Suppurative splenitis and peritonitis in a horse after gastric ulceration caused by larvae of Gasterophilus intestinalis

A 12-year-old Thoroughbred mare, with a history of anorexia, dramatic weight loss, fluctuating pyrexia and intermittent diarrhoea after an episode of colic, was presented for examination with depression, emaciation and ataxia. Thoracic and abdominal paracenteses yielded copious quantities of inflammatory exudate. Palpation per rectum revealed an enlarged spleen. The primary alterations in haematology included a severe leucocytosis with a left shift, and a hyperproteinaemia characterised by hypoalbuminaemia and hypergammaglobulinaemia. Post-mortem examination revealed a low grade pleurisy and peritonitis with fluid accumulation in both cavities. A suppurative gastritis with full thickness perforations of the stomach wall associated with Gasterophilus intestinalis larvae had extended to the juxtaposed organ initiating an extensive suppurative splenitis. Streptococcus zooepidemicus was cultured.     

Paratuberculosis with special reference to cattle. A review

Paratuberculosis is a chronic, granulomatous enteritis caused by Mycobacterium avium subspecies paratuberculosis affecting domestic and wild ruminants. The symptoms of clinical paratuberculosis are chronic diarrhoea and progressive weight loss while subclinically infected animals mainly have decreased production. The infection is widespread throughout the world and causes substantial financial losses for the farming industry. One of the major obstacles in the control of this disease, is the difficulty of identifying subclinically infected animals. This review gives a summary of several aspects of paratuberculosis including clinical importance, pathology, immunology and properties of the infectious agent. Special emphasis will be on the available diagnostic methods, their use and limitations.     

Studies on the contractility of follicular wall with special reference to the mechanism of ovulation in hens

1. To investigate the mechanism of ovulation in the hen, histological and physiological investigations on the contractility of the follicular wall were carried out.

2. Smooth muscle bundles in the loose connective tissue coat from the stalk to the equator showed spontaneous rhythmic contractions with an alternation of contraction and pausing periods of about 4 min. The administration of prostaglandins F_2α (PGF_2α), E₂ (PGE₂), ovarian oviposition inducing factor (OOIF), oxytocin and acetylcholine increased the frequency and amplitude of the contractions.

3. The theca layer showed spontaneous contractions at a frequency of about 30 per 10 min. PGF_2α, OOIF, acetylcholine, adrenaline and noradren‐aline induced tonic contractions, whereas PGE₂, oxytocin and histamine induced relaxation.

4. It is suggested that the contraction of the follicular wall promotes the rupture of the stigma at ovulation and the neurotransmitters as well as prostaglandins and OOIF may be involved in this event.     

Cardiac output technologies with special reference to the horse

Critical illness, anesthesia, primary cardiovascular disease, and exercise may result in marked hemodynamic alterations. Measuring cardiac output (CO) is central to defining these alterations for both clinician and researcher. In the past 10 years, several new methods of measuring CO have been developed for the human medical market. Some of these methods are now validated in the horse and are in clinical use. The Fick method has been used in equine research for more than a century. It depends on simultaneous measurement of mixed venous (pulmonary arterial) and peripheral arterial oxygen content and oxygen uptake by the lungs. The technique is technically demanding, which restricts its clinical use. Indicator dilution techniques, with indocyanine green, cold (thermodilution), or lithium as the marker, have also been widely used in the horse. The indocyanine technique is cumbersome, and thermodilution requires right heart catheterization, which is not a benign procedure, making both of these methods less than ideal for clinical use. Lithium dilution requires catheterization of a peripheral artery and a jugular vein. It has recently been validated in anesthetized adult horses and neonatal foals. Doppler echocardiography is a noninvasive ultrasound-based technique. More accurate measurements are obtained with transesophageal than with transthoracic measurements; however, both methods require considerable technical expertise. Bioimpedance and pulse contour analysis are 2 new methods that have yet to be validated in the horse. With the currently available technology, lithium dilution appears to be the method of measuring CO best suited to the equine clinic.     

