Leucoencephalomyelopathy in Australian Rottweiler dogs

Clinical and pathological studies of a neurological disorder of 3 adult Rottweiler dogs are described. Dogs developed proprioceptive losses involving the limbs, leading to progressively worsening ataxia and hypermetria. Blood and CSF fluid analyses were normal and radiographs and myelograms showed no compressive lesions of the spinal cord. At necropsy, severe demyelination of the dorsal and lateral funiculi of the cervical spinal cord was visible grossly. Microscopically there was more extensive, symmetrical involvement of the spinal cord and brain than was apparent grossly, with demyelination of white matter tracts and sparing of axons in affected areas. These changes were considered diagnostic for leucoencephalomyelopathy. This condition has not been previously reported in Australia, and is probably transmitted genetically, presumably as an autosomal recessive trait.     

Morphological study of bacterial pneumonia of feedlot cattle: Determination of age of lesions

Lungs from 48 feedlot cattle that had died from bacterial pneumonia were examined grossly and microscopically. Criteria based on microscopic lesions were adopted to age these pneumonias. In 38 cases, pneumonic lesions were of relatively uniform age throughout the affected tissue. In eight other cases, the presence of older lesions confined to one or two lobes suggested a previous episode of pneumonia. The aging criteria adopted were in agreement with the duration of the observed clinical signs in 26 cases. In 13 other cases, the pneumonia was estimated to be of longer duration than suggested by the history, whereas in the remaining nine cases, it was estimated to be more recent. Areas of tan discoloration of the parenchyma surrounded by white or yellow borders were considered the best areas to examine microscopically since they offered the best chances of revealing necrosis and fibrosis, the main lesions used to age the pneumonia.     

The occurrence of nymphal stage of Linguatula serrata in water buffaloes (Bubalus bubalis): nymphal morphometry and lymph node pathology

The mesenteric lymph nodes (MLN) of buffaloes (n = 100) were examined for the presence of parasitic infection. The nymphal stage of Linguatula serrata was observed in two buffaloes. A single white-coloured nymph with transversely striated spines on a segmented body, two pairs of oral suckers and hooks was observed in the MLN. The morphometrics of the nymphs were studied. The affected lymph nodes were grossly enlarged with cyst and showed pathological lesions of fibroblastic reaction with a mild underlying inflammatory zone.     

Pathophysiologic studies of calves given 3-methylindole intraruminally

Intraruminal administration of 0.25 g of 3-methylindole (3MI; skatole/kg of body weight) to seven young calves generally caused mild respiratory signs and lesions, accompanied by only slight changes in cardiopulmonary function. Moderate depression, trembling, and irregular respiratory rate were observed between postadministration hours (PAH) 6 and 12. By PAH 24 at this dosage, abnormal clinical signs were not present. Statistically significant (P less than or equal to 0.05) changes observed in blood gas data from the seven calves were a decrease in aortic oxygen tension at PAH 12, increases in free-flowing venous oxygen tension in the intervals between PAH 6 and 12 and between PAH 6 and 24, and an increase in occluded venous oxygen tension at PAH 24. All calves had increases (although generally not statistically significant) in heart rate, cardiac output, cardiac index, stroke volume, and stroke index after 3MI administration. Mean aortic and pulmonary arterial pressure changes were generally small and variable. At necropsy, the lungs of the calves did not collapse when the thorax was opened. Patchy areas of consolidation (0.5 cm in diameter) were scattered throughout the parenchyma. Pulmonary edema or emphysema was not observed grossly. Microscopically, the alveolar septae were irregularly thickened because of edema, infiltration by polymorphonuclear and mononuclear cells, and vascular congestion. Interstitial lesions were patchy in distribution and severity and corresponded to the areas of consolidation observed grossly. Alveolar epithelial hypertrophy and hyperplasia were present, and an occasional focus of alevoli contained fluid of edema. Degeneration of individual hepatocytes was observed in scattered areas of the liver, especially in the periportal areas. It was concluded that differences in 3MI dosage response may exist between young calves and adult cattle in which calves are more resistant to the pulmonary cytotoxicity of 3MI.     

