Non-endocrine Ferret Diseases

Question 1

What are the speculated etiologies of Ferret neoplasia (predisposing factors)

Answer 1

• Husbandry
  
  • early neutering
  • indoor housing/artificial lighting
  • high carb diets
• Genetic predisposition
  
  • american bloodlines vs European ferrets
• Infectious disease
  
  • Hilicobacter mustelae (GI adenocarincoma or lymphoma)
  • Retrovirus (Lymphoma)

Question 2

Ferrets

What is Ferret Lymphoma

Answer 2

• # 3 most common neoplasm overall
  • # 1 malignancy
• Proliferation of atypical lymphocytes/blasts
• Can arise from any organ w/ varying clinical presentations
• Can occur in young and middle aged-older ferrets
• Classified according to:
  
  • age of onset
  • organ system affected,
  • cell origin (B- vs T-cell)

Question 3

What are the classifications of Ferret lymphoma

Answer 3

• Multicentric
• Mediastinal
• Cutaneous
• Gastrointestinal
  
  • May arise due to chronic inflammation
  • Very short survival time
• Orbital or retrobulbar
• Skeletal
  
  • osteolytic lesions

Question 4

What is Ferret Multicentric Lymphoma?

Answer 4

• most common form of lymphoma
• Typically in older ferrets (>3yr)
• Neoplastic cells are small, mature, well differentiated lymphocytes
• Chronic course of disease w/ involvement of lymph nodes and spread to visceral organs
  
  • Spleen
  • liver
  • kidneys

Question 5

What is Ferret Mediastinal Lymphoma?

Answer 5

• Typically younger ferrets (<2 years of age)
• Neoplastic cells are large, immature, lymphoblasts of T-cell phenotype
• Acute onset of signs caused by a mediastinal mass (thymus) that displaces the heart and lungs
• Can also spread to other organs:
  
  • Spleen
  • Liver
  • Bone Marrow

Question 6

What are the clinical signs of Lymphoma in ferrets?

Answer 6

• Lethargy, weakness
• Inappetence, weight loss
• Lymphadenomegaly
• Abdominal distension
• Vomiting, diarrhea
• Respiratory signs
  
  • dyspnea, coughing
• Skin masses, ulcerations
• Exophthalmos
• Paresis

Question 7

How s Lymphoma diagnosd in Ferrets?

Answer 7

• CBC (nonspecific)
  
  • Non-regenerative anemia of chronic disease (80%)
  • Lymphocytosis (rare < 8%)
    
    • if present, typically in young ferrets w/ mediastinal lympohma
    • Neutropenia, especially older ferets, is more common
• Biochemistry (nonspecific, variable)
  
  • Hyperproteinemia
  • Hypoalbuminemia
  • Azotemia, increased liver enzymes
  • Hypercalcemia (rare <10%)
• FNA + Cytology
  
  • Reactive LNs may be mistakenly classified as lymphoma
  • Ideally sample peripheral LN or other abdominal organs
• Tissue biopsy + histopathology
  
  • preferred over cytology, if possible
• Concurrent corticosteroid therapy can confound results

Question 8

How is Lymphoma graded in ferrets?

Answer 8

• Description of the tumor cells based on histologic appearance
  
  • Degree of differentiation
  • cell size
  • Number of mitotic figures

Question 9

How is lymphoma phenotyped in Ferrets

Answer 9

• Description of the cell line of origin
  
  • immunohistochemistry or flow cytometry
  • CD3 marker (T-Cell)
  • CD79a marker (B-Cell)

Question 10

How is lymphoma staged in ferrets

Answer 10

• determining location and extent of disease w/ imaging

Question 11

What is the Treatment for Lymphoma in ferrets?

Answer 11

• Comparative data on protocols does not exist for ferrets
• Depends on stage of lymphoma and owner wishes
• Options:
  
  • Surgery
    
    • ideal for single affected organ/site
      
      • LN removal
      • splenectomy
    • can be followed w/ radiation or chemo as needed
  • Chemotherapy
    
    • Modifications of CHOP
      
      • Cyclophosphamide, hydroxydaunorubicin, vincristine, and prednisolone
      • +/- L-asparaginase
  • Radiation
    
    • Can be primary, adjunctive, palliative
    • Even a single treatment can shrink tumor
    • Multiple treatments preferred
  • Palliation
    
    • Prednisolone
    • +/- Chlorambucil
    • +/- L-asparaginase