Borrelia burgdorferi infections with special reference to horses. A review

This review discusses the literature on B. burgdorferi infections in view of the rising incidence of this infection in general and the increasing concerns of horse owners and equine practitioners. Lyme disease, the clinical expression of Borrelia infections in man is an important health problem. The geographic distribution of B. burgdorferi infections in equidae should resemble that of human cases because the vector tick involved, Ixodes ricinus, feeds on both species and, indeed, the infection has been established many times in horses. However, a definite diagnosis of the disease "Lyme borreliosis" in human beings as well as in horses and other animals is often difficult to accomplish. Although a broad spectrum of clinical signs has been attributed to B. burgdorferi infections in horses, indisputable cases of equine Lyme borreliosis are extremely rare so far, if they exist at all.     

Borrelia burgdorferi infections with special reference to horses. A review

Summary This review discusses the literature on B. burgdorferi infections in view of the rising incidence of this infection in general and the increasing concerns of horse owners and equine practitioners. Lyme disease, the clinical expression of Borrelia infections in man is an important health problem. The geographic distribution of B. burgdorferi infections in equidae should resemble that of human cases because the vector tick involved, Ixodes ricinus, feeds on both species and, indeed, the infection has been established many times in horses. However, a definite diagnosis of the disease "Lyme borreliosis" in human beings as well as in horses and other animals is often difficult to accomplish. Although a broad spectrum of clinical signs has been attributed to B. burgdorferi infections in horses, indisputable cases of equine Lyme borreliosis are extremely rare so far, if they exist at all.     

Immunology of helminth infections, with special reference to immunopathology.

Immune responses resulting in immunity to infection or disease, share the same basic humoral and cellular mechanisms. While immunity to helminth infection has evolved to mediate rapid elimination of the parasite, the strategies evolved by the parasites themselves aim to delay this rejection process and ensure the survival and distribution of their progeny. Ineffective or incomplete immunity results in persistence of parasites or their products within the host tissues, inappropriate or chronic stimulation by parasite antigens, hyper-reactivity and tissue damage or immunopathology. A long standing classification by Gell and Coombs identifies four major types of hypersensitivity responses accounting for most of the immunopathogenesis, three of which are mediated by antibody and one, delayed type hypersensitivity (DTH), by T cells. This paper aims to give a short review of these four classical hypersensitivity reactions with particular reference to infections of large animals with helminth parasites. In addition, in view of the functionally different helper T cell subsets now identified, the existing DTH response is redefined as DTH Type 1 (Th-1 mediated) and two new classes of T cell-dependent DTH responses are proposed; DTH Type II, associated with the Th-2 type cytokines IL-4 and IL-5 and eosinophilic granuloma formation, and DTH Type III, associated with IL-4 and TGF-beta and fibrosis. Finally, some implications of immunopathology on parasite control strategies are discussed.     

Humanized animal viruses with special reference to the primate adaptation of morbillivirus.

This review article discusses the evolution of human viruses with special reference to paramyxoviruses. This family of viruses causes epidemics representing the dissemination of infection from one acutely infected host to the next. Since there is no repository for human paramyxoviruses in animals or in the form of persistent infections in man, the history of epidemics afflicting human civilization is short, presumably not exceeding 4000-5000 years. Evolutionary relationships can be deduced for comparison of nucleotide sequences of genes or even complete genomes. The present paramyxovirus genus will probably in the future be divided into two separate genera. In the genus morbillivirus, two pairs of more closely related virus types can be distinguished: canine and phocid viruses, and rinder-pest and measles viruses, respectively. It is speculated that recombination events may have occurred in the evolution of the morbillivirus archetype.     

Post-hatching developmental changes in the ultrastructure of the duodenal absorptive epithelial cells in 1, 10 and 60-d-old chickens, with special reference to mitochondria.

