Rhodesian Ridgebacks have an increased risk to develop benign prostatic hyperplasia.

Benign prostatic hyperplasia (BPH) is an age-dependent primarily non-inflammatory enlargement of the accessory gland in the intact dog. The aim of the present study was to control a previously raised suspicion of a breed-related higher incidence of BPH in dogs of the Rhodesian Ridgeback breed. For this, 18 Labrador Retrievers/LR and 20 Rhodesian Ridgebacks/RR were assigned to the age groups 18-24 months (n = 12), 25-48 months (n = 13) and 49-72 months (n = 13). Prostate gland status was determined by rectal palpation, B-mode ultrasound, calculation of the prostate gland volume and semen analysis regarding haemospermia and was classified according to blood plasma concentrations of canine prostate-specific arginine esterase (CPSE) (normal ≤ 60 ng/ml, increased ≥ 61 ng/ml; Pinheiro et al., 2017). Concentrations of testosterone, 5α-dihydrotestosterone and estradiol were analysed in peripheral blood serum or plasma for detecting breed-specific conditions regarding the endocrine metabolism. Prostatic volume was significantly larger in RR irrespective of the CPSE status. In RR, BPH occurred more frequently and started at an earlier age compared with the LR. Breed-related specificities in steroid metabolism in the RR were indicated by correlations of 5α-dihydrotestosterone and estradiol with age and of testosterone with prostate gland volume. Although the incidence of sonographic signs of BPH and haemospermia did not fit with normal and increased CPSE concentrations, a breed-specific higher incidence of BPH in the RR breed could be clearly verified.

An investigation on the relevance of prolactin, insulin-like growth factor-1 and 25-hydroxyvitamin D3 (25-OHD3 ) in canine benign prostatic hyperplasia in a predisposed breed model.

Serum concentrations of prolactin (PRL), insulin-like growth factor-1 (IGF-1) and 25 hydroxyvitamin D3 (25-OHD3 ) were analysed to investigate their possible involvement in the pathogenesis of benign prostatic hyperplasia (BPH). For this, dogs of the Rhodesian Ridgeback (RR) breed were used because of a verified breed disposition for the development of BPH. Labrador Retrievers (LR) served as controls. The prostate gland status was characterised by the prostate gland volume, clinical signs of BPH (haemospermia and sonographic findings) and the plasma concentration of canine prostate-specific arginine esterase (CPSE). Breed specificity in the RR was expressed by a correlation of PRL with breed (p < 0.05). Similar relationships existed in the dogs with normal CPSE (CPSEn) with respect to the IGF-1 concentrations (LR: p < 0.05). The latter were negatively correlated with prostatic volume and age (both p < 0.05). Concentrations of 25-OHD3 were tendentially (p = 0.18) lower in the RR with increased CPSE (CPSEi) compared with the CPSEn LR and RR showing clinical signs of BPH. A negative correlation between serum 25-OHD3 and age (p < 0.05) existed in the CPSEi RR. Proof of 25-OHD3 in prostatic secretion proved to be a breed specific feature in the RR (p < 0.0001). For all RR dogs showing clinical signs of BPH, a close to significant (p = 0.06) positive correlation with prostate gland volume was found. The results of the present study reveal no clear hints towards the significance of PRL and IGF-1 in the pathogenesis of canine BPH. In the RR breed there were indications of a causal relationship with age-dependent changes in the vitamin D metabolism. The data suggest the possibility of preventing or treating canine BPH by administering vitamin D or substances involved in the intraprostatic vitamin D metabolism.

Urospermia indicating ectopic ureters in breeding dogs - 3 cases.

An Entlebucher Mountain Dog (57 months old, case 1), a Labrador Retriever (24 months, case 2) and an Irish Soft-Coated Wheaten Terrier (31 months old, case 3) were presented for breeding soundness evaluation to the clinic. During semen collection in all 3 dogs, the pre-secretion and the sperm-rich fraction showed normal consistency and colour, whereas the prostatic secretion (3 rd ejaculate fraction) appeared strikingly yellow. In cases 1 and 2, a severely decreased sperm motility (asthenozoospermia) and an increased amount of abnormal spermatozoa (teratozoospermia), and in case 3, a moderately decreased total sperm count (oligozoospermia) were detected. Sonographical examination revealed abnormal findings regarding the uretero-vesical junction and ectopic ureters. Therefore it is concluded that urine admixture to the 3 rd ejaculate fraction may indicate the presence of ectopic ureters and may cause impairment of semen quality and fertility. The present cases raise questions regarding urospermia concerning: 1. its incidence in dogs in general and in connection with ectopic ureters and 2. its relevance as a cause of deficient ejaculate quality and subfertility or infertility.

