Iatrogenic symptomatic hypoadrenocorticism after treatment with trilostane for hyperadrenocorticism in dogs: eight cases (2008-2019).

OBJECTIVES: Trilostane is the medical treatment of choice for hyperadrenocorticism. Iatrogenic hypoadrenocorticism is thought to be rare, with most cases being transient and only a few cases of permanent hypoadrenocorticism have been reported. This study reports findings from eight cases of iatrogenic hypoadrenocorticism and examines the presence of concurrent diseases at the time of diagnosis. MATERIALS AND METHODS: Medical records of dogs treated for hyperadrenocorticism with trilostane since 2008 were reviewed, and cases of clinical iatrogenic hypoadrenocorticism were extracted. Cases were considered permanent if long-term replacement therapy was required. RESULTS: Eight dogs met the inclusion criteria. The time between the beginning of trilostane treatment and the diagnosis of hypoadrenocorticism ranged from 4 days to 13 months, and the dosage of trilostane ranged between 1 and 8 mg/kg/day. Six dogs had a suspicion of concurrent disease at the time of hypoadrenocorticism diagnosis. The trilostane dose was decreased in two dogs; trilostane was withdrawn in one case without further relapse of hyperadrenocorticism; and glucocorticoids with or without mineralocorticoid supplementation were prescribed in five dogs. Two of these five dogs were lost to follow-up, and the other three had a diagnosis of permanent hypoadrenocorticism. Adrenal gland ultrasonography in these three dogs showed a progressive reduction in gland sizes with heterogeneous echogenicity. CLINICAL SIGNIFICANCE: Iatrogenic hypoadrenocorticism is a rare but potentially life-threatening complication of trilostane treatment in dogs with hyperadrenocorticism. The occurrence of a concurrent disease might trigger the development of clinical signs of hypoadrenocorticism in previously subclinical dogs.

Congenital duodenocolic fistula in a dog.

A one-year-old female cocker spaniel presented with a 6-month history of persistent diarrhoea. Abdominal ultrasonographic examination revealed mild diffuse thickening of the intestinal wall coupled with mesenteric lymphadenopathy. A connection between the duodenum and the colon was observed during an endoscopic procedure and confirmed by computed tomography. Surgical resection of the communication allowed remission of the diarrhoea. Histology showed a normal duodenal epithelium and muscular layer. A duodenocolic fistula is an abnormal connection within the digestive tract, which in humans is usually considered a complication of a local pathological condition. Due to the absence of a predisposing cause and, in view of the dog's age and histological results, a congenital origin was suspected.

Implication, clinical and biological impact of vector-borne haemopathogens in anaemic dogs in France: a prospective study.

OBJECTIVES: To prospectively describe the clinical and biological impact of vector-borne haemopathogens in anaemic dogs in France and occurrence of haemolysis. MATERIALS AND METHODS: This prospective descriptive cohort study includes 134 client-owned dogs that were anaemic on admission at the Veterinary Teaching Hospital of VetAgro Sup, Lyon, France. They underwent comprehensive screening with PCR to detect a panel of vector-borne haemopathogens, SNAP Leishmania and SNAP 4Dx Plus (IDEXX). RESULTS: Vector-borne haemopathogen-associated anaemia accounted for 17·2% (23/134) of anaemic cases. PCR for Babesia species, Mycoplasma species, Anaplasma platys or Ehrlichia canis and positive serology for Leishmania species, occurred in 11/23, 10/23, 2/23, 1/23 and 1/23 cases, respectively. Two dogs had positive PCR for both Babesia and Mycoplasma species. All dogs infected with Mycoplasma species alone had neoplastic disease. Vector-borne haemopathogens were the second most common cause of haemolysis (7/23, 30·4%). In the multivariable regression model, males were overrepresented ( OR : 2·82, P=0·03) and haemolysis ( OR : 3·31, P=0·01) was more frequent in dogs with vector-born haemopathogen-associated anaemia. CLINICAL SIGNIFICANCE: Vector-borne haemopathogens are a common cause of anaemia in this geographical region.

