Zoobiquity experiments show the importance of the local MMP9-plasminogen axis in inflammatory bowel diseases in both dogs and patients.

Using a zoobiquity concept, we directly connect animal phenotypes to a human disease mechanism: the reduction of local plasminogen levels caused by matrix metalloproteinase-9 (MMP9) activity is associated with the development of inflammation in the intestines of dogs and patients with inflammatory bowel disease. We first investigated inflammatory colorectal polyps (ICRPs), which are a canine gastrointestinal disease characterized by the presence of idiopathic chronic inflammation, in Miniature Dachshund (MD) and found 31 missense disease-associated SNPs by whole-exome sequencing. We sequenced them in 10 other dog breeds and found five, PLG, TCOF1, TG, COL9A2 and COL4A4, only in MD. We then investigated two rare and breed-specific missense SNPs (T/T SNPs), PLG: c.477G > T and c.478A>T, and found that ICRPs with the T/T SNP risk alleles showed less intact plasminogen and plasmin activity in the lesions compared to ICRPs without the risk alleles but no differences in serum. Moreover, we show that MMP9, which is an NF-κB target, caused the plasminogen reduction and that intestinal epithelial cells expressing plasminogen molecules were co-localized with epithelial cells expressing MMP9 in normal colons with the risk alleles. Importantly, MMP9 expression in patients with ulcerous colitis or Crohn's disease also co-localized with epithelial cells showing enhanced NF-κB activation and less plasminogen expression. Overall, our zoobiquity experiments showed that MMP9 induces the plasminogen reduction in the intestine, contributing to the development of local inflammation and suggesting the local MMP9-plasminogen axis is a therapeutic target in both dogs and patients. Therefore, zoobiquity-type experiments could bring new perspectives for biomarkers and therapeutic targets.

The role of heat shock protein 90 in the proliferation of Babesia gibsoni in vitro.

The present study investigated the role of heat shock protein 90 (HSP90) in the proliferation and survival of Babesia gibsoni in vitro. To detect the effect on the entry of B. gibsoni into host erythrocytes, the parasite was incubated with an antibody against B. gibsoni HSP90 (BgHSP90) for 24 h. The results of this experiment demonstrated that both the incorporation of [3H]hypoxanthine into the nucleic acids of B. gibsoni and the number of parasites were not altered, indicating that an anti-BgHSP90 antibody did not directly inhibit the entry of the parasite into erythrocytes. Moreover, two HSP90 inhibitors, geldanamycin (GA) and tanespimycin (17-AAG), were used to evaluate the function of BgHSP90. GA and 17-AAG decreased both the incorporation of [3H]hypoxanthine and the number of infected erythrocytes, suggesting that BgHSP90 plays important roles in DNA synthesis and the proliferation of B. gibsoni. The effect of 17-AAG on the parasites was weaker than that of GA. Additionally, the effect of GA on the survival and superoxide generation of canine neutrophils was assessed. The survival of canine neutrophils was not affected. The superoxide generation was strongly suppressed by GA. This result indicated that GA inhibited the function of canine neutrophils. Additional studies are necessary to elucidate the role of BgHSP90 in the proliferation of the parasite.

An experimental challenge model for Leishmania donovani in beagle dogs, showing a similar pattern of parasite burden in the peripheral blood and liver.

Leishmania donovani and Leishmania infantum are closely related species. However, the former is considered the causative agent for anthroponotic visceral leishmaniasis (AVL), while the latter is known to be responsible for zoonotic visceral leishmaniasis (ZVL) with dogs as the main reservoir host. Although molecular detection of L. donovani from naturally infected dogs has been reported in AVL endemic areas, the experimental infection of dogs with this species is very limited. Here, we constructed an experimental canine visceral leishmaniasis (CVL) model with L. donovani infection using beagle dogs. During an observation period of 8 months after parasite inoculation, few clinical symptoms were observed in the three inoculated dogs. The overall hematological and biochemical data of the dogs showed normal levels, and there were no remarkable changes in the peripheral CD4+, CD8+, CD25+, or FoxP3+ T cell populations. Liver biopsy sampling was conducted to monitor the parasite burden in the liver. A similar pattern of the amount of mitochondrial kinetoplast DNA was observed in the peripheral blood and liver by real-time PCR analysis. In addition, parasite antigens were detected from the liver biopsy sections by immunohistochemical analysis, further supporting the existence of parasites in the liver. These results showed a subclinical CVL model for L. donovani in beagle dogs with a similar kinetics of parasite burden in the peripheral blood and liver.

