Modular hybrid total hip arthroplasty. Experimental study in dogs

Background

This prospective experimental study evaluated the surgical procedure and results of modular hybrid total hip arthroplasty in dogs.

Methods

Ten skeletally mature healthy mongrel dogs with weights varying between 19 and 27 kg were used. Cemented modular femoral stems and uncemented porous-coated acetabular cups were employed. Clinical and radiographic evaluations were performed before surgery and at 30, 60, 90, 120, 180 and 360 days post-operation.

Results

Excellent weight bearing was noticed in the operated limb in seven dogs. Dislocation followed by loosening of the prosthesis was noticed in two dogs, which were therefore properly treated with a femoral head osteotomy. Femoral fracture occurred in one dog, which was promptly treated with full implant removal and femoral osteosynthesis.

Conclusions

The canine modular hybrid total hip arthroplasty provided excellent functionality of the operated limb.     

Effect of tylosin on dogs with suspected tylosin-responsive diarrhea: a placebo-controlled,randomized, double-blinded,prospective clinical trial

Background

The macrolid antibiotic tylosin has been widely used to treat canine chronic diarrhea, although its efficacy is based on anecdotal reports and experimental studies in dogs and not on strong scientific evidence. The term tylosin-responsive diarrhea (TRD) refers to diarrheal disorders responding to tylosin therapy within a few days. In TRD, the stool remains normal as long as tylosin treatment continues, but diarrhea reappears in many dogs within weeks after discontinuation. The aim of our trial was to assess the effect of tylosin on fecal consistency compared with a placebo treatment in dogs with suspected TRD and additionally to establish whether tylosin in dogs with recurrent diarrhea is as effective as empirical studies and anecdotal reports suggest.

Methods

Subjects comprised 71 client-owned dogs that, according to the owners, had previously been treated successfully with tylosin due to recurrent diarrhea of unknown etiology. At the initial examination, where there were no signs of diarrhea, the dogs were randomly assigned in a 2:1 ratio to a tylosin or placebo group. During a two-month follow-up the owners evaluated the fecal consistency according to previously published guidelines. When diarrhea recurred, either tylosin (25 mg/kg q 24 h, 7 days) or placebo treatment was initiated orally. Treatment outcome was evaluated as the mean of fecal consistency scores assigned during the last three days of the treatment period. To test for differences between the tylosin and placebo group in the proportion of responders, Pearson''s Chi-squared test and Fisher''s exact test were applied.

Results

Sixty-one dogs met the selection criteria and were followed for two months. During the follow-up 27 dogs developed diarrhea and either tylosin or placebo treatment was started. The proportion of dogs with normal fecal consistency at the end of treatment was 85% (17/20) in the tylosin group and 29% (2/7) in the placebo group (Pearson''s Chi-squared test p = 0.0049 and Fisher''s exact test two-sided, p = 0.0114).

Conclusions

Our findings indicate that tylosin is effective in treating recurrent diarrhea in dogs. The dose of 25 mg/kg once daily appears sufficient. No changes specific to TRD were detected in the examinations.     

Evaluation of LHP? (1% hydrogen peroxide) cream versus petrolatum and untreated controls in open wounds in healthy horses: a randomized,blinded control study

Background

Treatment and protection of wounds in horses can be challenging; protecting bandages may be difficult to apply on the proximal extremities and the body. Unprotected wounds carry an increased risk of bacterial contamination and subsequent infection which can lead to delayed wound healing. Topical treatment with antimicrobials is one possibility to prevent bacterial colonization or infection, but the frequent use of antimicrobials ultimately leads to development of bacterial resistance which is an increasing concern in both human and veterinary medicine.

Methods

Standardized wounds were created in 10 Standardbred mares. Three wounds were made in each horse. Two wounds were randomly treated with LHP^® or petrolatum and the third wound served as untreated control. All wounds were assessed daily until complete epithelization. Protocol data were recorded on day 2, 6, 11, 16, 21 and 28. Data included clinical scores for inflammation and healing, photoplanimetry for calculating wound areas and swab cytology to assess bacterial colonization and inflammation. Bacterial cultures were obtained on day 2, 6 and 16.

