Iatrogenic Postvaccinal Injection Site Granulomas in Cattle

Background: The Brazilian government has established disease eradication and control programs to protect livestock from pathogens that affect animal health and compromise animal protein production and food safety and quality. Vaccination campaigns against foot-and-mouth disease and other infectious diseases in cattle except brucellosis can be carried out bynon-veterinarian employees. However, vaccination errors can result in the formation of granulomas at injection sites that can affect animal welfare and production. The present study aimed to report two cases of granulomas at injection sites due to the inadvertent administration of vaccines containing saponins and mineral oil as adjuvants.Cases: Case 1. The history was that a 2-year-old Devon steer was down for 7 days and was vaccinated 20 days ago with a vaccine containing saponins and mineral oil as adjuvants. Case 2. A 7-month-old Holstein heifer was examinated due to a 40-day history of ataxia, forelimb paresis progressing to tetraparesis, and vaccination with a vaccine containing saponins and mineral oil as adjuvants 60 days ago. These two animals were admitted in the Veterinary Hospital from the University of Passo Fundo (UPF) with a clinical history of incoordination and permanent decubitus after vaccination. The disease had a similar clinical course in both animals. Clinical signs included the presence of a palpable cervical mass at the site of vaccination, forelimb paresis that progressed to tetraparesis, and decubitus scars. Treatment included intravenousadministration of anti-inflammatory steroids, antibiotic therapy, daily cleansing of the pressure sores, all four limbs were massaged, animals underwent several physiotherapy sessions, slings were used to mantain recumbent patients in a standing position and supportive therapy consisted of fluid therapy and oral supplementation. Animals remained hospitalizedfor approximately 40 days. Pacients experienced temporary improvement during treatment, and would walk with an uncoordinated gait. The clinical picture worsened after treatment was discontinued, necessitating euthanasia. At necropsy, gross lesions were similar in both animals. In case 1, the trapezius was firm and pale and had multiple granulomas whichextended into the cervical vertebral column at C3-C4 and invaded the spinal canal compressing the spinal cord. In case 2, there was extensive damage to the trapezius by granulomatous inflammation; numerous nodular granulomas exuded milky contents. These lesions extended deep into the muscle fibers and infiltrated the vertebral column at C5-C6, with involvement of the medullary canal and spinal cord compression. Microscopically there was severe, diffuse pyogranulomatous myositis. Each pyogranuloma had a central clear space. Nodal architecture was effaced by these inflammatory nodules.Discussion: Some drugs and vaccines contain irritating adjuvants and induce granuloma formation at the inoculation site. In both cattle, vaccines were injected intramuscularly in the cranial third of the neck in close proximity to the cervical vertebrae and surrounding tissues. These vaccines possibly induced an exuberant inflammatory reaction at the inoculationsite. An exacerbated inflammatory response following the administration of adjuvanted vaccines by improperly trained personnel caused substantial tissue damage at the injection site. Severe, locally extensive lesions were found at necropsy affecting adjacent structures including skeletal muscles and spinal cord. The clinical signs of ataxia and forelimb paresis thatprogressed to tetraparesis were due to the marked pyogranulomatous inflammation in C3-C4 in case 1 and in C5-C6 in case 2. The present study reinforces the importance of good farming practices and properly trained personnel working at farms.Keywords: bovine, vaccine, infection site, granuloma, iatrogenic