Focal intestinal lipogranulomatous lymphangitis in 10 dogs.

OBJECTIVES: To describe the clinical and pathological features of canine focal lipogranulomatous lymphangitis, to evaluate its underlying infectious cause and to compare it with human Crohn's disease. METHODS: Retrospective review of case records with a histopathological diagnosis of focal lipogranulomatous lymphangitis. Bacterial and fungal colonisation was evaluated using fluorescence in situ hybridisation and histochemical staining, respectively. A comparison with Crohn's disease was performed by a human pathologist. RESULTS: Ten dogs were evaluated. The historical complaints were predominantly chronic diarrhoea (10/10) and vomiting (5/10). The biochemical abnormalities included hypoalbuminaemia (6/10) and hypocobalaminaemia (4/6). Abdominal sonography revealed a thickened distal ileum±ileocolic junction. Colonoscopy showed a swollen caecal ostium and oedematous caecum in 7/10 dogs. A stenotic ileo-colic opening prevented endoscopic intubation in all dogs. Histology from the resected lesions revealed granulomatous inflammation involving the muscularis and serosa. Fluorescence in situ hybridization demonstrated invasive bacteria in 2/10 dogs. Post-resection, all dogs received metronidazole and tapering immunosuppressive doses of prednisolone. Remission (median 17 months) was achieved in 8/10 dogs. CLINICAL SIGNIFICANCE: Focal lipogranulomatous lymphangitis is a rare and severe form of canine inflammatory bowel disease with preferential localisation to the ileum and the ileocolic junction. An underlying infectious aetiology was not identified.

Prevalence of physiological heart murmurs in a population of 95 healthy young adult dogs.

OBJECTIVES: To determine the prevalence of physiological heart murmurs in healthy young adult dogs. MATERIALS AND METHODS: Healthy dogs aged between 1 and 5 years were enrolled prospectively. All participating dogs underwent physical examination, urinalysis, blood testing and blood pressure measurement. Cardiac auscultations were performed by three independent examiners. Dogs with heart murmurs underwent echocardiography, to exclude cardiovascular abnormalities. RESULTS: Of 109 dogs evaluated, 95 completed the study. Heart murmurs were detected in 22 dogs. Interobserver agreement for murmur detection was moderate to fair (weighted kappa 0 · 29-0 · 56). On the basis of two different sets of echocardiographic criteria, physiological heart murmurs were diagnosed in 6 and 11 dogs, respectively, giving a prevalence of 6-12%. All physiological heart murmurs were systolic and low-grade (I-III/VI). Most were louder towards the left heart base and some radiated up to the thoracic inlet. The epidemiological features of dogs with physiological heart murmurs did not differ significantly from those of dogs without murmurs (P > 0 · 10). CLINICAL SIGNIFICANCE: This study shows that physiological heart murmurs may not be limited to growing dogs or specific breeds, as they were commonly encountered in this population of healthy young adult dogs.

Causes of anaemia other than acute blood loss and their clinical significance in dogs.

OBJECTIVES: To identify the causes of anaemia, other than acute blood loss, in dogs and to determine whether severity of anaemia provides clues to the diagnosis. METHODS: The veterinary medical database of the Veterinary Campus Hospital, Lyon was searched. Dogs with anaemia (packed cell volume <37%) were included and assigned to different disease groups. Dogs with acute blood loss were excluded. The case records were examined for weakness at presentation, the severity and regeneration of anaemia and the final diagnosis including tumour type if applicable. RESULTS: The case records of 456 dogs with low packed cell volume were included. Cancer-related anaemia and anaemia of inflammatory disease accounted for 33·1 and 28·5% of cases, respectively. Most dogs with cancer-related anaemia had solid tumours (73%). The prevalence of immune-mediated anaemia increased with severity of anaemia (5·3, 15·5, 41·2 and 56·2% for mild, moderate, severe and very severe anaemia, respectively), whereas the prevalence of anaemia of inflammatory disease decreased (36·7, 22·5, 2·9 and 0% for mild, moderate, severe and very severe anaemia, respectively). CLINICAL SIGNIFICANCE: Anaemia of inflammatory disease and cancer-related anaemia were the most frequently identified causes of anaemia in dogs. The percentage of dogs with immune-mediated anaemia increased with anaemia severity, whereas the percentage of dogs with anaemia of inflammatory disease decreased with anaemia severity. Thus, severity of anaemia may provide clues to the diagnosis.