Results

Mean time to complete healing for LHP^® treated wounds was 32 days (95%CI = 26.9-37.7). Mean time to complete healing for petrolatum and untreated control wounds were 41.6 days (95%CI = 36.2-47.0) and 44.0 days (95%CI = 38.6-49.4) respectively. Wound healing occurred significantly faster in LHP^® wounds compared to both petrolatum (p = 0.0004) and untreated controls (p < 0.0001). There was no significant difference in time for healing between petrolatum and untreated controls. Total scores for bacteria and neutrophils were significantly (p < 0.0001) lower for LHP^® treated wounds compared to petrolatum from day 16 and onwards. Staphylococcus aureus and Streptococcus zooepidemicus were only found in cultures from petrolatum treated wounds and untreated controls.

Conclusions

Treatment with LHP^® reduced bacterial colonization and was associated with earlier complete wound healing. LHP^® cream appears to be safe and effective for topical wound treatment or wound protection.     

Experimental infection of dogs with a feline endogenous retrovirus RD-114

Background

The feline endogenous retrovirus RD114 is contained in the genome of cats. The virus may contaminate live canine vaccines based on cultured feline cells. The in vivo infectivity, acute and subacute pathogenicity, and viral proliferation of the RD114 virus were evaluated by experimental infection of dogs.

Methods

Nine specific pathogen free dogs were divided into three groups, with each group consisting of one female and two male dogs. Dogs were subcutaneously inoculated in the neck with either 1 ml RD114 stock virus (group A), inactivated RD114 virus suspension (group B), or cell culture medium (group C) as a negative control. To assess blood cell counts and biochemical properties, blood samples from each group were collected 5 days before inoculation, just prior to inoculation, and 1, 3, 7 and 10 days post-inoculation.

Result

During the experimental period of 51 days, none of the dogs inoculated with RD114 virus showed any clinical signs, significant increases in rectal temperature or abnormal blood biochemical characteristics including C-reactive protein when compared with the negative controls. We were not able to re-isolate the RD114 virus from buffy coat cells of group A dogs. Additionally, we could not detect RD114 provirus in the genomic DNA isolated from peripheral blood leukocytes, lymph node, spleen and sternal bone marrow cells.

Conclusions

Signs of RD114 virus proliferation were not found after subcutaneous infection of dogs. Although the potential risk caused by infection with RD114 virus in dogs could not be assessed in this study, we suspect that RD114 virus has little or no virulence in dogs.     

Efficacy of two low-dose oral tylosin regimens in controlling the relapse of diarrhea in dogs with tylosin-responsive diarrhea: a prospective,single-blinded,two-arm parallel,clinical field trial

Background

Despite its wide acceptance as a treatment for canine chronic enteropathies, the macrolide antibiotic tylosin lacks official oral dosage recommendations. Not even textbooks share consensus about the dose; daily recommendations vary from 25 to 80 mg/kg and dosing intervals from one to three times daily.The objective of this prospective, single-blinded, two-arm parallel, clinical field trial was to determine whether doses of 5 mg/kg or 15 mg/kg tylosin administered orally once daily for seven days would have a similar effect on fecal consistency in diarrhea relapses to that of a 25 mg/kg dose of tylosin administered once daily for seven days, a dosage that has proved effective in controlling canine tylosin-responsive diarrhea (TRD). A further objective was to compare the efficacy of the 5 mg/kg and 15 mg/kg tylosin dosages. Fifteen client-owned dogs diagnosed with TRD that had responded to a dose of 25 mg/kg tylosin once daily for seven days were enrolled in the study. After a relapse of diarrhea the dogs were allocated into two groups receiving tylosin orally in doses of either 5 mg/kg or 15 mg/kg once daily for seven days. The owners were blinded to the dosage. The elimination of diarrhea was the main criterion in assessing treatment success. The mean fecal consistency score of the last three treatment days for all dosages, including 25 mg/kg, as evaluated by the owners according to a standardized fecal scoring system, served as the primary outcome measures.

