Oxylipin profiling by LC-ESI-MS/MS in canine serum and plasma to investigate ovulation-specific changes.

New biomarkers that are directly associated with canine ovulation would be of value to ensure mating on optimal days of heat. In this study, canine plasma and serum were analyzed with liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) to quantify a broad range of oxylipins for the purpose of developing a method for biomarker discovery studies in canine reproduction. A majority of the 67 oxylipins probed for were detected at comparable levels in both sample types, but more oxylipins at higher concentrations were detected in serum than in plasma. Nine of the oxylipins were detected in a pilot study of serum at levels that significantly differed (p ≤ 0.1) between time-points before (n = 10), during (n = 10) and after (n = 10) ovulation, and might serve as putative biomarkers for canine ovulation. One oxylipin (20-HETE) was significantly altered after adjusting for multiple comparisons. In conclusion, the results showed that the LC-ESI-MS/MS method was suitable for quantification of canine oxylipins, revealing important similarities and differences between plasma and serum profiles as well as preliminary ovulation-specific changes in a subset of the investigated oxylipins.

Genomic Diversity and Runs of Homozygosity in Bernese Mountain Dogs.

Bernese mountain dogs are a large dog breed formed in the early 1900s in Switzerland. While originally farm dogs that were used for pulling carts, guarding, and driving cattle, today they are considered multi-purpose companion and family dogs. The breed is predisposed to several complex diseases, such as histiocytic sarcoma, degenerative myelopathy, or hip dysplasia. Using whole-genome sequencing (WGS) data, we assessed the genomic architecture of 33 unrelated dogs from four countries: France, Sweden, Switzerland, and the United States. Analysis of runs of homozygosity (ROH) identified 12,643 ROH with an average length of 2.29 Mb and an average inbreeding coefficient of 0.395. Multidimensional scaling analysis of the genetic relatedness revealed limited clustering of European versus USA dogs, suggesting exchanges of breeding stock between continents. Furthermore, only two mtDNA haplotypes were detected in the 33 studied dogs, both of which are widespread throughout multiple dog breeds. WGS-based ROH analyses revealed several fixed or nearly fixed regions harboring discreet morphological trait-associated as well as disease-associated genetic variants. Several genes involved in the regulation of immune cells were found in the ROH shared by all dogs, which is notable in the context of the breed's strong predisposition to hematopoietic cancers. High levels of inbreeding and relatedness, strongly exaggerated in the last 30 years, have likely led to the high prevalence of specific genetic disorders in this breed.

Cardiac troponin I in healthy Norwegian Forest Cat, Birman and domestic shorthair cats, and in cats with hypertrophic cardiomyopathy.

OBJECTIVES: The aims of this study were to assess the potential associations between the serum cardiac troponin I (cTnI) concentration in healthy cats and feline characteristics, systolic blood pressure, heart rate (HR), echocardiographic measurements and storage time; and to compare cTnI concentrations in healthy cats with concentrations in cats with hypertrophic cardiomyopathy (HCM), with or without left atrial enlargement (LAE) and in cats with HCM, to assess potential associations between cTnI concentration and echocardiographic variables. METHODS: Cardiac TnI was analysed using an Abbott ARCHITECT ci16200 analyser in serum from prospectively included healthy Norwegian Forest Cat (NF; n = 33), Birman (n = 33) and domestic shorthair (DSH; n = 30) cats, and from 39 cats with HCM, with or without LAE. RESULTS: In healthy cats, higher cTnI concentrations were found in Birman cats than in NF cats (P = 0.014) and in neutered male cats than in intact females (P = 0.032). Cardiac TnI was positively associated with HR (P <0.0001). In cats with HCM, cTnI concentration was positively associated with left ventricular wall thickness and with left atrial-to-aortic root ratio (all P ⩽0.010). Cats with HCM had higher cTnI concentrations than healthy cats, and cTnI concentrations were higher in cats with HCM and LAE than in those with HCM without LAE (all P = 0.0003). CONCLUSIONS AND RELEVANCE: Breed and sex may affect serum cTnI concentrations in healthy cats. The cTnI concentration increased with increasing severity of HCM.

