Thyroid function in the cat: assessment by the TRH response test and the thyrotrophin stimulation test

Changes in total thyroxine (T4), free T4 and total tri-iodothyronine (T3) were measured in 13 cats after the intravenous injection of varying doses of thyrotrophin stimulating hormone (TSH) (0–5 U/cat n = 6; 1 U/cat n = 8; 1 U/kg bodyweight, n = 7) or thyrotrophin releasing hormone (TRH) (100 ug/cat, n = 10). All three doses of TSH resulted in a significant (P < 0–05) rise in T4, free T4 and T3 levels, with the mean peak in hormone concentrations occurring six to eight hours after injection. The three doses of TSH all appeared to produce maximal stimulation of thyroid hormone secretion. The mean percentage increase in hormone concentrations at seven hours following the three doses of TSH ranged from 167 to 198 per cent for T4, 240 to 365 per cent for free T4, and 73 to 116 per cent for T3. Following administration of TRH there was also a significant (P < 0–05) rise in T4, and free T4. The mean peak in T4 and free T4 levels occurred at four hours, and mean increases in hormone levels at this time were 92 per cent for T4, and 198 per cent for free T4. The administration of TRH produced little change in T3 levels. TSH administration resulted in a significantly higher (P < 0–05) percentage peak increase in T4, free T4 and T3 levels at all three dosages than did TRH.     

Lack of antibodies to porcine circovirus type 2 virus in beef and dairy cattle and horses in western Canada.

Porcine circovirus type 2 (PCV2) is a recently recognized agent that is consistently associated with postweaning multisystemic wasting disease in swine. There are conflicting data concerning the ability of this virus to infect and cause disease in other species. To determine if normal cattle, cattle affected with various illnesses, and normal horses in endemic areas of PCV2 infection in swine have had PCV2 infections, 100 randomly selected bovine sera, 100 equine sera, and 100 colostrum samples from clinically normal dairy cattle were examined for the presence of antibodies to porcine circoviruses by using ELISAs. All samples tested were negative for antibodies to porcine circoviruses. As well, a seronegative neonatal Holstein calf and 6 seronegative, 6-month-old beef calves that were experimentally infected with PCV2 failed to develop antibodies to the virus. These results suggest that natural infection of cattle and horses with PCV2 does not occur, or is a rare event, in western Canada.     

Identification of Theileria infections in the salivary glands of Hyalomma anatolicum anatoli cum and Rhipicephalus appendiculatus using isoenzyme electrophoresis

Lysates prepared from the salivary glands of uninfected Hyalomma anatolicum anatolicum and Rhipicephalus appendiculatus and from ticks of these species infected with 2 strains of Theileria annulata and 1 strain of T. parva respectively have been examined for enzyme polymorphism using thin layer starch gel electrophoresis. Representative enzymes from 3 of the major metabolic pathways, the tricarboxylic acid cycle, the glycolytic pathway and the pentose phosphate pathway were investigated. Only 1 enzyme, glucose phosphate isomerase, showed differences between the host cell activity and the parasite activity and also inter- and intraspecific differences between the parasites. This technique represents a useful complement to the present histochemical methods for identification of Theileria infections in the salivary glands of ticks.     

Pulse Oximetry For Estimation Of Oxygenation In Dogs With Experimental Pneumothorax

The purpose of this study was the evaluation of pulse oximetry for estimating the oxygen saturation of hemoglobin (S_pO₂) in dogs with pneumothorax. Values for measured by pulse oximetry with transducers on the tongues and toes of six dogs were compared with saturation values (S_aO₂) computed from arterial oxygen tensions (P_aO₂) during experimentally induced pneumothorax (30,45, and 60 ml/kg of ambient air in the pleural space). Values for S_pO₂, S_aO₂, and P_aO₂ decreased with increasing volume of air. Compared to computed S_aO₂ values, S_pO₂ values obtained from the tongue tended to be less variable than those obtained from the toe, but both locations gave valuable information. Pulse oximetry appears to be a useful, relatively inexpensive method of estimating hemoglobin saturation in dogs with experimentally induced pneumothorax, and it appears to have clinical application in management of critical or traumartized dogs.     

