Coastal Prairie Recovery in Response to Shrub Removal Method and Degree of Shrub Encroachment

Shrub encroachment into grasslands is a worldwide phenomenon with no signs of abating and numerous ecological consequences. In South Texas, honey mesquite (Prosopis glandulosa Torr.) and huisache (Vachellia farnesiana [L.] Wight & Arn.) are two shrubs encroaching into coastal prairies, reducing cover of the dominant native grass, gulf cordgrass (Spartina spartinae [Trin.] Merr. ex Hitchc.), and decreasing habitat for the endangered Aplomado Falcon (Falco femoralis), which requires grasslands or savannas for survival. To determine the best management approach for deterring shrub encroachment and restoring native grasslands, the US Fish and Wildlife Service used several shrub removal techniques within coastal prairies of the Bahía Grande Wetland Complex of the Laguna Atascosa National Wildlife Refuge, a core site for Aplomado Falcon reintroductions. Here, we assess native grass recovery over a 2-yr period in response to these shrub removal methods (mechanical plus prescribed fire and/or herbicide treatments) and degree of shrub encroachment before treatment. In general, areas with high levels of shrub encroachment before treatment had the highest amount of bare ground and lowest grass cover immediately following an initial mechanical treatment; this legacy effect persisted throughout the study irrespective of shrub removal treatment. Regardless of degree of shrub encroachment before treatment, grasses in areas treated with either mechanical or mechanical followed by herbicide methods recovered the slowest, likely due to residual woody material that hindered seed germination. Herbicide treatment following mechanical removal or mechanical removal plus fire effectively hindered shrub regrowth. Overall, mechanical treatment followed by prescribed fire and then herbicide application most effectively promoted grass recovery while hindering shrub regrowth. These findings suggest that grassland recovery following shrub encroachment into South Texas coastal prairies may be promoted through the application of shrub removal methods that combine mechanical, fire, and herbicide treatments.     

Suspected myelodysplastic/myeloproliferative neoplasm in a feline leukemia virus‐negative cat

A 10‐year‐old castrated Domestic Short‐Haired cat was presented to a primary care veterinarian for a wellness examination and laboratory examination for monitoring of diabetes mellitus. The CBC revealed marked thrombocytosis, leukopenia and macrocytic, normochromic anemia. The cat tested negative for FeLV and feline immunodeficiency virus, but was positive for Mycoplasma haemominutum by PCR. Hematologic abnormalities were not responsive to therapy, so a repeat CBC and a bone marrow aspiration for cytology were performed. Additional blood smear findings included anisocytosis with megaloblastic erythroid precursors, large platelets, eosinophilic myelocytes and metamyelocytes, and rare unidentified blasts. The bone marrow smear was highly cellular, and the cytologic pattern was consistent with myelodysplastic syndrome with an erythroid predominance. At that time, 15% blasts were present. The cat was treated with a vitamin K₂ analog, doxycycline, and prednisolone, but without a clinical response. Within 3 months, euthanasia was elected due to declining quality of life, and a necropsy was performed. Postmortem bone marrow smears were highly cellular and dominated by monomorphic blasts of unknown line of origin (52%), persistent marked erythroid and megakaryocytic dysplasia, and ineffective erythropoiesis and granulopoiesis. Immunohistochemical, immunocytochemical, and cytochemical stains resulted in a diagnosis of acute myeloid leukemia of unclassified type. Additional histologic findings included mixed hepatitis with trematode infestation and lymphoplasmacytic interstitial nephritis with fibrosis. The marked thrombocytosis with myelodysplastic syndrome and the FeLV‐negative status of this cat were unusual. The difficulty in classifying the myelodysplasia and subsequent leukemia highlights a need for further reporting and characterization of these types of disease.     

Epidemiologic survey of thrombocytopenia in dogs: a report on 987 cases

Thrombocytopenia was documented in 987 of 18,910 (5.2%) dogs admitted to North Carolina State University, College of Veterinary Medicine, Veterinary Teaching Hospital, between 1983 and 1989. Classifying thrombocytopenic dogs by etiologic groups revealed the following proportionate ratios: 5% (48/987) immune-mediated thrombocytopenia; 13% (130/987) neoplasia-associated thrombocytopenia; 23% (224/987) inflammatory/infectious thrombocytopenia; and 59% (585/987) miscellaneous thrombocytopenia. Dogs with immune-mediated thrombocytopenia had significantly (P < 0.05) lower platelet counts (mean 36,760 +/- 50,288 microliter) than dogs in the other three groups, and Doberman Pinschers were overrepresented in all groups except the immune-mediated thrombocytopenic group. We conclude that thrombocytopenia is a prevalent and potentially important diagnostic finding in a variety of disease states.