Combination chemotherapy with L-asparaginase, lomustine, and prednisone for relapsed or refractory canine lymphoma

BACKGROUND: Canine lymphoma (LSA) is responsive to initial treatment, however, it then becomes resistant to drugs in the initial protocol. New rescue protocols are needed. HYPOTHESIS: A combination of L-asparaginase, lomustine, and prednisone will be well tolerated and efficacious as a rescue therapy for dogs with LSA. ANIMALS: Thirty-one client owned dogs with cytologically confirmed multicentric LSA who were refractory or whose disease had relapsed after a CHOP (cyclophosphamide/doxorubicin/vincristine/prednisone)-based chemotherapy protocol. METHODS: Prospective clinical trial. Lomustine (target dose, 70 mg/m2) was administered orally at 3-week intervals for a total of 5 doses or until disease progression. L-asparaginase (400 U/kg) was administered subcutaneously concurrently with the first 2 lomustine treatments. Prednisone was administered at a tapering dose for the duration of the protocol. RESULTS: Overall response rate for dogs treated with this protocol was 87% (27/31), with 52% (16/31) of dogs achieving a complete response. Median time to response was 21 days. Median time to progression was 63 days (111 days for dogs achieving a complete response and 42 days for dogs achieving a partial response). There were no significant differences in response rates and times to progression between dogs who had received L-asparaginase before beginning this rescue protocol and those who had not. Toxicoses were mild and self-limiting in 29 of 31 cases. CONCLUSIONS AND CLINICAL IMPORTANCE: This is a well-tolerated rescue therapy for relapsing LSA in dogs. Response rates and remission durations compare favorably to other rescue protocols. Therefore, this protocol is a viable rescue option.     

Comparative analysis of survivin expression in untreated and relapsed canine lymphoma

BACKGROUND: Survivin, a member of the inhibitor of apoptosis protein family, has a dual role in tumor cell proliferative and antiapoptotic pathways. Survivin expression has been shown to be a negative prognostic factor in several cancers of humans, including B-cell non-Hodgkin's lymphoma. HYPOTHESES: High survivin expression will be a negative prognostic factor in dogs with lymphoma (LSA) treated with chemotherapy. In addition, survivin expression will be upregulated in relapsed canine LSA when compared with patient-matched, pretreatment biopsies. ANIMALS: Thirty-one client-owned dogs with stage IIIa or IVa LSA. METHODS: Retrospective evaluation of survivin immunoreactivity was performed on pretreatment lymph node biopsies and patient-matched samples obtained from dogs at relapse after being treated with an abbreviated CHOP-based protocol. RESULTS: In this population of dogs presenting with stage IIIa or IVa B-cell LSA, those dogs that had high survivin immunoreactivity scores had a significantly (P < .01, hazard ratio = 0.30) shorter median disease-free interval than did dogs with low survivin immunoreactivity scores (171 days versus 321 days, respectively). Survivin immunoreactivity was not significantly different in relapsed canine LSA when compared with patient-matched, pretreatment biopsies. CONCLUSIONS AND CLINICAL IMPORTANCE: Survivin expression is a negative prognostic factor that can predict early treatment failure of dogs that present with stage IIIa or IVa, B-cell LSA when treated with a CHOP-based protocol.     

Eperythrozoonosis in swine--an overlooked disease?

In the present work a review is given on the aetiology, clinical symptoms, prevalence and significance of the disease eperythrozoonosis in swine. Clinical outbreaks are characterized by fever, anemia and icterus. Clinical signs are most likely to be observed in young suckling piglets and in sows at the time of farrowing. In most cases infection with Eperythrozoon suis leads to a carrier state of symptomless, subclinical infection which, however, may be activated under conditions of stress. Eperythrozoonosis in swine has been reported from the USA, England, Federal Republic of Germany, Belgium and a few other countries. Due to the latent nature and the non-specific clinical symptoms of the disease it seems likely that the prevalence of E. suis in swine populations may be considerably greater than the number of clinical cases might lead one to suppose. So far, E. suis has not been diagnosed in Scandinavia, but it should not be excluded that eperythrozoonosis may exist as a neglected disease in Nordic swine herds as well.     

