could be a novel component of tumor treatment in veterinary medicine.

Selection of suitable reference genes for mRNA quantification studies using common marmoset tissues.

The common marmoset (Callithrix jacchus) is increasingly being used as a non-human primate animal model in biomedical research. To perform accurate quantitative analysis of gene expression by quantitative reverse transcription polymerase chain reaction, reliable reference genes should be selected. In this study, we evaluated the expressions of 11 widely used reference genes: ACTB, ATP5F1, B2M, GAPDH, HPRT1, PGK1, PPIA, RN18S1, RPLP0, TBP and UBC in 12 tissues and five brain areas of healthy common marmosets. NormFinder and geNorm indicated that the most suitable reference genes for cross-sectional studies of the 17 tissues were RN18S1 and RPLP0. Conversely, ACTB and PPIA were the most suitable for analyzing brain samples; however, the expression of PGK1 fluctuated among brain areas. These results indicate that suitable reference genes differ between the tissues examined. This study provides fundamental information for gene expression studies of the common marmoset and highlights the importance of validating reference genes before quantification of target mRNAs.

Factors influencing measurement of serum iron concentration in dogs: diurnal variation and hyperferritinemia.

We evaluated diurnal variation and hyperferritinemia as factors that influence the values of serum iron concentration in dogs, using the International Committee for Standardization in Hematology (ICSH) colorimetric method. Serum iron levels were significantly higher in the morning than in the evening in 6 clinically healthy beagle dogs, and the maximum decrease in serum iron concentration was 47.3%. Moreover, the change in serum iron concentrations in 22 clinical canine cases with various serum ferritin levels was evaluated by immunoprecipitation of ferritin. The rate of decline in the serum iron concentrations positively correlated with serum ferritin levels (r=0.48, P=0.024). These results show that it is necessary to consider the sampling time and serum ferritin level for accurate interpretation of serum iron concentrations in dogs.

Relationship between major histocompatibility complex class I expression and prognosis in canine mammary gland tumors.

The aim of this study was to evaluate MHC class I expression and prognosis using tumor tissues surgically removed from 9 dogs with mammary gland carcinomas and from 13 dogs with complex carcinomas. We assessed MHC class I expression and its correlation with tumor size, B2M expression, infiltration of lymphocytes, histological grade and prognosis. Hematoxylin and eosin-stained sections were histologically graded using the Elston and Ellis grading method. MHC class I expression on tumor cells was evaluated using the avidin-biotin peroxidase complex method. Loss of MHC class I expression from canine mammary gland carcinomas was significantly correlated with poor prognosis (P<0.05). Loss of MHC class I expression showed no association with poor prognosis in canine mammary gland complex carcinomas, because the data were not balanced. Only 1 of 13 (7.6%) canine mammary gland complex carcinomas showed loss of MHC class I expression. All 13 of these dogs showed good prognosis. Thus, the low frequency of MHC class I expression loss from canine mammary gland complex carcinomas may be associated with good prognosis. Taken together, these results suggest that loss of MHC class I expression may be associated with poor prognosis in canine mammary gland carcinomas.

Hyperferritinemia in dogs with splenic hemangiosarcoma.

Serum ferritin concentration increases in dogs in association with various diseases. In this study, we measured serum ferritin levels in dogs with splenic masses, using a sandwich ELISA assay. Eleven dogs with hemangiosarcoma (HSA), six with hematoma, 1 with hemangioma and 3 with lymphoma were enrolled. All dogs with HSA had serum ferritin concentrations above the normal limit (1,357 ng/ml, mean + 2× standard deviation of normal). Increased serum ferritin concentrations have also been observed in few cases of hematoma, hemangioma and lymphoma. Therefore, hyperferritinemia is not specific for splenic HSA, but may have clinical usefulness as a sensitive test for the disease. Further evaluation of serum ferritin concentrations in dogs with splenic HSA is needed.

Change in serum ferritin concentration in experimentally induced anemia of chronic inflammation in dogs.

In veterinary medicine, hyperferritinemia is often observed in dogs with various diseases (e.g., histiocytic sarcoma and immune-mediated hemolytic anemia) without evidence of iron overload. The mechanism underlying hyperferritinemia development is not well understood. Anemia caused by inflammation is termed as anemia of chronic disease (ACD), and experimentally induced ACD is known to cause slight hyperferritinemia. However, almost all these studies were based on short-term acute inflammation. Hepcidin, a protein mainly produced by hepatocytes, is thought to be a key regulator in iron release from reticuloendothelial cells (RECs), and its expression is related to ACD. We hypothesized that in the case of long-term ACD, iron deposition in RECs increases through hepcidin, causing a diachronic increase in serum ferritin levels. In the present study, we used a canine model with repeated subcutaneous administration of turpentine oil every 3 days over a period of 42 days (15 injections) and induced long-term inflammatory conditions; furthermore, we evaluated the change in serum ferritin concentration. Hypoproliferative anemia, bone marrow iron deposition and hypoferremia, which are characteristic of ACD, were observed on administering the turpentine injections. Hepatic iron content, hepatic hepcidin mRNA expression and serum ferritin concentration increased during the early period after turpentine injection, but returned to normal levels later. These results show that experimentally induced long-term ACD caused hypoproliferative anemia without sustained increase in hepcidin expression and did not cause systemic iron overload. Thus, chronic inflammation may not contribute greatly to increase in hyperferritinemia.