Long term use of hydraulic artificial urethral sphincters in nine dogs from New Zealand with urethral sphincter mechanism incompetence

AIMS: To report on the long-term outcomes of hydraulic artificial urethral sphincter (HAUS) placement for the correction of urethral sphincter mechanism incompetence (USMI) in New Zealand dogs.

METHODS: Retrospective data were obtained from cases of dogs which had a HAUS placed after failed medical and/or surgical management of USMI between August 2012 and November 2016. Owner assessment of urinary incontinence was evaluated by an online survey in May 2017 using a visual analogue scale (0 being normal, 100 being severely affected) for the frequency, volume and severity of any straining to urinate, immediately prior to the placement of the HAUS and at the time of the survey. The number of days between surgery and the completion of survey were recorded.

RESULTS: Seven females and two male dogs, which were all desexed except for one female, were eligible for inclusion in the study. The period of follow-up following HAUS placement ranged from 206–1,685 days. Following HAUS placement, frequency and volume of urinary incontinence decreased for six dogs and were practically unchanged for three dogs. The median frequency score decreased from 70 to 13 and the volume score decreased from 73 to 12. There was no consistent change in the perceived degree of straining to urinate. Complications occurred in three dogs; one required repositioning of a dislodged injection port, one required management for haematuria and a hypoplastic bladder, and one required surgical removal of fibrous tissue around the HAUS cuff.

CONCLUSIONS AND CLINICAL RELEVENCE: HAUS placement was an effective method for the treatment of persistent USMI in most dogs and provided good clinical results based on owner assessment. The technique was associated with few complications and allowed successful long-term control of urinary incontinence without the need for medical management.     

Comparing different formulae to test for gastrointestinal nematode resistance to benzimidazoles in smallholder goat farms in Mexico

The objective was to examine the coincidence in the prevalence of benzimidazole (Bz) resistance in smallholder goat herds, as determined by three average-based and two individually-based faecal egg count reduction (FECR) tests. Nineteen smallholder goat herds with more than 30 animals were selected from 84 herds in Yucatan. Animals shedding 150 eggs/g of faeces (EPG) on day zero were randomly divided into two groups. The control group did not receive treatment and the treated group received fenbendazole (10mg/kg body weight per os). Feed was withdrawn for 16 h before treatment. Ten days after treatment, both groups were sampled to determine their FEC. Faecal cultures and identification of infective larvae were performed for estimating the proportions of genera of gastrointestinal nematodes (GIN) present. Presence of resistant GIN was determined with three different average-based FECR (FECR(1), FECR(2) and FECR(3)) and two individually-based FECR (iFECR(1) and iFECR(2)). The prevalence of herds with Bz resistant nematodes (and 95% confidence interval (95% CI)) was calculated using each formula. Coincidence among formulae was estimated with Kappa values. The prevalence (+/- 95% CI) of Bz resistance calculated with FECR(1) (57.89 +/- 22.20) had a high coincidence with iFECR(1) and iFECR(2) (Kappa values of 0.86 and 0.79, respectively). The prevalence with FECR(2) (31.58 +/- 20.90) and FECR(3) (21.05 +/- 18.33) had a low coincidence with FECR(1) (Kappa < 0.50). Trichostrongylids found on Bz resistant farms were mainly Haemonchus spp., however, some Trichostrongylus spp. and Oesophagostomum spp. were found too. The high coincidence between the standard average-based FECR(1) and the individually based formulae is encouraging and may suggest that either formula could be applied to smallholder farmers. Further laboratory studies are needed to confirm the resistance status in the herds.     

LOW-FIELD MRI AND ARTHROSCOPY OF MENISCAL LESIONS IN TEN DOGS WITH EXPERIMENTALLY INDUCED CRANIAL CRUCIATE LIGAMENT INSUFFICIENCY