Reduced expression levels of heat shock protein 90 in a diminazene aceturate-resistant Babesia gibsoni isolate.

Heat shock protein 90 (HSP90) is a molecular chaperon and an essential component for stage differentiation and intracellular growth inside the host cells of many protozoans. HSP90 of Babesia gibsoni (BgHSP90) was suggested to function in the development of diminazene aceturate (DA)-resistance. Therefore, we examined the expression level of BgHSP90 in a DA-resistant B. gibsoni isolate. Transcription of the BgHSP90 gene in the DA-resistant isolate and wild-type B. gibsoni was assessed by quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR). As a result, the copy number and relative amount of BgHSP90 transcripts in the DA-resistant isolate were significantly lower than those in the wild-type. Moreover, a rabbit anti-recombinant BgHSP90 antibody was developed, and the protein synthesis of BgHSP90 in the DA-resistant isolate was compared with that in the wild-type by Western blot analysis and indirect fluorescence assay. There was significantly less BgHSP90 protein than in the wild-type. Additionally, the relative intensity of BgHSP70 in DA-resistant isolate was also lower than that in the wild-type. This suggested that the expression of BgHSP90 and BgHSP70 in the DA-resistant B. gibsoni isolate was suppressed and that the reduced amount of BgHSP90 and BgHSP70 might cause the weak proliferation of the DA-resistant isolate. Further studies are necessary to elucidate the function of BgHSP90.

The effects of fipronil on emotional and cognitive behaviors in mammals.

Fipronil is a phenylpyrazole insecticide that is widely used as a pesticide and a veterinary drug, although studies suggest that it could be toxic to mammals. The objectives of this study were to examine the pharmacokinetic profile of fipronil in mice, dogs, and cats, and to evaluate its effects on emotional and cognitive behaviors of dogs and cats using the data obtained from mice. The assessment of in vivo kinetics of fipronil was conducted in mice and dogs. We also performed behavioral tests (elevated plus-maze and Y-maze) and measured the levels of neurotransmitters in mice exposed to fipronil. In addition, the in vitro metabolism of fipronil were evaluated using liver microsomes of rats, mice, dogs, and cats. The results revealed that fipronil is distributed throughout the body (blood, brain, adipose tissue, and liver) of mice after dermal application. It was metabolized to fipronil sulfone primarily in the liver. The data on kinetics show that both fipronil and fipronil sulfone have a longer half-life in dogs and cats than in mice. The behavioral tests indicated that fipronil and fipronil sulfone could affect emotional and cognitive behaviors and alter the levels of neurotransmitters (dopamine in the striatum and serotonin in the hippocampus) in mice. Furthermore, we found that dogs and cats have a low ability to metabolize fipronil than mice and rats. However, further comprehensive studies are needed to determine whether fipronil affects the emotional and cognitive behaviors when administered to dogs and cats. To the best of our knowledge, this is the first study to examine the pharmacokinetic data and verify the effects of fipronil on emotional and cognitive behaviors of dogs and cats using the data obtained from mice.

Cardiovascular effects of dose escalating of norepinephrine in healthy dogs anesthetized with isoflurane.

