Anemia, splenomegaly, and increased osmotic fragility of erythrocytes in Abyssinian and Somali cats

OBJECTIVE: To determine clinical and clinicopathologic features of a chronic intermittent severe hemolytic anemia characterized by erythrocyte osmotic fragility in Abyssinian and Somali cats. DESIGN: Case series. ANIMALS: 13 Abyssinian and 5 Somali cats. PROCEDURES: History, pedigree information, and results of routine laboratory tests, special erythrocyte studies, and histologic evaluation of splenic and hepatic specimens were analyzed. RESULTS: Age at which clinical signs of anemia were first apparent ranged from 6 months to 5 years. Ten cats had splenomegaly. Most often, the PCV was between 15 and 25%, but it was as low as 5% at some times. The anemia was characterized by macrocytosis and mild to moderate reticulocytosis, but no poikilocytosis. Hyperglobulinemia, lymphocytosis, mild hyperbilirubinemia, and high hepatic enzyme activities were common findings. Results of Coombs tests and tests for infectious diseases were negative. The erythrocytic osmotic fragility was high in affected cats (mean osmotic fragility, 0.66 to 0.78%), compared with healthy cats (0.48 to 0.58). No specific membrane protein abnormality, erythrocyte enzyme deficiency, or hemoglobinopathy was identified. Histologic evaluation of splenic and hepatic specimens revealed extramedullary hematopoiesis and hemosiderosis. Four of the 5 Somali cats were closely related. CONCLUSIONS AND CLINICAL RELEVANCE: On the basis of results of pedigree analyses, the apparent breed predilection, and the exclusion of other known causes of anemia in cats, we believe that the hemolytic anemia in these cats was likely a result of a novel hereditary erythrocyte defect. A genetic predisposition to immune-mediated destruction of erythrocytes could not be ruled out.     

Nasal polyps in dogs: five cases (2005 to 2011)

This series describes five dogs with nasal polyps diagnosed between 2000 and 2011. Clinical signs included reverse sneezing, nasal discharge, epistaxsis, and stertor when breathing. Computerised tomographic findings included soft tissue mass, turbinate destruction, extension through the bony nasal septum and partial lysis of bones surrounding the nasal cavity. Three dogs were treated by dorsal rhinotomy, one dog was treated by ventral rhinotomy, and in one dog the polyp tissue was removed during nasal flushing. Three dogs have no clinical signs of nasal disease. One dog had confirmed recurrence of nasal polyps and was successfully treated with megavoltage radiation. One dog had recurrent nasal disease eight months after dorsal rhinotomy. Nasal polyps are a possible cause of nasal disease in dogs with nasal discharge, epistaxsis and stertor, and a differential diagnosis for dogs with extensive soft tissue lesions of the nasal cavities on computerised tomography. Nasal polyps can be treated successfully by rhinotomy in some cases but may reoccur.     

Proposal of a 2-tier histologic grading system for canine cutaneous mast cell tumors to more accurately predict biological behavior

Currently, prognostic and therapeutic determinations for canine cutaneous mast cell tumors (MCTs) are primarily based on histologic grade. However, the use of different grading systems by veterinary pathologists and institutional modifications make the prognostic value of histologic grading highly questionable. To evaluate the consistency of microscopic grading among veterinary pathologists and the prognostic significance of the Patnaik grading system, 95 cutaneous MCTs from 95 dogs were graded in a blinded study by 28 veterinary pathologists from 16 institutions. Concordance among veterinary pathologists was 75% for the diagnosis of grade 3 MCTs and less than 64% for the diagnosis of grade 1 and 2 MCTs. To improve concordance among pathologists and to provide better prognostic significance, a 2-tier histologic grading system was devised. The diagnosis of high-grade MCTs is based on the presence of any one of the following criteria: at least 7 mitotic figures in 10 high-power fields (hpf); at least 3 multinucleated (3 or more nuclei) cells in 10 hpf; at least 3 bizarre nuclei in 10 hpf; karyomegaly (ie, nuclear diameters of at least 10% of neoplastic cells vary by at least two-fold). Fields with the highest mitotic activity or with the highest degree of anisokaryosis were selected to assess the different parameters. According to the novel grading system, high-grade MCTs were significantly associated with shorter time to metastasis or new tumor development, and with shorter survival time. The median survival time was less than 4 months for high-grade MCTs but more than 2 years for low-grade MCTs.     

Prostaglandin F2 alpha treatment of canine pyometra

Immediate and long-term outcomes of prostaglandin F2 alpha treatment for canine pyometra were studied in 10 bitches. Examination of pretreatment uterine biopsy specimens, taken for histopathologic diagnosis and classification of disease severity, revealed either type III or IV pyometra. Dinoprost tromethamine (0.25 or 0.5 mg/kg of body weight, SC) was given once daily for 3 days. Bitches were bred at the first posttreatment estrus and monitored for a minimum of one year. When pure cultures of Escherichia coli (n = 3) or Staphylococcus aureus (n = 1) were obtained from the vagina, these bacteria also were found in the uterus. Pretreatment WBC counts often did not reflect the severity of histopathologic findings in the uterus, but posttreatment WBC counts were useful in monitoring response to treatment. Four bitches produced a litter within one year of treatment. Four bitches (40%) had recurrence of pyometra within one year of treatment, and these same bitches had another recurrence after an additional prostaglandin treatment. Three additional bitches had a recurrence by 27 months after therapy, establishing a total recurrence rate of 77% (7/9). Results suggested that subclinical disease may persist after treatment, with clinical recurrence during diestrus. Despite the high recurrence rate, it was concluded that this treatment is a practical treatment for canine pyometra when reproduction is desired.     

