Proctitis associated with chlamydial infection in a koala

Objective To describe proctitis associated with chlamydial infection in a koala.
Design A pathological study  

Animal

A free living, male koala aged 17 years.
Procedure Rectum was examined histologically and chlamydial organisms visualised using Giminez stain and an immunoperoxidase staining method using an anti- Chlamydia lipopolysaccharide (genus specific) antibody.
Results An aged koala presented for euthanasia was found to have asymptomatic chronic proctitis, cystitis, prostatitis, urethritis and conjunctivitis associated with chlamydial infection. Inflammation was severe in the terminal rectum and extended into the proximal common vestibule. Chlamydial organisms were visualised in the rectal surface epithelium using Giminez stain and an immunoperoxidase staining method. Organisms were also detected in the epithelium of the bladder, prostate and urethra.  

Clinical Implications

Possible modes of transmission for the rectal infection are direct sexual transmission or ascending infection by organisms shed from the urogenital tract into the common vestibule. Previously unreported chlamydial proctitis in the koala may represent a potential reservoir of infection for other koalas.     

Diarrhoea associated with cryptosporidial oocyst shedding in a quarterhorse stallion

Cryptosporidial oocyst shedding was detected in a 2.5-year-old Quarterhorse stallion with diarrhoea. Based on the detection of cryptosporidial oocysts, and the absence of other aetiological agents or enteropathogens, cryptosporidiosis was presumptively diagnosed. This case was unusual because cryptosporidial oocyst shedding is primarily found in some immunocompromised or immature horses, and has not been reported in healthy mature horses.     

Impairment of neutrophil functions in a dog with an eosinophilic dermatosis.

An eosinophilic dermatosis was diagnosed in a dog with a multifocal distribution of pruritic, pustular and erosive lesions on the trunk. Ectoparasites, fungi and bacteria were not detected in the skin of the dog. At a subsequent admission to the university clinic, bacterial conjunctivitis and superficial pyoderma had developed. At a time when the dog received no medical therapy, evaluation of phagocytosis and chemotactic migration towards a variety of chemotactic factors revealed a general suppression of patient neutrophil responsiveness, as compared to a control dog. Viability of the patient's neutrophils was normal. It was proposed that deactivation of neutrophil functions occurred following exposure to suppressive factors from mast cells, or as a consequence of surface receptor down-regulation due to prolonged cell activation by as yet unknown stimulants. The observed susceptibility to infections in the dog suffering from a primary, sterile eosinophilic dermatosis may be related to impaired host defence against opportunistic microorganisms.     

Extreme eosinophilia with disseminated eosinophilic granulomatous disease in a horse

Extreme eosinophilia with disseminated eosinophilic granulomatous disease is described in a 4-year-old Arabian mare. Clinical signs included weight loss, coughing, jugular distention, and ventral edema. Cutaneous lesions were not observed. Eosinophilic inflammation was observed in cytologic specimens from the respiratory tract, body cavities, and lymph nodes. At necropsy, a 20-cm diameter intrathoracic mass was observed. Smaller nodules were present in the lymph nodes, liver, spleen, adrenal glands, pancreas, and skeletal muscle. Histologically, these masses and nodules were characterized by infiltrates of eosinophils, macrophages, and multinucleated giant cells, reactive fibroplasia; and multifocal eosinophilic coagula. Microscopically, mild eosinophilic infiltrates were observed in sections of stomach, small intestine, colon, and pleura; however, gross lesions were not observed in these tissues at necropsy. The etiology of the extreme eosinophilia and disseminated eosinophilic granulomatous disease in this horse was not determined.     

Idiopathic eosinophilic meningoencephalitis in a Dutch Warmblood gelding

An increased content of eosinophils in cerebrospinal fluid (CSF) and eosinophilic infiltration of brain tissue are observed in eosinophilic meningoencephalitis (EME). After exclusion of various infectious diseases and further known causes of EME in other species, the diagnosis idiopathic EME was made at necropsy in the case reported here. To the authors' knowledge, this is the first report of idiopathic EME in a horse similar to the disorder occurring in dogs.     