OBJECTIVE: To evaluate the systemic cardiovascular effects of dose escalating administration of norepinephrine in healthy dogs anesthetized with isoflurane. STUDY DESIGN: Experimental study. ANIMALS: A total of six adult laboratory Beagle dogs, 10.5 (9.2-12.0) kg [median (range)]. METHODS: Each dog was anesthetized with isoflurane at an end-tidal concentration of 1.7%, mechanically ventilated and administered a continuous rate infusion of rocuronium (0.5 mg kg-1 hour-1). Each dog was administered incremental dose rates of norepinephrine (0.05, 0.125, 0.25, 0.5, 1.0 and 2.0 µg kg-1 minute-1), and each dose was infused for 15 minutes. Cardiovascular variables were recorded before administration and at the end of each infusion period. RESULTS: Norepinephrine infusion increased mean arterial pressure (MAP), cardiac output (CO) and oxygen delivery in a dose-dependent manner. Systemic vascular resistance did not significantly change during the experiment. Stroke volume increased at the lower dose rates and heart rate increased at the higher dose rates. Oxygen consumption and lactate concentrations did not significantly change during infusions. CONCLUSIONS: In dogs anesthetized with isoflurane, norepinephrine increased MAP by increasing the CO. CO increased with a change in stroke volume at lower dose rates of norepinephrine. At higher dosage, heart rate also contributed to an increase in CO. Norepinephrine did not cause excessive vasoconstriction that interfered with the CO during this study. CLINICAL RELEVANCE: Norepinephrine can be useful for treating hypotension in dogs anesthetized with isoflurane.

CT morphology of anomalous systemic arterial supply to normal lung in dogs.

Anomalous systemic arterial supply to the normal lung (ASANL) is a rare congenital anomaly in humans, in which the systemic arteries supply the basal segments of the lower lobe. It has a normal bronchial connection, but lacks a normal pulmonary artery. This anomaly has not been previously reported in the veterinary literature. The objectives of this retrospective descriptive study were to characterize the CT findings and clinical features of ASANL , and to determine the breed predisposition in a population of referral canine cases. Thoracic CT images, in which the caudal lung lobes were fully inflated and the pulmonary artery could be traced to the periphery, were reviewed. A total of 1,950 dogs were enrolled, and the aberrant vasculature equivalent to ASANL in humans was detected in 48 dogs. Shetland Sheepdogs (7/48, odds ratio [OR] = 8.0, P < 0.00001), Miniature Dachshunds (19/48, OR = 3.9, P < 0.00001), and Labrador Retrievers (6/48, OR = 4.5, P = 0.0009) were over-represented. The affected lung lobes were the right caudal lobe (24/48, 50%), the left caudal lobe (21/48, 43.8%), and bilateral caudal lobes (3/48, 6.3%). The aberrant vessels originated from the left gastric artery (14/48), descending thoracic aorta (8/48), celiac artery (6/48), and splenic artery (1/48). In the remaining 19 cases, the origin of the aberrant vessels could not be determined. Although the clinical significance of ASANL in dogs remains unclear, surgeons should be aware of this finding prior to lobectomy of the caudal lung lobes to avoid intraoperative systemic arterial bleeding.

Extrahepatic biliary obstruction can interfere with hepatic fibrosis prediction using two-dimensional shear wave elastography in dogs.

Two-dimensional shear wave elastography (2D-SWE) can be used to quantitatively evaluate the elastic modulus of the liver as shear wave velocity (SWV), which can noninvasively predict clinically relevant hepatic fibrosis in both dogs and humans. However, extrahepatic biliary obstruction (EHBO), regardless of the presence of clinically relevant hepatic fibrosis, can influence SWVs in humans and thus may interfere with hepatic fibrosis prediction using 2D-SWE in dogs. The aim of this prospective, observational, and one-group pretest-posttest study is to investigate whether SWV measured by 2D-SWE displays a difference between dogs with and without EHBO. A total of 20 dogs were included (7 with EHBO and 13 with gallbladder pathology but no EHBO) that underwent preoperative SWV measurement using 2D-SWE. In all dogs, stages of hepatic fibrosis were evaluated histopathologically using a scoring scheme. In addition, postoperative SWVs in dogs with EHBO relieved via laparotomy were also evaluated. The median (range) SWVs in the dogs with and without EHBO were 1.91 (1.81-2.54) m/s and 1.57 (1.37-1.64) m/s, respectively. Although there was no significant difference in the histopathological hepatic fibrosis stages between the dogs with and without EHBO, the preoperative SWVs in the dogs with EHBO were significantly higher than in dogs without EHBO (P = .0004), and SWVs were found to decrease significantly after surgery (P = .0097). This study demonstrates that EHBO can increase the SWV of dogs without clinically relevant hepatic fibrosis and can interfere with the prediction of noninvasive hepatic fibrosis using 2D-SWE.

