BONE LESIONS IN FOUR DOGS WITH VISCERAL LEISHMANIASIS

Detection of vector-borne pathogens in owned dogs with cranial cruciate ligament rupture living in the Mediterranean area

Background

Cranial cruciate ligament rupture (CCLR) results from a multifactorial degenerative process that leads to rupture of the ligament. Vector-borne pathogens (VBP) in dogs can induce joint disease but their role in CCLR has not been previously investigated. The aim of the present work is to evaluate the prevalence of VBP in dogs with CCLR.

Methods

This was a prospective study that included 46 dogs presented for CCLR surgical treatment and 16 control dogs euthanized for diseases unrelated to the joints. Specimens collected included blood, synovial fluid, and synovial membrane biopsy. Pathogen testing consisted of serology for Leishmania infantum (quantitative ELISA), Ehrlichia canis/ewingii, Borrelia burgdorferi, Anaplasma phagocytophilum/platys, and Dirofilaria immitis (4DX IDEXX test), and PCR for L. infantum, Ehrlichia/Anaplasma spp., Bartonella spp., piroplasms (Babesia spp. and Theileria spp.), and filariae (D. immitis, Dirofilaria repens, Acanthocheilonema dracunculoides, Acanthocheilonema reconditum, and Cercopithifilaria spp.) on both EDTA-whole blood (EB) and synovial fluid (SF) samples. SF cytology and histopathological evaluation of synovial membrane were also performed.

Results

The prevalence of VBP was 19.6% in the CCLR group and 18.8% in the control group, with no statistical difference among them. The presence of synovitis was not more frequent in CCLR dogs (45.6%) than in control dogs (43.7%). Lymphoplasmacytic infiltration was the most common inflammatory pattern detected in the joints of both groups of dogs.

Conclusions

This study failed to demonstrate a role of canine VBP in CCLR or the presence or different pattern of joint inflammation in pathogen-positive dogs.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-022-05205-x.

Joint involvement in canine visceral leishmaniasis: Orthopedic physical examination, radiographic and computed tomographic findings

This study aimed to evaluate the joint involvement in dogs with visceral leishmaniasis by means of orthopedic physical examination, radiographic and computed tomographic (CT) findings. Of the 46 evaluated dogs, an overall of 91.3 % presented joint (carpal, tarsal, elbows, and stifle) abnormalities, observed on physical examination, radiography and/or CT. In 67.3 % of the dogs orthopedic examination showed no abnormalities. Among the 31 dogs with normal orthopedic examination, 61.3 % showed radiographic and CT findings suggestive of osteoarthritis, 25.8 % presented normal radiographs with abnormalities evidenced only on CT, while 12.9 % presented normal radiographs and CT imaging. From the 15 dogs with abnormal orthopedic examination, 80 % had abnormal radiographic and CT findings suggestive of osteoarthritis, while 20 % presented normal radiographs with abnormalities evidenced only in their CT. Radiographic and CT findings included evident trabecular pattern, subchondral bone sclerosis, osteolysis, mixed bone lesions (osteolytic-proliferative lesions), soft tissue swelling around the joint (edema), joint space narrowing, bone proliferation, osteophytes, bone cyst and cartilage flap. Based on CT results the most affected joints, among those assessed, were the tarsal (80.9 %), followed by stifle (78.5 %), carpal (64.2 %), and elbows (54.7 %). Except by one dog that presented only one stifle joint compromised, the other three joints presented bilateral abnormalities in all dogs.

[Leishmania infantum induced bone lesions in a dog]

A 3-year-old Labrador Retriever originating from Spain was presented with a left-sided hind limb lameness for several months. The orthopedic examination revealed a pain response when palpating the left tarsal joint. Radiographic and computed tomographic studies showed polyostotic, aggressive osteolytic bone lesions with mild erosive arthritis. The diagnosis of canine leishmaniasis was confirmed by bone biopsy and the detection of the pathogen by PCR. Three weeks after initiation of therapy with allopurinol, the dog presented no signs of lameness. Eight months after start of therapy, radiographic examination revealed moderate regression of the osteolytic bone lesions.

