Topic:Chemotherapy
Chemotherapy in horses involves the use of chemical agents to treat neoplastic conditions by targeting and destroying cancer cells. This therapeutic approach is adapted from human oncology and is applied to equine patients to manage various types of tumors, such as lymphoma and sarcoids. The administration of chemotherapy in horses requires careful consideration of dosage, administration routes, and potential side effects due to the differences in metabolism and size compared to other species. Common chemotherapeutic agents used in equine medicine include cisplatin, doxorubicin, and cyclophosphamide. This page compiles peer-reviewed research studies and scholarly articles that explore the pharmacokinetics, efficacy, and safety of chemotherapy protocols in horses, as well as their impact on equine health and welfare.
Enhanced cytotoxicity of bleomycin, cisplatin, and carboplatin on equine sarcoid cells following electroporation-mediated delivery in vitro. Electroporation is a method used to deliver poorly permeant chemotherapeutic drugs to tumor cells, potentiating the cytotoxic effects of drugs and overall clinical response. Despite existing evidence of the potential benefits of electroporation to enhance the antitumoral effects of drugs, there is a lack of understanding about the effects of electroporation on equine tumor cells. This study investigated the combined effects of electroporation and bleomycin, cisplatin, and carboplatin on an equine sarcoid cell line (EqS04b). The use of electroporation increases the cytotoxic effects of bleomyci...
Killing of Trypanozoon Parasites by the Equine Cathelicidin eCATH1. Trypanozoon parasites infect both humans, causing sleeping sickness, and animals, causing nagana, surra, and dourine. Control of nagana and surra depends to a great extent on chemotherapy. However, drug resistance to several of the front-line drugs is rising. Furthermore, there is no official treatment for dourine. Therefore, there is an urgent need to develop antiparasitic agents with novel modes of action. Host defense peptides have recently gained attention as promising candidates. We have previously reported that one such peptide, the equine antimicrobial peptide eCATH1, is highly active a...
Malignant Glomus Tumour (Glomangiosarcoma) with Additional Neuroendocrine Differentiation in a Horse. A 13-year-old Icelandic crossbred horse was presented with headshaking and progressive impairment of chewing. A slowly growing mass was identified in the anterior maxilla. This was associated with lysis of the alveolar bone and the roots of the incisors and there were nodular proliferations affecting the nasal septum and conchae. There was no response to chemotherapy and so the horse was humanely destroyed. Based on morphological, immunohistochemical and ultrastructural findings the mass was classified as a malignant glomus tumour with multifocal vascular spaces and additional neuroendocrine d...
In vitro anticancer activity of Betulinic acid and derivatives thereof on equine melanoma cell lines from grey horses and in vivo safety assessment of the compound NVX-207 in two horses. Betulinic acid, a pentacyclic triterpene, and its derivatives are promising compounds for cancer treatment in humans. Melanoma is not only a problem for humans but also for grey horses as they have a high potential of developing melanoma lesions coupled to the mutation causing their phenotype. Current chemotherapeutic treatment carries the risk of adverse health effects for the horse owner or the treating veterinarian by exposure to antineoplastic compounds. Most treatments have low prospects for systemic tumor regression. Thus, a new therapy is needed. In this in vitro study, Betulinic acid a...
Proton pump inhibitors for the treatment of cancer in companion animals. The treatment of cancer presents a clinical challenge both in human and veterinary medicine. Chemotherapy protocols require the use of toxic drugs that are not always specific, do not selectively target cancerous cells thus resulting in many side effects. A recent therapeutic approach takes advantage of the altered acidity of the tumour microenvironment by using proton pump inhibitors (PPIs) to block the hydrogen transport out of the cell. The alteration of the extracellular pH kills tumour cells, reverses drug resistance, and reduces cancer metastasis. Human clinical trials have prompted to c...
Suspected malignant transformation of B lymphocytes in the equine cornea from immune-mediated keratitis. To describe clinical, in vivo confocal microscopic, histopathologic, polymerase chain reaction assay for antigen receptor rearrangement (PARR) and immunohistochemical features of a horse with suspected malignant transformation of corneal B lymphocytes in immune-mediated keratitis (IMMK) and to also report surgical management and adjunctive treatment including topical and radiation therapies. Methods: A 15-year-old Oldenburg gelding was examined for presumptive progressive stromal IMMK of the right eye which became refractory to medical management. Corneal in vivo confocal microscopy revealed...