Contrast-enhanced ultrasonography is a feasible technique for quantifying hepatic microvascular perfusion in dogs with extrahepatic congenital portosystemic shunts.

Extrahepatic-congenital portosystemic shunt is a vascular anomaly that connects the portal vein to the systemic circulation and leads to a change in hepatic microvascular perfusion. However, an assessment of hepatic microvascular perfusion is limited by conventional diagnostic modalities. The aim of this prospective, exploratory study was to assess hepatic microvascular perfusion in dogs with extrahepatic-congenital portosystemic shunt using contrast-enhanced ultrasonography (CEUS) using perfluorobutane (Sonazoid® ). A total of 17 dogs were included, eight healthy dogs and nine with extrahepatic-congenital portosystemic shunt. The time-to-peak (TTP), rising time (RT), and rising rate (RR) in the hepatic artery, portal vein, and hepatic parenchyma, as well as the portal vein-to-hepatic parenchyma transit time (ΔHP-PV) measured from time-intensity curve on CEUS were compared between healthy and extrahepatic-congenital portosystemic shunt dogs. The RT of the hepatic artery in extrahepatic-congenital portosystemic shunt dogs was significantly earlier than in healthy dogs (P = 0.0153). The TTP and RT of the hepatic parenchyma were significantly earlier in extrahepatic-congenital portosystemic shunt dogs than in healthy dogs (P = 0.0018 and P = 0.0024, respectively). ΔHP-PV was significantly shorter in extrahepatic-congenital portosystemic shunt dogs than in healthy dogs (P = 0.0018). CEUS effectively revealed changes in hepatic microvascular perfusion including hepatic artery, portal vein, and hepatic parenchyma simultaneously in extrahepatic-congenital portosystemic shunt dogs. Rapid hepatic artery and hepatic parenchyma enhancements may reflect a compensatory increase in hepatic artery blood flow (arterialization) caused by a decrease in portal vein blood flow and may be used as an additional diagnostic test to distinguish extrahepatic-congenital portosystemic shunt dogs from healthy dogs.

Intracellular diminazene aceturate content and adenosine incorporation in diminazene aceturate-resistant Babesia gibsoni isolate in vitro.

The mechanism of the development of diminazene aceturate (DA) resistance in Babesia gibsoni is still unknown even though DA-resistant B. gibsoni isolate was previously developed in vitro. To clarify the mechanisms of DA-resistance in B. gibsoni, we initially examined the intracellular DA content in the DA-resistant isolate using high-performance liquid chromatography, and compared it with that in the wild-type. As a result, the intracellular DA content in the DA-resistant isolate was significantly lower than that in the wild-type, suggesting that the decreased DA content may contribute to DA-resistance. Additionally, the glucose consumption of the DA-resistant isolate was significantly higher than that of the wild-type, indicating that a large amount of glucose is utilized to maintain DA-resistance. It is possible that a large amount of energy is utilized to maintain the mechanisms of DA-resistance. It was reported that as the structure of DA is similar with that of adenosine, DA may be taken up by the P2 transporter, which contributes to the uptake of adenosine, in Trypanosoma brucei brucei, and that the uptake of adenosine is decreased in DA-resistant T. brucei brucei. In the present study, the adenosine incorporation in the DA-resistant B. gibsoni isolate was higher than in the wild-type. Moreover, the adenosine incorporation in the wild-type was not inhibited by the presence of DA. These results suggest that adenosine transport in B. gibsoni is not affected by DA and may not mediate DA-resistance. To clarify the mechanism of the development of DA resistance in B. gibsoni, we should investigate the cause of the decreased DA content in the DA-resistant isolate in the future.

