Clinical features of avian vacuolar myelinopathy in American coots

OBJECTIVE: To characterize clinical features of avian vacuolar myelinopathy (AVM) in American coots. DESIGN: Case-control study. ANIMALS: 26 AVM-affected American coots and 12 unaffected coots. PROCEDURES: Complete physical, neurologic, hematologic, and plasma biochemical evaluations were performed. Affected coots received supportive care. All coots died or were euthanatized, and AVM status was confirmed via histopathologic findings. RESULTS: 3 severely affected coots were euthanatized immediately after examination. Seventeen affected coots were found dead within 7 days of admission, but 5 affected coots survived > 21 days and had signs of clinical recovery. Abnormal physical examination findings appeared to be related to general debilitation. Ataxia (88%), decreased withdrawal reflexes (88%), proprioceptive deficits (81%), decreased vent responses (69%), beak or tongue weakness (42%), and head tremors (31%), as well as absent pupillary light responses (46%), anisocoria (15%), apparent blindness (4%), nystagmus (4%), and strabismus (4%) were detected. Few gross abnormalities were detected at necropsy, but histologically, all AVM-affected coots had severe vacuolation of white matter of the brain. None of the control coots had vacuolation. CONCLUSIONS AND CLINICAL RELEVANCE: Although there was considerable variability in form and severity of clinical neurologic abnormalities, clinical signs common in AVM-affected birds were identified. Clinical recovery of some AVM-affected coots can occur when supportive care is administered. Until the etiology is identified, caution should be exercised when rehabilitating and releasing coots thought to be affected by AVM.     

Endometrial Adenocarcinoma and Mucometra in a 6-year-old Alaska Malamute Dog

A 6-year-old female Alaska Malamute dog was presented for evaluation of abdominal enlargement referred by a local veterinarian. On the history, the owner complained of chronic abdominal enlargement initiated more than 4 months ago, reduced appetite, occasional vomiting and general dullness. He also complained of greenish mucous intermittent vaginal discharge starting 10 days ago. The bitch was chronically treated with medroxiprogesterone acetate. A laparatomy was performed and fluid in the abdomen was found and aspirated during the surgery. Also a very fluid-filled distended uterus and a mass in the distal part of the left uterine horn were found. The mass was encapsulated by the omentum, but areas of necrosis and calcification were identified. Histopathological diagnosis was endometrial adenocarcinoma.     

Oestradiol Induced Inhibition of Neuroendocrine Marker Expression in Leydig Cells of Adult Rats

The objectives of this work were to determine the changes in the expression of neuroendocrine markers in Leydig cell by oestradiol treatment, and to determine whether testosterone is able to recover partially the effects of hormonal suppression induced by oestradiol. Adult male rats were injected daily with either 50 microg of oestradiol or oestradiol plus testosterone propionate (25 mg every 3 days) for 15 days. The animals were sacrificed and testicles were dissected and processed by routine histological protocols. FSH and LH serum levels were determined by radioimmunoassay. The visualization of antigens was achieved by the streptavidin-peroxidase immunohistochemical method. Antibodies against chromogranin A (CrA), S-100 protein (S-100), P substance (PS), synaptofisin (SYN), neurofilament protein (NF), gliofibrillary acidic protein (GFAP) and neuron specific enolase (NSE) were used. The mean LH and FSH serum concentrations were consistently suppressed with hormonal treatments. Intermediate filaments (NF and GFAP) showed no difference in their expression. The expression of S-100, NSE and SYN was significantly lower in both hormone-treated groups. In oestradiol-treated rats, the immunoreactivity of CrA and SP decreased significantly but was restored after testosterone supplementation. Although the nature and functions of many of these substances in Leydig cells remain unknown, these results are consistent with the hypothesis that the expression of some neuroendocrine markers is hormonally controlled.     

Neosporosis, toxoplasmosis, and sarcocystosis in ruminants.

Neospora caninum, Sarcocystis spp, and Toxoplasma gondii are related coccidian parasites that can cause abortion and neonatal mortality in animals. In addition, T gondii and certain species of Sarcocystis are zoonotic. This article reviews information on the etiology, diagnosis, control, and prevention of these diseases.     

