Prognostic value of serum cystatin C concentration in dogs with myxomatous mitral valve disease.

BACKGROUND: Impaired renal function is 1 of the poor prognostic factors in dogs with myxomatous mitral valve disease (MMVD). However, the value of cystatin C (Cys-C), a marker of renal function, as a prognostic marker for MMVD in dogs has not yet been explored. OBJECTIVE: This study aims to investigate the prognostic value of Cys-C in dogs with MMVD. ANIMALS: Fifty client-owned small-breed dogs with MMVD were included in this study. METHODS: This is a retrospective, cross-sectional study. The prognostic value of serum Cys-C concentration was assessed using univariable and multivariable Cox hazard regression analyses. Kaplan-Meier survival curves for MMVD-specific survival in dogs stratified into high and low Cys-C groups were generated and analyzed using the log-rank test. RESULTS: Serum Cys-C concentrations were significantly associated with MMVD-related death (P < .01) in both univariable (hazard ratio [HR], 5.086; 95% confidence interval [CI], 1.950-13.270) and multivariable Cox hazard regression analysis (HR, 4.657; 95% CI, 1.767-12.270). The high Cys-C group (n = 14) had a significantly shorter MMVD-specific survival time than the low Cys-C group (n = 36; P < .01). In dogs with normal blood creatinine concentrations, the high Cys-C group (n = 10) had a significantly shorter MMVD-specific survival time than the low Cys-C group (n = 36; P < .01). CONCLUSIONS AND CLINICAL IMPORTANCE: High serum Cys-C concentrations were associated with a worse prognosis of MMVD. Furthermore, serum Cys-C could be a predictor of MMVD prognosis even in dogs with normal blood creatinine concentration.

Erythritol inhibits the growth of periodontal-disease-associated bacteria isolated from canine oral cavity.

Periodontal disease (PD) is the most common oral disease that is caused by infection with periodontal-disease-associated bacteria (PDAB) such as Porphyromonas gulae and Porphyromonas macacae in dogs as well as in humans. Unlike humans, most dogs do not follow daily oral hygiene routine, and this results in many dogs being affected by PD. Thus, to prevent PD, it is important to control PDAB. Xylitol is a sugar alcohol that inhibits the growth of oral bacteria in humans. However, xylitol is poisonous to dogs and can lead to hypoglycemia and hepatic failure. Herein, we show the inhibitory effect of erythritol, a sugar alcohol that can be used safely in dogs, on the growth of PDAB isolated from dogs with PD. Oral bacteria were isolated from the oral cavities of dogs with PD, and the distribution of PDAB was evaluated. Interestingly, Porphyromonas gingivalis, a bacterium typically responsible for PD in humans, was not isolated from dog samples. The bacteriostatic effect of erythritol supplementation was investigated on isolated PDAB in vitro. Our results show that erythritol exert bacteriostatic effects on PDAB comparable to xylitol. Thus, application of erythritol can be suggested to control PDAB in dogs in the future.

Visual and histological evaluation of the effects of trafermin in a dog oronasal fistula model.

The standard procedure to treat oronasal fistula in dogs requires tooth extraction to close the fistula; hence, the subject would lose its tooth. In this study, trafermin was applied to four dog models with oronasal fistula to investigate the periodontal tissue regenerative effects of trafermin in the treatment without tooth extraction. A fistula was created along the palatal side of each upper canine tooth. One of the fistulae was filled with trafermin, whereas that on the contralateral side was left unfilled as a control. The results showed a significant decrease in the non-calcified periodontal tissue volume on the trafermin side after the fourth week. In addition, oronasal fistula closure was visually and histologically confirmed at the eighth week on the trafermin side of all four models.

Detection of granzyme B in CD3-positive cells infiltrated in lesional skin of a dog with erythema multiforme associated with zonisamide.

