Lillian R. Aronson

A Newly Recognized Blood Group in Domestic Shorthair Cats: The Mik Red Cell Antigen

BACKGROUND Naturally occurring alloantibodies produced against A and B red cell antigens in cats can cause acute hemolytic transfusion reactions. Blood incompatibilities, unrelated to the AB blood group system, have also been suspected after blood transfusions through routine crossmatch testing or as a result of hemolytic transfusion reactions. HYPOTHESIS Incompatible crossmatch results among AB compatible cats signify the presence of a naturally occurring alloantibody against a newly identified blood antigen in a group of previously never transfused blood donor cats. The associated alloantibody is clinically important based upon a hemolytic transfusion reaction after inadvertent transfusion of red cells expressing this red cell antigen in a feline renal transplant recipient that lacks this red cell antigen. METHODS Blood donor and nonblood donor cats were evaluated for the presence of auto- and alloantibodies using direct antiglobulin and crossmatch tests, respectively, and were blood typed for AB blood group status. Both standard tube and novel gel column techniques were used. RESULTS Plasma from 3 of 65 cats and 1 feline renal transplant recipient caused incompatible crossmatch test results with AB compatible erythrocytes indicating these cats formed an alloantibody against a red cell antigen they lack, termed Mik. The 3 donors and the renal transplant recipient were crossmatch-compatible with one another. Tube and gel column crossmatch test results were similar. CONCLUSIONS AND CLINICAL IMPORTANCE The absence of this novel Mik red cell antigen can be associated with naturally occurring anti-Mik alloantibodies and can elicit an acute hemolytic transfusion reaction after an AB-matched blood transfusion.

Postoperative mortality in cats after ureterolithotomy.

OBJECTIVE To identify preoperative risk factors associated with mortality before discharge in cats having a single or multiple ureterotomy procedures to treat a ureteral obstruction. STUDY DESIGN Case series. ANIMALS Cats (n=47). METHODS Data were obtained from the medical records (2002-2009) of cats that had undergone ureterolithotomy procedures. Multiple preoperative factors were evaluated for association of survival to discharge. RESULT Survival to discharge after ureterolithotomy was 79% (37/47). Over 79% of cats were azotemic before surgery and 94% had chronic kidney disease changes at the time of ultrasonographic diagnosis. Six cats required an additional surgical procedure because of complications with ureterolithotomy. Overall prevalence of postoperative uroabdomen was 6% (3/47). On multivariate analysis, there were no preoperative variables significantly associated with survival to discharge. CONCLUSIONS Ureterolithotomy in cats was associated with a 21% mortality rate before hospital discharge. No preoperative variables associated with mortality were identified; therefore, further studies are needed to identify more discriminating preoperative characteristics for mortality after ureterolithotomy in this population of cats.

Prognostic factors for successful outcome following urethral rupture in dogs and cats.

Twenty dogs and 29 cats were identified with urethral rupture. Males predominated in both groups. The most common cause of urethral rupture in dogs was vehicular trauma, and in cats it was trauma associated with urethral obstruction and catheterization. Clinicopathological findings, type of surgical correction, time to surgery, type of urinary diversion, and duration of urinary diversion were not statistically associated with the outcome. In this study, the presence of multiple traumatic injuries was associated with a poor outcome.

Traumatic rupture of the ureter: 10 cases.

A retrospective study was performed on eight dogs, one cat, and one ferret with ruptured ureters secondary to blunt trauma. The most common physical examination findings were abdominal distension/discomfort (in five of 10 animals) and gross hematuria (in five of six animals). Multiple organ injury was also common (in seven of 10 animals). Loss of retroperitoneal and peritoneal detail was the most common radiographic finding (in four of six animals). Ureteronephrectomy was the most common surgical procedure (performed in five out of seven procedures). Three of the five cases discharged were available for follow-up and have had no evidence of associated problems.

