Expression of interleukin-1beta in the digital laminae of horses in the prodromal stage of experimentally induced laminitis

OBJECTIVE: To study expression of interleukin-1beta (IL-1beta) in the digital laminae of horses in the prodromal stage of experimentally induced laminitis. ANIMALS: 8 healthy adult horses with no signs of laminitis. PROCEDURES: Black walnut extract was administered via nasogastric tube to 4 horses, and water was administered to the remaining 4 (controls). Complete blood counts and physical examinations were performed every 30 minutes after administration of black walnut extract or water. General anesthesia was induced when total WBC count decreased by 30% in horses given the black walnut extract and 3 hours after water administration in control horses. The left forefoot was perfusion fixed with neutral-buffered 10% formalin, and paraffin-embedded sections of the digit were used for in situ hybridization with an equine-specific IL-1beta probe. RESULTS: IL-1beta mRNA expression was observed in perivascular cells of the small laminar venules and capillaries in all 4 horses given black walnut extract and in interstitial cells remote from the microvasculature in 1 of the 4. Other cellular components of the laminar tissue and cellular components of the digital arterioles and veins did not exhibit IL-1beta mRNA expression. Expression of IL-1beta mRNA was not detected in laminae from control horses. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that IL-1beta mRNA is expressed by perivascular cells in the laminar tissues of horses in the prodromal stage of experimentally induced laminitis. This provides evidence of an inflammatory process during the prodromal stage of laminitis, indicating that local digital proinflammatory cytokine expression may be an initiating factor in laminitis.     

Nasopharyngeal diseases in cats: a retrospective study of 53 cases (1991-1998)

The records of 53 cats with nasopharyngeal disease were examined. Of the cats with nasopharyngeal disease, 49% had lymphosarcoma and 28% had polyps. Clinical signs in these cats were compared to 24 cats with nasal disease alone. Cats with only nasal disease more commonly had historical nasal discharge and sneeze, whereas cats with nasopharyngeal disease more often had stertorous respiration, phonation change, and typically reported less nasal discharge or sneeze. It is important to include nasopharyngeal disease in the differential diagnosis for cats with nasal discharge, sneeze, stertor, or phonation change.     

EXCRETORY UROGRAPHY BY INTRAOSSEOUS INJECTION OF CONTRAST MEDIA IN A RABBIT MODEL

There are many indications for an intravenous excretory urogram. However, where intravenous access is not available, the intraosseous route to the circulation may be an alternative. We found that safe and diagnostic excretory urograms could be obtained in rabbits following the injection of different contrast media via the intraosseous route. In fact, these excretory urograms were indistinguishable from ones obtained by the conventional intravenous route. While the rabbits did not develop any abnormal clinical signs following the procedure, there were postmortem histologic lesions of osteochondrosis in 5 of 22 (22.7%) tibias receiving an intraosseous needle, but in none of the 14 tibias that did not receive an intraosseous needle. Further, the use of diatrizoate was associated with the development of osteochondrosis while the use of iopamidol was not.     

Cardiopulmonary effects of a halothane/oxygen combination in hypovolemic cats.

The cardiopulmonary effects of a halothane/oxygen combination were studied in eight cats subjected to a 25% whole blood volume loss. Test parameters included cardiac output measured via thermodilution, heart rate, respiratory rate, arterial blood pressure (systolic, diastolic and mean) and blood gas analysis. Values for cardiac index, stroke volume and systemic vascular resistance were calculated from these data. Posthemorrhage cardiac output, cardiac index, stroke volume and measurements of arterial blood pressure were significantly decreased (p less than 0.05). Heart rate remained unchanged. Following induction of halothane anesthesia the above parameters experienced a further significant decline (p less than 0.05) from their immediate preanesthetic (i.e. posthemorrhage) values. Heart rate also significantly decreased (p less than 0.05). Thirty minutes following the cessation of halothane anesthesia these values returned to near-hemorrhage levels, being above their respective preanesthetic values. Systemic vascular resistance initially rose, peaking ten minutes into halothane anesthesia, before gradually falling to prehemorrhage values at the end of halothane anesthesia. Following hemorrhage, respiratory rate demonstrated a transient increase, associated with an arterial CO2 tension fall, before returning to initial values at the preanesthetic time. During halothane anesthesia respiratory rate remained unchanged whereas arterial CO2 tension rose significantly (p less than 0.05) and pH declined slightly from preanesthetic readings. These returned to prehemorrhage values 30 minutes following the cessation of halothane anesthesia.     

Tetramine cupruretic agents: a comparison in dogs

The cupruretic effects of 2 tetramine (N,N'-bis (2-aminoethyl) alkane diamine) chelators were examined in healthy dogs fed a commercial dog food containing 12.2 micrograms of copper/g of dry diet. Two groups of 3 dogs each were given either 300 mg of 2,2,2-tetramine tetrahydrochloride or 2,3,2-tetramine tetrahydrochloride for 23 consecutive days. Serum and 24-hour urine samples obtained before drug administration and during therapy were analyzed for copper, zinc, and iron concentrations. Both tetramines produced a significant cupruresis without significant changes in serum copper or in serum or urine zinc and iron concentrations. The 2,3,2-tetramine tetrahydrochloride produced a 4- to 9-fold greater cupruresis than did 2,2,2-tetramine tetrahydrochloride and resulted in a daily loss of more than 2 mg of copper in the urine. The dogs had no laboratory or clinical evidence of toxic side effects to either cupruretic agent during the treatment period. The results of the present study indicate that 2,3,2-tetramine should be an effective decoppering drug for use in dogs.     

Parasites of Dogs from Indian Settlements in Northwestern Canada: A Survey with Public Health Implications

A total of 959 faecal samples were obtained from dogs in 12 native communities in Northern Saskatchewan, Central and Northern Alberta and the Northwest Territories. All samples were examined using a flotation technique. Samples from an area of endemic human amoebic infections were also examined by a formol-ether sedimentation method. Eighteen necropsies were performed.

Entamoeba histolytica cysts were recovered from dog faeces at Loon Lake, Saskatchewan.

Toxocara canis had low incidence in Saskatchewan and Central Alberta, and appeared to be almost non-existent further North. Toxascaris leonina was found in all areas surveyed. Canine hookworm infections were plentiful in all areas, the highest incidence being recorded from Northern Alberta and Northwest Territories. Many Taenia (or Echinococcus) infections were found consistently in all areas. Only one infection with Dipylidium caninum was discovered.

Metorchis conjunctus infections were found to be common in the Saskatchewan reserves. Infections with Diphyllobothrium sp. were found in all communities with access to good fishing. One specimen of Dioctophyma renale was recovered at necropsy.

Infections with parasites of no known zoonotic importance such as Trichuris, Alaria and Isospora species were also recorded.