Validation of a dry-slide immunoassay for progesterone analysis in canine plasma in a clinical setting.

BACKGROUND: The identification of canine ovulation is critical for successful breeding. Progesterone measurements are useful for identifying ovulation. Progesterone assays are also quantitative and easily accessed, making them valuable in veterinary practice. OBJECTIVES: We aimed to validate a dry-slide immunoassay (DSI) for use in dogs, including a method comparison with the chemiluminescence assay (CLIA) and mass spectrometry. METHODS: Twenty-nine bitches were prospectively recruited. Accuracy, precision, interference, and stability were evaluated. Method comparison between DSI and CLIA and mass spectrometry was conducted, and bias was calculated. RESULTS: Repeatability was 8.0%-10.8%, and within-laboratory imprecision was 8.8%-11.1% for four concentration levels. Recovery under dilution was 61%-100%, and the method was linear to a concentration of ~50 nmol/L. Recovery after the addition of a high progesterone sample was 76%-83%. Minor changes were seen in one hemolytic and two lipemic samples. Storage at room temperature for 12-24 hours resulted in concentrations that were 57%-96% of the initial concentrations. For samples frozen at -80°C, the concentrations were reduced 17%-27%. There was a significant difference between results from the DSI and CLIA, and a proportional bias was seen when DSI was compared with mass spectrometry, where CLIA correlated better than DSI. CONCLUSIONS: Precision and accuracy were acceptable. A proportional bias was seen between DSI and CLIA. A small amount of interference was seen with hemolysis and lipemia. Progesterone concentrations were decreased in samples stored at room temperature and -80°C. The results support the use of the DSI for ovulation timing but not for artificial insemination with frozen semen since progesterone concentrations might exceed the assay's linearity and precision limits.

Concentrations of canine prostate specific esterase, CPSE, at baseline are associated with the relative size of the prostate at three-year follow-up.

BACKGROUND: Enlargement of the prostate is associated with prostatic diseases in dogs, and an estimation of prostatic size is a central part in the diagnostic workup. Ultrasonography is often the method of choice, but biomarkers constitute an alternative. Canine prostate specific esterase (CPSE) shares many characteristics with human prostate specific antigen (PSA) and is related to prostate size. In men with clinical symptoms of prostatic disease, PSA concentrations are related to prostate growth. The aims of the present follow-up study were to evaluate if the concentration of CPSE is associated with future growth of the prostate, and if analysis of a panel of 16 steroids gives further information on prostatic growth. Owners of dogs included in a previous study were 3 years later contacted for a follow-up study that included an interview and a clinical examination. The prostate was examined by ultrasonography. Serum concentrations of CPSE were measured, as was a panel of steroids. RESULTS: Of the 79 dogs included at baseline, owners of 77 dogs (97%) were reached for an interview, and 22 were available for a follow-up examination. Six of the 79 dogs had clinical signs of prostatic disease at baseline, and eight of the remaining 73 dogs (11%) developed clinical signs between baseline and follow-up, information was lacking for two dogs. Development of clinical signs was significantly more common in dogs with a relative prostate size of ≥2.5 at baseline (n = 20) than in dogs with smaller prostates (n = 51). Serum concentrations of CPSE at baseline were not associated with the change in prostatic size between baseline and follow-up. Serum concentrations of CPSE at baseline and at follow-up were positively associated with the relative prostatic size (Srel) at follow-up. Concentrations of corticosterone (P = 0.024), and the class corticosteroids (P = 0.0035) were positively associated with the difference in Srel between baseline and follow-up. CONCLUSIONS: The results support the use of CPSE for estimating present and future prostatic size in dogs ≥4 years, and the clinical usefulness of prostatic size for predicting development of clinical signs of prostatic disease in the dog. The association between corticosteroids and prostate growth warrants further investigation.