In human erythema multiforme (EM), cytotoxic T lymphocytes (CTLs) play an essential role in the pathogenesis. In canine EM, immunohistochemical staining with anti-CD8 antibody using frozen sections has shown the involvement of CTLs; however, CTL infiltration has never been quantitatively analyzed. We herein quantitatively analyzed CTL infiltration by immunohistochemical staining with granzyme B and CD3 antibodies using paraffin sections of a dog with EM associated with zonisamide. The present results indicated approximately 70% of cells at the border between the epidermis and dermis consisted of CTLs. Detection of granzyme B and CD3 using paraffin sections employed in this study can be a clinically applicable method for detecting CTLs.

PCR-based genotyping assays to detect germline APC variant associated with hereditary gastrointestinal polyposis in Jack Russell terriers.

BACKGROUND: The prevalence of gastrointestinal (GI) neoplastic polyps in Jack Russell terriers (JRTs) has increased in Japan since the late 2000s. Recently, we demonstrated that JRTs with GI polyps harbor identical germline variant in the APC gene (c.[462_463delinsTT]) in the heterozygous state. Thus, this disease is an autosomal dominant hereditary disorder. Although the affected JRTs have distinct features, such as the development of multiple GI polyps and an early age of disease onset, genetic testing is indispensable for a definitive diagnosis. Here, polymerase chain reaction (PCR)-based assays capable of detecting germline APC variant were designed and validated using synthetic wild-type and mutant DNAs and genomic DNAs from carrier and non-carrier dogs. RESULT: First, the PCR-restriction fragment length polymorphism (PCR-RFLP) assay was developed by taking advantage of the germline APC variant creating a new restriction site for MseI. In the PCR-RFLP assay, the 156-bp region containing the variant site was amplified by PCR and subsequently digested with MseI, yielding diagnostic 51 and 58 bp fragments from the mutant allele and allowing determination of the APC genotypes. It was possible to determine the genotypes using genomic DNA extracted from the peripheral blood, buccal swab, or formalin-fixed paraffin-embedded tissue. Next, a TaqMan duplex real-time PCR assay was developed, where a 78-bp region flanking the variant was amplified in the presence of wild-type allele- and mutant allele-specific fluorescent probes. Using blood-derived DNA, altogether 40 cycles of PCR amplification determined the APC genotypes of all examined samples by measuring the fluorescence intensities. Importantly, false-positive and false-negative errors were never detected in both assays. CONCLUSION: In this study, we developed highly reliable genetic tests for hereditary GI polyposis in JRTs, providing accurate assessment of the presence of the causative germline APC variant. The genotyping assays could contribute to the diagnosis and prevention of hereditary GI polyposis in dogs.

Body surface area measurements in male Hartley guinea pigs using a computed tomography scanner.

The body surface area (BSA) of animals is generally estimated by multiplying the k value (constant) by the measured body weight (BW) raised to the power of 2/3 (Meeh's formula). Computed tomography (CT) scanners generate detailed 3-dimensional (3D) images of objects, and image analysis does not depend on operator skill. Therefore, the analysis of CT images provides accurate and reproducible BSA measurements. In this study, we measured the BSA of 25 male Hartley guinea pigs from 3 to 36 weeks of age (working BW range: 0.233 to 1.160 kg) using a CT scanner and 3D analysis software. We concluded that the k value for male Hartley guinea pigs was 8.37, based on the mean k value of the 25 animals.

Familial adenomatous polyposis in dogs: hereditary gastrointestinal polyposis in Jack Russell Terriers with germline APC mutations.

Many hereditary disorders in dogs have equivalents in humans and thus attract attention as natural animal models. Breed predisposition to certain diseases often provides promising clues to explore novel hereditary disorders in dogs. Recently, cases of gastrointestinal (GI) polyps in Jack Russell Terriers (JRTs) have increased in Japan. In 21 affected JRTs, polyps were found in either or both the stomach and colorectum, with a predilection for the gastric antrum and rectum. Multiple polyps were found in 13 of 21 examined dogs, including 5 dogs with both gastric and colorectal polyps. Some dogs were found to have GI polyps at an early age, with the youngest case being 2.3 years old. Histopathologically, 43 of 46 GI polyps (93.5%) were diagnosed as adenomas or adenocarcinomas. Immunohistochemical analysis revealed cytoplasmic and nuclear accumulation of ß-catenin in the tumor cells. As in the case of human patients with familial adenomatous polyposis, all examined JRTs with GI polyps (n = 21) harbored the identical heterozygous germline APC mutations, represented by a 2-bp substitution (c.[462A>T; 463A>T]). The latter substitution was a non-sense mutation (p.K155X) resulting in a truncated APC protein, thus suggesting a strong association with this cancer-prone disorder. Somatic mutation and loss of the wild-type APC allele were detected in the GI tumors of JRTs, suggesting that biallelic APC inactivation was involved in tumor development. This study demonstrated that despite differences in the disease conditions between human and dog diseases, germline APC mutation confers a predisposition to GI neoplastic polyps in both dogs and humans.