Combination Chemotherapy with Continuous l-Asparaginase, Lomustine, and Prednisone for Relapsed Canine Lymphoma

Background: The combination of lomustine, l -asparaginase, and prednisone (LAP) is an effective rescue treatment for canine lymphoma (LSA). In a previous study, we reported that remission was typically lost around the time l -asparaginase was discontinued.
Hypothesis: Use of l -asparaginase with each lomustine treatment will be well tolerated and efficacious as a rescue therapy for canine LSA.
Animals: Forty-eight client-owned dogs with cytologically confirmed multicentric LSA whose disease had relapsed after a cyclophosphamide, doxorubicin, vincristine, and prednisone-based chemotherapy protocol were included.
Methods: Lomustine was administered orally at 3-week intervals, concurrently with subcutaneous or intramuscular l -asparaginase for a total of 5 doses or until disease progression. Prednisone was administered at a tapering dose for the duration of the protocol.
Results: The overall response rate (ORR) for dogs treated with this protocol was 77%, with 65% achieving a complete response (CR). The median time to progression (TTP) was 70 days. Based on loose comparison, these findings are not significantly different from our previously reported historical control. The actual CCNU dosage administered did not affect response rate or remission duration.
Conclusions/Clinical Importance: These findings support previous data concluding that the LAP protocol is a viable rescue treatment option for dogs with LSA. However, results from this study suggest that continued use of l -asparaginase with each lomustine treatment does not significantly increase remission duration and toxicity appears greater.     

Prevalence of diseases of the spinal cord of cats

A retrospective review of records of 205 cats with histologically confirmed disease of the spinal cord was performed to identify the prevalence of disease in this nonrandomly selected population of cats. Clinical records were reviewed, and age, duration of neurologic illness, and clinical and histopathologic findings in cats with spinal cord disease were abstracted. Disease processes were classified into 7 categories and 23 groups. The most common diseases affecting the spinal cord of cats were feline infectious peritonitis (FIP), lymphosarcoma (LSA), and neoplasia of the vertebral column secondarily affecting the spinal cord. Information on age, onset and duration of clinical signs, and lesion localization at the postmortem examination in cats belonging to the 7 categories of disease were analyzed to create a practical list of differential diagnoses. Cats were also subcategorized into 3 groups based on their age at death. FIP was the most common disease of cats younger than 2 years of age. LSA and vertebral column neoplasia were the most common diseases affecting cats between 2 and 8 years of age. Vertebral column neoplasia was the most common disease affecting cats older than 8 years of age. Results of this histopathologic study showed that FIP and LSA were the most common disease processes affecting the spinal cord of cats. However, at least 21 other groups of diseases and their relative prevalence were identified.     

Lymphoma as a model for chronic illness: effects on adrenocortical function testing

Many dogs with chronic illness have serum biochemical abnormalities consistent with hyperadrenocorticism (HAC). Lymphoma (LSA) is a chronic disease of dogs. The purpose of this study was to evaluate adrenocortical screening test results in dogs with LSA to evaluate their specificity. Criteria for inclusion in the study included a diagnosis of LSA, an expected survival time of 16-56 weeks, no glucocorticoid treatment beyond 4 weeks after the initiation of chemotherapy, no evidence of HAC, and owner consent. Post-ACTH stimulation plasma cortisol concentrations (PACs), urine cortisol : creatinine (UC : Cr) ratios, and maximal left adrenal width measurements were performed at the time of LSA diagnosis before the initiation of chemotherapy and at 16, 24, 32, 40, and 52 weeks or until the loss of remission or the development of another disease. Ten dogs met the criteria for inclusion. Forty-two PACs were performed; 1 abnormal, 2 borderline, and 39 normal values were detected. Thirty-five maximal left adrenal width measurements were obtained; 0 abnormal, 5 borderline, and 30 normal measurements were detected. Thirty-six UC : Cr ratios were obtained, with 26 abnormal, 4 borderline, and 6 normal values detected and 9 of 10 dogs having at least 1 abnormal value. These data suggest that in dogs with LSA, the UC : Cr ratio frequently is abnormal and may not be a specific test for HAC, or it may be the most sensitive test for increases in cortisol secretion due to chronic illness. Maximal left adrenal width measurements and PACs were almost always normal and may be more specific for HAC or less sensitive for demonstrating chronic increases in cortisol secretion.     