Pathologic mechanisms underlying the clinical findings in canine leishmaniasis due to Leishmania infantum/chagasi

In dogs with symptomatic or asymptomatic leishmaniasis, Leishmania infantum appears to induce a mixed Th1/Th2 immune response that in the sick dog may eventually result in tissue damage via different pathomechanisms, notably granulomatous inflammation (eg, nodular dermatitis, osteomyelitis), immune complex deposition (eg, glomerulonephritis), and/or autoantibody production (eg, polymyositis). This is a compensatory but detrimental mechanism generated mainly because of the insufficient killing capacity of macrophages against the parasite in the susceptible dog. Clinical disease is typically exemplified as exfoliative and/or ulcerative dermatitis, with or without nasodigital hyperkeratosis and onychogryphosis, glomerulonephritis, atrophic myositis of masticatory muscles, anterior uveitis, keratoconjunctivitis sicca, epistaxis, and/or polyarthritis, appearing alone or in various combinations. The pathogenesis of these clinical conditions has recently been highlighted, to a greater or lesser extent. The usually subclinical conditions expressed as chronic colitis, chronic hepatitis, vasculitis, myocarditis, osteomyelitis, orchiepididymitis, and meningoencephalomyelitis, though uncommon, are of pathologic importance from a differential point of view. The leading cause of death among canine leishmaniasis patients is chronic proteinuric nephritis that may progress to end-stage kidney disease, nephrotic syndrome, and/or systemic hypertension. However, even the asymptomatic proteinuria, when profuse, may be a serious problem because it predisposes to arterial thromboembolism and eventually contributes to the deterioration of the body condition.

Experimental model of chronic osteomyelitis caused by Leishmania (L) amazonensis

Experimental animal models have been used for the study of the physiopathogenesis of leishmaniasis, on some occasions with success, while in other situations such as bone alterations that accompany tegumentary leishmaniasis, especially in diffuse cutaneous form (DCL), the mechanisms are still unknown. In the present study, we determined these alterations in an animal model susceptible to Leishmania (L) amazonensis. Amastigotes of L. (L) amazonensis isolated from patients with diffuse cutaneous leishmaniasis (DCL) were inoculated into the hind paws of eight BALB/c mice, macroscopic and histopathological aspects were analyzed. After 90 and 120 days of evolution, histopathological analysis demonstrated a mononuclear cell infiltrate rich in plasma cells and intense parasitism of intra- and extra-medullary macrophages, with areas of bone necrosis and discrete involvement of cartilaginous tissue. The results show that the inflammatory process developed during L. (L) amazonensis infection might cause bone tissue destruction and secondarily affect the joints.

Management of leishmanial osteolytic lesions in a hypothyroid dog by partial tarsal arthrodesis

A five-year-old male boxer, previously diagnosed with leishmaniasis and hypothyroidism, had gradually become unable to bear weight on its left hindlimb. Physical examination revealed a left popliteal lymphadenopathy, mild crepitus, and severe swelling of the left tarsal joint, a radiographic examination of which revealed severe bone destruction of the talus and a periosteal reaction of the calcaneus. Laboratory findings and serological tests suggested an active leishmanial infection, and a Leishmania species was identified by direct cytology of a sample from the osteolytic area and by indirect immunohistochemistry of a bone biopsy. The dog's condition improved when it was treated with meglumine antimonate and allopurinol. Because of the large osteolytic area and the increased use of the affected leg, a partial tarsal arthrodesis was performed to prevent a fracture. Five months after the surgery, the osteolytic area had healed completely and the calcaneus periosteal reaction had disappeared.

Clinical and radiographic study of bone and joint lesions in 26 dogs with leishmaniasis

Twenty-six dogs with parasitologically confirmed leishmaniasis and abnormalities of gait were studied to determine the most common radiological patterns of bone and joint lesions. The clinical findings included either lameness, joint pain and crepitation, soft tissue swelling and/or muscle atrophy. Bone lesions were observed radiographically in 12 of the 26 dogs; the radius and ulna were affected in seven, the tibia in six and the femur in six. Joint lesions were observed radiographically in 15 of the 26 dogs; the carpus and stifle were affected in all 15, and the tarsus in nine. There was a tendency for the bones and joints to be affected bilaterally. The radiographic patterns observed were different in the long bones and the joints. In the long bones, the most common pattern was periosteal and intramedullary proliferation, involving the diaphyses and related to the nutrient foramen; in the joints, two patterns, either non-erosive or erosive polyarthritis with soft-tissue swelling, were observed. The changes observed in the synovial fluid were associated in most cases with osteolytic lesions. However, Leishmania organisms were identified in the synovial fluid from joints without bony radiographic changes.

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.