Cavitating mycotic pulmonary infection in a German shepherd dog

A four-year-old German shepherd dog had a chronic cough unresponsive to antibacterial and anti-inflammatory therapy. Radiography revealed consolidation and cavitation in the anterior left lung field. Histological examination of the lung showed extensive necrosis, cavitation and chronic vascular lesions. Fungal infection of the lung was identified histologically and appeared to be an Aspergillus species. Necropsy confirmed extensive consolidation of the affected lung, but no other gross evidence of mycotic infection outside the lung.     

Candida albicans urocystitis in a cat.

Candida albicans urocystitis secondary to urethral stricture and administration of antibiotics was diagnosed in a cat by fungal culturing of urine and examination of specimens. Surgical repair of the stricture and administration of 5-fluorocytosine resulted in resolution of the cystitis. Related problems included anorexia and severe weight loss, which necessitated enteral nutritional support, dehydration, renal disease, and nosocomial Pseudomonas aeruginosa urocystitis.     

Causes of copulatory failure in beef bulls

A cow in full standing estrus is required to assess a bull's ability to copulate. Insufficient libido is not involved if the bull sniffs the cow's vulva and attempts to mount. Blood or pus exiting the penis or prepuce indicates penile or preputial lacerations or other lesions. Rear foot or stifle lesions, seminal vesiculitis, traumatic reticulitis or lumbar spinal injuries may prevent the bull from mounting. Preputial stenosis, penile adhesions, desensitization, hematomas or deviations, peripreputial abscess, cavernosal shunts, insufficient penile length and occlusions of the cavernosal canals may prevent intromission after mounting.     

Guaifenesin alone or in combination with ketamine or sodium pentobarbital as an anesthetic in rabbits.

Guaifenesin was administered alone and in combination with ketamine or sodium pentobarbital to adult New Zealand white rabbits. A solution of 5% guaifenesin in 5% dextrose given intravenously at a dosage of 200 mg/kg, abolished the pedal, palpebral and corneal reflexes for up to 15 minutes with little influence on cardiopulmonary function. Guaifenesin (200 mg/kg, intravenously) and ketamine (50 mg/kg, intramuscularly) produced effective and safe surgical anesthesia for over 30 minutes. This combination mildly depressed respiratory rate but heart rate and arterial blood pressure were not significantly affected. Guaifenesin (200 mg/kg, intravenously) was combined with sodium pentobarbital (20 mg/kg, intravenously) to produce surgical anesthesia for a period of more than 30 minutes. This combination depressed respiratory rate, produced a tachycardia and decreased arterial blood pressure.     

Prevalence and types of birth defects in Ontario swine determined by mail survey.

Preweaning mortality in piglets constitutes a major loss to the swine industry. Congenital defects account for a small but significant proportion of these losses. To implement appropriate strategies to reduce such losses, it is necessary to identify the specific causes and their relative importance. Consequently, a mail survey of swine production in Ontario was carried out to determine the prevalence and types of birth defects. Statistical comparisons of the prevalence of overall defects were made between accurate and estimate records, breeds (cross vs. purebred), size of operation (number of sows) and geographic location. The mean litter size of 11 pigs born per sow was not significantly different for those with accurate versus estimate records, but the difference in the prevalence of defective pigs (live and dead) was significant (accurate 3.1% vs. estimate 4.1%). Splayleg (spraddleleg) was the most common defect. The next four defects for both groups were belly rupture, other rupture, ridglings and other, but not in the same ranking. Purebred and small farm operations (< 25 sows) had a significantly higher prevalence of birth defects for estimated data only. Geographic location had no effect. Further work is required to determine whether recording prevalence of birth defects in Ontario swine will provide a useful monitor of environmental stress. The study provides a baseline for the prevalence and type of defects in Ontario swine.