Results

All eight dogs responded to the 5 mg/kg dose, and six of seven dogs responded to the 15 mg/kg dose. The mean fecal consistency scores at the 25 mg/kg tylosin dosage were no significantly different from scores at the 5 mg/kg or 15 mg/kg tylosin dosages (P = 0.672, P = 0.345).

Conclusions

Interestingly, 14/15 (93%) of the dogs responding to a dose of 25 mg/kg tylosin once daily for seven days also responded to the lower dosages at diarrhea relapse. The data indicate that a suitable dose of tylosin for treating diarrhea relapse in canine TRD could be as low as 5 mg/kg once daily for seven days.     

The carbon dioxide laser: an alternative surgery technique for the treatment of common cutaneous tumors in dogs

Background

Tumors of the skin and subcutaneous tissue are the largest group of canine neoplasms. Total excision is still the most effective method for treatment of these skin tumors. For its universal properties the carbon dioxide (CO₂) laser appears to be an excellent surgical instrument in veterinary surgery. Laser techniques are alternatives to traditional methods for the surgical management of tumors. The aim of this study was to compare various types of laser techniques in skin oncologic surgery: excision, ablation and mixed technique and to suggest which technique of CO₂ laser procedure is the most useful in particular case of tumors in dogs.

Findings

The study was performed on 38 privately-owned dogs with total number of 40 skin tumors of different type removed by various CO₂ laser operation techniques from 2010–2013. The treatment effect was based on the surgical wound evaluation, the relative time of healing and possible local recurrence of the tumor after 3 months post surgery. Local recurrence was observed in two cases. The study showed that in 30 cases time needed for complete resection of lesions was less than 10 minutes. Time of healing was longer than 12 days in 6 cases (42.8%) with tumor excision and in 14 cases (87.5%) where excision with ablation technique was performed.

Conclusions

The advantages of the CO₂ laser surgery were better hemostasis, precision of working, non-contact dissection, less instruments at the site of operation and minimum traumatization of the surrounding tissues.     

Clinical and biochemical changes in 53 Swedish dogs bitten by the European adder - Vipera berus

Background

Every year many dogs in Sweden are bitten by Vipera berus, the only venomous viper in Sweden. This prospective study investigated clinical signs, some biochemical parameters, treatment, and progress of disease after snakebite in 53 dogs. Effects of treatment with and without glucocorticoids were evaluated.

Methods

All fifty-three dogs bitten by Vipera berus were examined the same day the dog was bitten and the next day. Two more examinations during 23 days post snake bite were included. Creatinine, creatine kinase (CK), alanine aminotransferase (ALT), glutamate dehydrogenase (GLDH), alkaline phosphatase (ALP) and bile acid results were followed through 3 to 4 samplings from 34 of the dogs.

Results

All dogs had variable severity of local swelling in the bite area and 73 per cent had affected mental status. Initial cardiac auscultation examination was normal in all dogs, but six dogs had cardiac abnormalities at their second examination, including cardiac arrhythmias and cardiac murmurs. All dogs received fluid therapy, 36 dogs were given analgesics, 22 dogs were treated with glucocorticoids, and ten dogs were treated with antibiotics. Evidence of transient muscle damage (increased CK) was seen one day after the snake bite in 15 (54%) of 28 sampled dogs. Moderate changes in hepatic test results occurred in 1 dog and several dogs (22 of 34) had transient, minor increases in one or more hepatic test result. No dog died during the observation period as a consequence of the snake bite.

Conclusions

Snake bite caused local swelling in all dogs and mental depression of short duration in most dogs. Some dogs had transient clinical signs that could be indicative of cardiac injury and some other had transient biochemical signs of liver injury. Treatment with glucocorticoids did not have any clear positive or negative effect on clinical signs and mortality.     

No evidence of horizontal infection in horses kept in close contact with dogs experimentally infected with canine influenza A virus (H3N8)

Background

Since equine influenza A virus (H3N8) was transmitted to dogs in the United States in 2004, the causative virus, which is called canine influenza A virus (CIV), has become widespread in dogs. To date, it has remained unclear whether or not CIV-infected dogs could transmit CIV to horses. To address this, we tested whether or not close contact between horses and dogs experimentally infected with CIV would result in its interspecies transmission.

