A mycosis of juvenile spiny rock lobster, Jasus edwardsii (Hutton, 1875) caused by Haliphthoros sp., and possible methods of chemical control

Mortalities of puerulus and juvenile rock lobsters, Jasus edwardsii (Hutton, 1875), held in shore-based ongrowing facilities at water temperatures between 10 and 18 °C were associated with infection by an invasive oomycete identified as Haliphthoros sp. Gross signs of disease included loss of appetite, lethargy and 1–3 brown/black focal necrotic lesions in the gills near insertion of the walking legs. Hyphae were observed in wet preparations of gill filaments excised from lesions. Histology of gill lesions showed hyphae inside the gill cuticle, invasion and lysis of the skeletal muscle and massive haemocyte infiltration and melanization at the base of walking legs adjacent to infected gill filaments. Lobsters over approximately 30 mm carapace length appeared resistant to infection. Death of affected lobsters usually occurred prior to or during the moult and in some cases may have been associated with secondary bacterial infection. Haliphthoros sp. was isolated in pure culture and marine agar 2216 was the medium that produced best growth in vitro . Two isolates were exposed in vitro to five chemicals to determine if an effective treatment could be found. Chemicals that interrupted the life cycle by killing zoospores or preventing sporulation included malachite green, trifuralin, formalin and copper sulphate. The appearance of the disease was associated with poor hygiene and its elimination may be achievable by improving husbandry practices.     

High yield of PVY-free potato plants from axillary bud cultures after application of lysolecithin analogues and aminoadamantane

Summary Lysolecithin analogues and aminoadamantane were tested in vitro for their antiphytoviral effect on axillary bud cultures of potato infected with potato virus Y (PVY). Ethyllecithin added to the medium (700 mg/l) gave the best therapeutic effect on axenic axillary buds that were 1.67 mm long. Applying that compound, explant size may be increased and lead to virus elimination without thermal treatment. Thus viruses can be eliminated more effectively than with conventional methods.     

Utility of a multiple serum biomarker test to monitor remission status and relapse in dogs with lymphoma undergoing treatment with chemotherapy

A blinded retrospective study was conducted to investigate remission and recurrence of lymphoma in dogs receiving chemotherapy. The objective was to compare clinicians' assessment using palpation and cytology to the results of serum biochemical tests for haptoglobin (Hapt) and C‐reactive protein (C‐RP). These biochemical test results were combined using a diagnostic algorithm developed using data from 344 individual dogs. This multivariate approach, termed the canine lymphoma blood test (cLBT), was used to follow 57 dogs during and after treatment. cLBT of remission and recurrence compared well with clinicians' assessment and differentiated dogs in remission and those with recurring disease before appearance of lymphadenopathy (P < 0.001). The cLBT demonstrated prognostic potential based on pre‐treatment values on dogs with shorter survival times and on those achieving the lowest cLBT score during treatment that showed longer survival times. The test, therefore, demonstrates potential to assist in monitoring treatment of canine lymphoma.     

Clinical outcome,PDGFRβ and KIT expression in feline histiocytic disorders: a multicentre study

Information about histiocytic disease in cats is limited. The aim of this study was to document clinical findings and outcome in feline histiocytic disorders, and characterize the expression of PDGFRβ and KIT in order to identify potential treatment targets. Morphologically diagnosed feline histiocytic tumours were reviewed and characterized by immunohistochemistry (IHC). Five cases of feline progressive histiocytosis (FPH), eight histiocytic sarcomas (HS) and two haemophagocytic histiocytic sarcomas (HaeHS) were confirmed. PDGFRβ was variably positive in most histiocytic cases, while KIT was negative in all. Clinical presentation, treatment and outcome were also evaluated. Partial responses were recorded in measurable disease with tyrosine kinase inhibitors and lomustine, and radiotherapy achieved long‐term control in some cases. Survival times were shortest in HaeHS and disseminated disease. PDGFRβ, but not KIT, may represent a therapeutic target in feline histiocytic disorders but more studies are needed to investigate other potential treatment targets.     

Furosemide for prevention of cyclophosphamide‐associated sterile haemorrhagic cystitis in dogs receiving metronomic low‐dose oral cyclophosphamide

Sterile haemorrhagic cystitis (SHC) is a known risk of cyclophosphamide treatment. Diuresis using furosemide is effective in canines when maximally tolerated dosed cyclophosphamide is administered. This retrospective study aimed to determine whether orally administered furosemide decreased the incidence of SHC. Secondary aims were to identify predisposing factors for SHC. One‐hundred and fifteen dogs treated with metronomic cyclophosphamide were analysed retrospectively. Populations were not randomized. 25 dogs (21.7%) developed SHC. Furosemide administration significantly reduced the likelihood of SHC development (P = 0.010, where SHC was diagnosed in 30.3% of dogs administered cyclophosphamide without furosemide, and 10.2% of dogs administered cyclophosphamide with furosemide). Age, gender, breed, bodyweight, number of cyclophosphamide treatments, piroxicam use and previous or pre‐existing disease were not found to be associated with SHC development. This study demonstrates furosemide is effective in the prevention of SHC and its use may be considered when implementing metronomic cyclophosphamide therapy.     