Linfoma cutâneo em equino Quarto de Milha

Background: Lymphoma, although rare, is the most common hematopoietic neoplasia in horses. The overall incidence of lymphoma is between 1.3-2.8% of all equine neoplasia and it has a prevalence of 0.002-0.5% in the equine population. Lymphoma can be classified as multicentric, alimentary, mediastinal, cutaneous and solitary. The cutaneous is the rarest form and it usually presents with multifocal skin lesions, with no other clinical signs. The diagnoses is accomplished by histopathological examination of a biopsy or cytological examination of a fine needle aspirate. The aim of the current study is to report a case of the rarest form of equine lymphoma, the cutaneous.Case: An 8-year-old equine female, Quarter Mile, was evaluated due to volume’s increase and subcutaneous nodules disseminated along the body. These lesions developed gradually during 2 years. The mare was used for ridding, it was kept in the field with 10 other equines and was the only one affected. The mare was vaccinated for influenza and was negative for glanders and equine infectious anemia. During clinical exam, all vital parameters were within limits and body condition score was classified as 6 (Henneke Chart). It was observed bilateral nasal secretion and depigmentation in ocular and vulvar mucous. It was observed multiple delimited areas with size ranging from few cm up to 7 cm, hard, mobile, painless, located in the subcutaneous and disseminated in the body (including head, neck, thorax, limbs and perineum). Red blood cell, leucocytes, fibrinogen, total plasmatic protein were within normal limits. Due to clinical signs and the potential risk of a zoonosis, the glanders test was repeated (complement fixation test) and the result was negative. Differential diagnoses also included insect hypersensitive, which was discarded since the female did not presented pruritus nor alopecia, lesions gradually increased in size and no seasonality was observed. It was performed excisional biopsy for tissue culture, which revealed no growth of aerobic mesophile bacteria. Histopathological evaluation revealed rounded cell proliferation similar to lymphocytes situated in the deep derma and subcutaneous. After evaluation of history, clinical exam and complementary exams the mare was diagnosed with cutaneous lymphoma. The owner was instructed that there was no available specific treatment with good efficacy and viable for equines at this stage. Besides, it is important to evaluated the mare constantly due the possibility of future lesions in organs or intern lymph nodes.Discussion: Cutaneous lymphoma is an uncommon disease, especially in horses, that can present with variable clinical signs, immunosuppression, rapid systemic disease progression or none at all. In the present case report, during clinical examination lesions were observed in areas of lymphatic drainage. Identification of neoplastic lymphocytes during cytological examination or histopathological evaluation of biopsy tissue can confirm the presence of lymphoma, as performed in the present case. Treatment is palliative and occasionally results in complete cure, mainly in equine with single lesions. The mare had cutaneous lymphoma disseminated all long the body and no clinical signs that could suggest gastrointestinal neoplastic lesions, even though the owner was advised that this animal should be monitored regularly in the future, specially due the possibility of metastatic lesions in any other organ. In equine, lymphoma has low incidence and the cutaneous form is the rarest one. Clinical signs are typically non specific and develop insidiously, so it is important to perform complementary exams for accurate diagnoses and for differential diagnoses of tegumental and infectious diseases

Testicular Teratoma in a Unilateral Right-Sided Abdominal Cryptorchid Horse

Background: Cryptorchidism is characterized by the incomplete descent of one or both testicles to the scrotum, being a hereditary alteration and frequently an unilateral condition. Besides the sexual and aggressive behaviour, the retained testicle is commonly located in abdominal cavity, being considered a risk factor for neoplasm development. The most common testicular neoplasm reported in mammalian species are Sertoli cell tumors, Leydig cell tumors, seminomas and teratomas. A presumptive diagnosis of testicular tumor can be achieved by ultrasonography, although the definitive diagnosis is obtained only by histopathology. In this report, we are presenting a of testicular teratoma in an unilateral abdominal cryptorchid horse. Case: A stallion, American Quarter Horse, 3 year-old, was attended and presented right testicle retained and a left testicle in the scrotum. Transrectal palpation was used to identify a round and firm structure, presumably the right testicle, lateral to the urinary bladder and located in the right side of the abdomen.  Further, a transrectal ultrasound examination showed a complex, round mass with irregular edges containing both cystic and solid structures, hypoechoic fluid-filled cavities separated by linear hyperechoic septa. After a clinical examination, the animal was diagnosed with cryptorchidism and was submitted to orchiectomy and cryptorchidectomy by inguinal approach. Surgery was performed under general anesthesia and postoperative care included cold shower, anti-inflammatory and antibiotic therapy. Testicles were surgically removed and further sent for histopathological examination. The visual appearance of the right undescended testicle showed multiple round, cystic, and solid structures on outer surface, while the left descended testicle was apparently normal. The macroscopic evaluation showed that the affected testicle consisted of a firm to soft solid mass with multiple fluid-filled cystic areas. Microscopically, the testicular architecture was replaced by cysts, fibrous tissue, adipose tissue, glandular structures, and foci of calcification. The histology revealed that the retained testicle had a testicular teratoma. Discussion: Reproductive disorders are common in horses and represent a significant part of the equine practitioner routine. Equine cryptorchidism is the most common non-lethal developmental defect of stallions; Surgery is the best treatment, since this alteration is hereditary. Teratomas have been reported more often in cryptorchid testicles, being usually just diagnosed as an incidental finding during surgical procedure. Under field conditions, usually the testicles are not sent for histopathological evaluation and this fact can contribute to underdiagnoses. Ultrasonography allows clinicians to determine testis location as well as morphological changes in the testes, as well as to elaborate a presumptive diagnose of testicular neoplasm. Histopathology is the best exam to achieve definitive diagnoses in the presence of testicular alterations. In our report, diagnosis of testicular neoplasia was not made before surgery and testicular mass was an incidental finding during the pre-surgical examination. Before testicular enlargement or presence of testicular mass, neoplasia should be included in the differential diagnosis. In conclusion, although rare, teratoma should be included in differential diagnoses of retained testicles, especially those with morphological alterations