Methods

Three pairs of animals consisting of a dog inoculated with CIV (10^8.3 egg infectious dose₅₀/dog) and a healthy horse were kept together in individual stalls for 15 consecutive days. During the study, all the dogs and horses were clinically observed. Virus titres in nasal swab extracts and serological responses were also evaluated. In addition, all the animals were subjected to a gross pathological examination after euthanasia.

Results

All three dogs inoculated with CIV exhibited clinical signs including, pyrexia, cough, nasal discharge, virus shedding and seroconversion. Gross pathology revealed lung consolidations in all the dogs, and Streptococcus equi subsp. zooepidemicus was isolated from the lesions. Meanwhile, none of the paired horses showed any clinical signs, virus shedding or seroconversion. Moreover, gross pathology revealed no lesions in the respiratory tracts including the lungs of the horses.

Conclusions

These findings may indicate that a single dog infected with CIV is not sufficient to constitute a source of CIV infection in horses.     

Acute non-ambulatory tetraparesis with absence of the dens in two large breed dogs: case reports with a radiographic study of relatives

Background

Non-ambulatory tetraparesis with an absence of the dens of C2 (axis) has not previously been reported in large breed dogs. An absence or hypoplasia of the dens has been reported in both small, medium and large breed dogs, but not in closely related animals.

Methods

Two young large-breed dogs (a German shepherd and a Standard poodle) both with an acute onset of non-ambulatory tetraparesis were subjected to physical, neurological and radiographic examinations. Both dogs were euthanased and submitted for postmortem examination within one week of onset of clinical signs. To investigate possible heritability of dens abnormalities, oblique radiographs of the cranial cervical vertebrae were taken of nine and eighteen dogs related to the German shepherd and the Standard poodle, respectively.

Results

Absence of the dens, atlantoaxial instability and extensive spinal cord injury was found in both case dogs. Radiographs revealed a normal dens in both parents and in the seven littermates of the German shepherd. An absence or hypoplasia of the dens was diagnosed in six relatives of the Standard poodle.

Conclusions

Atlantoaxial subluxation with cervical spinal cord injury should be considered as a differential diagnosis in non-ambulatory tetraparetic young large breed dogs. Absence of the dens and no history of external trauma increase the likelihood for this diagnosis. This study provides evidence to suggest that absence or hypoplasia of the dens is inherited in an autosomal way in Standard poodle dogs.     

The Prognostic Value of Perioperative Profiles of ACTH and Cortisol for Recurrence after Transsphenoidal Hypophysectomy in Dogs with Corticotroph Adenomas

Background

Transsphenoidal hypophysectomy is an effective treatment for dogs with pituitary‐dependent hypercortisolism (PDH). However, long‐term recurrence of hypercortisolism is a well‐recognized problem, indicating the need for reliable prognostic indicators.

Objectives

The aim of this study was to evaluate the prognostic value of perioperative plasma ACTH and cortisol concentrations for identifying recurrence of hypercortisolism after transsphenoidal hypophysectomy.

Animals

A total of 112 dogs with PDH that underwent transsphenoidal hypophysectomy met the inclusion criteria of the study.

Methods

Hormone concentrations were measured preoperatively and 1–5 hours after surgery. Both absolute hormone concentrations and postoperative concentrations normalized to preoperative concentrations were included in analyses. The prognostic value of hormone concentrations was studied with Cox''s proportional hazard analysis.

Results

Median follow‐up and disease‐free period were 1096 days and 896 days, respectively. Twenty‐eight percent of patients had recurrence, with a median disease‐free period of 588 days. Both absolute and normalized postoperative cortisol concentrations were significantly higher in dogs with recurrence than in dogs without recurrence. High ACTH 5 hours after surgery, high cortisol 1 and 4 hours after surgery, high normalized ACTH 3 hours after surgery, high normalized cortisol 4 hours after surgery and the random slope of cortisol were associated with a shorter disease‐free period.