Impaired spermatogenesis, tubular wall disruption, altered blood-testis barrier composition and intratubular lymphocytes in an infertile Beagle dog - a putative case of autoimmune orchitis.

Impairment of blood-testis barrier integrity can be observed during inflammation, infection, trauma and experimental autoimmune orchitis, which is inducible in rodents. In the present study, an initially fertile two-year-old Beagle dog was presented with a decline in total sperm number resulting in azoospermia within five months, verified by twice-monthly semen analyses. The dog was clinically healthy with bilateral small testes and showed normal thyroid function. Bacterial cultures of semen were negative and serum biochemical analyses showed no abnormal findings. To determine causes of azoospermia, the dog was castrated. Histological examinations of hematoxylin-eosin stained testicular sections revealed impaired spermatogenesis, seminiferous tubules with spermatogenic arrest or Sertoli-cell-only syndrome as well as focal interstitial and even intratubular lymphocytic infiltrations. Germ cell sloughing, apoptosis and giant cells were also observed in some tubules. Subsequent immunostainings of smooth-muscle-actin, claudin3, claudin11 and connexin43 demonstrated, for the first time, a mechanical and functional disruption of the tubular wall and alterations of blood-testis barrier proteins in these tubules. Presence of claudin3 and claudin11 in canine testis was confirmed using RT-PCR and sequencing and/ or Western-blot analyses. All findings suggested a possible spontaneous autoimmune orchitis to be the underlying cause for the observed azoospermia.

Zoonotic intestinal helminths interact with the canine immune system by modulating T cell responses and preventing dendritic cell maturation.

Parasite co-evolution alongside the mammalian immune system gave rise to several modulatory strategies by which they prevent exaggerated pathology and facilitate a longer worm survival. As little is known about the immunoregulatory potential of the zoonotic canine parasites Ancylostoma caninum and Toxocara canis in the natural host, the present study aimed to investigate whether their larval excretory-secretory (ES) products can modulate the canine immune system. We demonstrated TcES to increase the frequency of CD4+ Foxp3high T cells, while both AcES and TcES were associated with elevated Helios expression in Foxp3high lymphocytes. ES products were further capable of inducing IL-10 production by lymphocytes, which was mainly attributed to CD8+ T cells. ES treatment of PBMCs prior to mitogen stimulation inhibited polyclonal proliferation of CD4+ and CD8+ T cells. Moreover, monocyte-derived ES-pulsed dendritic cells reduced upregulation of MHC-II and CD80 in response to lipopolysaccharide. The data showed that regulation of the canine immune system by A. caninum and T. canis larvae comprises the modification of antigen-specific and polyclonal T cell responses and dendritic cell maturation.

[Evaluation of the blood progesterone concentration in the bitch measured by chemiluminescence immunoassay at the day of ovulation]. / Evaluation der mittels Chemilumineszenztest gemessenen Blut-Progesteronkonzentration bei der Hündin am Tag der Ovulation.

OBJECTIVE: Modifications of human test systems used in veterinary laboratory practice could lead to reference-range adaptions for their veterinary use. In 2012 the manufacturer of a widely used chemiluminescence immunoassay modified the test for progesterone measurement leading to a reference range adaption for the breeding-time detection in the bitch. MATERIAL AND METHODS: The aim of the present study was to evaluate the mean progesterone concentration by using the modified chemiluminescence immunoassay at the time of ovulation in the bitch and to compare this with previously used reference ranges. Moreover, internal and external quality controls were performed and progesterone concentrations measured in different laboratories with different methods were compared at a national and international level. RESULTS: In the present study, it could be demonstrated that the concentration of progesterone of 0-6 ng/ml measured by the modified test was clearly lower than that measured by the previously delivered test. National and international quality control assurance showed a good agreement of progesterone measurements between different laboratories and with the modified test. In seven bitches, the mean progesterone concentration on the day of ultrasonographically detected ovulation was 3.4 ± 0.9 ng/ml (2.0-4.5 ng/ml). CONCLUSION: This analysis indicates the need to change the widely accepted reference value for ovulation from 5-8 ng/ml to ~ 3.5 ng/ml for the currently used method. Particularly in veterinary endocrinology, the routine evaluation of reference values should be standard for good laboratory practice. However, the respective reference range is laboratory specific. CLINICAL RELEVANCE: Reference ranges of the progesterone concentration indicating the day of ovulation should be provided by the respective laboratory.