Differences in metabolic profiles between the Burmese, the Maine coon and the Birman cat-Three breeds with varying risk for diabetes mellitus.

Feline diabetes mellitus shares many features with type 2 diabetes in people, regarding clinical presentation, physiology, and pathology. A breed predisposition for type 2 diabetes has been identified, with the Burmese breed at a fivefold increased risk of developing the condition compared to other purebred cats. We aimed to characterize the serum metabolome in cats (n = 63) using nuclear magnetic resonance metabolomics, and to compare the metabolite pattern of Burmese cats with that of two cat breeds of medium or low risk of diabetes, the Maine coon (MCO) and Birman cat, respectively. Serum concentrations of adiponectin, insulin and insulin-like growth factor-1 were also measured (n = 94). Burmese cats had higher insulin and lower adiponectin concentrations than MCO cats. Twenty one metabolites were discriminative between breeds using a multivariate statistical approach and 15 remained significant after adjustment for body weight and body condition score. Burmese cats had higher plasma levels of 2-hydroxybutyrate relative to MCO and Birman cats and increased concentrations of 2-oxoisocaproic acid, and tyrosine, and lower concentrations of dimethylglycine relative to MCO cats. The metabolic profile of MCO cats was characterized by high concentrations of arginine, asparagine, methionine, succinic acid and low levels of acetylcarnitine while Birman cats had the highest creatinine and the lowest taurine plasma levels, compared with MCO and Burmese. The pattern of metabolites in Burmese cats is similar to that in people with insulin resistance. In conclusion, the metabolic profile differed between healthy cats of three breeds. Detection of an abnormal metabolome might identify cats at risk of developing diabetes.

Influence of clinical setting and cat characteristics on indirectly measured blood pressure and pulse rate in healthy Birman, Norwegian Forest, and Domestic Shorthair cats.

BACKGROUND: Measured indirect blood pressure (BP) results in cats in a clinical environment might be affected by stress and characteristics of the cats. HYPOTHESIS: To investigate the influence of clinical setting, cat characteristics, and life situation on BP and pulse rate (PR) in healthy cats. ANIMALS: Ninety-four healthy Domestic Shorthair, Birman and Norwegian Forest cats. METHODS: Blood pressure measured by high-definition oscillometry in 3 settings: cat placed in its own carrier with veterinarian present; cat placed in carrier with owner alone present; and cat placed on table with veterinarian present. Statistical analyses were performed using mixed linear models. RESULTS: Systolic BP (SBP) did not differ among settings. Higher mean arterial pressure (MAP), diastolic BP (DBP), and PR were found when measurements were performed with cat placed on table, rather than in carrier. Coefficients of variation (CVs) higher for SBP, MAP, DBP, and PR when measured with cat placed on table than in carrier. Birman cats had lower BP than other breeds. Systolic BP, MAP, DBP, and PR increased with age. Cats allowed outdoors had lower PR than cats living strictly indoors. CONCLUSION AND CLINICAL IMPORTANCE: No difference in SBP was found among settings, but measuring BP with the cat placed on the examination table gave higher MAP, DBP, PR, and CV than measuring BP with the cat in its carrier. Breed affected BP, with lower BP in Birman cats than other breeds. Blood pressure increased with age. Pulse rate was lower in cats allowed outdoors than cats living strictly indoors.

Effect of feline characteristics on plasma N-terminal-prohormone B-type natriuretic peptide concentration and comparison of a point-of-care test and an ELISA test.

