Naci Öcal

Neospora caninum associated with epidemic abortions in dairy cattle: The first clinical neosporosis report in Turkey

Neospora caninum, a protozoan parasite, has been considered as one of the most important etiological agents responsible for abortion in dairy cattle throughout the world since it was first identified in dogs in 1988. In this report, characteristics of neosporosis, detected in a dairy cow ranch having epidemic abortions as high as 18.4%, were described. Blood samples were collected from 25 infertile or aborted dairy cattle, 6 calves born in 2006 and 40 heifers that were born in 2005 and raised in the same ranch. Necropsy was conducted in a 20-day-old Simmental calf that exhibited neurological signs including incoordination, head shaking, hyperextension in forelimbs and hindlimbs and tremor. The seroprevalance in aborted or infertile dairy cattle, heifers, and calves was 60%, 40%, and 33.3%, respectively. The mothers of seropositive two calves including clinically affected calf and its dam were N. caninum seropositive. In immunoperoxidase examinations, N. caninum antigen immunopositivity was observed in the degenerative and necrotic neurons in the brain, cerebellum as well as neurons in dorsal root ganglia of the cervical and thoracic regions of the spinal cord. In the heart, myocytes and Purkinje cells exhibited granular and linear patterns of immunoreactivity. Striated myofibers around the eyeball also showed immunolocalization for N. caninum antigen. Ultrastructurally, tachyzoites with typical apical complex, rhoptries and double-layered parasitic membrane were detected in the brain and heart sections. In conclusion, this report described clinical neosporosis for the first time in Turkey with tissue localization of the causative agents. This scientific communication also discusses the possible impact of cattle neosporosis by clinical, serologic and pathologic evidences collected from the survey of calves born in two successive generations in a ranch.

Azithromycin therapy of papillomatosis in dogs: a prospective, randomized, double‐blinded, placebo‐controlled clinical trial

Azithromycin, an azalide subclass macrolide antibiotic, is an effective, well-tolerated and safe therapeutic option for treatment of papillomatosis in humans. This study reports the clinical and histopathological results from a prospective, randomized, double-blinded, placebo-controlled trial of 17 dogs of various breeds with diagnosis of oral (n = 12) and cutaneous papillomatosis (n = 5) treated with azithromycin. Papillomas appeared as whitish, verrucous, hyperkeratotic papules 1-2.7 mm in size. The cases were randomly assigned to azithromycin (n = 10) and placebo treatment groups (n = 7). Both owners and investigators were blinded to the allocation to the groups. Azithromycin (10 mg/kg) was administered per os every 24 h for 10 days. Clinical evaluations were done by the same investigator throughout the trial. Azithromycin treatment significantly decreased clinical scores (P < 0.001), whereas there was no change seen in the placebo group. In the azithromycin treatment group, skin lesions disappeared in 10-15 days. One case in the placebo had spontaneous regression of its papillomas by day 41, but lesions were still evident at day 50 in the remaining six cases. There was no recurrence of papillomatosis in the azithromycin treated dogs (follow up 8 months). No adverse effects were seen in either group. In conclusion, azithromycin appears to be a safe and effective treatment for canine papillomatosis.

In-vivo efficacy of toltrazuril on experimentally induced Toxoplasma gondii tissue cysts in lambs: A novel strategy for prevention of human exposure to meat-borne toxoplasmosis

The aim of the present study was to investigate in vivo efficacy of toltrazuril on Toxoplasma gondii tissue cysts following induction of chronic toxoplasmosis in 4-week-old lambs (n=27) by inoculation of 1×10(5) T. gondii ME 49 strain oocysts (day 0). Beginning at the 15th day after inoculation, lambs in Group T20 and Group T40 were given toltrazuril orally 2 times, once every week (Baycox 5%, Bayer Animal Health) at a dose of 20 mg/kg and 40 mg/kg, respectively. Positive control (PC) lambs were not given any therapy, and 2 clinically healthy non-infected lambs were used as negative controls (Group NC). Two out of 9 lambs in PC group (oocyst inoculated but non-treated) were killed on toltrazuril treatment days (day 15 and 22) to evaluate the tissue cyst presence in their muscles. On day 90, the remaining 25 lambs were necropsied, and samples from the brain and 11 different muscle groups were collected. The tissues were examined for the presence of tissue cysts by histopathology, immunohistochemistry, nested-PCR and percoll gradient centrifugation. Anti-T. gondii antibodies were screened by IFAT throughout the experiment. The increased T. gondii seropositivity beginning from the 15th day of inoculation remained steady at Day 45 and Day 90 in Groups PC while it was significantly lower at Day 90 in toltrazuril receiving groups. In toltrazuril treated groups, histopathological findings included degenerative changes in the cyst wall, complete macrophage invasion to the cysts, and reduction or removal of the cysts in toto. Four out of 9 lambs (44.4%) in both toltrazuril treated group (Group T20 and T40) did not contain tissue cyst in any examined tissues while all positive control animals had T. gondii tissue cysts at least in one muscle group. The toltrazuril treatment efficacy on the cyst presence was determined as 44.4%. The number of the cysts in the musculature was significantly different between non-treated and toltrazuril treated lambs (X(2)=6.613; p=0.037). For the total number of cysts, the positive control lambs had higher number of cysts compared to both toltrazuril treated lambs (T20 and T40) (X(2)=5.629; p=0.018 and X(2)=5.629; p=0.018, respectively) while there were no differences between Group T20 and Group T40 (X(2)=0.000; p=1.000). According to PCR results, the brain and M. semitendinosus were positive in all 7 control lambs while 12 out of 18 lambs were positive in toltrazuril treated lambs. In conclusion, the results are promising as the toltrazuril treated lambs had markedly less parasite counts compared to those of untreated lambs. Further research should be conducted to reveal if toltrazuril treatment in sheep could be used as a strategy to minimize the cyst exposure of humans through consumption of raw or undercooked mutton.

The efficacy of a combination of azithromycin and toltrazuril for the treatment of calves naturally infected with cryptosporidiosis: a randomised, double-blind, placebo-controlled comparative clinical trial

Cryptosporidium spp. are important emerging pathogens that can cause infections in humans, especially in immunosuppressed patients. Treatment of diseased calves that shed the infectious stage of the protozoon is critically important to prevent contamination by Cryptosporidium spp. oocysts. The objective of this study was to determine if a combination of azithromycin and toltrazuril provides a better treatment option for calf cryptosporidiosis compared to the use of either agent alone. A total of 55 Holstein calves with cryptosporidiosis were randomly assigned into four groups. Group A (n = 15) received azithromycin at a dose of 20 mg/kg/day per os for six days, group T (n = 15) received toltrazuril at a dose of 20 mg/kg per os every other day on a total of three occasions, and group AT (n = 15) received the combination of both drugs. The control group (n = 10) received purified water. A randomised, placebo-controlled, double-blinded clinical study was designed. The number of oocysts in faeces and clinical parameters were followed daily. Selected haematological and biochemical parameters were measured at the beginning and end of the study. The calves receiving the combination of azithromycin and toltrazuril exhibited a better clinical score as well as the lowest number of oocysts at all time-points. In conclusion, the combination of azithromycin and toltrazuril promotes rapid clinical recovery in calves infected with cryptosporidiosis and stops oocyst shedding. Thus, the combination of azithromycin and toltrazuril is an effective alternative treatment option for calf cryptosporidiosis.