Zonal dermal separation: a distinctive histopathological lesion associated with hyperelastosis cutis in a Quarter Horse

This case report describes a distinctive deep cutaneous lesion in a 1-year-old Quarter Horse filly with hyperelastosis cutis. The horse had a typical clinical presentation of hyperelastic skin associated with a 6-month history of cutaneous wounds that developed following minor cutaneous trauma. Punch biopsies of skin from the affected horse were thinner than similar biopsies from an age- and breed-matched control. Significant microscopic lesions were not seen in cutaneous punch biopsies stained with haematoxylin and eosin and Masson's trichrome stains, but the ultrastructure of the dermis from the affected horse was characterized by variation in collagen fibre diameter and loose packing of collagen fibres within bundles. The horse was euthanized and necropsied, and full-thickness sections of skin were collected and examined microscopically. Affected skin was of normal thickness; however, the deep dermis contained a distinctive horizontal linear zone in which separation of collagen bundles resulted in the formation of large empty cleft-like spaces between the upper and lower regions of the deep dermis. We suggest the term 'zonal dermal separation' for this microscopic lesion. Incisional full-thickness skin biopsies should be taken in suspected cases of equine hyperelastosis cutis because punch biopsies may not obtain enough deep dermis to adequately represent pathological change in the skin of horses with this disorder.     

Ultrasound as a diagnostic tool in the investigation of a pony with intestinal lymphoma

A 21‐year‐old New Forest pony presented for evaluation of lethargy and colic. Transcutaneous abdominal ultrasonography revealed a cavitary, thick walled, mass‐like lesion that appeared continuous with the small intestine. The thick walls of the mass‐like lesion were of heterogeneous echogenicity with hyperechoic foci extending from the hyperechoic luminal surface to within the wall and there was loss of normal wall layering. These findings were confirmed grossly at exploratory celiotomy and histopathological examination of affected tissues confirmed lymphoma. The ultrasound findings facilitated a preoperative presumptive diagnosis that allowed informed decision‐making and aided case management.     

Posterior lens luxation with associated glaucoma in a pony

Secondary lens luxation is an infrequent consequence of equine recurrent uveitis (ERU). This Case Report describes a pony with posterior lens luxation with associated glaucoma, thought to be secondary to ERU.     

Severe eosinophilic cholangiohepatitis due to fluke infestation in a pony in Scotland

Fasciola hepatica infestation is reported as a cause of severe eosinophilic cholangiohepatitis in a 28‐year‐old Warmblood cross pony gelding. The gelding presented initially for investigation of acute laminitis found to be secondary to pars pituitary intermedia dysfunction (PPID). Six weeks of treatment including administration of pergolide achieved good control of the laminitis but there was a marked general clinical deterioration over this period with notable weight loss, tachycardia, anorexia and ventral oedema. Hepatobiliary enzymes were increased significantly and there was mild elevation of plasma bile acid concentration. An eosinophilia in both blood and peritoneal fluid specimens and histopathological confirmation of an eosinophilic cholangiohepatitis on examination of liver biopsies supported a primary parasitic aetiology. The pony was treated for Fasciola hepatica with triclabendazole 12 mg/kg bwt but clinical signs continued to progress. Due to poor clinical response the pony was subjected to euthanasia and post mortem examination revealed an overwhelming infestation of the biliary tracts with Fasciola hepatica and a secondary chronic and severe cholangiohepatitis with marked fibrosis. To the authors' knowledge this is the first equine report demonstrating the relationship between the clinical disease syndrome, eosinophilic cholangiohepatitis and hepatic fluke infestation. Depending on geographical location, fasciolosis should be considered as a differential diagnosis for equine hepatopathies and can result in severe disease.     

Bicavitary eosinophilic effusion in a dog with coccidioidomycosis

This is a case of coccidioidomycosis in a dog, examined for vomiting and labored breathing. Physical examination and thoracic and abdominal imaging revealed pleural and peritoneal effusions, both of which exhibited neutrophilic inflammation with a substantial eosinophilic component. The dog had positive IgM and IgG coccidioidomycosis titers at initial evaluation. The eosinophilic component of the inflammation was attributed to coccidioidomycosis. The dog underwent approximately 6 months of fluconazole treatment, with both effusions and clinical signs improving after 6 weeks. Three months after cessation of antifungal treatment, the dog developed a mid-diaphyseal lytic and proliferative lesion in the left radius caused by Coccidioides spp. This case illustrates the importance of consideration of coccidioidomycosis when an eosinophilic cavitary effusion is present in dogs that live in or have traveled to endemic regions.     

Metabolic changes associated with anaesthesia and cherry poisoning in a pony

Observations  A case of a pony with severe cyanide intoxication as a result of cherry ingestion is presented. General anaesthesia was performed for colic surgery. Severe metabolic lactate acidosis in combination with a high arterial oxygen partial pressure and clinically good peripheral perfusion parameters were the remarkable signs during anaesthesia. Severe hypothermia was obvious during recovery. Ten hours post-surgery the pony was euthanized as a result of neurological signs. The diagnosis of cyanide intoxication was made post-mortem.
Conclusion  Cherry ingestion can lead to lethal cyanide intoxication in horses indicated by severe nonhypoxic lactic acidosis during anaesthesia.     

