Equine oncology Flashcards
Main tumours seen in horses?
Approx 90% are skin tumours
- sarcoids
- SCC
- papilloma
- melanoma
- mast cell tumour
Risk factors for tumours in horses?
Age
Breed - melanoma in Lipizzaner, ocular SCC in shires and clydesdales
Sex - penile SCC in males (and SCC in other locations)
Location and management - SCC with UV exposure
Definition of paraneoplastic syndromes?
Diseases or combination of signs that arise as a direct consequence of a tumour but not deriving from the simple physical presence of the tumour
What are the 4 main groups of paraneoplastic syndromes in horses?
- Mucocutaneous and skin syndromes: paraneoplastic pemphigus, pruritis
- Neurological syndromes
- Haematological syndromes: anaemia, plycytaemia, granulocytosis
- Endocrine and metabolic: cachexia, hypercalcaemia, hypertrophic (pulmonary) osteopathy (Marie’s disease)
Diagnosis of tumours in horses?
Direct tests: biopsy, tumour markers
Imaging: US, Rx, endoscopy, CT, MRI
Indirect tests: haematology, biochemistry, urinalysis
Methods of treating cancers in horses?
Ablative - surgery, laser/diathermy, cryotherapy, hypothermia
Cytotoxic - chemotherapy, radiotherapy, phototherapy, electrochemotherapy
Biological - immunotherapy, vaccines, cytokine therapy, gene therapy
Forms of lymphoma?
Multicentric
Alimentary
Mediastinal, thoracic or thymic
Cutaneous
Clinical presentation and signs of multi centric lymphoma in horses? Diagnosis and treatment?
Mature young horses: 4-12yo
Involvement of many organs and metastasis common
Weight loss, depression, ventral oedema, recurrent fever (vague signs)
Diagnosis - cytology or biopsy
Treatment - surgical removal if solitary lesions, chemotherapy?
Clinical presentation and signs of alimentary lymphoma in horses? Diagnosis and treatment? Prognosis?
20% of lymphoma cases and most common intestinal neoplasia
Older horses: >12y
Malabsorption, weight loss, colic
Diagnosis - cytology (peritoneal fluid, negative doesn’t rule out), biopsy
Treatment - surgical removal if solitary lesions, chemotherapy?
Prognosis depend on stage of disease, typically poor
Clinical presentation and signs of mediastinal, thoracic or thymic lymphoma in horses? Diagnosis and treatment? Prognosis?
Most common thoracic neoplasia
Horses of all ages
Weight loss, depression, ventral and forelimb oedema (right leg first), pleural effusion
Diagnosis - cytology (pleural effusion, lots tumour cells shed so easy diagnosis), biopsy
Palliative treatment - drain fluid to help breathing (but fill up again quickly)
Prognosis hopeless
Clinical presentation and signs of cutaneous lymphoma in horses? Diagnosis and treatment? Prognosis?
Rare Older horses Subcutaneous and cutaneous nodules Diagnose with biopsy Treatment - removal of solitary masses Prognosis - less aggressive than the other forms, may become static for years or even regress
Clinical presentation and signs of haemangiosarcoma in horses? Diagnosis, treatment and prognosis?
Uncommon
Middle aged to older horses (but all ages possible)
No sex or breed predilection
Respiratory and musculoskeletal systems most commonly affected
Haemorrhage - haemoabdomen, haemothorax etc
Diagnosis - cytology, biopsy (difficult0
Limited and palliative treatment
Prognosis very poor
Tumours of the oral cavity in horses?
SCC - most common oral neoplasm
Ameloblastoma - odontogenic epithelium
Ossifying fibroma - young horses, rostral mandible
Melanoma - lip, parotid region
Tumours of the GIT in horses?
Gastric SCC
Intestinal lymphoma
Intestinal adenocarcinoma
Lipoma
Tumours of the liver in horses?
Hepatic adenocarcinoma