Feline Visceral Hemangiosarcoma

BACKGROUND Feline visceral hemangiosarcoma (HSA) is an uncommon tumor, and the clinical progression and outcome are rarely reported. HYPOTHESIS The prognosis of feline visceral HSA is poor because of severe clinical signs, anemia, and a high rate of metastasis. ANIMALS The medical records of 26 client-owned cats with visceral HSA were reviewed. METHODS Multi-institutional retrospective study. RESULTS The most common historical findings and clinical signs included lethargy, anorexia, respiratory difficulty, collapse, and vocalizing. Eighty-two percent of cats were anemic, and aspartate transaminase was increased in 53% of the study population. Metastatic lung disease was noted in 33% of affected cats. In 75% of the cats, abdominal ultrasonography identified a specific location of HSA. However, ultrasound identification of all multifocal lesions was successful only in 3/9 cats (33%). Tumor location was identified in the following organs: liver (35%), small intestine (31%), large intestine (31%), abdominal lymph node (31%), mesentery (27%), spleen (23%), lung (19%), omentum (12%), brain (8%), pancreas (8%), and diaphragm (8%). Multifocal HSA was noted in 77% of cats. Three cats received adjuvant chemotherapy (doxorubicin). Seventy-one percent of euthanized cats were euthanized within 1 day of diagnosis. The median survival time of the remaining cats (n = 6) was 77 days (range, 23-296 days). CONCLUSION AND CLINICAL IMPORTANCE Feline visceral HSA is most often multifocal at the time of diagnosis. The prognosis appears poor, and the number of cats receiving chemotherapy is low.

Pyogranulomatous cystitis associated with Toxoplasma gondii infection in a cat after renal transplantation

CASE DESCRIPTION An 8-year-old spayed female domestic shorthair cat was evaluated for azotemia and a suspected mass in the urinary bladder 6 weeks after receiving a renal transplant. Ultrasonography revealed a mass at the ureteroneocystostomy site, and the mass was excised. Both the donor and recipient cats were seronegative for Toxoplasma gondii-specific IgG antibodies prior to transplantation. CLINICAL FINDINGS Histologic evaluation of the mass revealed lesions indicative of extensive necrotizing pyogranulomatous cystitis with numerous intralesional T gondii tachyzoites and bradyzoite cysts. TREATMENT AND OUTCOME Treatment with clindamycin was initiated; however, the cats clinical condition continued to decline, and it was euthanized 9 days after the mass was excised. Necropsy revealed T gondii cysts within the renal allograft and the transplanted ureter, with no evidence of systemic spread of organisms. CLINICAL RELEVANCE Toxoplasmosis should be considered as a differential diagnosis for azotemia in feline renal transplant recipients regardless of the results of assays for T gondii antibodies in the serum of donors or recipients. This report illustrated the need for improved screening of donor and recipient cats and the importance of minimizing exposure to potential sources of T gondii after transplantation.

Effect of cyclosporine, dexamethasone, and human CTLA4-Ig on production of cytokines in lymphocytes of clinically normal cats and cats undergoing renal transplantation.

OBJECTIVE To evaluate effects of cyclosporine, dexamethasone, and the immunosuppressive agent human CTLA4-Ig on cytokine production by feline lymphocytes in vitro and to assess patterns of cytokine production for 5 immunosuppressed renal transplant recipient cats. ANIMALS 21 clinically normal cats and 5 immunosupressed renal transplant recipient cats. PROCEDURES Peripheral blood mononuclear cells were isolated from clinically normal cats and stimulated with concanavalin A (Con A; 10 μg/mL) alone or Con A with cyclosporine (0.05 μg/mL), dexamethasone (1 × 10(-7)M), a combination of cyclosporine-dexamethasone, or human CTLA4-Ig (10 g/mL). Cells from transplant recipients were stimulated with Con A alone. An ELISA was performed to measure production of interferon (IFN)-γ, granulocyte macrophage-colony stimulating factor (GM-CSF), interleukin (IL)-2, IL-4, and IL-10. Proliferation of CD4+ and CD8+T cells from immunosuppressed cats were also evaluated. Pairwise comparisons were performed via a Wilcoxon signed rank test or Wilcoxon rank sum test. RESULTS Cyclosporine, dexamethasone, cyclosporine-dexamethasone combination, and CTLA4-Ig caused a significant decrease in IL-2, IFN-γ, and GM-CSF production. Cyclosporine and cyclosporine-dexamethasone, but not human CTLA4-Ig, caused a significant decrease in IL-10 production. High basal concentrations of IL-2 and IL-10 were identified in transplant recipients, and IL-10 was significantly increased in stimulated cultures. In immunosuppressed cats, there was a decrease in frequency of responders and proliferative capacity of CD4+ and CD8+T cells. CONCLUSIONS AND CLINICAL RELEVANCE CTLA4-Ig successfully inhibited proinflammatory cytokines while sparing cytokines critical for allograft tolerance. These data may be useful for developing better strategies to prevent rejection while sparing other immune functions.