Conclusions and clinical importance

Individual perioperative hormone curves provide valuable information about the risk of recurrence after hypophysectomy. However, because no single cutoff point could be identified, combination with other variables, such as the pituitary height/brain area (P/B) ratio, is still needed to obtain a good estimate of the risk for recurrence of hypercortisolism after hypophysectomy.     

Assessment of postoperative pain after unilateral mastectomy using two different surgical techniques in dogs

Background

There are few studies reporting pain and postoperative analgesia associated with mastectomy in dogs. The aim of this study was to evaluate postoperative pain after unilateral mastectomy using two different surgical techniques in the dog.

Findings

Twenty female dogs were assigned (n=10/group) to undergo unilateral mastectomy using either the combination of sharp and blunt dissection (SBD) or the modified SBD (mSBD) technique, in which the mammary chain is separated from the abdominal wall entirely by blunt (hand and finger) dissection except for a small area cranial to the first gland, in a prospective, randomized, clinical trial. All dogs were premedicated with intramuscular acepromazine (0.05 mg/kg) and morphine (0.3 mg/kg). Anesthesia was induced with intravenous ketamine (5 mg/kg) and diazepam (0.25 mg/kg), and maintained with isoflurane. Subcutaneous meloxicam (0.2 mg/kg) was administered before surgery. Postoperative pain was evaluated according to the University of Melbourne pain scale (UMPS) by an observer who was blinded to the surgical technique.. Rescue analgesia was provided by the administration of intramuscular morphine (0.5 mg/kg) if pain scores were >14 according to the UMPS. Data were analyzed using t-tests and ANOVA (P>0.05). There were no significant differences between the groups for age, weight, extubation time, and duration of surgery and anesthesia (P>0.05). There were no significant differences for postoperative pain scores between groups. Rescue analgesia was required in one dog in each group.

Conclusions

The two surgical techniques produced similar surgical times, incidence of perioperative complications and postoperative pain. Multimodal analgesia is recommended for treatment of postoperative pain in dogs undergoing unilateral mastectomy.     

Surgical stress and postoperative complications related to regional and radical mastectomy in dogs

Background

Surgery is the treatment of choice for regional control of mammary neoplasms in female dogs. Various surgical techniques may be used, as long as mammary gland anatomy, lymphatic drainage, and known prognostic factors are respected. The purpose of this study was to compare surgical stress—including duration of surgery, nociception and hematological changes—and postoperative complications in dogs undergoing regional and unilateral radical mastectomy. Eighteen dogs were selected for each technique. Postoperative pain (nociception), hematological changes, and postoperative complications were compared between the two groups.

Results

The group treated with radical mastectomy had a longer surgical duration, showed more intense physiological changes, achieved higher scores on nociception scales, and experienced more postoperative complications.

Conclusion

Compared to regional mastectomy, radical mastectomy was associated with longer surgical duration, greater nociceptive stimulus, greater surgical stress, and higher incidence of postoperative complications in dogs. Although evaluation of long-term results was not a goal of this study, it is suggested that postoperative recovery and patient quality of life should be considered when choosing a surgical approach for treating mammary tumors in dogs.     

Effect of acetazolamide and subsequent ventriculo-peritoneal shunting on clinical signs and ventricular volumes in dogs with internal hydrocephalus

Background

Acetazolamide is recommended for the reduction of cerebrospinal fluid production in canine internal hydrocephalus. The efficacy of the drug in terms of alleviation of the clinical symptoms and the restoration of normal ventricular volume has not been documented. We hypothesize that acetazolamide inadequately improve clinical signs and has no effect on the ventricular volume. Six dogs with internal hydrocephalus underwent neurological examination and were examined by magnetic resonance imaging, on the day of the diagnosis, after treatment with acetazolamide directly before surgery, and 6 weeks after implantation of a vetriculo-peritoneal shunt due to lack of improvement after medical therapy with 10 mg/kg acetazolamide three times daily (TID). The ventricular volume in relation to the total brain volume was determined on each occasion. The changes in relative ventricular volume and of the neurological status were assessed and compared.