Little is known about the magnetic resonance imaging (MRI) appearance of canine meniscal lesions. The aim of this study is to describe the MR appearance of meniscal lesions in dogs with experimentally induced cranial cruciate ligament (CCL) deficiency. The pilot study revealed dogs weighing approximately 10 kg to be too small for meniscal evaluation on low-field MRI. In the main study, dogs weighing approximately 35 kg were used. The left CCL was transected and low-field MRI was performed regularly until 13 months post-surgery. Normal menisci were defined as grade 0. Intrameniscal lesions not reaching any surface corresponded to grade 1 if focal and to grade 2 if linear or diffuse. Grade 3 lesions consisted in linear tears penetrating a meniscal surface. Grade 4 lesions included complex signal changes or meniscal distortion. Between 2 and 13 months post-surgery, all dogs developed grade 4 lesions in the medial meniscus. Most of them corresponded to longitudinal or bucket handle tears on arthroscopy and necropsy. Two dogs showed grade 3 lesions reaching the tibial surface of the lateral meniscus on MRI but not in arthroscopy. Such tears are difficult to evaluate arthroscopically; MRI provides more accurate information about the tibial meniscal surface. Grades 1 and 2 lesions could not be differentiated from presumably normal menisci with our imaging technique. An MRI grading system better adapted to canine lesions has yet to be developed. MRI is a helpful tool for the diagnosis of complete tears in the canine meniscus, especially in larger dogs.     

Evaluation of an Immunochromatographic Test to the Diagnosis of Canine Brucellosis Caused by Brucella canis

This study evaluated the performance of an immunochromatographic test (ICT) for the diagnosis of canine brucellosis caused by Brucella canis, comparing its results with that of the rapid slide agglutination test with and without the use of 2‐mercaptoethanol and the agar gel immunodiffusion test (AGID). The microbiological culture, PCR and clinical examination were used as reference. According to the results obtained in clinical examination, blood culture, culture of semen and vaginal swab and PCR in blood, semen and vaginal swab, a total of 102 dogs were divided into three groups: B. canis‐infected dogs (Group 1), B. canis‐non‐infected dogs (Group 2) and dogs with suspected brucellosis (Group 3). The diagnostic sensitivity of RSAT, 2ME‐RSAT, AGID and ICT in Group 1 was, respectively, 75%, 37.5%, 27.8% and 89.58%. The diagnostic specificity of RSAT, 2ME‐RSAT, AGID and ICT in Group 2 was, respectively, 91%, 100%, 100%, and 100%. In dogs with suspected brucellosis, 9.67% were RSAT positive, none was positive by 2ME‐RSAT, 3.22% were AGID positive and 6.45% were ICT positive. The main drawback concerning canine brucellosis diagnosis is the lack of a highly sensitive serological assay to be used as a screening test to the rapid identification of infected animals. The ICT showed a high diagnostic specificity and a diagnostic sensitivity value greater than that observed in the RSAT, 2ME‐RSAT and AGID. However, 10.41% of infected dogs had negative results by ICT. These dogs were positive by microbiological culture and/or PCR, indicating active infection and consequently a higher potential of spreading Brucella. Although rapid and simple to perform, the ICT lacked sensitivity to be used as a screening test.     

Prevalence of cattle herds with ivermectin resistant nematodes in the hot sub-humid tropics of Mexico

The objective was to determine the prevalence of semi-intensive Bos indicus and Bos indicus × Bos taurus cattle herds with ivermectin (IVM) resistant nematodes in a sub-humid tropical zone of Mexico using the faecal egg count reduction test (FECRT). Thirty-three herds (28 beef and 5 dual purpose herds) were monitored in a period of 6 months (September 2008 to February, 2009). Only 14 of the 33 herds were included in the trial. The other herds had not enough animals with sufficient nematode eggs per gram of faeces (EPG) to be included in a FECRT. Some farms were visited twice trying to find more animals with egg counts higher than 150 EPG. In the 14 surveyed herds the calves were randomly distributed into two groups: (a) treatment group received 0.2mg of IVM/kg BW sc on day 0, and (b) control group without treatment. Faecal samples were obtained from each animal on days 0 and 14 post-treatment. Reduction percentages (% R) and 95% CI were calculated. The prevalence of cattle herds with IVM resistant nematodes was 78.6%. Those suspected of IVM resistance were 21.4%. All surveyed herds used IVM from two to three times a year (mainly beginning and end of the wet season) during 1-11 consecutive years. The farm with stronger resistance used IVM for 11 consecutive years (% R=0%; 95% CI=0-47%). Genera of nematodes resistant to IVM were: Ostertagia, Haemonchus, Cooperia and Trichostrongylus. A considerable effort is needed to perform FECRT in cattle herds under hot sub-humid tropical conditions.