Retrospective evaluation of COX‐2 expression,histological and clinical factors as prognostic indicators in dogs with renal cell carcinomas undergoing nephrectomy

Limited veterinary literature is available regarding prognostic markers for canine renal cell carcinoma (CRCC). We retrospectively evaluated COX‐2 expression, histological and clinical features associated with prognosis of CRCC. Sixty‐four cases post‐nephrectomy were included, 54 had histopathological assessment and 30 had COX‐2 immunostaining performed. Eight dogs (13%) had metastatic disease at initial diagnosis. Twenty‐seven dogs (42%) received adjuvant therapy after nephrectomy. On univariate analysis, COX‐2 expression, mitotic index (MI), histologic type, vascular invasion, neoplastic invasiveness and metastasis at diagnosis were significantly associated with overall median survival time (MST). COX‐2 score (COX‐2 score > 3 MST 420 days versus 1176 days if COX‐2 score <3; P = 0.011) and MI (MI > 30 MST 120 days versus 540 days for MI < 30; P = 0.003) were the only variables associated with CRCC outcome on multivariate analysis. The addition of MI and COX‐2 immunostaining to standard histopathological evaluation would help predicting outcome in CRCC patients.     

Risk factors for treatment‐related adverse events in cancer‐bearing dogs receiving piroxicam

Piroxicam has antitumour effects in dogs with cancer, although side effects may limit its use. The purpose of this study was to retrospectively identify factors predisposing cancer‐bearing dogs to adverse events (AEs) following piroxicam therapy. Medical records of dogs presented to the Purdue Veterinary Teaching Hospital between 2005 and 2015 were reviewed, and 137 dogs met the criteria for study inclusion. Toxic effects of piroxicam in these dogs were graded according to an established system. Multivariate logistic regression was used to estimate the extent to which certain factors affected the risk for AEs. Age [odds ratio (OR) 1.250, P = 0.009; 95% confidence interval (CI) 1.057–1.479] and concurrent use of gastroprotectant medications (OR 2.612, P = 0.025; 95% CI 1.127–6.056) significantly increased the risk for gastrointestinal AEs. The results of this study may help inform the risk versus benefit calculation for clinicians considering the use of piroxicam to treat dogs with cancer.     

Safety evaluation of combination doxorubicin and toceranib phosphate (Palladia®) in tumour bearing dogs: a phase I dose‐finding study

Combination chemotherapy holds promise for improving outcomes in malignancy when compared with single‐agent approaches. Care must be taken to avoid overlapping toxicity and to utilize agents with differing mechanisms of action. A phase I dose‐finding trial was performed to determine the maximally tolerated dose (MTD) of a concurrent toceranib and doxorubicin (DOX) combination protocol where toceranib dose was maintained at or near 2.75 mg kg^?1 by mouth every other day (PO EOD) while escalating DOX dosage. The dose‐limiting toxicity was found to be neutropenia and the MTD of the combination was determined to be 25 mg m^?2 of DOX q 21 days given concurrently with toceranib 2.75 mg kg^?1 PO EOD. This combination was well tolerated with no excessive gastrointestinal toxicity nor novel adverse events (AEs) noted. Anti‐tumour activity was observed in the majority of cases. This combination warrants further investigation in the context of phase II/III clinical trials to characterize efficacy and long‐term AE profiles.     

Efficacy and toxicity of carboplatin in the treatment of macroscopic mesenchymal neoplasia in dogs

Palliative chemotherapy options for dogs with macroscopic non-osseous mesenchymal tumours are limited. The purpose of this study was to assess the response rate of these tumours to carboplatin chemotherapy. Medical records of 28 dogs treated with carboplatin for macroscopic mesenchymal neoplasia between 1990 and 2022 were retrospectively reviewed. Sixteen dogs with soft tissue sarcoma and 12 dogs with haemangiosarcoma were included. Responses observed included one complete response and three partial responses, for an overall response rate of 14.2% (4/28) and median time to progression of 42 days (range 21–259 days). Responses were only seen in patients with haemangiosarcoma, for a response rate of 33.3% (4/12) and median time to progression for responders of 103 days (range 39–252 days). Median time to progression for dogs with metastatic disease was similar to those with only local disease (distant median: 44 days; local median: 23 days, p = 0.56). Dogs with chemotherapy-naïve disease were compared to dogs having received previous chemotherapy treatment and had a median time to progression of 75 days and 40.5 days respectively (p = 0.13). Twenty-two dogs experienced 48 adverse events, with most being grade 1 or 2 (79%). Carboplatin was well tolerated, with variable macroscopic anti-tumour activity and short response duration. Carboplatin may be an acceptable rescue option for dogs with macroscopic haemangiosarcoma, especially those patients that cannot receive doxorubicin.