Body Temperature Fluctuation After Ovariohysterectomy in Dogs in Luteal Phase, Inactive Phase and Pyometra: A Clinical Study of 77 Cases.

Progesterone (P4) has a thermogenic effect in the bitch and a decrease in P4 has been associated with a mild transient decrease in body temperature. The aim of this study was to investigate the presence, the extent and the pattern of possible hypothermia after ovariohysterectomy (OHE) in healthy dogs in luteal phase and in bitches with pyometra that underwent therapeutic OHE. Sixty-two healthy dogs and 15 dogs with pyometra that underwent standardized OHE were included. Rectal temperature was measured 1 hour preoperatively (pre-op) and 6, 9, 12, 18, 24, 30, 36, 42, and 48 hours postoperatively (post-op). Serum P4 was measured 30 minutes pre-op and 6 and 24 hours post-op. Healthy dogs were classified in 3 groups based on their initial P4 concentration and in 3 separate groups based on their oestrus cycle stage. The temperature differentiation between the groups of the study was assessed using the repeated measures mixed-design ANOVA analysis. Temperature measured 18-42 hours post-op was significantly decreased compared to pre-op when initial P4 >8 ng/mL but not significantly decreased when P4 <8 ng/mL. Post-op temperature fluctuation in pregnant dogs showed no significant difference compared to dogs in diestrus. Dogs with pyometra had significantly lower temperature 6-48 hours post-op compared to all other groups. Conclusively, mild hypothermia (37.5-37.9°C) may be anticipated 18-42 hours after OHE performed in early diestrus or pregnancy in healthy dogs. More significant hypothermia (37.1-37.5°C) may be anticipated in normally recovering pyometra cases.

Evaluation of blood T-lymphocyte subpopulations involved in host cellular immunity in dogs with mammary cancer.

Cancer-bearing patients are often immunosuppressed. In dogs with mammary or other cancers, various alterations in blood cell populations involved in host cellular immunity have been reported; among these cell populations some T-lymphocyte subsets play an important role against cancer. The purpose of the present study was to investigate any alterations in circulating T-lymphocyte subpopulations involved in cellular immunity in bitches with mammary cancer, in comparison to age-matched healthy intact bitches. Twenty eight dogs with mammary cancer and 14 control dogs were included in this study. Twelve out of the 28 bitches had mammary cancer of clinical stage II and 16/28 of stage III. Histological examination revealed that 23/28 animals had carcinomas, 3/28 sarcomas and 2/28 carcinosarcomas. White blood cell, neutrophil and lymphocyte absolute numbers were measured by complete blood count. Furthermore, blood T-lymphocyte population (CD3+) and the subpopulations CD4+, CD8+ and CD5low+ were assessed by flow cytometry. White blood cell and neutrophil but not lymphocyte absolute numbers were higher (P=0.003 and P=0.001, respectively) in cancer patients than controls. Flow cytometric analysis revealed that the relative percentage of T-lymphocytes (CD3+) and of CD4+, CD8+ subpopulations was lower (the CD4+/CD8+ ratio was higher), whereas the percentage of CD5low+ T-cells was higher, in dogs with cancer compared to controls; however, a statistically significant difference was found only in the case of CD8+ T-cells (P=0.014), whereas in the case of the CD4+/CD8+ ratio the difference almost reached statistical significance (P=0.059). Based on these findings, it can be suggested that, although the absolute number of blood lymphocytes is unchanged, the relative percentages of T-lymphocyte subpopulations involved in host cell-mediated immunity are altered, but only cytotoxic CD8+ T-cells are significantly suppressed, in dogs with mammary cancer of clinical stage II or III compared to age-matched healthy controls.

Gastro-oesophageal reflux in large-sized, deep-chested versus small-sized, barrel-chested dogs undergoing spinal surgery in sternal recumbency.

