The mechanisms governing corpus luteum (CL) function in domestic dogs remain not fully elucidated. The upregulated expression of cyclooxygenase 2 and prostaglandin (PG) E2 synthase (PGES) at the beginning of the canine luteal phase indicated their luteotrophic roles, and the steroidogenic activity of PGE2 in the early canine CL has been confirmed in vitro. Recently, by applying a cyclooxygenase 2 (COX2)-specific inhibitor (firocoxib [Previcox]; Merial) from the day of ovulation until the midluteal phase, the luteotrophic effects of PGs have been shown in vivo. This is a follow-up study investigating the underlying endocrine mechanisms associated with the firocoxib-mediated effects on the canine CL. Experimental groups were formed with ovariohysterectomies performed on Days 5, 10, 20, or 30 of firocoxib treatments (10 mg/kg bw/24h; TGs = treated groups). Untreated dogs served as controls. A decrease of steroidogenic acute regulatory (STAR) protein expression was observed in TGs. The expression of PGE2 synthase was significantly suppressed in TGs 5 and 10, and both PGE2 and PGF2 levels were decreased in luteal homogenates, particularly from CL in TG 5. Similarly, expression of the prolactin receptor (PRLR) was diminished in TGs 5 and 20. The expression of PGE2 receptors PTGER2 (EP2) and PTGER4 (EP4), the PG-transporter (PGT) , and 15-hydroxy PG dehydrogenase (HPGD) was not affected in TGs. Our results substantiate a direct luteotrophic role of PGs in the early canine CL, i.e., by upregulating the steroidogenic machinery. Additionally, the possibility of an indirect effect on PRL function arises from the increased prolactin receptor expression in response to PGE2 treatment in canine lutein cells observed in vitro.

Thirty clinically healthy dogs with poor semen quality were used in the study. Fifteen dogs were supplemented daily with selenium (0.6 mg/kg organic selenium from yeast) and vitamin E (5 mg/kg) per os for 60 d. The control group (15 dogs) was not supplemented. Semen was collected from all dogs by manual manipulation on days 0, 30, 60, and 90. The sperm concentration and motility parameters were evaluated with a Hamilton Thorne sperm analyser, version IVOS 12.3. For the assessment of sperm morphology, Diff-Quik stain was used. The percentage of live and dead spermatozoa was estimated on dried smears stained with eosin-nigrosin. The concentration of spermatozoa, most motility parameters determined (PMOT, VSL, VCL, ALH, BCF, RAPID, MEDIUM, SLOW, and STATIC), and the percentage of spermatozoa morphologically normal and live increased significantly (P < 0.05) after 60 d of supplementation. In the control group, there were no changes in motility parameters while the concentration and total sperm count decreased over the duration of the study. In conclusion, supplementation with selenium and vitamin E for 60 d can improve the quality of semen in dogs with lowered fertility.

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The aim of this study was to compare the frequency of the occurrence of lip and/or palate cleft (CL/CP) in new-borns of two breeds, Pugs and Chihuahuas, and to measure the folic acid blood levels in bitches during gestations both with and without folic acid oral supplementation. Bitches of 13 Pugs and 17 Chihuahuas with CL/CP cases were used in the study. In trial 1, the animals of the experimental group (n=25) were given additional folic acid from the onset of heat till the 40 th day of gestation. The females of the control group (n=12) were fed a traditional diet. From all the animals blood was collected at the onset of heat, 14 days later and on the 30 th day of the gestation to estimate folic acid concentration. In trial 2, the prevalence of CP/CL cases in litters from pregnancies before and after supplementation was compared. The percentage of puppies with CL/CP after supplementation decreased in both Pugs and Chihuahua puppies (10.86% and 15.78% vs. 4.76% and 4.8% respectively). On Day 0, the concentrations of folic acid were at a low physiological level (around 8 ng/ml) in all the animals. In bitches of the experimental group the blood level of folic acid on day 14 th and 30 th of the treatment showed an increase in both breeds (13.65 ± 4.27 ng/ml in Pugs, 10.79 ± 2.84 ng/ml in Chihuahuas, and 14.94 ± 3.22 ng/ml in Pugs, 12.95 ± 3.58 in Chihuahuas, respectively) while in the control group, this level decreased with time of gestation both in Pugs and in Chihuahuas (around 6 ng/ml). Folic acid supplementation seems to be a simple, effective preventive method to reduce the risk of CL/CP, especially in the predisposed breeds.

Twenty bitches with acute endometritis-pyometra complex (EPC) and 20 clinically healthy bitches were examined. The following coagulation parameters were determined in haemostatic evaluations: prothrombin time (PT), activated partial thromboplastin time (aPTT), thrombin time (TT), fibrinogen concentrations (FBG), D-dimer concentrations (D-D), antithrombin activity (AT), and blood platelet counts (PLT). Morphological and biochemical blood parameters were also analysed. Examinations of animals affected by EPC revealed blood coagulation and fibrinolytic disorders, and the noted results (PT 13.7 ±1.06 s, aPTT 23.4 ±1.04 s, TT 15.6 ±0.68 s, FBG 2.2 g/L, D-D 785.4 ±103.05 μg/L, AT 111.1 ±13.51%, PLT 169.30 ±126.31 103/μL) point to a high risk of disseminated intravascular coagulation. The findings indicate that the coagulation parameters of bitches affected by EPC should be analysed before treatment as the noted disorder can significantly complicate therapy and ovariohysterectomy, and endanger the patients' life.