Development of a composite orthopaedic pain scale in horses.

This study addresses development and validation of a composite multifactorial pain scale (CPS) in an experimental equine model of acute orthopaedic pain. Eighteen horses were allocated to control (sedation with/without epidural analgesia - mixture of morphine, ropivacaine, detomidine and ketamine) and experimental groups: amphotericin-B injection in the tarsocrural joint induced pain and analgesia was either i.v. phenylbutazone administered post-induction of synovitis, or pre-emptive epidural mixture, or a pre-emptive combination of the 2. Inter- and intra-observer reproducibility was good (0.8

Fungal isolation and identification in 21 cases of guttural pouch mycosis in horses (1998-2002).

This aetiological study of guttural pouch mycosis (GPM) in the horse was based on the retrospective study of 21 horses brought into the National Veterinary School of Lyon (France) between 1998 and 2002. Biopsies were taken from the lesions caused by GPM during endoscopic examination. In 87% of the cases, direct examination gave positive results, whereas 43% of the cultures were found to be negative. The main fungi observed were Aspergillus fumigatus (in three cases), A. versicolor (in two cases, together with other fungi), and A. nidulans and A. niger (one case each). In six cases, the Aspergillus species could not be identified. In two cases, cleistothecia and/or Hulle cells were observed. In three cases, fungi other than Aspergillus were seen, mixed or not with Aspergillus. These results underline the importance of Aspergillus fumigatus in the development of GPM in horses.

[EIAV (equine infectious anemia virus): to better understand the lentiviral pathogenesis]. / EIAV (equine infectious anemia virus) : mieux comprendre la pathogenèse des infections lentivirales.

Equine infectious anemia virus (EIAV) is a lentivirus related to HIV (human immunodeficiency virus). EIAV causes a persistent infection characterized by recurring febrile episodes associating viremia, fever and thrombocytopenia. Despite a rapid virus replication and antigenic variation, most animals progress from a chronic stage characterized by recurring peaks of viremia and fever to an asymptomatic stage of infection. The understanding of the correlates of this immune control is of great interest in defining vaccine strategies. Research on EIAV over the last five decades has produced some interesting results on natural immunological control of lentivirus replication and disease and on the nature and role of virus variation in persistence and pathogenesis. This review focuses on the most recent results on EIAV biology, replication and control by the host immune response.

The mystery of fungal infection in the guttural pouches.

Advances in the understanding of guttural pouch physiology and novel therapeutic approaches to mycotic infections in the horse are reviewed. It is suggested that the guttural pouches may contribute to the regulation of arterial blood temperature, cooling the circulation to the brain to below body temperature. Aspergillus spp. is the major organism found in a guttural pouch affected with mycosis but it is unclear why this agent becomes aggressive. Conventional therapy aims to prevent fatal haemorrhage and to treat any neurological lesions but it is desirable to try to prevent the disease. A technique consisting of inserting a transarterial coil into the internal carotid, external carotid and maxillary arteries in normal and affected horses has been reported to be rapid, safe and effective in occluding the arteries and in inducing regression of the mycotic lesions without adjunctive medical treatment. When faced with acute and uncontrollable epistaxis in the field, the most effective means to reduce haemorrhage is probably the occlusion of both common carotid arteries. However, how such arterial occlusions can result in the successful management of guttural pouch mycosis without antifungal medication remains a mystery.