Measurements of body surface area and volume in male Japanese White rabbits using a computed tomography scanner: comparison with male New Zealand White rabbits.

The body surface area (BSA) of animals has generally been estimated by multiplying the k value by the measured body weight (BW) raised to the power of 2/3 (Meeh's formula). In mathematical terms, the assumption that the density and body shape of animals are essentially constant means that the BSA is proportional to BW2/3. In this study, we measured the BSA and volume of 50 male Japanese White rabbits (JW) at 10 to 54 weeks of age using a computed tomography scanner, then calculated the k value, density, and sphericity. The variations in these parameters were then analyzed in relation to growth. The obtained results indicated that the k value was negatively correlated to BW, and that this negative correlation was mainly due to the variation in density. Based on the regression analysis, we propose the following linear regression equation for calculating the k value in male JW at 10-54 weeks of age: the k value = 14.602 - 0.959 × BW [kg]. The calculated values ranged from 10.9 to 12.7 (working BW range: 1.98 to 3.81 kg). The k value of male New Zealand White rabbits (NZW) determined in our previous study and that of male JW in the present study were compared. It was revealed that the k value of male JW was larger than that of male NZW. We concluded that different breeds of rabbits express different k values.

Hypofractionated radiotherapy in nine dogs with unresectable solitary lung adenocarcinoma.

Although lung lobectomy is the most common treatment option for dogs with solitary lung tumors, surgery often cannot be performed at the time of diagnosis. In this retrospective, case series study, we described the effects of hypofractionated radiotherapy for tumor mass reduction in nine dogs with solitary lung adenocarcinoma that were later considered for surgical resection, and we assessed the tolerability of the radiation protocol. Tumors were deemed unresectable by the attending veterinarian. The dose prescription was 7.0-12.0 Gy/fraction in four to seven fractions, administered weekly for a total dose of 40-50 Gy. Treatment planning prioritized normal tissue dose constraints. The median interval between the last radiotherapy session and maximum tumor size reduction was 56 (range: 26-196) days, with six and three dogs exhibiting a partial response and stable disease, respectively. Although acute and late radiation-induced toxicity to the skin and/or lungs developed in all nine dogs, it was self-limiting or improved with short-term anti-inflammatory treatment. Tumor progression after initial size reduction was confirmed in three dogs at 62, 126, and 175 days, respectively, after the last radiotherapy session. Seven of the nine dogs underwent lobectomy a median of 68 days after radiotherapy when tumors were in partial response or stable disease or at the time of progression, and five received systemic chemotherapy concurrent with or after radiotherapy. These findings suggest that hypofractionated radiotherapy for canine solitary lung adenocarcinoma is useful when the tumor is large or when surgery cannot be performed immediately after diagnosis.

Survival analysis in dogs with urinary transitional cell carcinoma that underwent whole-body computed tomography at diagnosis.