Comparative analysis of cryoprotective agents influence on thermodynamic and kinetic parameters of equine and human hemoglobin molecules. Critical to the understanding the mechanism of destruction and protection during cryopreservation of biological objects is the knowledge of the conformational transitions of biopolymers experiencing low temperatures in the presence of cryoprotective agents. This information may be derived from the kinetic and thermodynamic parameters of macromolecular thermal denaturation kinetics under different environmental conditions. Objective: The study deals with the influence of cryoprotective agents (glycerol, 1.2-propanediol (1.2-PD), and dimethyl sulfoxide (DMSO)) on thermodynamic and kinetic parame...
Characterization and outcome following excision of masses in the nictitating membranes of horses: 50 cases (1998-2012). To determine the histologic findings associated with masses in the nictitating membranes (third eyelids) of horses and to identify prognostic factors associated with recurrence and the outcome. Methods: Retrospective case series. Methods: 50 horses with masses in a third eyelid. Methods: Medical records of horses with partial or complete excision of a third eyelid and submission for histologic evaluation between September 1998 and November 2012 were reviewed. Horses were included if follow-up information for at least 1 year after surgery was available. Information regarding signalment and trea...
Use of lomustine (CCNU) in a case of cutaneous equine lymphoma. A 12-year-old gelding was diagnosed with recurrent lymphoma in multiple cutaneous sites. A highly invasive preputial mass caused urethral obstruction. The horse was treated with surgery and chemotherapy consisting of lomustine (CCNU) and prednisolone. The treatment was well-tolerated and effective. This is the first reported use of lomustine (CCNU) in a horse for the treatment of equine lymphoma. Utilisation de lomustine (CCNU) dans un cas de lymphone cutané équin. Un hongre âgé de 12 ans a été diagnostiqué avec un lymphome récurrent sur plusieurs sites cutanés. Une masse préputiale ...
A pilot phase II study of the efficacy and biosafety of doxorubicin chemotherapy in tumor-bearing equidae. The efficacy and biosafety of a previously established tolerable dosage of doxorubicin have not been established in horses. Objective: To provide preliminary evidence of the efficacy of doxorubicin in tumor-bearing horses, explore drug pharmacokinetics profile, and estimate period of risk of exposure to drug residues. Methods: Twelve horses with 37 tumors. Methods: Treatment protocol included 6 treatments at 3-week intervals. Eight horses were uniformly treated at a dosage of 70 mg/m(2) and 4 horses received 4 of 6 treatment cycles at 70 mg/m(2) . Clinical signs, tumor responses, and toxicoses...
Phase I dose escalation of doxorubicin chemotherapy in tumor-bearing equidae. There is no information on the use of doxorubicin in horses with tumors. Objective: To determine dose-limiting toxicosis (DLT) and maximum tolerated dose (MTD) of doxorubicin in tumor-bearing horses. Methods: Seventeen horses with 34 localized or multicentric advanced tumors. Methods: Two-stage dose-ranging design involving intrapatient and interpatient dose escalation. Treatment protocol included 6 treatment cycles given at 3-week intervals with dosages ranging from 40 to 85 mg/m(2). Clinical signs, hematologic, and nonhematologic changes were evaluated. Results: Total doses ranged from 1,127...
BAG3 protects bovine papillomavirus type 1-transformed equine fibroblasts against pro-death signals. In human cancer cells, BAG3 protein is known to sustain cell survival. Here, for the first time, we demonstrate the expression of BAG3 protein both in equine sarcoids in vivo and in EqS04b cells, a sarcoid-derived fully transformed cell line harbouring bovine papilloma virus (BPV)-1 genome. Evidence of a possible involvement of BAG3 in equine sarcoid carcinogenesis was obtained by immunohistochemistry analysis of tumour samples. We found that most tumour samples stained positive for BAG3, even though to a different grade, while normal dermal fibroblasts from healthy horses displayed very weak ...