Canine T-cell lymphomas: a morphological, immunological, and clinical study of 46 new cases.

The aim of this study is to report 46 new cases of canine T-cell lymphomas among a series of 140 lymphomas studied by immunophenotyping (incidence 32.8%). According to the updated Kiel classification adapted to the canine species, 13 were classified as low-grade and 33 as high-grade lymphomas. Among the low-grade lymphomas, five were small clear-cell lymphomas, three were pleomorphic small-cell lymphomas, and five mycosis fungoides. Among the high-grade cases, there were 11 pleomorphic mixed-, small-, and large-cell lymphomas, 6 pleomorphic large-cell lymphomas, 11 lymphoblastic lymphomas, and 5 unclassifiable high-grade plasmacytoid lymphomas. The cytohistologic features were highly suggestive of a T-cell phenotype on the basis of cell morphology (irregular nuclei and clear cytoplasms) (30/46 cases), a T-cell zone pattern, and the presence of hyperplastic postcapillary venules (22/46 cases). All 46 cases were CD3+ CD79a-, and among 34 cases investigated for CD4 and CD8 expression, 13 were CD4+CD8-, 13 were CD8+CD4-, and 8 were CD4CD8 double positive or double negative. The pleomorphic mixed lymphomas were mainly CD4+CD8- (6/7) and the lymphoblastic lymphomas were double positive or double negative (6/8). The main clinical, hematologic, and biochemical features were generalized (28/46) or regional lymphadenopathy (16/46), hepatosplenomegaly (15/46), extranodal involvement (11/46), mediastinal mass (9/46), and leukemia (8/46), which were mainly present in cases of lymphoblastic lymphomas and hypercalcemia (16/46).

Atypical forms of canine leishmaniosis.

Canine leishmaniosis is a common disease in the Mediterranean area, but sporadic cases in dogs having travelled through endemic regions are also reported. The disease's evolution is usually chronic and symptoms are either non-specific (fever, weight loss, lethargy, enlarged lymph nodes), dermatological, renal or ocular. The purpose of this article is to review the literature and to describe our own experience of certain atypical forms of canine leishmaniosis. These include specific skin lesions, monoclonal gammopathy, renal failure (without any other signs), chronic colitis, haemostatic problems and disorders of the cardiovascular, respiratory and musculo-skeletal systems.

Early diagnosis of lentivirus-induced infiltrative lung disease in sheep by high resolution computed tomography.

The visna-maedi lentivirus can induce an interstitial pneumonitis in sheep, and provides a convenient example to study natural or experimental lentiviral pathology. We wanted to determine whether high resolution computed tomography (HRCT) is able to detect early morphological changes following lentiviral infection in the lungs. Spontaneously infected adult sheep (n=3) and experimentally infected lambs (n=5) were compared to uninfected controls (n=4). The HRCT scans generally showed abnormal features in infected animals, including: increased parenchymal density; alveolar oedema; thickened interlobular septa; and increased density in peribronchiolar areas. HRCT was more sensitive than chest radiography for the early diagnosis of interstitial pneumonitis, although one sheep with advanced disease and radiographic and histopathological abnormalities had a paradoxically normal scan. One control animal showed minor abnormalities on scanning, which were probably due to the procedure used for anaesthesia. The HRCT observations were confirmed by postmortem histological examination of the lungs. In conclusion, high resolution computed tomography provides a noninvasive means of following the development of lung pathology in a natural ovine model of lentiviral disease.

Interstitial lung disease in feline immunodeficiency virus (FIV) infected cats.

Postmortem bronchoalveolar lavage of feline immunodeficiency virus-infected cats indicated an alveolitis process, and histological examination of their lungs confirmed the occurrence of alveolitis, parenchymatous lymphoplasmocytic infiltration and myomatosis. Similar lymphoid interstitial pneumonitis has been described in human and animal lentiviral diseases: lymphocytic interstitial pneumonitis in HIV-1-infected human beings, and maedi in sheep infected by the maedi-visna virus. Such lymphoid interstitial pneumonitis may thus be a common feature of lentiviral infections.