Changes in right ventricular function assessed by echocardiography in dog models of mild RV pressure overload.

BACKGROUND: The assessment of hemodynamic change by echocardiography is clinically useful in patients with pulmonary hypertension. Recently, mild elevation of the mean pulmonary arterial pressure (PAP) has been shown to be associated with increased mortality. However, changes in the echocardiographic indices of right ventricular (RV) function are still unknown. The objective of this study was to validate the relationship between echocardiographic indices of RV function and right heart catheterization variables under a mild RV pressure overload condition. METHODS AND RESULTS: Echocardiography and right heart catheterization were performed in dog models of mild RV pressure overload induced by thromboxane A2 analog (U46619) (n=7). The mean PAP was mildly increased (19.3±1.1 mm Hg), and the cardiac index was decreased. Most echocardiographic indices of RV function were significantly impaired even under a mild RV pressure overload condition. Multivariate analysis revealed that the RV free wall longitudinal strain (RVLS), standard deviation of the time-to-peak longitudinal strain of RV six segments (RV-SD) by speckle-tracking echocardiography, and Tei index were independent echocardiographic predictors of the mean PAP (free wall RVLS, ß=-0.60, P<.001; RV-SD, ß=0.40, P=.011), pulmonary vascular resistance (free wall RVLS, ß=-0.39, P=.020; RV-SD, ß=0.47, P=.0086; Tei index, ß=0.34, P=.047), and cardiac index (Tei index, ß=-0.65, P<.001). CONCLUSIONS: Free wall RVLS, RV-SD, and Tei index are useful for assessing the hemodynamic change under a mild RV pressure overload condition.

Diastolic heart failure associated with hemangiosarcoma infiltrating left ventricular walls in a dog.

A 9-year-old Shetland sheepdog was diagnosed with cardiogenic pulmonary edema. Echocardiography revealed focally thickened left ventricular free wall and interventricular septum and left atrial dilation. Left ventricular systolic function was preserved. Doppler echocardiography of transmitral flow indicated restrictive left ventricular filling. Cardiac histopathology demonstrated hemangiosarcoma infiltrating the left ventricular walls.

Insuffisance cardiaque diastolique associée à l'infiltration d'un hémangiosarcome dans les parois ventriculaires gauches chez un chien. Un chien berger des Shetlands âgé de 9 ans a été diagnostiqué avec un oedème pulmonaire cardiogénique. L'échocardiographie a révélé un épaississement focal de la paroi libre du ventricule gauche et du septum interventriculaire et une dilatation atriale gauche.. La fonction systolique ventriculaire gauche était préservée. L'échographie Doppler de l'écoulement transmitral indiquait un remplissage ventriculaire gauche restreint. L'histopathologie cardiaque a démontré l'infiltration des parois ventriculaires gauches par l'hémangiosarcome.(Traduit par Isabelle Vallières).

Contrast-enhanced ultrasonographic findings in three dogs with pancreatic insulinoma.

Abdominal ultrasonography is one of the most common diagnostic imaging modalities used for dogs with suspected insulinoma; however, pancreatic masses are clearly identified in fewer than half of affected dogs and benign pancreatic nodules can be difficult to differentiate from malignant ones. The purpose of this prospective study was to describe contrast-enhanced ultrasonography (CEUS) characteristics of confirmed pancreatic insulinoma in a group of dogs. Inclusion criteria were as follows: (1) repeated hypoglycemia (blood glucose levels <60 mg/dl, twice or more); (2) elevated blood insulin levels with hypoglycemia; (3) pancreatic nodules detected with conventional ultrasonography; and (4) histological confirmation of pancreatic islet cell carcinoma. Immediately following conventional ultrasonography of the entire abdomen, CEUS of the pancreatic nodule and adjacent parenchyma was performed using contrast-specific technology pulse inversion imaging and perflubutane microbubble contrast agent. Three dogs met inclusion criteria. Pancreatic nodules in all the three dogs became more clearly demarcated after injection of the contrast agent. Each nodule showed different enhancement patterns: markedly hyperechoic for 5 s, slightly hyperechoic for 1 s, and clearly hypoechoic for over 30 s. These results were not in complete agreement with previously reported CEUS findings in human patients with insulinoma. All nodules were surgically resected and histopathologically confirmed as malignant insulinomas. Findings from the current study indicated that contrast-enhanced ultrasound may help to increase conspicuity of pancreatic insulinomas in dogs and that enhancement characteristics may be more variable in dogs than in humans.