Left subclavian artery dissection associated with connective tissue abnormalities resembling Marfan-like syndrome in an English bulldog

The unexpected demise of a 12-year-old male neutered English bulldog solicited a gross examination, which revealed a blood-filled space occurring in the proximal left subclavian artery (LSA). It originated about 1 cm from the branching point of the vessel and progressively dilated for 3 cm distal to this origin. Histopathological investigation showed that the tunica media of the LSA was more than 50% split, with the blood-filled space dissecting through the arterial wall. In the tunica media of the LSA, severe multifocal fragmentation and/or loss of the elastic fibers was observed. The retained disorganized elastic fibers were separated and disoriented due to accumulations of acid mucopolysaccharide. Marked, diffuse medial, and adventitial fibrous tissue deposition was also identified. The cause of death was attributed to acute hemorrhagic and necrotizing pancreatitis with pulmonary edema, suggesting that LSA dissection was an incidental finding. Subclavian artery dissection is extremely rare in humans, where the involvement of the LSA in cases of aortic dissection both with or without Marfan syndrome has been reported. Aortic and pulmonary artery dissection in bovines and aortic aneurysm and dissection in dogs have been reported to be associated with Marfan and Marfan-like syndromes, respectively. Histopathological findings suggestive of underlying connective tissue abnormalities resembling Marfan-like syndrome (i.e., the appearance of the elastic tissue and the degenerative changes of the tunica media) were detected in the first case of LSA dissection in dogs and veterinary medicine, herein described.     

Gingivitis/stomatitis in cats.

Any alteration in the balance of bacterial challenge versus the host's ability to resist and repair will result in oral lesions that are similar in appearance. The bacterial cause of gingivitis and periodontitis in humans and in all other animals in which it has been studied is firmly established, and specific species of predominantly gram-negative anaerobes have been implicated. Naturally occurring or acquired immunopathologies are likely to result in premature dental disease. When oral disease is associated with the accumulation of plaque, a positive response can be achieved by reducing the bacterial challenge to the host through the maintenance of oral hygiene by timely professional dental prophylaxis and home care. Disease that is the result of atypical immune responses, however, can be much more difficult to manage. Such oral disease can occur with either immune deficiencies or exaggerated immune responses, and it is likely that multiple mechanisms are active concurrently. In any case, gram-negative anaerobes present in plaque are likely to be a major contributing factor. Therefore patients with chronic refractory gingivitis-stomatitis must be considered to be plaque intolerant. Only with a frequent regimen of aggressive and thorough professional dental treatment plus meticulous oral home care on a daily basis can one expect to keep these cases in remission. Because this is often unrealistic, the only other way to keep these patients free of disease is by total dental extraction. The tissues that are colonized by the causative organisms must be eliminated. All root tips and bony sequestra must be removed and healing with intact epithelium accomplished before these cases will go into remission. Edentulous feline patients that continue to have signs of gingivostomatitis have been found to have an area of nonhealed bony sequestrum and chronic osteomyelitis. Once effective debridement has been accomplished and epithelial healing completed, nonresponsive cases can be expected to go into remission (Color Plate 2, Figure 7). It is hoped that as more is learned about this frustrating problem, the many factors influencing feline oral disease will be scientifically documented. In the future, actual diagnoses can be systematically made early on in disease, and treatment will be more than just symptomatic.     