Nutritional myodegeneration in dairy cows

A syndrome is described in which parturient dairy cows showed clinical signs consistent with milk fever but failed to respond to conventional therapy. The affected cows were reluctant to walk, moved stiffy and in severe cases became recumbent. The condition was apparently precipitated by low vitaimin E and selenium intake, stress of pregnancy and in one outbreak erratic feeding. Skeletal and cardiac myodegeneration were observed grossly and histologically but an almost full term fetus from an affected cow showed no muscle lesions. A high incidence of retained placentae was also recorded.     

Pathology of AA amyloidosis in domestic sheep and goats

We describe the main pathologic changes in small ruminants affected by AA amyloidosis, together with the partial sequence of the protein involved. Twenty-one sheep and one goat were selected for presenting macroscopic kidney lesions compatible with systemic amyloidosis. Available tissue samples were studied by histologic, immunopathologic, and ultrastructural means. Renal lesions were characterized grossly by pale cortical surfaces with scattered, miliary, whitish-yellow foci and on cut cortical surfaces by straight, whitish-yellow striations. Gangrenous pneumonia was observed in 16 out of 21 affected sheep (76.2%), although other chronic inflammations were also observed. Amyloid was detected in all grossly affected kidneys using Congo red staining, lesions being most remarkable in glomeruli, affecting 95.5% of animals studied. Congophilic deposits were also observed in intertubular interstitium (68.2%) and medulla (57.1%). All amyloid-affected animals presented proximal convoluted tubule lesions, mostly characterized by an increase in diameter and by hyaline granular degeneration that were responsible for the macroscopic appearance of the kidney. Histologically, amyloid was also seen in blood vessels, spleen, liver, lymph nodes, gastrointestinal tract, and adrenal glands. All amyloid deposits demonstrated greenish-yellow birefringence with polarized light, and the antisera prepared against goat amyloid extracts specifically reacted with birefringent congophilic deposits of both sheep and goats. Ultrastructurally, these deposits were formed by masses of straight, nonbranching fibrils located predominantly in the basement membranes of glomerular capillaries and in the mesangium. Partial sequence of the protein in sheep and goats indicated a high degree of homology with the previously reported sequence of sheep Serum Amyloid A.     

Nutritional myopathy in goats

A nutritional myopathy in unweaned fibre goats aged 2 to 4 mths is described in 3 flocks from the tablelands of New South Wales. Clinically affected animals were illthrifty and in circulatory failure prior to being found dead. At necropsy, there was pronounced ascites, pulmonary congestion and marked mottling of the liver. Chalky white streaks and patches were obvious in the myocardium, particularly in the right ventricular wall. Skeletal muscles varied from grossly normal to generally pale. Histologically, the myocardium exhibited areas of severe acute myonecrosis with mineralisation and adjoining areas of phagocytosis and fibrosis. In 2 of 3 flocks, some skeletal muscles showed a mild subacute myopathy. Marked hepatic congestion extended to periacinar haemorrhage and necrosis in some areas. Dietary imbalances of selenium, vitamin E and polyunsatured fatty acids were probable factors in the pathogenesis of the condition.     

Exercise-induced pulmonary haemorrhage in the horse: results of a detailed clinical, post mortem and imaging study. III. Subgross findings in lungs subjected to latex perfusions of the bronchial and pulmonary arteries

Latex was injected under pressure into bronchial and pulmonary arteries of the inflated lungs of Thoroughbreds and transverse sections taken to calculate the area of lesions resulting from exercise-induced pulmonary haemorrhage. Extensive areas of dense brown haemosiderin varying from 0 to 45 per cent of total lung volume were identified, predominantly in the dorsocaudal lungfields. Bronchial arterial proliferation appeared to have replaced the pulmonary supply in affected areas of the lung. Closely associated with the staining and bronchial arterialisation, there was widespread small airway disease. The most severely affected bronchioles contained thick gelatinous or mucous exudate or mucoid plugs and had grossly thickened walls. These lesions suggest that the source of haemorrhage in exercise-induced pulmonary haemorrhage is from alveolar capillaries anomalously supplied by the bronchial arterial circulation through the development of pathological shunts. Small airway disease is suggested as being of major importance in the pathogenesis of the disease and may have led to the initial proliferation of the bronchial circulation.     