Efficacy of imidocarb dipropionate in eliminating Theileria equi from experimentally infected horses. Theileria equi, one of the causative agents of equine piroplasmosis, is endemic in many regions of the world but is considered a 'foreign' animal disease in the USA. In an effort to prevent the importation of T. equi, stringent serological screening of horses is practiced prior to entry to the USA. Current regulatory options available where horses are found to be infected include permanent quarantine with or without chemotherapy, repatriation, or euthanasia. Chemotherapeutics that eliminate infection and subsequently transmission risk are critical in the management of infected horses. In this ...
Epidemiology, chronobiology and taxonomic updates of Rhinoestrus spp. infestation in horses of Sardinia Isle, Western Mediterranean (Italy). From January to December 2008, 265 horses slaughtered in Sardinia (Italy) were examined for the presence of Rhinoestrus spp. (Diptera: Oestridae) through the examination of the nasal cavities and pharynges. Larvae were detected in 49% of the horses, with a mean intensity of infestation of 16.09 and abundance of 7.95. A total of 2108 larvae were collected, 66% of which were classified in first instar (L1), 22% in second instar (L2) and 12% in third instar (L3). The most frequent localization of larvae was the ethmoid, while the less one the larynx. According to the dynamics of Rhinoestrus larva...
Re-emergence of the apicomplexan Theileria equi in the United States: elimination of persistent infection and transmission risk. Arthropod-borne apicomplexan pathogens that cause asymptomatic persistent infections present a significant challenge due to their life-long transmission potential. Although anti-microbials have been used to ameliorate acute disease in animals and humans, chemotherapeutic efficacy for apicomplexan pathogen elimination from a persistently infected host and removal of transmission risk is largely unconfirmed. The recent re-emergence of the apicomplexan Theileria equi in U.S. horses prompted testing whether imidocarb dipropionate was able to eliminate T. equi from naturally infected horses and rem...
Performance characteristics of a conformal ultra-wideband multilayer applicator (CUMLA) for hyperthermia in veterinary patients: a pilot evaluation of its use in the adjuvant treatment of non-resectable tumours. Performance and clinical characteristics of a novel hyperthermia antenna operating at 434 MHz were evaluated for the adjuvant treatment of locally advanced superficial tumours in cats, dogs and horses. Electromagnetic simulations were performed to determine electric field characteristics and compared to simulations for a flat microwave antenna with similar dimensions. Simulation results show a reduced skin surface and backfield irradiation and improved directional irradiation (at broadside) compared to a flat antenna. Radiated power and penetration is notably increased with a penetration depth...
A retrospective comparison of surgical removal and subsequent CO2 laser ablation versus topical administration of mitomycin C as therapy for equine corneolimbal squamous cell carcinoma. To compare the complications and nonrecurrence rate following topical mitomycin C (MMC) therapy vs. CO(2) laser ablation for treating equine corneolimbal squamous cell carcinoma (SCC). Methods: Retrospective study. Methods: Twenty-five horses with corneolimbal SCC. Methods: Medical records of horses undergoing surgical tumor resection followed by either topical MMC therapy (0.04%) or CO(2) laser ablation between the years of 2004 and 2010 were reviewed. Recurrence and complications were compared between groups and within MMC subgroups defined by the time at which treatment was ...
Successful treatment of equine sarcoids with cisplatin electrochemotherapy: a retrospective study of 48 cases. Sarcoids are the commonest form of equine skin tumour. Several therapeutic measures have been described but none is considered to be universally effective. Electrochemotherapy (ECT) is a new anticancer therapy that utilises electrical field pulses to induce increased cell membrane permeability to antitumour hydrophilic drugs, such as cisplatin. The increased intracellular concentration of the drugs has a significant therapeutic benefit. The procedure has not been previously reported in a large number of horses. Objective: To validate ECT as a novel alternative treatment for equine sarcoids. Me...
Radiation therapy in horses. Although the diagnosis of cancer is relatively uncommon in horses, tumors do occur in this species. Surgery, radiation, and chemotherapy are traditional cancer treatments in all species. In equine patients, surgery has often been the only treatment offered; however, not all tumors can be controlled with surgery alone. In small animal oncology, newer and better therapies are in demand and available. Radiation therapy is often used to control or palliate tumors locally, especially to satisfy clients who demand sophisticated treatments. The large size of equine patients can make radiation therapy...