Ultrasound image-guided therapy enhances antitumor effect of cisplatin.

PURPOSE: The aim of this study was to clarify whether ultrasound image-guided cisplatin delivery with an intratumor microbubble injection enhances the antitumor effect in a xenograft mouse model. METHODS: Canine thyroid adenocarcinoma cells were used for all experiments. Before in vivo experiments, the cisplatin and microbubble concentration and ultrasound exposure time were optimized in vitro. For in vivo experiments, cells were implanted into the back of nude mice. Observed by a diagnostic ultrasound machine, a mixture of cisplatin and ultrasound contrast agent, Sonazoid, microbubbles was injected directly into tumors. The amount of injected cisplatin and microbubbles was 1 µg/tumor and 1.2 × 10(7) microbubbles/tumor, respectively, with a total injected volume of 20 µl. Using the same diagnostic machine, tumors were exposed to ultrasound for 15 s. The treatment was repeated four times. RESULTS: The combination of cisplatin, microbubbles, and ultrasound significantly delayed tumor growth as compared with no treatment (after 18 days, 157 ± 55 vs. 398 ± 49 mm(3), P = 0.049). Neither cisplatin alone nor the combination of cisplatin and ultrasound delayed tumor growth. The treatment did not decrease the body weight of mice. CONCLUSION: Ultrasound image-guided anticancer drug delivery may enhance the antitumor effects of drugs without obvious side effects.

Antimicrobial resistance and self-reported hand hygiene awareness before and after an infection prevention and control programme: A 7-year analysis in a small animal veterinary teaching hospital.

Infection prevention and control (IPC) in veterinary medicine is crucial to protect patients, owners, staff, and the public. An IPC programme is recommended for every animal hospital. The objective of this retrospective longitudinal study was to describe the changes in bacterial and multidrug-resistant (MDR) bacterial isolates and self-reported hand hygiene awareness and practices after an IPC programme to assess the long-term effect of this programme in small animal veterinary medicine. The IPC programme was implemented at our veterinary teaching hospital in April 2018, which included the establishment of an infection control task force, regular IPC lectures and poster campaigns, infrastructure improvement, and manual refinement. Laboratory-based surveillance was retrospectively conducted before and after the programme (January 2016-December 2022). Level and slope changes in bacterial isolates were evaluated using interrupted time-series analysis. Self-reported hand hygiene awareness and practices were assessed using an annual questionnaire. Additionally, hygiene product purchases during the study period were investigated. The monthly number of total and MDR bacterial isolates decreased significantly after the programme (MDR level change: -0.426; 95% confidence interval: -0.744, -0.109; P = 0.009; and MDR slope change: -0.035; 95% confidence interval: -0.058, -0.011; P = 0.003). Additionally, awareness of hand hygiene before touching animals improved after the programme. Overall self-reported hand hygiene practices improved, and hygiene product purchases significantly increased. These results suggested that the IPC programme may have long-term effects regarding reducing total and MDR bacterial isolates and improving hand hygiene awareness in veterinary medicine.

Use of genome-wide DNA methylation analysis to identify prognostic CpG site markers associated with longer survival time in dogs with multicentric high-grade B-cell lymphoma.