Functional anatomy of the equine tarsocrural collateral ligaments

Equine tarsocrural collateral ligaments (CL) were dissected grossly. The areas of attachment and fiber arrangements were described for the long lateral CL, long medial CL, 3 short lateral CL, and 3 short medial CL. Sequential cutting of CL in any order indicated that the short medial CL were responsible for the snap-joint phenomenon observed at the equine tarsocrural joint.     

Observations on an outbreak of nutritional steatitis (yellow fat disease) in fitch (Mustella putorius furo)

An outbreak of nutritional steatitis in farmed fitch (Mustella putorius furo) caused by feeding high levels of dietary polyunsaturated fat was investigated. The disease affected mainly 13 to 15 week rapidly growing kits; 793 kits were affected and 183 died. The outbreak was quickly controlled by lowering the level of polyunsaturated fat in the diet and administering high doses of vitamin E. Affected animals had severe generalised steatitis characterised grossly by yellow brown granular fat, which histologically consisted of diffusely necrotic adipose tissue heavily infiltrated with macrophages and neutrophils. There were extensive deposits of PAS-positive, fluorescent lipopigment within macrophages and extracellularly throughout the inflamed fat. Affected fitch had normochromic microcytic anaemia, lowered liver iron levels, increased thrombocytes and acute inflammatory leucograms. Skeletal or cardiac myopathy was not observed grossly or histologically in any of the animals examined. The diet contained high levels of polyunsaturated fat (7.7%DM), a high proportion being docosahexaenoic and eicosapentaenoic acids which were derived from the squid component (40%) of the ration. The livers from affected fitch contained correspondingly high levels of polyunsaturated fatty acids. The diet provided 13 mg Vitamin E per fitch daily, which was clearly inadequate considering the high levels of polyunsaturated fat being fed. Liver selenium levels were extremely high as a result of the high selenium levels in the squid portion of the diet.     

Aplasia cutis congenita (epitheliogenesis imperfecta) in swine: observations from a large breeding herd.

Epitheliogenesis imperfecta has been reported in several animal species, and its inheritance is suspected to be autosomal recessive. This term has been used to describe two different diseases, namely epidermolysis bullosa and aplasia cutis congenita, which are both grossly characterized by an absence of epidermis or mucosal epithelium and are most frequently reported on the distal limbs and oral cavity. Epitheliogenesis imperfecta has been described in swine, but the literature on the subject is scarce. To better characterize this condition, 70 piglets with congenital skin defects macroscopically compatible with epitheliogenesis imperfecta were examined. In all but 1 case, only 1 piglet per litter was affected. Of the affected piglets, 65 (93%) were male, suggesting a sex-related problem. More than half of the piglets had multiple skin lesions. All defects were located on the caudal half of the body, and none was found in the oral cavity. Most lesions were characterized by an absence of epidermis and part of the dermis and adnexae. Adnexal dysplasia was also observed at several sites, both with and without epitheliogenesis imperfecta, suggesting a developmental problem. Fluid-filled, congenital subcutaneous bullae were noted grossly on 7 piglets; their relationship, if any, with epitheliogenesis imperfecta remains unknown. As the term epitheliogenesis imperfecta has been used in cases of epidermolysis bullosa, the term aplasia cutis congenita seems to be more appropriate to describe these lesions in swine.     