BACKGROUND: Increased plasma concentration of N-terminal-prohormone B-type natriuretic peptide (NT-proBNP) can be detected in cats with cardiac disease. Potential effects of feline characteristics on NT-proBNP concentration may influence clinical usefulness. OBJECTIVES: To evaluate potential effects of feline characteristics on NT-proBNP plasma concentration and to compare NT-proBNP plasma concentrations in healthy cats with results in hypertrophic cardiomyopathy (HCM) cats with or without left atrial enlargement (LAE) using an ELISA and a point-of-care test (POCT), and assess if POCT results reflect ELISA results. ANIMALS: One hundred healthy cats of 3 breeds and 39 HCM cats were included. METHODS: Diseases other than HCM were excluded by physical examination, blood pressure measurement, echocardiography, hematology, and serum biochemistry. RESULTS: Higher NT-proBNP concentrations were found in males than in females in healthy (P = .005) and in HCM cats (P = .0021), but breed had no effect on NT-proBNP concentrations. Using ≥100 pmol/L as a cutoff for abnormal samples, ELISA and POCT had similar sensitivity (SE; 72 and 74%) and specificity (SP; 97 and 98%) for detecting cats with HCM, cats with HCM and LAE (SE, both 100%; SP, 97 versus 98%), and cats with HCM without LAE (SE, both 69%; SP, 97 versus 98%), respectively, when compared to healthy cats. CONCLUSIONS AND CLINICAL IMPORTANCE: Breed had no effect on plasma NT-proBNP concentrations, but higher concentrations were found in male than in female cats. The ELISA and POCT had similar SE and SP for detecting HCM. Both tests could identify all HCM cats with LAE but not all HCM cats without LAE.

Inflammatory changes during canine pregnancy.

Pregnancy is considered a pro-inflammatory state that requires physiologic adaptation of the immune system of the mother. The aim of the present study was to study inflammatory and hormonal changes during canine pregnancy. Studies included analyses of peripheral concentrations of the acute phase proteins fibrinogen and C-reactive protein (CRP), the hormones progesterone and insulin-like growth factor I (IGF-I), hemoglobin, and analyses of the total leukocyte numbers and expression of cell surface antigens. Twenty bitches were included in the present study; 12 pregnant bitches and eight non-pregnant control bitches that were followed during the corresponding phase of the oestrous cycle. Blood samples were collected at the day of optimal mating (day 0) and then on days 7, 14, 21, 28 and 42. Progesterone, IGF-I and CRP were analysed in serum and fibrinogen in EDTA plasma. Haematology and leukocyte expression of a panel of inflammation-associated adhesion molecules (CD 11a, CD 18 and CD 49d) were evaluated from EDTA blood. The data were analyzed as repeated-measures data, using a mixed model approach. Progesterone varied with time in both pregnant and control bitches, and IGF-I varied with time in pregnant bitches. Both fibrinogen and CRP increased significantly with time for the pregnant bitches, but no significant change was detected for the control bitches. Increases were seen from day 21. The hemoglobin concentration decreased significantly with time in both pregnant and non-pregnant bitches. The neutrophil and monocyte numbers increased significantly in pregnant but not in control bitches. Pregnancy induced increased granulocyte expression of cell surface marker CD 18, increased monocyte expression of CD 18 and CD 49d, and increased lymphocyte expression of CD 49d. In conclusion, we describe inflammatory changes during canine pregnancy that are manifested as increases in concentrations of CRP and fibrinogen, an increase in neutrophils and monocytes, and in activation of granulocytes, monocytes and lymphocytes. The changes should be taken into account when evaluating concentrations of APPs and WBC in bitches during pregnancy. A variation in IGF-I concentrations was detected during pregnancy.

Development of MS-based methods for identification and quantification of proteins altered during early pregnancy in dogs.