Results

McNemar’s test revealed no significant differences in clinical symptoms before and after medical treatment (P > 0.05). However, clinical symptoms changed significantly after surgical treatment (P = 0.001). The ventricle-brain ratio was not significantly changed after therapy with acetazolamide (P > 0.05); however, after subsequent shunt implantation, it was significantly reduced (P = 0.001).

Conclusion

Acetazolamide (10 mg/kg TID) showed no effects on clinical signs or ventricular volume in dogs with internal hydrocephalus. After subsequent ventriculo-peritoneal shunting, the dogs had a significantly reduced cerebral ventricular volume and five out of six dogs had no abnormal findings in neurological examination.     

Original surgical treatment of thoracolumbar subarachnoid cysts in six chondrodystrophic dogs

Background

Subarachnoid cysts are rare conditions in veterinary medicine, associated with spinal cord dysfunction. Most of the 100 cases of subarachnoid cysts described since the first report in 1968 were apparently not true cysts. Reported cysts are usually situated in the cervical area and occur in predisposed breeds such as the Rottweiler. The purpose of this retrospective study, from May 2003 to April 2012, was to describe the distinctive features of thoracolumbar spinal subarachnoid cysts, together with their surgical treatment and outcome in 6 chondrodystrophic dogs.

Results

Five Pugs and 1 French Bulldog were examined. Images suggestive of a subarachnoid cyst were obtained by myelography (2/6) and computed tomography myelography (4/6), and associated disc herniation was observed in 3/6 dogs. A hemilaminectomy was performed. The protruding disc eventually found in 5/6 dogs was treated by lateral corpectomy. The ventral leptomeningeal adhesions observed in all dogs after durotomy were dissected. No or only mild post-operative neurological degradation was observed. Follow-up studies (7 months to 4 years) indicated good outcome and no recurrence.

Conclusions

All the thoracolumbar subarachnoid cysts described in these 6 chondrodystrophic dogs were associated with leptomeningeal adhesions. Good results seemed to be obtained by dissecting and removing these adhesions. A protruding disc, found here in 5/6 dogs, needs to be ruled out and can be treated by lateral corpectomy.     

Effect of a povidone-iodine intrauterine infusion on progesterone levels and endometrial steroid receptor expression in mares

Background

Intrauterine infusions have been widely used for the treatment of endometritis in the mare. Nevertheless, their consequences on endocrine and endometrial molecular aspects are unknown. We studied the effect of a 1% povidone-iodine solution intrauterine infusion on progesterone levels, endometrial histology and estrogen (ERα) and progesterone (PR) receptor distribution by immunohistochemistry.

Methods

Fourteen healthy mares were used in this study. Estruses were synchronized and seven mares were treated with intrauterine infusions at days 0 and 2 post ovulation of two consecutive estrous cycles. Uterine biopsy samples were taken on days 6 and 15 post ovulation.

Results

The treatment did not induce an inflammatory response indicating endometritis, neither affected the ERα. However, it reduced the percentage of PR positive cells (PPC) on day 6 (deep glandular epithelium, control: 95.7 vs. infused: 61.5, P < 0.05). Treated mares tended to have lower progesterone levels on day 2 (3.9 ng/ml vs. 6.6 ng/ml, P = 0.07), and higher levels on day 15 compared with controls (4.4 ng/ml vs. 1.3 ng/ml, P = 0.07).

Conclusion

a 1% povidone-iodine infusion during days 0 and 2 post ovulation in healthy mares did not induce histological changes indicating endometritis, but altered progesterone concentrations and reduced the expression of endometrial PR at day 6 without affecting the ERα. These changes could reduce embryo survival.     

Clinical Features and Treatment Outcomes of 41 Dogs with Sublingual Ectopic Thyroid Neoplasia

Background

Thyroid neoplasia is common in dogs, but there are few reports of dogs with ectopic, sublingual thyroid tumors.

Objectives

To describe clinical features and outcomes of dogs with ectopic, sublingual thyroid neoplasia.

Animals

Five hundred and forty‐four dogs with thyroid neoplasia.