Tegumental surface changes in juvenile Fasciola hepatica in response to treatment in vivo with triclabendazole

Eight indoor-reared crossbred sheep with no pre-exposure to Fasciola hepatica were infected, by oral gavage, with 200 metacercarial cysts of the triclabendazole (TCBZ)-susceptible Cullompton isolate of F. hepatica. Anthelmintic dosing occurred at 4 weeks post-infection with 10 mg/kg triclabendazole. Two treated sheep were euthanized at 48 h, 72 h and 96 h post-treatment with triclabendazole. Two control sheep were euthanized alongside the 48 h triclabendazole-treated sheep. Juvenile flukes were recovered from each of the sheeps' liver and processed for scanning electron microscopy (SEM). Flukes were still active 48 h post-treatment and displayed limited morphological disruption. There was some blebbing and sloughing of the tegument around the oral sucker. In several of the specimens, an extra layer had been deposited on the fluke surface, giving it a flattened appearance. At 72 h post-treatment, only one fluke remained alive and the disruption varied in degree. In the majority of flukes, there was severe swelling of the tegument, accompanied by isolated areas of flattening along the lateral margins of the flukes and in the tail region. Limited areas of sloughing occurred in the tail region. In more seriously affected specimens, the syncytium had been stripped away to reveal the basal lamina and some deeper lesions were also observed. By 96 h post-treatment, all the flukes were dead and were grossly disrupted. They were totally devoid of tegument and deep lesions exposed the internal tissues of the fluke.     

HYPERTROPHIC OSTEOPATHY CHARACTERIZED BY NUCLEAR SCINTIGRAPHY IN A HORSE

A five year old American Saddlebred gelding was admitted to the University of Illinois Veterinary Medical Teaching Hospital with a history of multiple leg lameness, depression and intermittent fever for a duration of six months. Physical examination revealed the horse to be underweight, depressed and afebrile. No abnormalities were detected during auscultation of the heart and lungs. All limbs possessed multiple hard swellings of the distal long bones and digits. The horse walked with a stiff gait and was reluctant to trot. Nuclear scintigraphy of the distal limbs revealed multiple areas of focally increased uptake in all limbs. Radiographs of several sites on the distal limbs showed evidence of periosteal new bone production corresponding to the areas of abnormal uptake. The horse was euthanized and at necropsy chronic, multifocal, fibrous pericarditis and epicarditis were observed grossly. The left atrial myocardium contained areas of osseous metaplasia. Histological evaluation of the distal long bones revealed proliferative periosteal new bone formation consistent with a diagnosis of hypertrophic osteopathy.     

Histopathological findings in the medial palmar and dorsomedial intercarpal ligaments of the equine midcarpal joint

Medial palmar intercarpal ligaments (MPICL) and dorsomedial intercarpal ligaments (DMICL) from the midcarpal joints of 11 adult horses in training were examined histopathologically. These were compared with ligaments from seven horses less than 12 months of age, and 10 grossly enlarged DMICLs of adult horses. Tearing of the MPICL was observed in 15 of 22 joints from adult horses. Collagen fibre bundles of the MPICLs generally were disorganized and poorly aligned, and there were large areas of loose connective tissue. In young horses there was more parallel alignment of collagen bundles and less loose connective tissue. Collagen bundles of adult DMICLs were well organized and showed parallel alignment, whereas in foals the structure appeared more like that of fibrous joint capsule. Grossly enlarged DMICLs in adults consistently had discrete areas of fibrovascular infiltration. Degeneration of the MPICL was associated with increasing age and could explain the high incidence of tearing of the ligament. Enlargement of the DMICL was associated with low-grade tearing and repair.     

Histopathological Findings in the Medial Palmar and Dorsomedial Intercarpal Ligaments of the Equine Midcarpal Joint; Book Review

Medial palmar intercarpal ligaments (MPICL) and dorsomedial intercarpal ligaments (DMICL) from the midcarpal joints of 11 adult horses in training were examined histopathologically. These were compared with ligaments from seven horses less than 12 months of age, and 10 grossly enlarged DMICLs of adult horses. Tearing of the MPICL was observed in 15 of 22 joints from adult horses. Collagen fibre bundles of the MPICLs generally were disorganized and poorly aligned, and there were large areas of loose connective tissue. In young horses there was more parallel alignment of collagen bundles and less loose connective tissue. Collagen bundles of adult DMICLs were well organized and showed parallel alignment, whereas in foals the structure appeared more like that of fibrous joint capsule. Grossly enlarged DMICLs in adults consistently had discrete areas of fibrovascular infiltration. Degeneration of the MPICL was associated with increasing age and could explain the high incidence of tearing of the ligament. Enlargement of the DMICL was associated with low-grade tearing and repair.     