Increased knowledge on serum protein profiles during early pregnancy in dogs would be valuable for several reasons, including animal welfare. Inflammatory changes during this period have been described. Today, mass spectrometry (MS) is a well-established technique to perform unbiased qualitative and quantitative studies of proteins in body fluids regardless of species. In the present study, a shotgun proteomic analysis based on nano-liquid chromatography-MS was performed to identify proteins of altered abundance during canine pregnancy, and, thereafter, a targeted parallel reaction monitoring (PRM)-method was developed and applied to absolutely quantify the concentrations of a selection of these proteins. Among the 32 proteins found altered between pregnant and non-pregnant dogs in the initial analysis, 12 were selected based on their changes in concentration and known biological importance, and these were analyzed using the PRM method. The PRM method showed good linearity, repeatability and sensitivity, and confirmed the higher concentration of Fibrinogen A, protein S alpha and C-reactive protein at early time points in pregnant bitches. In conclusion, the combination of both methods allowed the identification of several altered proteins, and the quantification and description of the concentration patterns for a selection of them during the early stage of dog pregnancy. SIGNIFICANCE: MS is a powerful technique that allows the investigation of protein variations in samples from different origin, such as serum from dogs. The application of a shotgun proteomic analysis as a screening method has revealed the alteration of several proteins after fifteen days of pregnancy in dogs. The complementary development of a PRM MS-based method for several of these proteins has enabled the absolute quantification of their concentrations at five different time points during early pregnancy. With the MS technique, a combination of proteins can be studied with lower limits of detection than with immunoassays. Care should be taken not to interpret the observed changes in pregnant dogs as signs of disease.

Effect of insulin treatment on circulating insulin-like growth factor I and IGF-binding proteins in cats with diabetes mellitus.

BACKGROUND: Insulin-like growth factor-I (IGF-I) is used to screen for acromegaly in diabetic cats. In humans, most circulating IGF-I forms ternary complexes (TC) with IGF-binding protein (IGFBP-3) and an acid-labile subunit. Compared to humans, the amount of TC in cats is more variable. Insulin-like growth factor-I concentrations are reported to increase during insulin treatment, more rapidly in cats achieving remission. OBJECTIVES: To investigate (i) factors associated with circulating IGF-I concentrations, including IGFBP-profiles (ii) effect of insulin treatment on IGF-I concentrations and (iii) IGF-I as prognostic marker of diabetes mellitus remission. ANIMALS: Thirty-one privately owned diabetic cats of which 24 were followed 1 year, and 13 healthy cats. METHODS: Prospective study. Serum insulin, IGF-I, glucose, and fructosamine concentrations were measured. IGF-binding forms were determined by chromatography in 14 diabetic and 13 healthy cats; and IGF-I, IGF-II, IGFBP-3, and IGFBP-5 by mass spectrometry in 3 cats achieving remission. RESULTS: Insulin-like growth factor-I median (interquartile range) before start of insulin treatment was 300 (160-556) ng/mL. Insulin-like growth factor-I was positively associated with TC (P < .0001) and endogenous insulin (P = .005) and negatively associated with fructosamine (P < .0001). Median IGF-I was higher 2-4 weeks after start of insulin treatment compared with baseline (300 versus 670 ng/mL, P = .0001) and predicted future remission (P = .046). In cats that went into remission, the amount of TC and IGFBP-3 increased, suggesting increase in IGF-I is dependent on TC formation. CONCLUSIONS: Insulin treatment should be accounted for when interpreting IGF-I in diabetic cats. Insulin-like growth factor-I 2-4 weeks after initiation of insulin treatment shows promise as prognostic marker for remission in diabetic cats.

An empirical examination of the conceptualization of companion animals.