Methods

This retrospective study reviewed the medical records of dogs referred for thyroid neoplasia between 1995 and 2013. Data extracted included signalment, extent of thyroid disease (eutopic or ectopic; metastasis), serum thyroxine (T₄) concentration, treatment, and survival.

Results

Of 544 dogs with thyroid neoplasia, 41 (7.5%) dogs had ectopic sublingual thyroid tumors. The clinical features of these 41 dogs were similar to the cohort group of 503 dogs with eutopic or ectopic mediastinal thyroid tumors, but dogs with sublingual tumors were younger and less likely to have metastatic disease (15% versus 30%, P < .05). Of the 41 dogs, 28 received treatment: 21 with surgery (which included partial hyoidectomy in 13), 7 with radioiodine alone, and 13 with surgery followed by administration of radioiodine. Overall median survival was 562 days (range, 1‐1,850 days).

Conclusions and Clinical Importance

When compared with eutopic thyroid carcinomas, ectopic sublingual thyroid tumors generally have a less aggressive biologic behavior. Many dogs have prolonged survival, even without treatment, although death because of local tumor invasiveness or metastasis can develop in some dogs. Surgical thyroidectomy, including partial hyoidectomy, is generally effective for control of local disease. Administration of radioiodine, alone or in combination with surgical treatment, is recommended for multifocal disease or metastasis.     

Concentrations of cardiac Troponin I before and after ovariohysterectomy in 46 female dogs with pyometra

Background

Canine pyometra is a common disease in countries where routine spaying of young dogs is not common practice. This disease is known to lead to systemic inflammation potentially affecting multiple organs in the body, including the heart. Cardiac-specific Troponin I (cTnI) is a sensitive marker of myocardial cell damage, which can result from ischemia, trauma, toxins or inflammation. Dogs with pyometra are also exposed to anaesthesia which can potentially result in myocardial cell damage. The aims of the study were 1) to evaluate the occurrence of myocardial cell damage as indicated by increased serum concentrations of cTnI in dogs with pyometra and relate these to presence of systemic inflammation and 2) to evaluate the change in cTnI-concentrations after anaesthesia and surgery.

Methods

Serum cTnI concentration was measured preoperatively and one day after surgery in 46 female dogs with pyometra and 15 female dogs that underwent surgery for other reasons (ovariohysterectomy and mammary tumours).

Results

Forty-six female dogs of different breeds diagnosed with pyometra were included. The dogs had a median age of 8.5 years (IQR 7.5–10) and a median weight of 29 kg (IQR 9–32). Of the 46 dogs, 37 (80%) fulfilled the chosen criteria for systemic inflammatory response syndrome (SIRS) at inclusion. Thirteen (28%) of the dogs had increased cTnI concentrations (> 0.2 μg/l) before surgery and 18 (39%) had increased cTnI-concentrations the day after surgery. The cTnI concentrations in the 13 dogs with increased preoperative cTnI concentrations decreased in 8 dogs, increased in 4 dogs, and was unchanged in one dog. Seven dogs with nondetectable preoperative cTnI concentrations had increased postoperative concentrations. The only significant association between the studied laboratory or clinical variables (including SIRS) and cTnI concentration was preoperative percentage band neutrophils (PBN) and postoperative cTnI concentration (P = 0.016). In total, 20 dogs (43%) had increased pre- or postoperative cTnI concentrations. Seven dogs (15%) had pre-or postoperative concentrations of cTnI of 1.0 μg/l or higher.

Conclusion

Mild to moderate increases in cTnI appears to be common in dogs with pyometra before and after surgery, but the clinical importance of this finding is uncertain. None of the studied clinical variables were found to reliably predict increased preoperative cTnI concentrations. Because of the pre- and postoperative variation in cTnI concentrations, it was not possible to identify a negative effect of anaesthesia and surgery on myocardial cell integrity.     