Neoplasms in the oviducts of turkeys

The reproductive tracts of turkey breeder hens from five flocks were examined grossly and histologically. Hens from one flock had a normal reproductive history, but hens from the four other flocks had poor records in both egg production and hatchability. Nodular growths occurred in the oviducts of birds in all five flocks. The incidence of lesions varied from flock to flock and from bird to bird. In four flocks, lesions were small and consisted of areas of dysplasia with adenomatous change. Histologically, the lesions in some birds in the fifth flock were adenocarcinomas. No metastases were observed.     

Subepidermal bullous dermatosis due to topical corticosteroid therapy in dogs

Six adult dogs were presented with an unusual bullous dermatosis affecting the glabrous skin of the ventral abdomen and medial thighs. Clinically, flaccid bullae were accompanied by erythema, ulceration, haemorrhage and hyperpigmentation in four of six dogs; the remaining two dogs had thin skin without grossly apparent bullae. Histologically, subepidermal bullae and clefting, vascular proliferation and dilatation (phlebectasia), and alteration in the density and staining of superficial dermal collagen were seen in all dogs. In all cases, corticosteroid-containing topical products had been applied to the affected areas prior to the development of the dermatosis; skin lesions resolved when topical corticosteroids were withdrawn. Follow-up biopsy of three dogs showed resolution of the previously abnormal collagen and subepidermal clefting. Residual lesions included phlebectasia, comedones and hyperpigmentation. The authors postulate that subepidermal clefting was due to local, corticosteroid-induced skin fragility. This is the first report, to our knowledge, of bullous skin disease in dogs resulting from topical corticosteroid therapy.     

Clinical and pathological findings in a HERDA-affected foal for 1.5 years of life

A Quarter horse filly bred from two horses affected with HERDA (hereditary equine regional dermal asthenia) was observed clinically and its skin histologically for the 1.5 years of its life. Severe signs of the disease did not manifest until 1.5 years of age, and were not temporally related to saddling. Histological comparison to an age-, breed- and sex-matched control did not show any consistent diagnostic features. Monitoring of the proband substantiated previous reports of (i) the autosomal recessive nature of the disease, (ii) mares affected with HERDA being able to foal without damage to the skin or reproductive tract, (iii) HERDA foals appearing phenotypically normal throughout the first year of life, and (iv) demonstrated that histological interpretation of skin specimens from grossly normal skin may be insufficient to differentiate HERDA-affected horses from controls.     

Abstracts: LVII Annual Meeting of the Italian Society for Veterin Ary Sciences (SISVET), Ischia 2003

The Bactrian camel is an important domestic animal in some of the desert and semi-desert areas of the world. However, there is no detailed report about the nervous supply to the nasal cavity of the Bactrian camel. In the present study, seven heads of adult Bactrian camels were collected and the nerve distribution in the nasal cavity was dissected grossly. The results demonstrated that the nerves supplying to the nasal cavity included the olfactory nerve, the ethmoidal nerve from the ophthalmic nerve, and the caudal nerve from the maxillary nerve. The general patterns of nervous distribution in the nasal cavity of the Bactrian camel corresponded with those of other domestic animals. However, the terminal nerve was not observed by this gross anatomical method in the Bactrian camel.     

The Serosal Patch Clinical Use in 12 Animals

Hollow viscus perforation and leakage were treated successfully in eight dogs by suturing the surface of a loop of healthy bowel over the leaking areas, forming a serosal patch. The technique also was employed in three dogs and one cat to reinforce areas of potential leakage in the urinary bladder, small intestine, and colon.
Healthy bowel serosa was used to seal perforations in both clean-contaminated and grossly infected visceral wounds. The serosal patch, with its muscular and submucosal reinforcing layers, resisted intraluminal pressure and proved successful in some animals where omental patching or wrapping had failed.