Retroperitoneal fibrosis in feline renal transplant recipients: 29 cases (1998-2011)

OBJECTIVE To evaluate features, treatment, and prognosis associated with retroperitoneal fibrosis that developed after renal transplantation in cats. DESIGN Retrospective case series. ANIMALS 29 cats. PROCEDURES Medical records of cats that developed retroperitoneal fibrosis after renal transplantation at the College of Veterinary Medicine, University of Pennsylvania, between 1998 and 2011 were reviewed for signalment, date of transplantation, age, results of urine and blood analyses, blood pressure at the time of diagnosis, infectious disease and medication anamneses, anesthetic protocols, and intraoperative complications. RESULTS Of 138 transplant recipients, 29 (21%) developed clinically important retroperitoneal fibrosis. Nineteen (66%) were male, and median age at the time of renal transplantation was 8 years (range, 4 to 13 years). Median number of days after transplantation to diagnosis of retroperitoneal fibrosis was 62 (range, 4 to 730 days; mean, 125 days). The most common clinical signs were lethargy and anorexia. All affected cats were azotemic (BUN concentration > 32 mg/dL; creatinine concentration > 2.0 mg/dL) and anemic (PCV < 35%) at the time of retroperitoneal fibrosis diagnosis, although cats were nonazotemic at the time of discharge following transplantation, and anemia was less pronounced. Twenty-five cats successfully underwent surgical ureterolysis in which scar tissue was dissected away from the allograft ureter to relieve extraluminal compression. Retroperitoneal fibrosis recurred in 6 (22%) cats a median of 180 days (range, 8 to 343 days) following the original diagnosis and was treated successfully by repeated ureterolysis. CONCLUSIONS AND CLINICAL RELEVANCE Retroperitoneal fibrosis occurred in a substantial percentage of feline renal transplant recipients and should be considered a differential diagnosis in any feline renal transplant recipient with clinicopathologic findings, imaging abnormalities, or signs suggestive of obstructive uropathy.

Outcomes of ureteral surgery and ureteral stenting in cats: 117 cases (2006–2014)

OBJECTIVE To evaluate and compare outcomes in cats following ureteral surgery or ureteral stent placement. DESIGN Retrospective case series. ANIMALS 117 cats. PROCEDURES Data regarding signalment, history, concurrent disease, clinical signs, clinicopathologic tests, surgical procedures, and perioperative complications (including death) were recorded. Follow-up data, including presence of signs of chronic lower urinary tract disease, chronic urinary tract infection, reobstruction, and death, if applicable, were obtained by records review or telephone contact with owners. Variables of interest were compared statistically between cats treated with and without stent placement. Kaplan-Meier analysis and Cox regression were performed to assess differences in survival time between cats with and without ureteral stents. RESULTS Perioperative complications referable to the urinary tract were identified in 6 of 43 (14%) cats that had ≥ 1 ureteral stent placed and 2 of 74 (3%) cats that underwent ureteral surgery without stenting. Perioperative mortality rates were similar between cats with (4/43 [9%]) and without (6/74 [8%]) stents. After surgery, signs of chronic lower urinary tract disease and chronic urinary tract infection were significantly more common among cats with than cats without stents. Nineteen of 87 (22%) cats with follow-up information available had recurrent obstruction; incidence of reobstruction did not differ between cats with and without stents. Median survival time did not differ between the 2 groups. CONCLUSIONS AND CLINICAL RELEVANCE The potential for signs of chronic lower urinary tract disease and chronic infection, particularly among cats that receive ureteral stents, warrants appropriate client counseling. Judicious long-term follow-up for detection of reobstruction is recommended.

Use of end-to-side arterial and venous anastomosis techniques for renal transplantation in two dogs

CASE DESCRIPTION A sexually intact male Old English Sheepdog and a sexually intact female Bull Terrier were evaluated for renal dysplasia and chronic renal failure, respectively. CLINICAL FINDINGS Both dogs were anemic and had high serum concentrations of urea nitrogen and creatinine. Electrolyte abnormalities (calcium and phosphorus) were also evident. The decision was made to pursue renal transplantation, and donor dogs were identified. TREATMENT AND OUTCOME End-to-side anastomosis of the renal artery and vein of each donors left kidney to the recipients ipsilateral external iliac artery and vein, respectively, was performed. The left caudal abdominal musculature was scarified by making an incision, and nephropexy to that musculature was performed with a simple interrupted pattern of polypropylene sutures. No intraoperative or postoperative complications associated with the vascular anastomoses were encountered. Azotemia, anemia, and electrolyte imbalances resolved after transplantation. CLINICAL RELEVANCE The end-to-side anastomosis technique described here, which is a preferred method in human medicine, was successful, providing an alternative to other renal transplantation techniques in dogs. Additional studies are needed to determine whether any vascular anastomosis technique is preferable for use in dogs requiring renal transplantation.