Urinary and faecal N-methylhistamine concentrations do not serve as markers for mast cell activation or clinical disease activity in dogs with chronic enteropathies

Background

This study sought to correlate faecal and urinary N-methylhistamine (NMH) concentrations with resting versus degranulated duodenal mast cell numbers in dogs with chronic enteropathies (CE), and investigate correlations between intestinal mast cell activation and clinical severity of disease as assessed by canine chronic enteropathy clinical activity index (CCECAI), and between urinary and faecal NMH concentrations, mast cell numbers, and histopathological scores. Twenty-eight dogs with CE were included. Duodenal biopsies were stained with haematoxylin and eosin (H&E), toluidine blue, and by immunohistochemical labelling for tryptase. Duodenal biopsies were assigned a histopathological severity score, and duodenal mast cell numbers were counted in five high-power fields after metachromatic and immunohistochemical staining. Faecal and urinary NMH concentrations were measured by gas chromatography–mass spectrometry.

Results

There was no correlation between the CCECAI and faecal or urinary NMH concentrations, mast cell numbers, or histopathological score – or between faecal or urinary NMH concentration and mast cell numbers. Post hoc analysis revealed a statistically significant difference in toluidine blue positive mast cells between two treatment groups (exclusion diet with/without metronidazole versus immunosuppression (IS)), with higher numbers among dogs not requiring IS.

Conclusion

Faecal and urinary NMH concentrations and duodenal mast cell numbers were not useful indicators of severity of disease as assessed by the CCECAI or histological evaluation. The number of duodenal mast cells was higher in dogs that did not need IS, i.e. in dogs responding to an exclusion diet (with/without metronidazole), than in dogs requiring IS. Further studies comparing the role of mast cells in dogs with different forms of CE are needed.     

Cortisol secretion after adrenocorticotrophin (ACTH) and Dexamethasone tests in healthy female and male dogs

Background

For the conclusive diagnosis of Cushing''s Syndrome, a stimulating ACTH test or a low suppressive Dexamethasone test is used. Reports in other species than the dog indicate that plasma cortisol concentration after ACTH administration is affected by gender. We investigated the effect of gender on the cortisol response to ACTH and Dexamethasone tests in dogs.

Methods

Seven healthy adult Cocker Spaniels (4 females and 3 males) were assigned to a two by two factorial design: 4 dogs (2 females and 2 males) received IV Dexamethasone 0.01 mg/kg, while the other 3 dogs received an IV saline solution (control group). Two weeks later the treatments were reversed. After one month, ACTH was given IV (250 μg/animal) to 4 dogs (2 female and 2 males) while the rest was treated with saline solution (control group). Cortisol concentrations were determined by a direct solid-phase radioimmunoassay and cholesterol and triglycerides by commercial kits.

Results and Discussion

No effect of treatment was observed in metabolite concentrations, but females presented higher cholesterol concentrations. ACTH-treated dogs showed an increase in cortisol levels in the first hour after sampling until 3 hours post injection. Cortisol concentrations in Dexamethasone-treated dogs decreased one hour post injection and remained low for 3 hours, thereafter cortisol concentrations increased. The increase in cortisol levels from one to two hours post ACTH injection was significantly higher in females than males. In Dexamethasone-treated males cortisol levels decreased one hour post injection up to 3 hours; in females the decrease was more pronounced and prolonged, up to 5 hours post injection.

Conclusion

We have demonstrated that cortisol response to ACTH and Dexamethasone treatment in dogs differs according to sex.     

The effects of repeated intravenous iohexol administration on renal function in healthy beagles – a preliminary report

Background

Contrast induced nephrotoxicity (CIN) is a well described syndrome in humans undergoing contrast medium examinations. To date CIN has received minimal attention in the veterinary literature despite increasing use of contrast medium examinations in computed tomographic studies.

Methods

This prospective study evaluated the effect of 1290 mg/kg iohexol given intravenously to 5 normal beagle dogs in a divided dose at an interval of 6–8 weeks. Renal function was evaluated by means of scintigraphically determined glomerular filtration rate (GFR) and a variety of laboratory assays.

Results

Only GFR showed a significant decrease (17%) after the second injection but not to a clinically or pathologically significant level.

Conclusions

No clinically significant effect of repeated contrast medium administration was determined in this limited study. However in dogs with reduced renal function the risk of CIN is likely to increase dramatically post contrast administration.