Effects of L-asparaginase on plasma amino acid profiles and tumor burden in cats with lymphoma

BACKGROUND: L-Asparaginase (Elspar(a)), is an Escherichia coli-derived enzyme that depletes lymphoma cells of asparagine, inhibiting protein synthesis and resulting in cell death. The single agent response rate in cats with lymphoma and impact of L-asparaginase on plasma amino acid concentrations is unknown. HYPOTHESES: L-Asparaginase significantly reduces plasma asparagine concentrations and has demonstrable efficacy against untreated lymphoma in cats. ANIMALS: Thirteen cats with confirmed lymphoma (LSA) of any anatomic site were given 1 dose 400 IU/kg IM) of L-asparaginase for initial LSA treatment. METHODS: Plasma collected at 0, 2, and 7 days after L-asparaginase therapy was assayed for ammonia, asparagine, aspartic acid, glutamine, and glutamic acid concentrations. Cats were restaged 7 days later to assess tumor response. Results: Eight cats had T-cell LSA, 4 cats had B-cell LSA, and 1 cat's immunophenotype was unknown. Two complete and 2 partial responses to L-asparaginase were seen. Four cats had stable disease, and 5 cats had progressive disease. Ammonia and aspartic acid concentrations were increased from baseline at 2 and 7 days posttreatment. Asparagine concentrations were decreased from baseline at 2 days but not 7 days posttreatment. Glutamic acid concentrations were increased at day 2 compared to day 7 posttreatment but not compared to baseline. Glutamine concentrations were unchanged. CONCLUSIONS AND CLINICAL IMPORTANCE: L-asparaginase significantly reduced asparagine concentrations within 2 days of treatment, but this effect was lost within 7 days. The apparent overall response rate of feline LSA to L-asparaginase in this study was 30%.     

Efficacy of doxorubicin as an induction agent for cats with lymphosarcoma

OBJECTIVE: To determine the efficacy of doxorubicin when used alone in inducing remission in cats with lymphosarcoma. DESIGN: Prospective multi-institutional study of naturally occurring disease. METHODS: Cases were accrued from veterinary institutions in Australia and New Zealand after obtaining consent from informed owners. Cats were treated with doxorubicin every 3 weeks for three treatments. If there was no response to the first dose of doxorubicin or if the cat relapsed during the doxorubicin regimen, the cat was withdrawn from the trial and either euthanased or treated with other agents. Age, breed, gender and anatomic site of the lymphosarcoma (multicentric, alimentary, mediastinal, extranodal) were recorded for each cat. Clinical remission was assessed before each treatment by physical examination, radiography, ultrasonography and computed tomography where appropriate. Complete remission was defined as the disappearance of all clinical signs and clinically detectable tumour. RESULTS: Twenty-one cases were accrued over a 2-year-period but only 19 were available for data analysis. Young Siamese cats were over-represented and all cats with mediastinal tumours were young Siamese. There was a significant difference between the mean ages of cats with mediastinal or multicentric lymphosarcoma (mean +/- SD: 3.5 +/- 3.0 and 4.3 +/- 2.6 years, respectively) and cats with alimentary or extranodal LSA (11.4 +/- 0.9 and 11.0 +/- 0.9 years, respectively). Of 19 cats treated with doxorubicin alone, 6 (32%) had complete remission, 6 (32%) had partial remission and 7 (36%) did not respond. CONCLUSIONS: The results suggest that doxorubicin cannot be recommended as a single agent for treatment of feline lymphosarcoma because of the rather poor remission rate achieved.     

Retinal detachment and bovine tuberculosis in cats

Bovine tuberculosis has been virtually eradicated from Britain. It was a disease to which cats were susceptible, mainly from the consumption of infected cow's milk. This report discusses four cases of ocular tuberculosis which, although of limited clinical significance today, could be of some value to veterinary clinical history. In the past, there has been a tendency to associate retinal haemorrhages with a choroidal tuberculosis, but with reference to the veterinary literature and two of the cases cited here, it would appear that either haemorrhage or uveitis, from whatever cause, is more likely to be linked to retinal detachment than to tuberculosis.     