BACKGROUND: The extensive keeping of companion animals and the substantial monetary amount we spend on these animals indicate that they are highly valued. Although the benefits humans derive from keeping cats and dogs have been extensively studied, how we conceptualize these animals has received limited attention. How people conceptualize cats and dogs is important as it influences human behavior and the well-being of humans as well as animals. The objective of this paper was to examine the conceptual meaning of dogs and cats and the relative importance of meanings assigned to these species. METHODS: Based on a Swedish on-line survey (n = 2028) the free-elicitation method was used to measure the salience of conceptualizations for dogs and cats as this method measures the accessibility of the focal object in people's memory. An R-index approach was used to analyze the importance and dominance of attributes on the premise that the order in which attributes were listed by respondents reflects their relative importance. The sum of the choice probability was used to evaluate the stochastic rank order of attributes and Somers' D was used to examine difference in rankings between groups of respondents. RESULTS: For dogs, human well-being in terms of emotional and social support, and emotional attachment (friendship, love, companionship, joy and loyalty) were found to be most important while elements related to the animals themselves (e.g. personality of the animal) were found to be less important. For cats, personality of the animal was along with love found to be most important. The results were largely consistent across different types of households. CONCLUSIONS: The results provide information on the relative importance of salient attributes and thus indicate which attributes that are important to consider, for example, when analyzing human-animal interaction, animal welfare, human health and subjective-well-being, or the economic value of cats and dogs.

Identifying ovarian tissue in the bitch using anti-Müllerian hormone (AMH) or luteinizing hormone (LH).

Reliable methods for determining whether or not a bitch has ovarian tissue present are needed for cases with unknown neutering status. Vaginal cytology consistent with heat is indicative of functional ovarian tissue. Other methods are required when the bitch is not presented in suspected heat. Progesterone can be analyzed during 2 months after suspected heat. During other stages, assays for the analyses of anti-Müllerian hormone (AMH) and luteinizing hormone (LH) have been used. The AMH assay is expected to give detectable concentrations (positive) in bitches with ovarian tissue, and the LH assay should give negative results in intact bitches, except during the pre-ovulatory LH peak. The aim of the present study was to study the diagnostic efficiency for detecting ovarian tissue in bitches using an AMH assay developed for human samples, and a semi-quantitative rapid immune migration (RIM™) LH assay developed for use in dogs. An AMH concentration of ≥0.1 µg/L, and an LH concentration of ≤1 µg/L, was set as the cut-off for presence of ovarian tissue. Client or staff owned bitches were included (N = 125). There were 73 intact bitches that were classified as being in heat (N = 25); in luteal phase (N = 12); or in anestrus (N = 36), and 52 spayed bitches that showed no clinical signs of estrogen influence. In total 64 of the 73 intact bitches (88%) were correctly identified using AMH, and 70/73 (96%) intact bitches were correctly identified using the LH assay. Excluding bitches in heat, the corresponding figures were 42/48 (88%) for AMH and 48/48 (100%) for LH. Of the 52 spayed bitches, 51 (98%) were correctly identified using the AMH assay and 49 (94%) were correctly identified using the LH assay. In this population, the predictive value of a positive AMH for intact bitches was 98%, and of a negative AMH for spayed bitches was 85%. Excluding bitches in heat, the predictive value of a negative LH test for intact bitches was 94%, and the predictive value of a positive LH test for identifying spayed bitches was 100%. It was concluded that analyses of AMH and LH are useful for detecting ovarian tissue in bitches, but that low concentrations of AMH may be obtained in intact bitches, classifying them as spayed. For LH, bitches in suspected estrus should not be tested to avoid the pre-ovulatory LH-surge, that otherwise may cause intact bitches being incorrectly identified as spayed.

Ambulatory electrocardiogram recordings in cats with primary asymptomatic hypertrophic cardiomyopathy.

Objectives The aims of the study were to determine the heart rate, rhythm, number of ventricular premature complexes (VPCs) and atrial premature complexes (APCs) in unsedated cats with asymptomatic hypertrophic cardiomyopathy (HCM), using 24 h ambulatory electrocardiogram (ECG) (Holter) in the home environment and to compare the results with those from healthy control cats. Methods Fifteen privately owned cats with asymptomatic HCM entered the study. Data from 23 healthy cats, previously published by our group, were used as the control. Clinical examination, measurement of blood pressure, echocardiographic examination, Holter recordings and biochemical analyses were performed in all cats. Holter recordings were obtained in the home environment. Results Three-lead ECGs of good quality were obtained from 15 cats with HCM. The median heart rate was 145 (interquartile range [IQR] 137-184) beats per minute for the cats with HCM. All cats with HCM presented with normal sinus rhythm; 60% of cats had intermittent sinus arrhythmia. Median number of VPCs was 3 (IQR 1-17). Three cats had APCs and three cats had both escape beats and intermittent sinus arrhythmia. Conclusions and relevance Asymptomatic cats with HCM had few VPCs and APCs on 24 h ambulatory ECG in the home environment. Intermittent sinus arrhythmia was observed in 60% of cats with HCM. The present study shows that the heart rate and the number of VPCs and APCs in cats with asymptomatic HCM are similar to that found in healthy control cats.