1. Post-hatching developmental changes in the ultrastructure, cell area and histological RNA content of duodenal absorptive epithelial cells were observed in 1, 10 and 60-d-old White Leghorn (WL) and broiler (BR) chickens, with special reference to the mitochondria (Mt). 2. Epithelial cells in 1-d-old WL and BR had a well-developed Golgi area and a dense cluster of rod type Mt near the cell surface and at the infranuclear region. In BR, cells included well developed profiles of endoplasmic reticulum but fewer supranuclear vacuoles than those of WL, in which numerous free ribosomes were also found. Some Mt in BR showed a bud-like protrusion from the main body (tadpole type Mt). These suggest that the fine structural maturation of the epithelial cells in WL is involved in the process of cell maturation but epithelial cells of BR have almost matured at hatching. 3. In 10-d-old WL and BR, supranuclear vacuoles had disappeared and Mt increased in number. In WL, in addition to a decrease in free ribosomes, Mt developed to the tadpole type and further to dumbbell type ones. In BR, Mt also aggregated at the perinuclear region and some of them had developed from dumbbell shapes to a thick doughnut type. These findings indicate that epithelial cells in both breeds are more developed ultrastructurally than those in 1-d-old and that epithelial cells in BR are more activated for digestive and absorptive functions than those in WL. 4. In 60-d-old WL and BR, Mt showed various types with thinner matrices than 10-d-old, suggesting that the cell structure and function had reached a stable state. 5. BR revealed higher values for cell area and RNA content than WL at every age and RNA content of both breeds were maximal at 10 d, followed by 60 d. 6. Mt changed their shapes from rod type to tadpole type. The latter then developed to doughnut type via dumbbell type, related to an increase of epithelial cell functions. 7. Epithelial cells of BR are thus more highly activated than WL cells at each age and reach morphological and physiological maturation around 10 d.     

First-time endoscopic detection of larvae of Gasterophilus spp. in the oral cavity in 14 warmblood horses

Intraoral endoscopy is used as a standard diagnostic technique at the reporting clinics in horses presented with stomatological problems. Endoscopy of the oral cavity was performed using a chip camera, camera control unit, xenon cold light source and a rigid endoscope. In a three year period (2002 to 2004), second instars of Gasterophilus spp. were diagnosed in 14 warmblood horses 2 to 17 years of age. All horses were presented with masticatory problems or problems accepting the bit. In one horse oesophageal obstruction occurred in the course of larval migration. Oral endoscopy can not only be used for the diagnosis of dental disease but also for detection of instars of Gasterophilus spp. in the interdental spaces of maxillary cheek teeth.     

Salmon in New Zealand with special reference to the quinnat salmon

Of the 3 species of salmon successfully acclimatised in New Zealand, the quinnat, Oncorhynchus tshawytscha (Walbaum) is the most widespread. It is found mainly in the east coast rivers of the South Island. Although adults live in the sea and return to freshwater to breed, lake populations have developed either voluntarily or because egress to the sea is blocked by dams. Sea-living adult quinnat salmon return to rivers in summer to spawn in their natal streams and once in freshwater, cease feeding and the gut degenerates. Eggs laid by the females in redds are fertilised by the male, after which both parents die. Most young salmon emerging from the redds migrate downstream but their fate is uncertain. The few remaining feed and grow and migrate to sea in early summer. Examination of the ridges on fish scales reveals information about migration patterns which assists in studies conducted by the Ministry of Agriculture and Fisheries in the Glenariffe Stream. Marking and tagging of smelts is expected to provide information on survival to adult return and on movements of salmon at sea. The quinnat is the salmon species most favoured by anglers and it is also considered to have a commercial future in New Zealand, using the method of ocean ranching.     

Post-partum ovarian activity in Finnhorse mares with special reference to seasonal effects.

In a previous study, times from parturition to the first ovulation were followed in 55 Finnhorse mares on the basis of milk progesterone determinations. Ninety-six per cent of mares had ovulated by day 20 post-partum. If intervals of more than 19 days are excluded from the data, the time from parturition to 1st ovulation was 117 days. However, in cases of foaling before and after the beginning of June the times were 13.0 days and 8.8 days, respectively (p less than 0.001). Long intervals (over 16 days) occurred mainly before 1st May (in 6 out of 7 cases). In a 2nd study, 25 post-partum Finnhorse mares were examined by rectal palpation and ultrasonic scanning. Five and 7 days post partum, but not 2 days post partum there was a statistically significant difference between ovulatory ovaries and non-ovulatory ovaries regarding size of whole ovary and the largest follicle. Six to 8 days before the first post-partum ovulation, the size of the preovulatory follicle was greater in mares which had foaled before the middle of May (32 mm) than in those which had foaled after the middle of May (20 mm) (p less than 0.05). Within 2 days before ovulation there was no statistical difference between the sizes (43 mm and 42 mm, respectively). The growth rate was therefore slower in cases of early foaling (1.8 mm/day) than in cases of late foaling (3.7 mm/day).