BACKGROUND: DNA methylation analysis might identify prognostic CpG sites in CHOP-treated dogs with multicentric high-grade B-cell lymphoma (MHGL) with heterogenous prognosis. OBJECTIVE: To identify prognostic CpG sites of MHGL through genome-wide DNA methylation analysis with pyrosequencing validation. ANIMALS: Test group: 24 dogs. Validation group: 100 dogs. All client-owned dogs were diagnosed with MHGL and treated with CHOP chemotherapy. METHODS: Cohort study. DNA was extracted from lymph node samples obtained via FNA. Genome-wide DNA methylation analysis using Digital Restriction Enzyme Analysis of Methylation (DREAM) was performed on the test group to identify differentially methylated CpG sites (DMCs). Bisulfite pyrosequencing was used to measure methylation status of candidate DMCs in the validation group. Median survival times (MST) were analyzed using Kaplan-Meier (log-rank) product limit method. RESULTS: DREAM analyzed 101 576 CpG sites. Hierarchical clustering of 16 262 CpG sites in test group identified group with better prognosis (MST = 55-477 days vs 10-301 days, P = .007). Volcano plot identified 1371 differentially methylated CpG sites (DMCs). DMC near the genes of FAM213A (DMC-F) and PHLPP1 (DMC-P) were selected as candidates. Bisulfite-pyrosequencing performed on validation group showed group with methylation level of DMC-F < 40% had favorable prognosis (MST = 11-1072 days vs 8-1792 days, P = .01), whereas group with the methylation level combination of DMC-F < 40% plus DMC-P < 10% had excellent prognosis (MST = 18-1072 days vs 8-1792 days, P = .009). CONCLUSION AND CLINICAL IMPORTANCE: Methylation status of prognostic CpG sites delineate canine MGHL cases with longer MST, providing owners with information on expectations of potential improved treatment outcomes.

A de novo nonsense variant in the DMD gene associated with X-linked dystrophin-deficient muscular dystrophy in a cat.

BACKGROUND: X-linked dystrophin-deficient muscular dystrophy (MD) is a form of MD caused by variants in the DMD gene. It is a fatal disease characterized by progressive weakness and degeneration of skeletal muscles. HYPOTHESIS/OBJECTIVES: Identify deleterious genetic variants in DMD by whole-genome sequencing (WGS) using a next-generation sequencer. ANIMALS: One MD-affected cat, its parents, and 354 cats from a breeding colony. METHODS: We compared the WGS data of the affected cat with data available in the National Center for Biotechnology Information database and searched for candidate high-impact variants by in silico analyses. Next, we confirmed the candidate variants by Sanger sequencing using samples from the parents and cats from the breeding colony. We used 2 genome assemblies, the standard felCat9 (from an Abyssinian cat) and the novel AnAms1.0 (from an American Shorthair cat), to evaluate genome assembly differences. RESULTS: We found 2 novel high-impact variants: a 1-bp deletion in felCat9 and an identical nonsense variant in felCat9 and AnAms1.0. Whole genome and Sanger sequencing validation showed that the deletion in felCat9 was a false positive because of misassembly. Among the 357 cats, the nonsense variant was only found in the affected cat, which indicated it was a de novo variant. CONCLUSION AND CLINICAL IMPORTANCE: We identified a de novo variant in the affected cat and next-generation sequencing-based genotyping of the whole DMD gene was determined to be necessary for affected cats because the parents of the affected cat did not have the risk variant.

Effectiveness of 2-dimensional shear wave elastography for noninvasive and reliable estimation of right atrial pressure in dogs with induced volume overload.