Osteomyelitis and arthrosynovitis associated with Leishmania donovani infection in a dog

A 10-month-old male maremma shepherd dog was presented with chronic diarrhoea, moderate polyuria/polydipsia, lethargy, dysorexia and stiffness. Pain was elicited in the distal parts of all four limbs. Radiographs of the limbs showed increased endomedullary radiopacity and lysis, with thick periosteal proliferations at the metadiaphyseal areas of each radius-ulna and tibia and of the distal metacarpus on one side. Polyclonal hypergammaglobulinaemia was documented and a similar electrophoretic protein pattern was also found in the synovial fluid. Leishmania amastigotes were found in the macrophages in a bone marrow aspirate performed at the level of a distal radius and in a synovial fluid sample obtained from a carpal joint. An indirect immunofluorescence test confirmed the infection. Treatment with N-methyl-glucamine antimoniate was successful and the osteoarticular changes progressively disappeared.

Destructive polyarthritis in a dog with leishmaniasis

The clinical history and diagnosis of a dog with leishmaniasis involving both elbow joints and the skin is described. The dog, a female, five-year-old crossbreed, had been imported from Majorca (Balearic Islands, Spain) four years before the diagnosis was made. For two years, the dog had had bilateral forelimb lameness. Physical examination revealed swollen, painful and crepitating elbow joints. Furthermore, an ulcerating dermatitis was found on the concave surface of the left pinna and necrotising margins on both ears. Radiographs of the elbow joints revealed complete destruction of the joint surfaces with dislocation of the radius and the ulna, compatible with severe osteolytic arthritis. The diagnosis of leishmaniasis was confirmed by a direct agglutination test.

Monoclonal gammopathy in a dog with visceral leishmaniasis

One dog with visceral leishmaniasis associated with monoclonal gammopathy is described. Most dogs with visceral leishmaniasis present with hyperproteinemia due to a polyclonal gammopathy, but the possibility of monoclonal gammopathy must be considered. Because dogs accompany their owners when they travel, the diagnosis of leishmaniasis should be considered if an animal with monoclonal gammopathy has visited an area where the disease is endemic. The observation of Leishmania in the macrophages of a bone marrow, lymph node smear, or skin biopsy specimen is diagnostic.

Endemic visceral leishmaniasis in a dog from Texas

Visceral leishmaniasis was diagnosed by cytology and positive indirect immunofluorescent antibody titers to Leishmania donovani in a 7-month-old female Basenji dog from Texas. Clinical and laboratory findings included weight loss, hematochezia, hyperglobulinemia, hypoalbuminemia, anemia, and neutrophilic leukocytosis. Evidence of response to treatment with diminazene aceturate and ketoconazole included improvement in the abnormal clinical, hematologic, and biochemical findings, decreased serum globulin concentration and antibody titer to Leishmania donovani, and absence of organisms in examined tissues. Several foci of endemic leishmaniasis have been reported in the United States. Because of its zoonotic potential and the lack of approved treatments for dogs with leishmaniasis in the United States, the development of effective treatment strategies is needed.

Canine leishmaniasis caused by Leishmania leishmania infantum in two Labrador retrievers

Canine leishmaniasis, a generally fatal parasitic disease, was diagnosed in 2 dogs with a medical history of foreign travel, lymphadenopathy, emaciation, anorexia, intermittent fever, and cutaneous lesions. Clinically, hyperproteinemia, proteinuria, azotemia, and glomerulopathy were evident. Isolation of Leishmania species was done using Schneider's Drosophila medium. Syrian hamsters were used for infectivity studies. Clear taxonomic identification was done biochemically by isoenzyme analysis and comparison of zymogram banding patterns with 6 World Health Organization reference strains. Based on the geographic origin of affected dogs, clinicopathologic presentation, visceralization with hepatosplenomegaly in hamsters, and isoenzyme analysis, a diagnosis of Leishmania leishmania infantum was made. This study, representing the first taxonomic identification of an isolate from canine leishmaniasis, demonstrates the zoonotic and epidemiologic implications of this disease.

Canine leishmaniasis. A review based on 95 cases in The Netherlands

The clinically relevant aspects of canine leishmaniasis are reviewed. Included are data from 92 dogs imported from the Mediterranean basin and at least 2 autochthonous cases. New aspects on pathogenesis are presented, including evidence that canine leishmaniasis is an immune complex disease. Therapy with meglumine antimonate (Glucantime) is evaluated. The hazards of imported canine leishmaniasis for public health are discussed.