Retrospective study of 108 foals with septic osteomyelitis

Objective   To determine the clinical characteristics, short-term outcome and future athletic performance of foals with septic osteomyelitis.
Design   Retrospective clinical study of 108 Thoroughbred foals with radiographic evidence of bone infection that were presented at the Scone Veterinary Hospital between August 1995 and December 2001. Medical records were reviewed and information concerning signalment, the clinical, laboratory and radiographic findings, treatment and outcome was obtained. Racing records were obtained and evaluated for surviving foals that had reached racing age.
Results   Mean age of foals at initial evaluation was 39 days (range 1–180 days); 21 foals had multiple radiographic bone lesions (19.4%), and 76 had concurrent septic arthritis (70.4%). The most frequently affected bones were the femur, tibia and distal phalanx. In total, 87 foals were discharged from the hospital (80.6%), 79 survived long-term to reach racing age and 52 raced (65.8%). Overall, 48% (52/108) of the foals treated for osteomyelitis raced. Foals less than 30 days of age at the time of diagnosis, critically ill foals and those with multiple bones or joints affected were significantly less likely to be discharged from hospital. Multiple septic joints, but not multiple bone involvement, had an unfavourable prognosis for racing.
Conclusions   The prognosis for survival of foals with septic osteomyelitis or osteitis is favourable. Multiple bone or joint involvement is an important short-term prognostic indicator; however, the involvement of multiple joints, but not multiple infected bones, is associated with an unfavourable prognosis for racing.     

Prevalence of Bartonella species,Rickettsia felis,haemoplasmas and the Ehrlichia group in the blood of cats and fleas in eastern Australia

Objectives To define the prevalence of Bartonella spp., Rickettsia felis, Mycoplasma haemofelis, ‘Candidatus Mycoplasma haemominutum’ (Mhm) and ‘Candidatus Mycoplasma turicensis’ (Mtc) in cats and their fleas in eastern Australia. Design and procedure Conventional PCR assays that detect Bartonella spp., M. haemofelis, Mhm, Mtc, Rickettsia spp., Ehrlichia spp., Anaplasma spp. and Neorickettsia spp. were performed on DNA extracted from blood and fleas collected from 111 cats. Cat sera were assayed by ELISA for IgG of Bartonella spp. Results DNA of M. haemofelis, Mtc and Mhm was amplified from 1 (0.9%), 1 (0.9%) and 17 cats (15.3%), respectively. Only DNA of Mhm was amplified from the 62 of 111 pooled flea samples (flea sets; 55.9%). Overall, the prevalence rates for Bartonella spp. DNA in the cats and the flea sets was 16.2% (18 cats) and 28.8% (32 flea sets), respectively. Bartonella spp. IgG was detected in 42 cats (37.8%), of which 11 (26.2%) were positive for Bartonella spp. DNA in their blood. R. felis DNA was amplified from 22 flea sets (19.8%), but not from cats. Overall, DNA of one or more of the organisms was amplified from 27% (30) of cats and 67.6% (75) of the flea sets. Conclusions This is the first Australian study to determine the prevalence of R. felis and B. clarridgeiae in both fleas and the cats from which they were collected. Flea-associated infectious agents are common in cats and fleas in eastern Australia and support the recommendation that stringent flea control be maintained on cats.     

In this issue – May 2012

Breech‐strike in Merinos in south‐eastern Australia · Risk factors for clinical mastitis in dairy cows · Tick (Ixodes holocyclus) envenomation in horses · Attitudes to and use of analgesia by Queensland veterinarians · Treatment of anoestrus in bitches · Risk of arboviruses following waterbird movement     

Microemulsified cyclosporine-based immunosuppression for the prevention of acute renal allograft rejection in unrelated dogs: preliminary experimental study