Complications and survival associated with surgical compared with medical management of horses with duodenitis-proximal jejunitis

REASONS FOR PERFORMING STUDY: Based on clinical observation, it is hypothesised that horses with duodenitis-proximal jejunitis (DPJ) that are treated surgically have a shorter duration, smaller volume, and slower rate of nasogastric reflux (NGR) compared to horses treated medically, are more likely to develop diarrhoea than medically managed cases, and have a higher incisional infection rate than a sample population of horses undergoing abdominal exploration for gastrointestinal disease other than DPJ. OBJECTIVES: To compare: 1) duration, volume and rate of NGR and the percentage of horses with diarrhoea between medically and surgically treated DPJ cases; and 2) incisional infection rate in horses with DPJ undergoing abdominal exploration to a sample population of horses undergoing abdominal exploration for gastrointestinal disease other than DPJ. METHODS: Medical records of cases with DPJ diagnosed 1995-2006 were reviewed. Information obtained included subject details, presenting clinical findings, treatment category (medical/surgical), complications (diarrhoea, incisional infection), and outcome (survival/nonsurvival). Data were analysed using a Chi-squared test and a mixed model analysis of variance. Level of significance was P<0.05. RESULTS: Compared to medical cases, surgical cases had significantly decreased survival, a longer duration and larger total volume of NGR, and were more likely to develop diarrhoea. The incisional infection rate for horses with DPJ undergoing abdominal exploration was 16% compared to 7% for the sample population of horses. CONCLUSIONS: Surgical treatment of horses with DPJ did not lead to resolution of NGR faster than medical treatment. Surgical cases were more likely to develop diarrhoea and did not have a significantly higher incisional infection rate than the sample population.     

Immunophenotyping of lymphosarcoma in South American camelids on six British premises

Six cases of lymphosarcoma (LSA) in South American camelids (SACs) were selected from submissions to a diagnostic laboratory network servicing England and Wales. Immunophenotyping was carried out using anti-human CD3 and anti-human CD5 for T-cells; and anti-human CD79a and anti-human CD79b for B-cells/plasma cells. On the basis of labelling with mainly anti-CD3, four of the tumours were classified as T-cell tumours. One case was labelled with anti-CD79a and anti-CD79b, and was classified as a B-cell tumour. In the other case the majority of cells were labelled with anti-CD3, anti-CD79a and anti-CD79b, and was classified as a mixed T- and B-cell tumour. To the authors' knowledge this is the first reported attempt at immunophenotyping LSA in SACs on British premises and is only the second time that a presumptive mixed T- and B-cell LSA has been reported in alpacas and the veterinary literature in general.     

Neoplasia associated with feline immunodeficiency virus infection in cats of southern California.

Between 1988 and 1991, feline immunodeficiency virus (FIV) infection status was evaluated in 1,160 cats examined at an oncology referral and general practice in Los Angeles, California. Twenty-nine (2.5%) cats were FIV positive. Neoplasia was present in 18 of the 29 (62%) cats. Sampling for neoplasia was intentionally biased in the oncology referral group. However, 33% (6/18) of FIV-infected cats with neoplasia originated from the general practice. Three neoplastic processes were observed; myeloproliferative disease (MPD; 5/18), lymphoma (LSA; 5/18), and squamous cell carcinoma (SCC; 7/18). One cat had LSA and SCC. Extranodal sites of LSA were common (66%) in FIV-infected cats. Sites of LSA were submandibular and mesenteric lymph nodes, liver, kidneys, periorbital area, and diffuse (heart, pancreas, bladder). Sites of SCC were sublingual (n = 2), nasal planum (n = 3), nasal planum and eyelids (n = 1), and mandible (n = 2). Feline leukemia virus co-infection was observed in 17% (5/29) of FIV-infected cats. The FIV-infected cats with MPD were young (range, 8 months to 13 years; median, 4 years) and had short survival duration (2, 6, 21, 134, 249 days) even in response to aggressive treatment. The FIV-infected cats with LSA were older (median age, 8 years; range, 4 to 14 years) and survived 60 days if untreated. Cats administered chemotherapy survived 39, 45, 217, and 243 days; the latter 2 cats had partial remission of 2 months' duration. Older FIV-infected cats had SCC (median age, 12 years; remission range, 7 to 16 years) because of more frequent association of both diseases in older cats with outdoor environment.(ABSTRACT TRUNCATED AT 250 WORDS)     

