Age and the ability of calves to respond to a leptospiral vaccine

The serological responses of calves at two different ages to a commercial hardjo/pomona vaccine were examined. Microscopic agglutination test (MAT) titres of a group of ten three-month-old calves and three groups of 11,12 and 12 six-month-old calves were monitored over a period of 28 weeks. The calves vaccinated at three months of age had a poorer serological response rate to vaccination (30% responded to pomona and 40% responded to hardjo) compared with those vaccinated at six months of age (91-100% responded to pomona and 83-91% responded to hardjo). Those three-month-old calves which did respond also produced a lower level of-antibody than six-month-old calves. It was concluded that in order to achieve adequate protection using commercially available leptospiral bacterins at the recommended dose, vaccination should not be undertaken routinely with animals less than six months of age. Where circumstances arise in which earlier vaccination is necessary, repeat vaccination for continued protection at six months or older is suggested.     

Plasma cell sarcoma in a cat

Lytic lesions occurring in conjunction with plasma cell sarcoma (multiple myeloma) have rarely been reported in cats.

A plasma cell sarcoma was diagnosed in a 13 year old castrated male Siamese cat with hind limb paresis resulting from osteolysis of the second lumbar vertebra. Serum electrophoresis showed a monoclonal gammopathy. A uniform population of plasma cells was found in and around the second lumbar vertebra and in the bone marrow of the femora, humeri, pelvis and the fifth lumbar vertebra. The neoplastic cells were identified as IgA and kappa chain specific by direct immunofluorescence.

     

Submitting canine blood for prothrombin time and partial thromboplastin time determinations

Practitioners commonly submit samples from dogs for partial thromboplastin time and prothrombin time determinations. Controversy exists as to the necessity for rapid separation of plasma and cells, and submission of the plasma on ice (or frozen). The purpose of this study was to address three questions. First, is it better to submit plasma or is whole blood satisfactory? Second, is it necessary to refrigerate the sample or is maintenance at room temperature (20° C) adequate? Third, does the sample have to arrive at the laboratory within a few hours of collection or can reliable partial thromboplastin time/prothrombin time determinations be made on samples up to 48 hours old?It has been shown by this study that reliable partial thromboplastin time and prothrombin time determinations can be carried out on canine plasma for up to 48 hours after collection regardless of whether or not the plasma is separated immediately; however the samples must be kept at 4°C. If the samples are maintained at room temperature, reliable prothrombin time determinations can be obtained for up to six hours after collection regardless of whether or not the plasma is separated immediately. Reliable partial thromboplastin time determinations can be made on plasma stored at 20°C for up to 24 hours after collection and possibly longer (up to 48 hours) if the plasma has been separated immediately.     

Fascioloides magna: Occurrence in Saskatchewan and Distribution in Canada

Infection with Fascioloides magna, the large American liver fluke, was diagnosed in two moose (Alces alces) and six wapiti (Cervus elaphus) from central Saskatchewan. This is believed to be the first record of the parasite in the province. Fecal samples collected from wild wapiti at five sites in the commercial forest zone in Saskatchewan contained eggs believed to be those of F. magna. Trematode eggs were not found in feces from five captive herds of wapiti in the province, nor in samples from wild wapiti in Moose Mountain Provincial Park. Operculate eggs were found in feces of wild wapiti from Cypress Hills, but these were believed to be from trematodes other than F. magna. The distribution and significance of F. magna in Canada, based partially on responses to a mail questionnaire, are reviewed.     

Blood coagulation parameters in clinically normal intensively farmed red deer (Cervus elaphus) and fallow deer (Dama dama)

Reference ranges for five parameters of blood coagulation were established in clinically normal farmed fallow deer (Dama dama) and red deer (Cervus elaphus). Storage of plasma at -15 degrees C resulted in small increases in activated partial thromboplastin time (APTT) for both species, and in the one stage prothrombin time (OSPT) of fallow deer, between days 1 and 30. These times were then stable between days 30 and 60. The fibrinogen levels of fallow deer plasma showed a small apparent increase over 60 days. These storage artefacts were not of sufficient magnitude to preclude the use of such plasma for diagnostic purposes although they could limit its use in research. Levels of fibrin/fibrinogen degradation products (FDP) were not affected by storage at -15 degrees C. Rabbit brain thromboplastin appeared adequate for OSPT determination in both species. The activated clotting time (ACT) is recommended as a field test for screening the intrinsic and common pathways of blood coagulation in deer.     

The efficacy of levamisole and ivermectin against a morantel-resistant strain of Trichostrongylus colubriformis

A controlled slaughter trial was undertaken to evaluate the efficacy of ivermectin (0.2 mg/kg) and levamisole (8 mg/kg) against a morantel-resistant field strain of Trichostrongylus colubriformis in sheep. Mean worm count reductions of greater than 99% were recorded with both anthelmintics. The apparent contradiction between the high efficacy of levamisole and the common belief that resistance to levamisole and morantel is co-inherited, is discussed.     

The effect of gastro-intestinal parasitism on the temporary dentition of lambs

The temporary dentitions of 18 to 39-week-old lambs with a very light or a very heavy parasite burden are compared. The heavily parasitised lambs developed longer temporary incisors which tended to protrude further forward in relation to the upper dental pad. They showed absolute hypocalcaemia and hypoalbuminaemia and relative hypophosphataemia and hypoproteinaemia and in the alveolar bone of the mandible there was a reduction in ash and matrix densities and matrix mineralisation. The incisor protrusion and lengthening may have been a consequence of the loss of supporting bone, but inappetance was likely to have been a factor contributing to the lengthening.     

Roaring in Clydesdales

An endoscopic survey was performed to assess arytenoid cartilage movement during quiet respiration in 48 Clydesdale horses. Physical characteristics which could influence the length of the recurrent laryngeal nerves were also recorded from these horses and the relationship of these characteristics to the presence of abnormal left arytenoid cartilage movements was assessed statistically. Some degree of abnormal arytenoid movement was observed in 50% of the animals over one year of age. No significant correlation between sex, age, estimated weight, height, or neck length could be found although affected animals were, on average, slightly taller, lighter and longer necked.