Quantitative and Selective Analysis of Feline Growth Related Proteins Using Parallel Reaction Monitoring High Resolution Mass Spectrometry.

Today immunoassays are widely used in veterinary medicine, but lack of species specific assays often necessitates the use of assays developed for human applications. Mass spectrometry (MS) is an attractive alternative due to high specificity and versatility, allowing for species-independent analysis. Targeted MS-based quantification methods are valuable complements to large scale shotgun analysis. A method referred to as parallel reaction monitoring (PRM), implemented on Orbitrap MS, has lately been presented as an excellent alternative to more traditional selected reaction monitoring/multiple reaction monitoring (SRM/MRM) methods. The insulin-like growth factor (IGF)-system is not well described in the cat but there are indications of important differences between cats and humans. In feline medicine IGF-I is mainly analyzed for diagnosis of growth hormone disorders but also for research, while the other proteins in the IGF-system are not routinely analyzed within clinical practice. Here, a PRM method for quantification of IGF-I, IGF-II, IGF binding protein (BP) -3 and IGFBP-5 in feline serum is presented. Selective quantification was supported by the use of a newly launched internal standard named QPrEST™. Homology searches demonstrated the possibility to use this standard of human origin for quantification of the targeted feline proteins. Excellent quantitative sensitivity at the attomol/µL (pM) level and selectivity were obtained. As the presented approach is very generic we show that high resolution mass spectrometry in combination with PRM and QPrEST™ internal standards is a versatile tool for protein quantitation across multispecies.

Colonization with methicillin-resistant Staphylococcus pseudintermedius in multi-dog households: A longitudinal study using whole genome sequencing.

Despite a worldwide increase in the presence of methicillin-resistant Staphylococcus pseudintermedius (MRSP) in dogs and its potential to cause serious canine health problem, the understanding of the transmission and long-term carriage of MRSP is limited. The objective of this study was to investigate the transmission of MRSP to contact dogs living in multiple dog households where one or more of the dogs had been diagnosed with a clinically apparent infection with MRSP. MRSP carriage was investigated over several months in 11 dogs living in four separate multiple dog households where an MRSP infection in a dog had been diagnosed. Whole-genome sequencing was used for genotypic characterization. Contact dogs were only MRSP-positive if the index dog was positive on the same sample occasion. Three contact dogs were consistently MRSP-negative. The data from whole genome sequencing showed similarities between isolates within each family group, indicating that MRSP was transmitted within each family. The results show that the risk of MRSP-colonization in dogs living with an MRSP-infected dog is reduced if the index dog becomes MRSP negative. All of the contact dogs will not carry MRSP continuously during the time the index dog is MRSP-positive. The information yielded from whole genome sequencing showed the methodology to be a promising additional tool in epidemiologic investigations of MRSP transmission.

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) for analysis of endogenous steroids in the luteal phase and early pregnancy in dogs: a pilot study.