Medical management of a corneal stromal abscess in a female Asian elephant (Elephas maximus).

A 47-yr-old female Asian elephant (Elephas maximus) developed a corneal stromal abscess in her right eye. The elephant was trained to open her eye for topical ophthalmic therapy, and was treated six times daily with antibiotics and an antifungal solution for almost 2 mo. Nonsteroidal anti-inflammatory drugs were used to control pain, and atropine was applied topically to dilate the pupil and provide additional comfort. Vascularization of the abscess began shortly after initiating therapy, and complete resolution was obtained by 7 wk.     

PrP genotype and lamb birth weight in a scrapie-free environment: Is there an association?

The National Scrapie Plan (NSP) for Great Britain includes selective breeding programmes. These aim to reduce the frequencies of the ovine prion protein (PrP) genotypes at high risk of developing clinical disease (principally those containing the VRQ allele) within the national flock, and select for the low-risk ARR-containing genotypes. The aim of this work was to use available data from embryo transfer programmes in guaranteed scrapie-free environments to investigate whether there was a difference in lamb birth weight associated with the lamb's PrP genotype, which might affect survival. The first analysis utilised data from 355 Cheviot lambs born between 2001 and 2004. The analysis was then repeated using a larger data set of 737 Cheviot, Dorset and Suffolk lambs born between 1999 and 2003. The most important determinants of mean lamb birth weight were litter size, sex and recipient ewe breed, plus lamb breed in the three breed analysis. In both analyses the effects of all these variables are consistent and of the same order of magnitude. In the first analysis there was evidence for an apparent increase in mean lamb birth weight for the ARR-containing genotypes of 0.3 kg (95% C.I. 0.1–0.5 kg). Whereas, in the second data set there was evidence for a decrease in mean lamb birth weight for the VRQ-containing genotypes of − 0.6 kg (95% C.I. − 0.8 to − 0.4 kg). This had been masked in the first analysis by the categorisation of these genotypes with the ARQ/ARQ genotype. Within these flocks, in a scrapie-free environment, neither finding provides support for concerns that selection for low risk ARR-containing genotypes would be detrimental to lamb birth weight, which is considered to be the most important determinant of lamb survival. Extension of this work into field flocks, where scrapie-status cannot be easily assured, will require the collection of sufficient data to adjust for known direct effects as well as any additional potential confounding effects.     

Relationship of blood corticosterone, immunoglobulin and haematological values in young crocodiles (Crocodylus porosus) to water temperature, clutch of origin and body weight

Objective To examine whether sub-optimal temperature induced stress and immunosuppression in farmed saltwater crocodile (Crocodylus porosus) hatchlings. Design A clinico-pathological study. Animals A total of 140 hatchlings were used. Procedure Body weight and length, plasma corticosterone and immunoglobulin concentrations and total and differential white blood cell counts were measured in 140 hatchlings from five clutches divided between five water temperature treatment groups. Initially all groups were housed at 32°C for 10 weeks, then two groups (L, LC) were changed to low temperature (28°C) and two groups (H, HC) to high temperature (36°C), while one group (C) remained at 32°C. The LC and HC groups were maintained at these temperatures for 10 days, after which the water temperature of both groups was returned to 32°C. Blood samples were collected twice (at 6 and 9 weeks of age) before the initial temperature change, and at 10 days and 4 weeks after the initial temperature change (at 11.5 and 14 weeks of age). Results Except for an increase in plasma corticosterone in the HC group and a decrease in the L group when the temperature change was first introduced, changes in plasma corticosterone were not significant. There were no significant changes in immunoglobulin concentrations. There were, however, significant decreases in the total white cell and lymphocyte counts in the LC group after the temperature was decreased to 28°C, and an increase in these counts after water temperature was returned to 32°C. Clutch of origin had significant effects on body weight and length gains, and there were negative relationships between body weight and corticosterone concentrations and between body weight and immunoglobulin concentrations. Conclusions As haematological changes indicative of stress were not associated with significant changes in serum corticosterone, immunosuppression in young crocodiles may be independent of the hypothalamic-pituitary-adrenal cortical axis.