The aim of this study was to evaluate the efficacy of tacrolimus eye drops in alleviating the clinical symptoms of canine keratoconjunctivitis sicca (KCS) and to compare this efficacy with that of cyclosporine. The clinical study was conducted on 40 dogs diagnosed with idiopathic KCS. The dogs were divided into two groups of 20 animals each. In Group I, 0.75% cyclosporine eye drops were administered three times a day, while in Group II 0.02% tacrolimus eye drops were given twice daily. In addition, each group was subdivided into three subgroups based on the results of Schirmer tear test I (STT I). Clinical and ophthalmologic examinations were performed prior to the treatment as well as after one and two months of therapy. The application of both tacrolimus and cyclosporine resulted in a significant reduction of neovascularisation after the first and second month of treatment (P < 0.05, P < 0.001); however, in moderate and advanced stages, the observed efficacy of tacrolimus was higher. Across all patients, a significant increase in STT I values was observed after both the first and second month of treatment with tacrolimus (P < 0.01), as well as after two months of treatment with cyclosporine (P < 0.05). In both groups, some patients were observed to exhibit inhibited development of pigmentation, but an analysis of particular clinical cases and statistical data revealed no statistically significant discrepancies in the course of the study. In cases of advanced canine KCS, the efficacy of tacrolimus may be higher than that of cyclosporine.

The objective of this study was to assess the treatment of chronic superficial keratitis (CSK) in dogs with the use of tacrolimus and DMSO. The study was conducted on 16 dogs - 7 males and 9 females, aged 3 to 11 years, diagnosed with CSK. The disease was treated with ophthalmic drops containing 0.02% tacrolimus and 50% DMSO, administered to the ocular surface three times a day. Prior to the treatment and after 5 weeks of therapy, the corneal neovascularisation, pigmentation, and also the redness and depigmentation of the third eyelid margin were assessed. The percentage of the corneal surface afflicted with inflammatory processes was calculated on the basis of photographs taken with the use of IsoCalc.com’s Get Area software for Corel DRAW 12. It was found that the application of tacrolimus and DMSO caused a reduction of inflammatory process and neovascularisation in the cornea. The mean corneal surface afflicted with inflammatory processes was statistically significantly reduced from 69.9% to 43.9% (p ≤ 0.01) - in case of the right corneas, and from 58.9% to 38.6% in case of the left corneas. Of 32 corneas diagnosed with the pigmentation, the reduction of the pigmentation was observed in 14, while in 16 the pigmentation increased. The treatment of CSK with the use of tacrolimus and DMSO causes the reduction in terms of inflammatory processes and neovascularisation, but in many cases does not inhibit the progress of the pigmentation.

The aim of the study was to assess the genetic variability of the Polish Greyhound population based on pedigree analysis and molecular DNA testing and to determine the degree of relatedness among individuals in the population. Pedigree data of 912 Polish Greyhounds recorded in pedigree books since they were opened for this breed were analyzed. For molecular testing, DNA was obtained from cheek swabs taken from 235 dogs of the tested breed. A panel of 21 markers (Short Tandem Repeat—STR) was used. The mean inbreeding determined for the Polish Greyhound population based on pedigree analyses was low and amounted to 11.8%, but as many as 872 individuals of the 912 dogs in the studied population were inbred. A total of 83 founders (at least one unknown parent) were identified, among which 27 founders had both unknown parents. Full-sibling groups consisted of 130 individuals, with a minimum and maximum litter size of 2 and 16, respectively. The average litter size was 5.969. Gene diversity calculated based on the mean kinship matrix was 0.862 and the population mean kinship was 0.138. The founder genome equivalent based on the mean kinship matrix was 3.61; the founder genome surviving level was 12.34; the mean Ne was estimated at 21.76; and the Ne/N ratio was 0.135. The FIS inbreeding coefficient for 21 STR was negative, and the mean FIS value for all loci had a low negative value (−0.018). These values suggest a low level of inbreeding in the examined breed as well as the avoidance of mating related animals.

The choroid, a multifunctional tissue, has been the focus of research interest for many scientists. Its morphology and morphometry facilitate an understanding of pathological processes within both the choroid and retina. This study aimed to determine the choroidal layer thicknesses in healthy, mixed-breed mesocephalic dogs, both male (M) and female (F), using spectral domain optical coherence tomography (SD-OCT) with radial, cross-sectional, and linear scans. The dogs were divided into two groups based on age: middle-aged (MA) and senior (SN). Thicknesses of choroidal layers, namely RPE–Bruch’s membrane–choriocapillaris complex (RPE-BmCc) with tapetum lucidum in the tapetal fundus, the medium-sized vessel layer (MSVL), and the large vessel layer with lamina suprachoroidea (LVLS), as well as whole choroidal thickness (WCT), were measured manually using the caliper function integrated into the OCT software. Measurement was performed dorsally and ventrally at a distance of 5000–6000 μm temporally and nasally at a distance of 4000–7000 μm to the optic disc on enhanced depth scans. The measurements were conducted temporally and nasally in both the tapetal (temporal tapetal: TempT, nasal tapetal: NasT) and nontapetal (temporal nontapetal: TempNT, nasal nontapetal: NasNT) fundus. The ratio of the MSVL thickness to the LVLS thickness for each region was calculated. In all examined dogs, the RPE-BmCc in the dorsal (D) region and MSVL in the Tt region were significantly thicker than those in the other regions. The MSVL was thinner in the ventral (V) region than in the D, TempT, TempNT and NasT regions. The MSVL was significantly thinner in the NasNT region than in the D region. LVLS thickness and WCT were significantly greater in the D and TempT regions than those in the other regions and significantly lesser in the V region than those in the other regions. The MSVL-to-LVLS thickness ratio did not differ between the age groups. Our results reveal that the choroidal thickness profile does not depend on age. Our findings can be used to document the emergence and development of various choroidal diseases in dogs in the future.