Mycobacterial infections in striped bass from Delaware Bay

Eighty striped bass Morone saxatilis were obtained from Delaware Bay using commercial gill nets set adjacent to Woodland Beach (n = 70) and Bowers Beach (n = 10) in December 2003. Fish were examined for gross lesions. Total lengths (TLs) and eviscerated weights were determined to calculate condition factors (K). Portions of spleens were aseptically harvested for bacterial culture, and portions of spleens, kidneys (anterior and posterior), livers, and gonads were obtained for histological examination. The size distribution of the striped bass was relatively homogeneous; the mean TL was about 600 mm for all samples. Mean K exceeded 0.95 in all samples and was not significantly different (P > 0.05) among samples. Significant differences in mycobacterial infection prevalence (P < or = 0.05) were observed among samples; samples obtained at Woodland Beach (WB) on December 10 (53.8%, n = 13) and December 17 (7.1%, n = 42) exhibited the most striking differences in prevalence. Mycobacterial infection intensity ranged from 1 X 10(2) to 1 X 10(7) colony-forming units per gram of spleen. Acanthocephalan infection prevalence and intensity, non-acid-fast bacterial infection prevalence, and fish sex ratio were also significantly different among the samples (P < or = 0.05). Similar to the mycobacterial infections, differences in sex ratio, acanthocephalan infection, and non-acid-fast bacterial infection were observed between the WB samples taken on December 10 and 17. However, no significant associations (P > 0.05) were observed between sex ratio or these infections and mycobacterial infection. The differences in bacterial and parasite infection prevalence and intensity and fish sex ratio in some samples indicate that these fish had a different history and that the epizootiology of mycobacterial infection in striped bass from Delaware Bay may be relatively complex.     

Comparison of diagnostic techniques during subclinical single infections of trypanosomiasis in goats

Parasitological diagnostic techniques were compared in caprine hosts in which single subclinical infection with Trypanosoma vivax, Trypanosoma congolense or Trypanosoma brucei brucei had been established. The haematocrit centrifuge technique (HCT) was the most sensitive for the diagnosis of T. vivax and T. b. brucei while the buffy coat method (BCM) proved superior to all other techniques for T. congolense. Except with the miniature anion-exchange/centrifugation technique (mAEC), each of the concentration methods proved as sensitive as a combination of the Standard Trypanosome Detection Methods (STDM) and could detect trypanosomes at concentrations which were five times lower than those required by the STDM. The HCT diagnosed 60.8-90%, with a mean of 78.8%. Corresponding figures for other methods were: wet film, 33.3-50.8 (39.8); mouse inoculation, 0.0-82.5 (47.8); thin film, 43.3-73.3 (52.6); mAEC, 42.4-60.0 (53.2); thick film, 52.9-60.0 (56.2); silicone centrifugation 60.8-77.7 (67.3), and BCM, 60.0-78.4 (71.6). A combination of the HCT and BCM is suggested for routine diagnosis of caprine trypanosome infections.     

Equine ophthalmic examination: Routine diagnostic techniques

A complete, thorough ophthalmic examination is essential in the clinical approach to equine ocular diseases. In the majority of cases and more than in most systems, an ophthalmic diagnosis can be achieved at the time of examination because most ocular structures can be visualised either directly or indirectly. This article describes examination protocol and the techniques, instruments and diagnostic procedures currently available to equine general practitioners.     

Oxibendazole: critical anthelmintic trials in equids.

The efficacy of oxibendazole against gastrointestinal parasites of horses was evaluated by the critical test method. Naturally infected ponies of various ages were given single oral doses of 5, 10, or 15 mg-kg of bodyweight. The drug was highly effective against adult large strongylids (Strongylus vulgaris, S edentatus, S equins), adult small strongylids (especially species of the genera Cylicostephanus, Cylicocyclus, Cyaathostomum, and Triodontophorus), and adult and larval stages of the large pinworm, Oxyuris equi. There was no apparent dose-related differences in efficacy. Oxibendazole was less effective against fourth-stage small strongylid larvae than it was against adults. The drug was inactive against stomach bots (Gasterophilus spp), tapeworms (Anoplocephala magna and A perfoliata), lungworms (Dictyocaulus arnfieldi), abdominal worms )Setaria equina), and mature or immature nematodes in locations other than the lumen of the gastrointestinal tract.     

Osteochondrosis and juvenile spavin in equids

Thirty-six of 50 young equids examined at necropsy for gross pathologic and histopathologic evidence of osteochondrosis were determined to have lesions characteristic of this disorder in the distal joints of the tarsus. Abnormalities ranged from retained endochondral cores underlying undisturbed articular cartilage surfaces to clefts, subchondral osseous cyst-like lesions, and cartilage ulceration. Our findings supported the conclusion that osteochondrosis may cause spavin in the juvenile equid.     