Diagnostic Process in a Crioulo Horse with Cushing’s Syndrome

Background: Equine pituitary pars intermedia dysfunction, also known as equine Cushing’s syndrome, is a neurodegenerative disease. An important risk factor for Cushing’s is advanced aging and it is the most common endocrine disorder in older horses. The prevalence in horses aged over 10 and 15 years is reported as 9.3% and 21%, respectively. Due to the slow progressive nature of the disease, seasonal variation in hormone output and overlapping endocrine response to other events, accurate diagnosis is challenging. The diagnosis requires the combination of anamnesis, clinical signs, in addition to laboratory tests results. This study aimed to report Cushing’s syndrome in a Crioulo breed horse focusing on diagnostic methods.Case: A 13-year-old male Crioulo breed, orchiectomized, was attended at the Universidade de Passo Fundo (UPF), in Passo Fundo, RS, Brazil. The owner reported that the animal had progressive weight loss and coat abnormal growth, with curly appearance. From visual inspection, body condition score was 4 (1-9) bulging abdomen was noticed, hirsutism, depression and lethargy. Also, there was a large neoplastic mass on the left side of gluteal region. Later, this mass was classified in histopathological examination as a fibroblastic sarcoid and was treated. The animal presented physical parameters within the physiological limits of the specie. Normochromic normocytic anemia and neutrophilic leukocytosis were reported in the hematologic evaluation. In coproparasitological examination, there were 300 eggs per gram of feaces. Hyperadrenocorticism was suspected in the clinical examination and dexamethasone suppression test was performed to confirm the fact. Basal serum was collected at 17 h (M0) and subsequently 40 µg/kg of dexamethasone was administered intramuscularly. Serum samples were taken after 15 (M15) and 19 (M19) h, resulting in cortisol levels of 1.7 and 1.8 μg/dL, respectively. The M15 and M19 results were above reference values for horses (below 1 μg/dL). Combination of information gathered from anamnesis, clinical examination and dexamethasone suppression test resulted in the definitive diagnosis of hyperadrenocorticism, also known as Cushing’s syndrome. Paliative treatment included shearing all over the body and vitamin supplementation.Discussion: In animals without obvious clinical signs, Cushing's syndrome diagnosis is challenging. The most unique and specific clinical signs are the development of abnormal hair coat, mainly hirsutism, delayed or incomplete shedding, and in aged horse, lightening of coat color. The mechanistic cause of these signs is still barely understood. Cushing's is a collection of syndromes each with a unique set of clinical signs and hormone profiles, which varies according to each individual. Complementary examinations are extremely important and endocrine tests are highly recommended in addition to suggestive findings. However, despite the variety of existing tests, false negatives or false positives can frequently happen. Dexamethasone suppression test is considered the gold standard, well validated, practical and low cost for the diagnosis of this disease. In the present report, the combination of anamnesis (13 years old, weight loss, and abnormal coat), clinical exam (hirsutism) and dexamethasone suppression test (over 1 μg/dL of cortisol 15 h and 19 h after dexamethasone administration) resulted in the definitive diagnosis of Cushing’s syndrome. Measurements of plasma concentrations of cortisol and adrenocorticotropic hormone (ACTH), thyrotropin releasing hormone (TRH) stimulation test, serum insulin concentration and necropsy are other available tests. History, clinical signs and test results are important to achieve the definitive diagnoses, and when possible, it is advisable to perform post-mortem evaluation of the pituitary gland