Efficacy and safety of mitomycin C as an agent to treat corneal scarring in horses using an in vitro model. Mitomycin C (MMC) is used clinically to treat corneal scarring in human patients. We investigated the safety and efficacy of MMC to treat corneal scarring in horses by examining its effects at the early and late stages of disease using an in vitro model. Methods: An in vitro model of equine corneal fibroblast (ECF) developed was used. The ECF or myofibroblast cultures were produced by growing primary ECF in the presence or absence of transforming growth factor beta-1 (TGFbeta1) under serum-free conditions. The MMC dose for the equine cornea was defined with dose-dependent trypan blue exclusion...
Cisplatin: a review of toxicities and therapeutic applications. Cisplatin is a platinum chemotherapeutic used in a variety of malignancies. The antineoplastic activity occurs from DNA cross-links and adducts, in addition to the generation of superoxide radicals. Nephrotoxicity is the most well-known and potentially most clinically significant toxicity. Unfortunately, the mechanism for cisplatin nephrotoxicity has not been completely elucidated; however, many theories have been developed. Other toxicities include gastrointestinal, myelosuppression, ototoxicity and neurotoxicity. Saline diuresis is currently the most accepted way to prevent cisplatin nephrot...
Electrochemotherapy in veterinary oncology. Electropermeabilization is a method that uses electric field pulses to induce an electrically mediated reorganization of the plasma membrane of cells. Electrochemotherapy combines local or systemic administration of chemotherapeutic drugs such as bleomycin or cisplatin that have poor membrane permeability with electropermeabilization by direct application of electric pulses to the tumors. Preclinical studies have demonstrated excellent antitumor effectiveness of electrochemotherapy on different animal models and various tumor types, minimal toxicity, and safety of the procedure. Based on resul...
Ruthenium anticancer drugs and proteins: a study of the interactions of the ruthenium(III) complex imidazolium trans-[tetrachloro(dimethyl sulfoxide)(imidazole)ruthenate(III)] with hen egg white lysozyme and horse heart cytochrome c. The interactions with protein targets of the ruthenium(III) complex imidazolium trans-[tetrachloro(dimethyl sulfoxide)(imidazole)ruthenate(III)], NAMI-A, an effective anticancer and antimetastatic agent now in clinical trials, deserve great attention as they are believed to be at the basis of the mechanism of action of this innovative molecule. Here, we report on the reactions of NAMI-A with two well-known model proteins, namely, hen egg white lysozyme and horse heart cytochrome c; these reactions were investigated by a variety of physicochemical methods, including optical spectroscopy, (1)H N...
Establishment of a panel of reference Trypanosoma evansi and Trypanosoma equiperdum strains for drug screening. The animal pathogenic protozoan, Trypanosoma evansi, leads to a wasting disease in equines, cattle and camels, commonly known as Surra. It is extensively distributed geographically with a wide range of mammalian hosts and causes great economical loss. Trypanosoma equiperdum causes a venereal disease called Dourine in horses and donkeys. Chemotherapy appears to be the most effective form of control for T. evansi, whereas infections caused by T. equiperdum are considered incurable. Due to emerging drug resistance, efficient control of T. evansi is severely threatened, emphasising the urgent need...
Long-term outcome associated with intratumoral chemotherapy with cisplatin for cutaneous tumors in equidae: 573 cases (1995-2004). To determine outcome associated with cutaneous tumors treated via intratumoral chemotherapy with cisplatin and identify risk factors affecting local tumor control and complications in equidae. Methods: Retrospective case series. Methods: 573 equidae with 630 cutaneous tumors. Methods: Medical records of horses, mules, donkeys, and ponies with cutaneous tumors treated via intratumoral chemotherapy with cisplatin were analyzed. Results: 549 horses, 13 mules, 8 donkeys, and 3 ponies with 630 histologically confirmed cutaneous tumors were included. Tumors included sarcoids (n = 409), squamous cell...
Equine osteosarcoma: a series of 8 cases. In horses, osteosarcoma is a rare tumor, with the majority of reported cases occurring in the head, and, more specifically, in the mandible of young horses. The following report documents 8 cases of equine osteosarcoma, the majority occurring in male horses aged 7 years or older with a lack of metastasis identified in any horse. Six arose in the maxilla or mandible and one in the proximal tibia. The predominant subtype was fibroblastic osteosarcoma with fewer osteoblastic type tumors. All had osteoid and most had a chondromucinous matrix. Surgical excision was attempted in the majority of case...