Marked subcutaneous mast cell and eosinophilic infiltration associated with the presence of multiple Dirofilaria repens microfilariae in 4 dogs

Dirofilaria repens is a parasitic nematode in the subcutaneous tissue of carnivores, including dogs and cats, transmitted by mosquitoes. Human beings may be accidental hosts. Infection of a dog with D repens was first reported in Palestine in 1934, and 2 additional cases were reported in dogs in Israel to date. This report describes D repens infection in 4 dogs in Israel that presented with subcutaneous masses, which were cytologically characterized by marked mast cell and eosinophil infiltration. In 3 cases, multiple microfilariae were present in the lesions; rare microfilariae were present in the 4^th case. In all 4 dogs, PCR of fine‐needle aspirates from the lesions were positive for D repens. The mast cells observed in all lesions were uniform and highly granulated, and with the presence of the microfilariae, a mast cell tumor was considered less likely. This report suggests that D repens infection‐associated subcutaneous lesions, characterized cytologically by massive mast cell and eosinophil infiltration, should be considered a differential diagnosis for mast cell tumor, especially in geographic locations endemic for this nematode. Notably, all 4 dogs were infected with D repens despite a routine prophylactic doramectin therapy administered every 3 months, probably due to the relatively long time interval between treatments.     

Clinical findings associated with chronic ischial fracture in a gelding

An 8-year-old show-jumper gelding was referred for examination as a result of a purchase dispute for reported back pain. Clinical examination identified back pain and atrophy of the left semimembranosus and semitendinosus muscles, but no lameness. Standing pelvic radiography demonstrated a chronic nonunion fracture of the left ischium, the clinical significance of which was uncertain. The apparent back pain was thought to be probably unrelated to the pelvic lesion. We conclude that chronic ischial fracture in the horse can lead to specific atrophy of the semimembranosus and semitendinosus muscles, which originate from this bone.     

Pulmonary ultrasonographic abnormalities associated with naturally occurring equine influenza virus infection in standardbred racehorses

The purpose of this investigation was to determine if naturally occurring acute infectious upper respiratory disease (IRD) caused by equine influenza virus is associated with ultrasonographically detectable pleural and pulmonary abnormalities in horses. Standardbred racehorses were evaluated for signs of IRD, defined as acute coughing or mucopurulent nasal discharge. For every horse with IRD (n = 16), 1 or 2 horses with no signs of IRD and the same owner or trainer (n = 30) were included. Thoracic ultrasonography was performed within 5-10 days of the onset of clinical disease in horses with IRD. Horses without IRD were examined at the same time as the horses with IRD with which they were enrolled. The rank of the ultrasound scores of horses with IRD was compared to that of horses without IRD. Equine influenza virus was identified as the primary etiologic agent associated with IRD in this study. Mild lung consolidation and peripheral pulmonary irregularities were found in 11 (69%) of 16 of the horses with IRD and 11 (37%) of 30 of control horses. Lung consolidation (median score = 1) and peripheral irregularities scores (median score = 1) were greater in horses with IRD compared to horses without IRD (median score = 0; P < .05). Pleural effusion was not observed. Equine influenza virus infection can result in abnormalities of the equine lower respiratory tract. Despite the mild nature of IRD observed in this study, lung consolidation and peripheral pulmonary irregularities were more commonly observed in horses with clinical signs of IRD. Further work is needed to determine the clinical significance of these ultrasonographic abnormalities.     

Severe hypophosphataemia associated with the management of hyperlipaemia in a miniature pony

This report describes a case of severe hypophosphataemia associated with the management of hyperlipaemia in a miniature pony following colic surgery. Clinical signs attributed to hypophosphataemia included obtundation, anorexia, tachycardia, tachypnoea and generalised muscle fasciculations. Hyperlipaemia was managed with enteral and partial parenteral nutrition; insulin was also administered to control hyperglycaemia after the initiation of caloric support. Specific therapy for hypophosphataemia consisted of parenteral potassium phosphate at 0.03 mmol/kg bwt/h (i.v.). The pony made a full recovery without further complications. Hypophosphataemia may be an under‐recognised clinical problem in certain populations of critically ill equids, such as those with hyperlipaemia and receiving insulin as part of their management. The routine measurement of phosphate concentration in these cases is recommended.