This retrospective study aimed to evaluate factors associated with survival and to compare characteristics between tumour localizations in dogs with urinary transitional cell carcinoma (TCC) that underwent whole-body computed tomography (CT) at diagnosis. Dogs with histologically confirmed TCC that received medical therapy between 2010 and 2017 were included; dogs that underwent surgery or radiotherapy for the primary tumour were excluded. According to the CT findings, primary tumour localization (classified into the Bladder, Urethra and Bladder and Urethra groups), prostate involvement, iliosacral lymphadenomegaly, sternal lymphadenomegaly and metastasis to the bone and lung were evaluated for survival analysis. CT at diagnosis revealed iliosacral lymphadenomegaly, sternal lymphadenomegaly, bone metastasis and lung metastasis in 47.7%, 18.5%, 24.6% and 35.4% of the 65 included dogs, respectively. The overall median survival time was 196 days. On multivariable analysis, TCC localization (hazard ratio [HR], 1.90; P = .037), bone metastasis (HR, 2.76; P = .013) and sternal lymphadenomegaly (HR, 3.56; P = .004) were significantly associated with survival. Compared to the Bladder group (n = 16), the Urethra group (n = 26) had higher metastasis rates to the bone (6.3% vs 42.3%; P = .045) and lung (6.3% vs 46.2%; P = .022). The survival time was shorter in the Urethra group than in the Bladder group (121.5 vs 420 days; P < .001), and it was similar only in female dogs (247 vs 420 days; P = .031). These findings suggest that whole-body CT could be valuable for predicting the prognosis in urinary TCC.

Short-Term Administration of Single-Agent Toceranib in Six Cases of Inoperable Massive Canine Hepatocellular Carcinoma.

Six dogs with massive hepatocellular carcinoma that was not amenable to surgery were treated by oral administration of single-agent toceranib at a dose of 2.0-3.0 mg/kg every other day for a minimum of 60 days. Partial response was achieved in three dogs, stable disease was achieved in one dog, and progressive disease occurred in two dogs, according to the canine Response Evaluation Criteria in Solid Tumors v1.0. Observed adverse events were mild to moderate in severity and reported in accordance with the Veterinary Cooperative Oncology Group's common terminology criteria for adverse events v1.1. Activities of alanine aminotransferase and alkaline phosphatase decreased in the cases that were sensitive to treatment with toceranib, whereas the activities remained high in resistant cases. Additionally, the level of phospho-vascular endothelial growth factor receptor 2 was found to be increased in a resistant case. Single-agent toceranib might prove to be an effective treatment for canine hepatocellular carcinoma pending further validation.

Measurements of body surface area and volume in laboratory rabbits (New Zealand White rabbits) using a computed tomography scanner.

The body surface area (BSA) of an organism is one of the important parameters for evaluating physiological functions. In drug development, normalization by BSA is an appropriate method for extrapolating doses between species. The BSA of animals has generally been estimated by multiplying the k value by 2/3 of the power of the body weight (BW) (Meeh's formula). In mathematics, if it is assumed that the density and body shape of the animals are essentially constant, the BSA is proportional to BW2/3. In this study, we measured the BSA and volume (V) of 72 laboratory rabbits (48 males and 24 females of New Zealand White rabbits [NZW]), using a computed tomography scanner. After BSA and V determination, the k value, density, and sphericity were calculated. We analyzed variations in the k value, density, and body shape of laboratory rabbits. The mean k value of the 72 NZW was 11.0. We advocate using Meeh's formula, as follows, for estimating BSA of laboratory rabbits (NZW): 100 × BSA [m2] = 11.0 × BW [kg]2/3.

Combination Chlorambucil/Firocoxib or Chlorambucil/Prednisolone Treatment for Inflammatory Colorectal Polyps in Miniature Dachshunds.

Inflammatory colorectal polyps (ICRP), which are more commonly recognized in miniature dachshunds, are thought to represent an immune-mediated disease. This retrospective case series describes six miniature dachshunds with refractory ICRP, who were treated with chlorambucil (CLB) combined with firocoxib or prednisolone. Improvement in clinical manifestations was seen in five of the six dogs by the end of the study period; four were treated with CLB/firocoxib and one with CLB/prednisolone. One dog had nonregenerative anemia after 23 mo of treatment with CLB, but whether there was a causative relationship was unclear. No severe adverse events were observed during treatment in the remaining five dogs. CLB in combination with firocoxib or prednisolone appears to be an effective alternative treatment for ICRP in dogs. Further studies are needed to confirm the effectiveness and long-term complications of CLB treatment for ICRP in dogs.

Hypofractionated radiation therapy in the treatment of canine thymoma: Retrospective study of eight cases.