Asymmetric growth of citrus fruit peel induced by localized application of gibberellins in lanolin pastes

Lanolin pastes containing 0.02–1.0% gibberellin A₄₊₇(GA₄₊₇) were applied to one side of developing citrus fruitlets and caused thickening of the peel in the proximity of the treated zone. Enlargement of albedo (= the white portion of citrus peel) cells was involved, as revealed by scanning electron microscopy. The flavedo (= the coloured portion of the peel) and the pulp were not affected by the hormone. Gibberellin A₃ was slightly less active than GA₄₊₇. Cultivars with a naturally thick peel, such as ‘Marsh’ grapefruit (Citrus paradisi Macf.) and ‘Shamouti’ orange (Citrus sinensis (L.) Osbeck) responded more strongly than thin-peel cultivars. The role of gibberellins in the differential growth of citrus fruit tissues is discussed.     

Systemic paecilomycosis in a dog

Disseminated paecilomycosis was diagnosed in an adult dog without underlying immunosuppressive disease. During the 3-month illness (before euthanasia), the dog had ulcerative granulomatous inguinal lymphadenitis, fever, anorexia, dyspnea, generalized lymphadenopathy, retinochoroiditis, and seizures. Fungal organisms isolated from inguinal and prescapular lymph nodes before the dog was euthanatized were identified histologically. Paecilomyces variotii was isolated from the prescapular lymph node specimen. Paecilomyces variotii may be more pathogenic (once it has gained bodily entry) than previously thought.     

Cutaneous reactive histiocytosis in dogs: a retrospective evaluation of 32 cases

Thirty-two cases of canine cutaneous histiocytosis were retrospectively evaluated. Median age at onset was 4 years. Lesions included nodules and plaques affecting the head/face, trunk and limbs, and erythema, swelling and depigmentation of the nasal planum/nares. Systemic involvement was not ruled out in all cases. All dogs had complete resolution of dermatological lesions after initial treatment (median 45 days). Initial treatment included prednisone +/- antibiotics (12 of 32 dogs), prednisone and tetracycline/niacinamide (four of 32), prednisone and azathioprine (three of 32), tetracycline/niacinamide +/- vitamin E/essential fatty acids (six of 32), antibiotics +/- antihistamines (three of 32), cyclosporine and ketoconazole (one of 32), topical therapy (two of 32), and no treatment (one of 32). Seventeen dogs received maintenance therapy which consisted of tetracycline/niacinamide +/- vitamin E/essential fatty acids (12 of 17), cyclosporine/ketoconazole (two to three times a week) (two of 17), azathioprine daily (one of 17), prednisone/azathioprine (two times a week) (one of 17), and prednisone daily (one of 17). Median follow up was 25 months. Nine dogs had a recurrence of cutaneous histiocytosis (median days to recurrence 130 days), with seven of nine having more than one recurrence. At study completion, six dogs were deceased (no lesions at the time of death) and 26 of 32 were alive with no lesions. Ten of 26 dogs were on maintenance treatment (eight tetracycline/niacinamide, one azathioprine, one vitamin E). Previous dermatological disease and season had no detectable influence on recurrence. Recurrence was significantly more likely in dogs with nasal planum/nares lesions than dogs without these lesions. Tetracycline/niacinamide was an effective treatment option for dogs in this study population.     

Nasal and nasopharyngeal lymphoma in cats: 50 cases (1989-2005)

Lymphoma is the most common nasal cavity tumor in cats, yet few reports specifically address the anatomic, immunohistologic, and cytologic features of this neoplasm. Fifty cats were diagnosed with lymphoma at necropsy, via biopsy or by cytology alone. Ten cats displayed multiorgan involvement, and in 2 of these the involvement was limited to the cerebellum and frontal cortex, respectively. Of the tumors, 41 of 50 (82%) were classified as nasal lymphoma, 5 of 50 (10%) were classified as nasopharyngeal lymphoma, and 4 of 50 (8%) involved both nasal and nasopharyngeal tissue. Histologically, all were considered diffuse lymphoid neoplasms and no cats displayed features of follicular lymphoma. Of the 44 cases available for slide review by the pathologist, 40 of 44 (91%) were classified as immunoblastic lymphoma, 2 of 44 (5%) as diffuse large cell, and 1 as diffuse mixed; 1 was unclassified. Of the 45 cats for which immunohistochemical stains were available, 32 were uniformly positive for CD79a, 7 were uniformly CD3 positive, and 6 had a mixed population of CD79a and CD3 cells. Epithelioptropism was exhibited in 4 of 5 (80%) cats in which there was sufficient epithelium present for evaluation. Of those 4, 3 were B-cell and 1 was a granulated T-cell lymphoma. In the 21 cats which nasal cytology was performed, 15 were cytologically diagnosed with lymphoma; the diagnoses in the remaining five cats were inflammatory (n = 4), normal lymphoid tissue (n = 1), or nondiagnostic (n = 1). The most common biochemical abnormalities were panhyperproteinemia in 26/46 (57%) of cats and hypocholesterolemia in 11/46 (24%) of cats.