Anti-alpha chain monoclonal antibodies of equine MHC class-II antigens: applications to equine infectious anaemia.

This paper describes the characteristics of a monoclonal antibody (mAb), 6B11C3, that recognises most equine monocytic cells, as well as B- and T-lymphocytes. The T CD4+ and T CD8+ of this latter population are also stained by the 6B11C3 mAb. On the basis of the distribution of membrane antigens on these cell populations, and of immunohistochemistry results, this mAb appears to be an anti-equine class-II major histocompatibility complex (MHC) antigen. In horses, the hyperexpression of the MHC class-II antigen on T cells is an indication of activated lymphocytes. A decrease in the percentage of lymphocytes stained by 6B11C3 was observed in horses with persistent equine infectious anaemia.

Toxicity and kinetics of amitraz in dogs.

OBJECTIVE: To evaluate the toxic effects of amitraz in dogs and their reversal by various doses of atipamezole. ANIMALS: 6 male 1-year-old Beagles. PROCEDURE: Dogs were given 100 mg of amitraz/kg of body weight, PO. Atipamezole was administered at 3 dose rates. Clinical examination and blood sample collection were performed regularly for 48 hours to examine biological parameters and determine the toxicokinetics of amitraz as well as the efficacy of the antidote. A specific high-performance thin layer chromatographic method was developed to determine plasma amitraz concentrations. RESULTS: Clinical signs of toxicosis included sedation, bradycardia, polyuria, hypothermia, and hyperglycemia, all of which could be related to the alpha 2-agonist activity of amitraz, and were reversed by low doses of atipamezole (50 micrograms/kg, IM), a potent alpha 2-antagonist, within 10 minutes after injection. Peak plasma concentrations were observed after 5 hours, and the elimination half-life was long (about 24 hours). CONCLUSIONS: All clinical and biological effects observed during the course of amitraz poisoning could be attributed to the parent compound itself and were reversed by low doses of atipamezole. The half-life of amitraz was substantially longer than that in other studies because of the high dose administered. CLINICAL RELEVANCE: Atipamezole can be administered i.m. to dogs with severe amitraz poisoning to reverse all the effects observed.

Visna-maedi virus-induced expression of interleukin-8 gene in sheep alveolar cells following experimental in vitro and in vivo infection.

Visna-maedi virus is a lentivirus which causes inflammatory disorders in sheep, including a chronic interstitial lung disease resembling that observed in human immunodeficiency virus type 1 (HIV 1) infection. In view of our previous demonstration of the production of neutrophil chemotactic activity by alveolar macrophages, and given the lymphocytic and neutrophilic nature of the alveolar cell infiltrate in both naturally and experimentally infected animals, we hypothesized that interleukin-8 (IL8) could be a candidate for at least part of the chemotactic activity we described. In this study, we investigated IL8 mRNA expression following visna-maedi virus infection. Northern analysis of total RNA using an ovine IL8-specific probe demonstrated that the IL8 gene is upregulated in alveolar macrophages as a consequence of in vitro infection and in alveolar cells from experimentally infected animals. Using a semi-quantitative RT-PCR method, we showed that various levels of IL8 mRNA are expressed by alveolar cells from infected animals and that they correlate with the intensity of the lesions. In conclusion, visna-maedi virus is able to induce IL8 mRNA expression in sheep alveolar cells. Results from in vivo infected animals suggest that IL8 could play a role in the early build-up of visna-maedi virus-induced lesions.

Loperamide poisoning in the dog.

A retrospective study was conducted of 40 loperamide poisoning cases recorded at the Centre National d'Informations Toxicologiques Veterinaires. An apparent breed susceptibility of Collie dogs was observed. Neurologic disturbances (ataxia and prostration) were significant clinical findings. Treatment with naloxone resulted in rapid reversal of signs without sequelae.