Thymomas are one of the most common tumors of the cranial mediastinum in dogs; however there is limited information available on the use of radiation therapy for treating this neoplasm. Objectives of the current retrospective observational study were to describe outcomes and side effects of a hypofractionated radiation therapy protocol in a group of dogs with confirmed thymoma. A total of eight dogs were included. To generate individualized treatment plans, we designed the planning target volume according to the limits on mean lung dose and the percentage of the total lung volume exceeding 20 Gy (V20). The total administered dose was 48-49 Gy, with one fraction per week for a total of six to seven fractions. After therapy, two dogs achieved complete responses, two achieved partial responses, and the disease remained stable in two. Two dogs died during the radiation therapy protocol and were not classified. The median mean lung dose and V20 were 6.0 Gy (range: 3.1-15.0 Gy) and 12.4% (range: 2.3-27.5%), respectively. The overall response rate was 50.0%, and the median time to response following treatment initiation was 22 days (range: 14-115 days). Acute and late side effects were common in the skin and/or lung and were self-limiting or asymptomatic. The median survival time was not reached (range: 8-1128 days) and the 1 year survival rate was 75.0%. Hypofractionated radiation therapy was well tolerated in this sample of dogs with thymoma and may be considered when owners decline surgical treatment or the tumor is deemed unresectable.

Body surface area measurement in juvenile miniature pigs using a computed tomography scanner.

The use of miniature pigs in non-clinical studies for medical drugs or devices has gradually been increasing in recent years. It is anticipated that the use of juvenile miniature pigs in laboratory practice will also increase. Therefore, it is important to investigate various parameters of juvenile miniature pigs. The body surface area (BSA) of an organism is one of the important parameters for evaluating physiological functions. In drug development, normalization by BSA is an appropriate method for extrapolating doses between species. The BSA of animals has generally been estimated by multiplying the k value by 2/3 of the power of the body weight (BW) (Meeh's formula). To our knowledge, the BSA of juvenile miniature pigs has not as yet been reported. In this study, we measured the BSA of 13 miniature pigs less than 1 month old, using a computed tomography scanner and 3-dimensional analysis software. The measurement results showed the BSAs of these 13 juvenile miniature pigs to be in the range of 386 to 1,672 cm2(working BW range: 278 to 3,200 g). After BSA determination, the k values were calculated from the BSA and the BW. The mean calculated k value was 8.58. We advocate using Meeh's formula, as follows, for estimating the BSA of juvenile miniature pigs less than 1 month old (before weaning): BSA (cm2)=8.58 × BW (g)2/3.

Computed Tomographic Evaluation of Presumptively Normal Canine Sternal Lymph Nodes.

The sternal lymph nodes receive drainage from a wide variety of structures in the thoraco-abdominal region. Evaluation of these lymph nodes is essential, especially in cancer patients. Computed tomography (CT) can detect sternal lymph nodes more accurately than radiography or ultrasonography, and the criteria of the sternal lymphadenopathy are unknown. The purpose of this retrospective study was to describe the CT characteristics of the sternal lymph nodes in dogs considered unlikely to have lymphadenopathy. The ratio of the short axis dimension of the sternal lymph nodes to the thickness of the second sternebra was also investigated. At least one sternal lymph node was identified in each of the 152 dogs included in the study. The mean long axis and short axis dimensions were 0.700 cm and 0.368 cm, respectively. The mean ratio of the sternal lymph nodes to the second sternebrae was 0.457, and the 95% prediction interval ranged from 0.317 to 0.596 (almost a fixed value independent of body weight). These findings will be useful when evaluating sternal lymphadenopathy using CT.

Body surface area measurement in laboratory miniature pigs using a computed tomography scanner.