A feline retrovirus induced T-lymphoblastoid cell-line that produces an atypical alpha type of interferon

A cell-line, designated LSA-1, was derived from a thymic lymphosarcoma that occurred in a cat with experimentally induced feline leukemia virus (FeLV) infection. LSA-1 cells possessed surface receptors and antigens of normal T-lymphocytes, but were unresponsive to interleukin-2 stimulation. The LSA cell-line was found to constitutively produce and release an interferon into the culture supernatants. Production of this interferon was enhanced in certain clones of the original LSA-1 cell lines. The interferon produced by LSA-1 cells and some of its clones was compared to the standard alpha, beta, and gamma interferons of cats. Unlike alpha and beta interferons, which were acid, SDS, and heat stable, LSA interferon was acid labile and SDS and heat stable. In comparison, standard feline gamma interferon was acid, SDS, and heat labile. LSA interferon had a molecular weight of 20,000 daltons, compared to 17-19,000 daltons for gamma, 19-25,000 for beta, and 25-45,000 daltons for alpha interferons. Standard feline interferons were active only on cat cell lines, with the exceptions of alpha interferon, which also reacted with MDCK canine cells. LSA interferon resembled the standard feline alpha interferon because it also reacted with feline and canine cells. It was concluded that LSA interferon was an atypical acid labile alpha interferon, resembling in this respect the abnormal alpha interferon seen in humans with AIDS and SLE, and mice with retrovirus infections. LSA-1 cells produced high levels of FeLV structural proteins but very little infectious virus. This effect was due to endogenously produced interferon; LSA cell clones that were selected for low interferon production produced much higher levels of infectious FeLV than parent cells or clones selected for high interferon production. Cat cells pretreated with LSA or with standard feline alpha and beta interferons, and then infected with FeLV, produced high levels of FeLV proteins but very little infectious virus.     

Progression of chronic renal disease in the dog

Progressive loss of nephron function may be caused by persistence of factors that initiated renal disease. However, newer studies suggest that nephron damage is self-perpetuating once renal mass is reduced to some critical level. Original theories on mechanisms of self-perpetuated nephron injury focused on intraglomerular hypertension and glomerular hypertrophy, but several other factors have now been incriminated, including tubulointerstitial responses, proteinuria, and oxidative stress. Studies of dogs with surgically reduced renal mass (remnant kidney model of chronic renal disease) have allowed investigation of the self-progression theory in this species. Use of this model eliminates pre-existing renal disease as a confounding factor. Data from these studies indicate that self-perpetuated renal injury is initiated when mild azotemia is induced (plasma creatinine concentration = 2 to 4 mg/dL). Thus, with naturally occurring renal disease(s), it is likely that self-perpetuated nephron damage is occurring before or at the time when most cases of chronic renal disease are diagnosed. In dogs with remnant kidneys, loss of renal function often occurs at a linear rate over time, but non-linear patterns are common as well. The reciprocal of plasma creatinine concentration, which has been used to monitor rate of progression, is only a fair marker of renal function when compared to GFR. Thus, clinical results from creatinine measurements on cases of naturally occurring disease should not be interpreted too stringently. In remnant kidney dogs, the magnitude of proteinuria (UPC ratio) was not predictive of the rate in decline of GFR, casting doubt on importance of proteinuria in causing progression of renal disease. However, progressive increases in UPC may be a marker of an accelerated rate of renal injury. Self-perpetuation of renal injury in dogs could be the sole mechanism by which naturally occurring renal diseases progress. When more information is available on the rate of progression of naturally occurring diseases, it may become apparent whether factors initially inciting renal damage have an additive effect on rate of progression.     