BACKGROUND: Blood samples from dogs are often limited in volume, only allowing few steroids to be quantified with immunoassays. In addition, immunoassays may be compromised by interferences such as anti-reagent antibodies. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) can be used for the simultaneous quantitation of several steroids. This has not been described in dogs before. OBJECTIVES: The aims were to use LC-MS/MS to study steroid profiles in early pregnancy and luteal phase in dogs, and to determine if differences exist between pregnant (P) and nonpregnant (NP) dogs. METHODS: Nine female dogs were included, 4 during a NP luteal phase, 4 during a P luteal phase, and one during one NP and one P luteal phase. Blood samples were collected around the time of the LH surge (Day 0) and on Day 26. Serum was analyzed for 5 classes of steroids, including glucocorticoids, androgens, estrogens, pregnanes, and progestins, using LC-MS/MS methods. RESULTS: The concentration of progesterone was significantly higher on Day 26 in P than in NP bitches. Distribution of concentrations of glucocorticoids, androgens, estrogens, or pregnanes in P and NP dogs were not statistically different. The predominating glucocorticoid was cortisol, and dihydroepiandrosterone (DHEA) was the predominating androgen. Concentration of estrone was comparable to oestradiol, whereas concentrations of pregnenolone were higher than those of 17-OH pregnenolone. CONCLUSIONS: Only concentration of progesterone differed between P and NP bitches, being significantly higher on Day 26 in P than in NP bitches. LC-MS/MS offers interesting possibilities for studies of canine reproductive endocrinology.

Anti-Müllerian hormone: a potentially useful biomarker for the diagnosis of canine Sertoli cell tumours.

BACKGROUND: Testicular tumours are common in dogs and in many cases do not give rise to clinical signs. In other cases, signs of feminization, hyperpigmentation or alopecia may be observed, most commonly associated with Sertoli cell tumours (SCT). Although these signs are often associated with elevated concentrations of oestradiol, analysis of oestradiol may give inconclusive results due to large variations among individuals. Other biomarkers are therefore needed. Anti-Müllerian hormone (AMH) is expressed by the Sertoli cell. In humans, AMH has been shown to be a specific marker of Sertoli cell origin in gonadal tumours. Using immunohistochemistry, AMH has been shown to be a useful marker of immature and neoplastic Sertoli cells in dogs. The aim of the present study was to evaluate the clinical relevance of AMH analysis in peripheral blood in the diagnostic workup of dogs with suspected testicular tumours. RESULTS: Blood was collected from 20 dogs with a palpable testicular mass and from 27 healthy controls. Serum was analysed for oestradiol-17ß using a RIA and for AMH using an ELISA. The Mann-Whitney U test was used to compare hormone concentrations between different groups. All control dogs had AMH concentrations ≤ 10 ng/mL, except one outlier that had a concentration of 43 ng/mL. Six dogs with SCT or mixed tumours containing SCT had AMH concentrations higher than 22 ng/mL, significantly higher than AMH concentrations in control dogs (P = 0.0004). Concentrations between 10 and 22 ng/mL were found in about half of the dogs with non-neoplastic testicular pathologies or with testicular tumours other than SCTs. Age did not significantly affect concentrations of AMH in the control dogs. CONCLUSION: AMH was shown to be a promising biomarker for the diagnosis of Sertoli cell tumours in dogs.

Markers of Borna disease virus infection in cats with staggering disease.

Borna disease virus (BDV) is a RNA-virus causing neurological disorders in a wide range of mammals. In cats, BDV infection may cause staggering disease. Presently, staggering disease is a tentative clinical diagnosis, only confirmed at necropsy. In this study, cats with staggering disease were investigated to study markers of BDV infection aiming for improvement of current diagnostics. Nineteen cats fulfilled the inclusion criteria based on neurological signs and pathological findings. In 17/19 cats, BDV infection markers (BDV-specific antibodies and/or BDV-RNA) were found, and antibodies in serum (13/16, 81%) were the most common marker. BDV-RNA was found in 11/19 cats (58%). In a reference population without neurological signs, 4/25 cats were seropositive (16%). The clinical history and neurological signs in combination with presence of BDV infection markers, where serology and rRT-PCR on blood can be helpful tools, improve the diagnostic accuracy in the living cat.