The body surface area (BSA) of an organism is an important parameter for evaluating physiological functions. In drug development, normalization by BSA is an appropriate method for extrapolating doses between species. The BSA of animals has generally been estimated by multiplying a constant by the power of the body weight (BW). Recently, the use of miniature pigs in non-clinical studies for medical drugs or devices has gradually been increasing. However, verification of their BSA is not as yet sufficient. In this study, we measured the BSAs of 40 laboratory miniature pigs (11 males and 9 females of Göttingen minipig and 14 males and 6 females of Nippon Institute for Biological Science [NIBS] miniature pig) by analyzing computed tomography (CT) images, since measurements using a CT scanner were expected to more precisely determine BSA than classical measuring techniques. The measurement results showed the BSAs of the 20 Göttingen minipigs to range from 0.4358 to 0.8356 m(2) (the working BW range: 12.7-37.0 kg) and 20 NIBS miniature pigs to range from 0.2906 to 0.8675 m(2) (the working BW range: 7.9-41.5 kg). Since accuracy and reproducibility were confirmed by measuring the surface area of an acrylic cuboid, we concluded the measurement method employed in this study to be very reliable. We propose the following estimating formula for BSA of laboratory miniature pigs: 100 × BSA [m(2)] = 7.98 × BW [kg](2/3).

Canine tumor development and crude incidence of tumors by breed based on domestic dogs in Gifu prefecture.

We analyzed the status of tumor development in dogs by breed based on tumor cases that presented to the Department of Veterinary Pathology of the Gifu University for diagnostic examinations over eight years (2005-2012). We also calculated the crude incidence of tumors in dogs by breed based on the results of a survey conducted in 2011 in Gifu Prefecture. The most common sites of tumor development included the skin, digestive organs and mammary glands. Smaller dogs showed a tendency to have a higher incidence of breast tumors. We thus identified dog breeds with a higher crude incidence of tumors (Bernese mountain dog, golden retriever, corgi, etc.) and those with a lower crude incidence of tumors (Pomeranian, poodle, Chihuahua, etc.). Unlike the current trends for domestic dogs in the US and Europe, Japan has a higher number of small dogs as pets; it is therefore necessary to develop a policy for canine cancer specific to Japan.

Outcomes of dogs undergoing radiotherapy for treatment of oral malignant melanoma: 111 cases (2006-2012).

OBJECTIVE: To evaluate the characteristics and outcomes of dogs with stage I, II, III, or IV oral malignant melanoma treated by various types of radiotherapy. DESIGN: Retrospective case series. ANIMALS: 111 dogs. PROCEDURES: Medical records of dogs with oral malignant melanoma treated by radiotherapy (with or without adjunctive treatments) at a veterinary medical center between July 2006 and December 2012 were reviewed. Information regarding signalment, tumor location, disease stage, treatment protocols, adverse effects, and survival time were obtained from medical records and by telephone follow-up. Associations between variables of interest and outcome were analyzed. RESULTS: Dogs received orthovoltage x-ray (n = 68), megavoltage x-ray (39), or electron beam (4) radiotherapy. Adjunctive treatments included debulking surgery (n = 18), chemotherapy (39), or both (27). Median survival times for dogs with stage I, II, III, and IV melanoma were 758 days (n = 19), 278 days (24), 163 days (37), and 80 days (31), respectively, and differed significantly between dogs with stage I disease and those with all other disease stages. Among dogs with stage III melanoma, risk of death was significantly higher in those that received orthovoltage x-ray treatment than in those that received megavoltage x-ray treatment. Severe (primary or secondary) adverse effects were identified in 9 dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Median survival time was significantly longer for dogs with stage I oral malignant melanoma than for dogs with more advanced disease at the time of staging. The staging system used may be a useful tool for prognosis prediction in dogs undergoing similar treatment protocols for oral malignant melanomas.

Profiling of plasma metabolites in canine oral melanoma using gas chromatography-mass spectrometry.

Malignant melanoma is one of the most common and aggressive tumors in the oral cavity of dog. The tumor has a poor prognosis, and methods for diagnosis and prediction of prognosis after treatment are required. Here, we examined metabolite profiling using gas chromatography-mass spectrometry (GC-MS) for development of a discriminant model for evaluation of prognosis. Metabolite profiles were evaluated in healthy and melanoma plasma samples using orthogonal projection to latent structure using discriminant analysis (OPLS-DA). Cases that were predicted to be healthy using the OPLS discriminant model had no advanced lesions after radiation therapy. These results indicate that metabolite profiling may be useful in diagnosis and prediction of prognosis of canine malignant melanoma.