OBJECTIVES: To determine whether the microemulsified formulation of cyclosporine (MCsA; Neoral; Novartis A.G.), combined with azathioprine (Imuran; Glaxo Wellcome), and prednisolone (Delta-Cortef; Upjohn), would be effective in preventing acute renal allograft rejection in unrelated mongrel dogs. To document any toxic effects associated with this drug combination. STUDY DESIGN: rospective, pilot study. ANIMALS: Four healthy, adult, mongrel, canine renal allograft recipients. METHODS: Heterotopic renal transplantation, with bilateral nephrectomy, was performed in 4 dogs. Allografts were harvested from 2 unrelated dogs that were to be euthanatized for reasons unrelated to this study. The dogs were treated for 100 days or until signs of illness or allograft rejection required euthanasia. Microemulsified cyclosporine (20 mg/kg/day), azathioprine (5 mg/kg every other day), and prednisolone (1 mg/kg/day) were administered for the prevention of acute rejection. Body weight, serum biochemistry profiles, complete blood counts, and trough whole-blood cyclosporine concentrations were measured throughout the study. Cyclosporine dose was adjusted to maintain a trough concentration of 400-500 ng/mL. Azathioprine dose was decreased if evidence of hepatotoxicity developed or if the total blood white cell count was <4,000 cells/micro L. The prednisolone was tapered by 0.25 mg/kg increments every 3 weeks and discontinued 14 days before the end of the study in the surviving dogs. Complications were recorded. A complete necropsy and histopathologic examination were performed in each recipient. RESULTS: Two of the 4 dogs survived the 100-day period. One dog was euthanatized at 8 days because of an intestinal intussusception. One dog was euthanatized at 64 days because of a severe upper respiratory infection. At the time of death, these 2 dogs had plasma creatinine concentrations of 1.5 and 2.6 mg/dL, respectively, with no histopathologic evidence of allograft rejection. All dogs had transient weight loss (range, 4.6%-17.7% of preoperative body weight) between days 7 and 14. Two dogs had evidence of hepatotoxicity. The 2 dogs surviving to 100 days had normal serum creatinine concentrations and no clinical signs of rejection. One of these dogs had evidence of a grade IIa acute/active rejection based on the modified BANFF 97 histopathologic classification. The second dog had no evidence of rejection or inflammation within the allograft. CONCLUSIONS: This preliminary experimental study shows that immunosuppression using MCsA, combined with azathioprine and prednisolone, may be effective in preventing acute renal allograft rejection in unrelated mongrel dogs for 100 days. Complications included ileocolic intussusception, upper respiratory infection, weight loss, and transient hepatotoxicity. CLINICAL RELEVANCE: Immunosuppression using MCsA, azathioprine, and prednisolone may be effective in preventing acute renal allograft rejection in unrelated, mongrel dogs. This triple drug protocol is cost-effective and was easy to administer. Further investigation is warranted to minimize toxic effects and to determine the efficacy of prophylactic renal biopsies to detect and treat subclinical acute/active rejection.     

Nontraumatic rupture of an adrenal gland tumor causing intra-abdominal or retroperitoneal hemorrhage in four dogs

Diagnosis and surgical management of intra-abdominal or retroperitoneal hemorrhage in 4 dogs with rupture of an adrenal gland tumor were determined. All 4 dogs were lethargic and weak with pale mucous membranes on initial examination. Three dogs did not have any history of clinical signs of hyperadrenocorticism or pheochromocytoma prior to examination. In 3 of the dogs, a mass in the area of the adrenal gland was identified with ultrasonography prior to surgery. All dogs developed ventricular premature contractions before or during anesthesia. Three dogs survived adrenalectomy; 1 dog was euthanatized during surgery because of an inability to achieve adequate hemostasis. The remaining 3 dogs all survived more than 5 months after surgery; 1 was euthanatized 9 months after surgery because of rupture of a hepatic mass. On the basis of these results, we suggest that hemodynamic stabilization followed by adrenalectomy is the treatment of choice for dogs with nontraumatic rupture of an adrenal gland tumor and resulting life-threatening hemorrhage.