OBJECTIVE: The aim of this study was to investigate whether an increased frequency of gastro-oesophageal reflux (GOR) is more common in large-sized, deep-chested dogs undergoing spinal surgery in sternal recumbency than in small-sized, barrelchested dogs. STUDY DESIGN: Prospective, cohort study. ANIMALS: Nineteen small-sized, barrel-chested dogs (group B) and 26 large-sized, deep-chested dogs (group D). METHODS: All animals were premedicated with intramuscular (IM) acepromazine (0.05 mg kg-1) and pethidine (3 mg kg-1) IM. Anaesthesia was induced with intravenous sodium thiopental and maintained with halothane in oxygen. Lower oesophageal pH was monitored continuously after induction of anaesthesia. Gastro-oesophageal reflux was considered to have occurred whenever pH values > 7.5 or < 4 were recorded. If GOR was detected during anaesthesia, measures were taken to avoid aspiration of gastric contents into the lungs and to prevent the development of oesophagitis/oesophageal stricture. RESULTS: The frequency of GOR during anaesthesia was significantly higher in group D (6/26 dogs; 23.07%) than in group B (0/19 dogs; 0%) (p = 0.032). Signs indicative of aspiration pneumonia, oesophagitis or oesophageal stricture were not reported in any of the GOR cases. CONCLUSIONS AND CLINICAL RELEVANCE: In large-sized, deep-chested dogs undergoing spinal surgery in sternal recumbency, it would seem prudent to consider measures aimed at preventing GOR and its potentially devastating consequences (oesophagitis/oesophageal stricture, aspiration pneumonia).

Anesthetic management of a 4-month-old red fox (Vulpes vulpes) for orthopedic surgery.

A 4-mo-old red fox (Vulpes vulpes) was found recumbent after a vehicular accident. Radiology revealed several limb fractures and the fox underwent surgery after 24 hr of initial stabilization. Premedication consisted of dexmedetomidine and morphine. Anesthesia was induced with ketamine and midazolam and maintained with isoflurane. Lidocaine, bupivacaine, and morphine were administered epidurally and further analgesia was provided with meloxicam. The heart rate and respiratory rate of the fox remained stable during surgery and, except for a mild hypothermia, the recovery from anesthesia was uneventful. The postoperative pain scores were low and the animal was transported to a rehabilitation facility and eventually released to the wild. The low pain scores postoperatively should be attributed to the successful application of epidural anesthesia and analgesia.

The effect of the stage of the ovarian cycle (anoestrus or dioestrus) and of pregnancy on the incidence of gastro-oesophageal reflux in dogs undergoing ovariohysterectomy.

OBJECTIVE: To investigate the potential association of increased blood progesterone (P4 ) concentrations and/or late pregnancy with the incidence of gastro-oesophageal reflux (GOR), in healthy bitches undergoing ovariohysterectomy under general anaesthesia during anoestrus or dioestrus or during the second half of pregnancy. STUDY DESIGN: Prospective observational study. ANIMALS: Ninety-four healthy, female, dogs, aged 1-8 years presented for elective ovariohysterectomy. METHODS: Non-pregnant animals were classified into group A (anoestrus) (n = 35) if blood P4 concentration was sufficiently low or group D (dioestrus) (n = 26) if blood P4 concentration was sufficiently high. All animals in the second half of pregnancy were classified into group P (n = 33). Acepromazine (0.05 mg kg(-1) ) was administered intramuscularly as preanaesthetic medication, and sodium thiopental (10 mg kg(-1) , with additional doses if needed) was administered intravenously (IV) for induction of anaesthesia. After endotracheal intubation, halothane (1.1-1.3% end-tidal concentration) in oxygen was used for maintenance of anaesthesia. Lower oesophageal pH was monitored continuously throughout surgery using a pH-measuring probe. Reflux was considered to have occurred whenever pH values of >7.5 (alkaline reflux) or <4 (acid reflux) were recorded. On completion of surgery, carprofen (4 mg kg(-1) ) was administered IV. Further administration of analgesics post-operatively was dictated by visual analogue scale pain scoring. RESULT: Acid GOR was observed in five of 26 dogs in group D, six of 35 group A, and 12 of 33 group P (p = 0.152). The incidence of GOR in group P approached statistical significance and was higher than the incidence in the combined group A + D (one sided p = 0.044, two sided p = 0.077). CONCLUSIONS: In dogs undergoing ovariohysterectomy, GOR during anaesthesia occurs with a high incidence in dogs in the second half of pregnancy compared to non-pregnant animals during anoestrus or dioestrus. CLINICAL RELEVANCE: Measures could be taken in such cases to avoid the consequences of potential reflux.