Enteroliths in horses

Many cases of enteroliths were reported in the nineteenth century but the number greatly decreased in the early twentieth century. However, in recent years the number of cases in certain parts of the United States such as California has greatly increased. The reasons for the increase are obscure. The intake of nitrogen, magnesium and phosphorus (the primary components of enteroliths) from water and food is likely to be a factor. Arabians may be more likely to develop enteroliths than horses of other breeds. A nidus such as a small stone is needed because a nidus has been found in every enterolith that has been examined. Further studies in which the effect of mineral intake and form of the mineral on enterolith formation are needed. Studies of enterolith formation in the past have all been retrospective. Models for the development of enteroliths are needed.     

Sequential opportunistic infections in two German Shepherd dogs

Two German Shepherd dogs with sequential opportunistic infections are described. The first was a 2-year-old male with cryptococcal rhinitis that spread to involve the optic nerves and brain. It was successfully treated with combination therapy utilising amphotericin B administered for 2 years, but the dog developed a disseminated Aspergillus deflectus infection 5 years later and was euthanased. The second case was a 4-year-old male that presented for a severe, deep-seated infection of the right antebrachium, with gradual extension to contiguous tissues. Neosartorya fischeri (anamorph; Aspergillus fischerianus) was isolated in pure culture and detected in histological sections. The infection was refractory to itraconazole, but resolved after amputation of the affected limb. Five months later, the dog developed a localised cutaneous lesion on the proximal pelvic limb, from which Pythium insidiosum was isolated and then visualised in tissue sections, together with a structure thought to be grass seed. This lesion was treated by wide surgical resection, although it was reported that the dog died of disseminated disease some months later. These cases provide further circumstantial evidence that young adult German Shepherd dogs have a predilection to developing invasive infections with fungi and other saprophytic pathogens.     

Evaluation of optimal water fluoridation on the incidence and skeletal distribution of naturally arising osteosarcoma in pet dogs

Experimental toxicological studies in laboratory animals and epidemiological human studies have reported a possible association between water fluoridation and osteosarcoma (OSA). To further explore this possibility, a case‐control study of individual dogs evaluated by the UC Davis Veterinary Medical Teaching Hospital was conducted using ecologic data on water fluoridation based on the owner's residence. The case group included 161 dogs with OSA diagnosed between 2008–2012. Two cancer control groups included dogs diagnosed with lymphoma (LSA) or hemangiosarcoma (HSA) during the same period (n = 134 and n = 145, respectively). Dogs with OSA were not significantly more likely to live in an area with optimized fluoride in the water than dogs with LSA or HSA. Additional analyses within OSA patients also revealed no significant differences in age, or skeletal distribution of OSA cases relative to fluoride status. Taken together, these analyses do not support the hypothesis that optimal fluoridation of drinking water contributes to naturally occurring OSA in dogs.     

Nocardial infections of animals in New Zealand, 1976–78

Nocardiaspecies that are common in the soil environment can cause disease in man and animals. These infections are usually considered rare, and there have been only four cases of animal disease previously reported in the New Zealand literature. A limited survey, with the co-operation of staff from animal health laboratories, revealed a further 34 cases of Nocardia infection between 1976–78, and this figure is likely to be conservative. Twenty-six cases were mastitic infections and one was an isolate from a bovine placenta; the majority of infected animals were reported from the South Auckland and Waikato regions. The remaining cases were fatal infections of cats, dogs and a seal. Diagnostic tests on the causative organisms from 27 cases for which cultures were available all proved to be N. asteroides strains. Improved epidemiological data may help relate occurrence of disease in animals to the distribution of Nocardia in nature, but this is dependent on recognition of the organism by the specialists involved in the field and laboratory. Without epidemiological data, it will not be possible to evaluate the effects on animals of increasing the multiplication of Nocardia, for example by adding sewage sludge to soil.