Laryngeal chondronecrosis after radiation therapy in a dog.

A 5-year-old pug presented with a soft tissue swelling on the ventral neck and moderate stridor with associated respiratory effort. This patient received hypofractionated radiotherapy for metastatic upper lip mast cell tumour and to the submandibular lymph nodes 6 months before presentation. Oral examination showed moderate elongation of the soft palate, stage III laryngeal collapse with only the right laryngeal saccule mildly everted and exuberant pale epiglottal and left pharyngeal mucosa. Staphylectomy, resection of the epiglottal mucosa and left arytenoid lateralisation were performed. One day after surgery, temporary tracheostomy was performed after respiratory distress due to the severe laryngeal and pharyngeal oedema. A third oral exam showed pale and redundant caudal pharyngeal mucosa obstructing the rima glottis, soft and collapsible arytenoid cartilage with pale mucosa and bilateral everted laryngeal saccules. Permanent tracheostomy was elected and laryngeal cartilage biopsies were taken. Histologic diagnosis showed cartilage necrosis and abundant tissue oedema. The patient was euthanased 1 week later.

Autologous peripheral blood hematopoietic cell transplantation in dogs with T-cell lymphoma.

BACKGROUND: Peripheral blood hematopoietic cell transplantation (PBHCT) is a feasible treatment option for dogs with B-cell lymphoma. OBJECTIVE: To examine apheresis and PBHCT outcomes in dogs diagnosed with T-cell lymphoma (TCL). ANIMALS: Fifteen client-owned dogs diagnosed with high-grade TCL. METHODS: After high-dose cyclophosphamide and rhG-colony-stimulating (rhG-CSF) factor treatment, peripheral blood mononuclear cells were collected using cell separators. The harvested cells then were infused after varying doses of total body irradiation (TBI). Postirradiation adverse effects were managed symptomatically and dogs were discharged upon evidence of hematopoietic engraftment. RESULTS: More than 2 × 10(6) CD34+ cells/kg were harvested from 15/15 dogs. Thirteen of 15 (87%) dogs engrafted appropriately, whereas 2 (13%) of the dogs died in the hospital. One dog developed cutaneous B-cell lymphoma 120 days post-PBHCT. The median disease-free interval and overall survival (OS) of the 13 dogs transplanted in first remission from the time of PBHCT were 184 and 240 days, respectively. Stage and substage of disease at diagnosis had no effect on OS. Two of 13 (15%) dogs were alive 741 and 772 days post-PBHCT. CONCLUSIONS AND CLINICAL IMPORTANCE: PBHCT may be considered as a treatment option for dogs with TCL.

Pharmacokinetics of cyclophosphamide after oral and intravenous administration to dogs with lymphoma.

BACKGROUND: Cyclophosphamide is an alkylating chemotherapeutic drug administered i.v. or p.o.. It is currently assumed that exposure to the active metabolite, 4-hydroxycyclophosphamide (4-OHCP), is the same with either route of administration. OBJECTIVES: To characterize the pharmacokinetics of cyclophosphamide and 4-OHCP in dogs with lymphoma when administered p.o. or i.v.. ANIMALS: Sixteen client-owned dogs with substage A lymphoma were enrolled in the study. Eight dogs received cyclophosphamide i.v. and 8 received it p.o.. METHODS: Prospective randomized clinical trial was performed. Blood was collected from each dog at specific time points after administration of cyclophosphamide. The serum was evaluated for the concentration of cyclophosphamide and 4-OHCP with mass spectrometry and liquid chromatography. RESULTS: Drug exposure to cyclophosphamide measured by area under the curve (AUC)(0-inf) is significantly higher after intravenous administration (7.14 ± 3.77 µg/h/mL) compared with exposure after oral administration (P-value < .05). No difference in drug exposure to 4-OHCP was detected after i.v. (1.66 ± 0.36 µg/h/mL) or p.o. (1.42 ± 0.64 µg/h/mL) administered cyclophosphamide. CONCLUSIONS AND CLINICAL IMPORTANCE: Drug exposure to the active metabolite 4-OHCP is equivalent after administration of cyclophosphamide either p.o. or i.v..