BACKGROUND: Two-dimensional shear wave elastography (2D-SWE) provides information on hepatic elastic modulus as shear wave velocity (SWV). HYPOTHESIS/OBJECTIVES: To assess SWV using 2D-SWE in dogs with induced volume overload, investigate the relationship between this information and right atrial pressure (RAP) measured by invasive right heart catheterization, and also evaluate the difference in SWV before and after diuretic administration. ANIMALS: Six healthy beagles. METHODS: Prospective experimental study. Right heart catheterization and 2D-SWE were performed in 6 anesthetized beagles at baseline and after the induction of volume overload. Volume overload was induced by IV hydroxyethyl starch 70/0.5 infusion (100 mL/kg/h). Furosemide (4-6 mg/kg, IV) was administered, and the SWVs were measured. RESULTS: Shear wave velocity showed a significant gradual increase during acute volume overload compared to baseline. SWV was significantly positively correlated with RAP (P < .0001, ρ = 0.9729). The area under the curve of SWV to predict RAP at >10, >15, and >20 mm Hg was 0.9896 (95% confidence interval [95% CI], 0.9690-1.000), 0.9907 (95% CI, 0.9701-1.000), and 0.9722 (95% CI, 0.9280-1.000), respectively. The SWV after diuretic use decreased significantly. CONCLUSIONS AND CLINICAL IMPORTANCE: Two-dimensional shear wave elastography might be useful for noninvasive and reliable estimation of RAP in dogs with acute volume overload and has potential as a quantitative biomarker for evaluating therapeutic response in dogs with right sided congestive heart failure.

Biological effects related to exposure to polychlorinated biphenyl (PCB) and decabromodiphenyl ether (BDE-209) on cats.

As an animal familiar to humans, cats are considered to be sensitive to chemicals; cats may be exposed to polychlorinated biphenyls (PCBs) and decabromodiphenyl ether (BDE-209) from indoor dust, household products, and common pet food, leading to adverse endocrine effects, such as thyroid hormone dysfunction. To elucidate the general biological effects resulting from exposure of cats to PCBs and PBDEs, cats were treated with a single i.p. dose of a principal mixture of 12 PCBs and observed for a short-term period. Results revealed that the testis weight, serum albumin, and total protein of the treated group decrease statistically in comparison with those in the control group. The negative correlations suggested that the decrease in the total protein and albumin levels may be disturbed by 4'OH-CB18, 3'OH-CB28 and 3OH-CB101. Meanwhile, the serum albumin level and relative brain weight decreased significantly for cats subjected to 1-year continuous oral administration of BDE-209 in comparison to those of control cats. In addition, the subcutaneous fat as well as serum high-density lipoprotein (HDL) and triglycerides (TG) levels increased in cats treated with BDE-209 and down-regulation of stearoyl-CoA desaturase mRNA expression in the liver occurred. These results suggested that chronic BDE-209 treatment may restrain lipolysis in the liver, which is associated with lipogenesis in the subcutaneous fat. Evidence of liver and kidney cell damage was not observed as there was no significant difference in the liver enzymes, blood urea nitrogen and creatinine levels between the two groups of both experiments. To the best of our knowledge, this is the first study that provides information on the biochemical effects of organohalogen compounds in cats. Further investigations on risk assessment and other potential health effects of PCBs and PBDEs on the reproductive system, brain, and lipid metabolism in cats are required.

Investigation of the therapeutic effects, predictors, and complications of long-term immunosuppressive therapy in dogs with precursor-targeted immune-mediated anemia.

Dogs with precursor-targeted immune-mediated anemia (PIMA) are commonly treated with immunosuppressive therapy, but information on predictors of treatment response and response time is limited. Therefore, we retrospectively investigated predictive factors that influenced the treatment response and duration required to observe a response in dogs with PIMA receiving continuous immunosuppressive therapies for more than 105 days. Of 50 client-owned dogs that developed PIMA, 27 were included in this study, of which 18 were responders and 9 were non-responders to immunosuppressive therapies. Sixteen of the 18 responders responded to treatment within 60 days and the remaining 2 responded at 93 and 126 days, respectively. We found that an erythroid-maturation ratio of <0.17 may be a useful predictor for treatment response. In addition, complications of immunosuppressive therapies were investigated further in 50 dogs. Pancreatitis (n=4) and pneumonia (3) occurred over the entire treatment period, and infections such as abscesses (3) tended to be more common in dogs on an extended period of immunosuppressive therapy. These findings may be helpful when planning for the initial treatment and may provide evidence for informed consent about potential comorbidities throughout the treatment course.