Fenbendazole in equids: further controlled tests with emphasis on activity of multiple doses against naturally occurring infections of migratory large strongyles

Two controlled tests (experiments D and E) were done to evaluate a fenbendazole (FBZ) paste dosage regimen (10 mg/kg once a day for 5 days) for activity against naturally occurring infections of migrating Strongylus vulgaris and S edentatus in the mesenteric arteries and ventral abdominal wall, respectively. Data were also obtained on other internal parasites of the gastrointestinal tract and eyes in experiment E. Eight pony yearlings were used in experiment D (4 treated and 4 nontreated) and 6 horse weanlings were used in experiment E (3 treated and 3 nontreated). Intervals, expressed as days between treatment and necropsy of animals, were 42 (n = 1) or 52 (n = 7) for experiment D and 52 or 53 for experiment E. Animals were on pasture during all or a portion of post-treatment intervals of both experiments. Efficacious killing of retroperitoneal forms of S edentatus in the ventral abdominal wall was observed in both experiments. The average numbers of live 4th-stage forms in equids were 0.0 (treated) and 2.25 (nontreated) for experiment D and 2.0 (treated) and 1.7 (nontreated) for experiment E. The average numbers of 5th-stage S edentatus were 0.5 (treated) and 4.0 (nontreated) for experiment D and 1.3 (treated) and 23.3 (nontreated) for experiment E. Fragments of dead specimens of S edentatus were also found in nodules in treated animals in both experiments, but not in nontreated animals. Consistency of the retroperitoneal lesions provided additional evidence of the killing action of the FBZ treatment.(ABSTRACT TRUNCATED AT 250 WORDS)     

Green iguana nephrology: a review of diagnostic techniques.

There is still much to learn about renal physiology and pathophysiology in reptiles. In the case of the green iguana, initiating causes are often inferred from poor husbandry and nutrition, or extrapolated from histopathologic interpretations made late in the course of the disease, or at postmortem. The link between parathyroid hormone and renal disease in humans has been well documented and, given the high prevalence of clinical (and subclinical) secondary nutritional hyperparathyroidism in iguanas, this certainly warrants further investigation in saurians [31,32,34,35]. Apart from hyperparathyroidism, chronic water deprivation also appears to be a common historic factor. As a foliovore originating from the high humidity rain forests of central and South America, water recovery is not considered to be an adaptive stress in Iguana iguana, and therefore, renal anatomy and physiology are considered to be non-specialized compared to more arid or aquatic reptiles [21]. These arboreal lizards do not voluntarily drink from open water but instead imbibe rain or dew droplets from foliage [2]. Maintaining such a species in low relative humidity with a water bowl from which to drink is likely to both increase insensible water losses and interfere with normal water intake. Appropriate therapeutic decisions (including euthanasia) can only be made following an accurate diagnosis. To date, our diagnoses are based largely upon the structural evaluations of renal histopathology, and renal biopsy remains our most useful tool. However, in the future it may become possible to evaluate renal function by quantifying glomerular filtration rate, proximal tubular secretion, or functional renal mass. Glomerular filtration rate may be estimated by measuring the rate of glomerular clearance of substances from the blood (e.g., iohexol). Phenolsulphonphthalein assays may offer an insight into proximal tubule secretion and renal blood flow.     

Common diagnostic and clinical techniques for fish.

Fish medicine has common diagnostic and clinical procedures that are essential for disease diagnosis and patient management. With a few modifications for handling of the fish patient, these resemble procedures performed in most veterinary hospitals and clinics in our other companion species. The predictive value of these diagnostic methods is improving with the ever-increasing number of publications in fish medicine. Training in aquatic clinical procedures is offered at most large continuing education conferences and as specialty courses. These basic procedures are the important first steps toward improving the health of our aquatic companion animals.     

Controlled tests of activity of ivermectin against natural infections of migratory large strongyles and other internal parasites of equids

Four controlled tests (experiments A, B, C, and D) were conducted in naturally infected yearling equids to evaluate activity of ivermectin (0.2 mg/kg IM) against migrating Strongylus vulgaris and S edentatus in mesenteric arteries and ventral abdominal wall, respectively. Data were also obtained on activity against other internal parasites of the gastrointestinal tract and eyeworms. The type and number of equids in the experiments were as follows: experiment A-3 ponies, 2 treated and 1 non-treated; experiment B-4 mixed-bred horses, 2 treated and 2 nontreated; experiment C-5 mixed-bred horses, 3 treated and 2 nontreated; experiment D-4 mixed-bred horses, 2 treated and 2 nontreated. Intervals between treatment and necropsy were 35 days in experiment A, 52 to 53 days in experiment B, 38 to 41 days in experiment C, and 45 days in experiment D. Efficacious killing of retroperitoneal forms of S edentatus in the ventral abdominal wall was obtained in the 4 experiments. Only dead worms or fragments were recovered from treated animals, while living 4th-stage and/or 5th-stage S edentatus was present in nontreated equids in each test. A similar killing effect on S vulgaris in cranial mesenteric arteries was recorded in 2 experiments (B and D); only 1 dead 5th-stage worm was found in 1 of the treated yearlings in experiment B, whereas living 4th- and 5th-stages of S vulgaris were found in the nontreated controls in both experiments.(ABSTRACT TRUNCATED AT 250 WORDS)