Apso Research Articles

Identification and Characterization of Megakaryoblasts in Acute Megakaryoblastic Leukemia in a Dog

Megakaryoblastic leukemia is diagnosed infrequently in human beings, and there are few reports describing megakaryoblastic leukemia in dogs. Since the identification of blast cells as precursors of the megakaryocytic cell line using conventional light microscopy is virtually impossible, megakaryoblasts often are confused with myeloblasts (Ml) or lymphoblasts (L1 or L2). The French-American-British Co-operative Group' has proposed specific criteria for identification and classification of acute megakaryoblastic leukemia (M7): 1) the blast cell population in the bone marrow must be 30% or more of all nucleated cells; 2) the leukemic cells are negative for Sudan black B or peroxidase activity; and 3) leukemic cells in the bone marrow and peripheral blood are identified as megakaryoblasts by ultrastructural evaluation for platelet peroxidase activity or by immunologic phenotyping for platelet glycoproteins Ib, IIb/IIIa, IIIa, or factor VIIIrelated In this report, cytochemical staining, ultrastructural morphology, and immunocytochemical staining were used to identify and characterize acute megakaryoblastic leukemia in a dog. A 2.5-year-old intact male Lhasa Apso was presented to the Ohio State University Teaching Hospital for anorexia, weight loss, and intermittent vomiting of several months duration. The dog was thin and had pale mucous membranes. A complete blood count revealed normocytic, normochromic, nonregenerative anemia (packed cell volume = 0.14, reference values- 0.37-0.52), leukocytosis (38.9 x 1 09/liter, reference values-6.5-19.0 x 109/liter), neutrophilia (24.1 x l09/liter, reference values-3.0-1 1.5 x 109/liter) with a left shift (band neutrophils, 3.9 x 109/liter, reference values-0.0-0.3 x 109/liter), circulating blast cells (7.4 x lo9/ liter), and many morphologically bizarre macroplatelets. Blast cells in the peripheral blood were characterized by conspicuous cytoplasmic blebs, vacuolation, and variable granulation (Fig. 1). Macroplatelets had similar cytoplasmic char

Familial renal disease in dogs

ABSTRACTJuvenile renal disease in dogs has been encountered in over 20 breeds but in only nine of these (cocker spaniel, Norwegian elkhound, lhasa apso, shih tzu, samoyed, dobermann, standard poodle, soft‐coated wheaten terrier and bull terrier) have familial nephropathies been reported, and in only two (samoyed and cocker spaniel) has the exact mode of inheritance been elucidated. Reasons for this unsatisfactory state of affairs are: 1 Renal failure in young dogs may not be due to a familial nephropathy, and while helpful diagnostic information may be gained from blood and urine analysis, accurate diagnosis of the specific type of renal disease requires examination of renal biopsy or post mortem material by an experienced pathologist. 2 Not all affected animals show clinical signs at the same age, making collection of data, often from widely dispersed animals, both difficult and slow. 3 The disease process in one breed may be very different from that in another, so that each breed has to be investigated separately. 4 There has to be a willing determination to face the problem by individual breed clubs, with the commitment of a large number of breeders, owners and veterinary surgeons.Resistance or inertia at any level will prevent or delay successful investigation and possible prevention of the disease.

Developmental constraints on limb growth in domestic and some wild canids

The domestic dog varies remarkably in limb size. Presumably, such differences in limb size stem from inequities in postnatal specific growth rate. I test this hypothesis by examining the postnatal growth of limb bones (40–250 days post‐partum) in four dog breeds of dramatically different adult size; Lhasa Apso, Cocker Spaniel, Labrador Retriever and Great Dane. The results show that the limb bones of these four breeds have similar specific growth rates throughout most of postnatal development. Thus, proportionate differences in limb bone length are established during perinatal growth (0–40 days post‐partum) or before birth.Comparisons of postnatal growth in the Great Dane and two wild canids of dramatically different leg length, the Bush dog (Speothos venaticus) and the Maned wolf (Chrysocyon brachyurus) also show a near congruency of specific growth rate curves. However, despite these similarities, the adult limb proportions of small dogs and small wild canids are different. Dogs also differ from wild canids in the relative variability of gestation time. All dogs have a similar gestation period of 60–63 days which is independent of birth weight, whereas the two are directly related in wild canids. I suggest that small dogs may differ in limb proportions from small wild canids because the latter have a shorter gestation period. Thus, the relative invariability of gestation time in domestic dogs may act as a fundamental constraint on their morphologic variability.

Canine intervertebral disc disease — Occurrence by age, breed, and sex among 8,117 cases

To study the effect of the variables breed, age and sex on the occurrence of canine intervertebral disc disease (CIVDD), 8,117 cases reported by 13 veterinary colleges in the United States and Canada were contrasted with a reference of 356,954 dog-years at risk; the data indicated a crude hospital/clinic-rate of 23 cases of CIVDD/1,000 dogs/year. While 84 individual breeds of dogs were reported to have at least one case of CIVDD, only the Dachshund, Pekingese, Beagle, Welsh Corgi, Lhasa Apso, and Shih Tzu had 5 or more cases reported for the breed and a significantly increased risk (p≤0.01). The age distributions for new cases of CIVDD by individual breeds showed a rapid rise to a peak at 4–6 years for high risk breeds, followed by a somewhat less rapid decline, and a peak at 6–8 years for low risk breeds, followed by a gradual decline. There were small, but significant, differences in R by sex, with males and spayed females at a higher risk than females.