OBJECTIVE To characterize and identify factors associated with intraoperative and postoperative complications of maxillectomy in dogs with oral tumors.
DESIGN Retrospective cohort study.
ANIMALS 193 dogs that underwent maxillectomy for oral tumor excision from 2000 through 2011.
PROCEDURES Data were extracted from the medical records regarding dog signalment, tumor location and size, histologic findings, clinical stage, maxillectomy category, surgical approach, and additional treatments provided. These factors were examined for associations with recorded intraoperative and postoperative outcomes.
RESULTS The most common intraoperative complication was excessive surgical bleeding (103/193 [53.4%]), for which 44 (42.7%) dogs received an intraoperative blood transfusion. These outcomes were both significantly associated with tumor size and location, maxillectomy type, and surgical approach. Dogs treated with a dorsolateral combined intraoral surgical approach were more likely to have excessive surgical bleeding (48/58 [83%]) and had a longer mean duration of surgery (106 minutes) than those treated with an intraoral approach (29/54 [54%] and 77 minutes, respectively). Complications developing within 48 hours after surgery included epistaxis (99/193 [51.3%]), excessive facial swelling (71/193 [36.8%]), facial pawing (21/193 [10.9%]), and difficulty eating (22/193 [11.4%]). Complications developing within 48 hours to 4 weeks after surgery included lip trauma (22/164 [13.4%]), oronasal fistula formation (18/164 [11.0%]), wound dehiscence (18/164 [11.0%]), and infection (13/164 [7.9%]).
CONCLUSIONS AND CLINICAL RELEVANCE Complications associated with maxillectomy in dogs were generally minor. Aggressive surgical planning, preparedness for hemorrhage and transfusion, careful tissue dissection, and comprehensive pain control are recommended, particularly for dogs with large, caudally located oral tumors requiring extensive excision.
Contrast-enhanced CT of the cranial part of the abdomen was performed with 3-mm slice thickness. Postprocessing computer software designed for evaluation of human patients was used to calculate perfusion data for the pancreas and liver by use of 3-mm and reformatted 6-mm slices. Differences in perfusion variables between the pancreas and liver and differences in liver-specific data of interest were evaluated with the Friedman test.
Multiple pancreatic perfusion variables were determined, including perfusion, peak enhancement index, time to peak enhancement, and blood volume. The same variables as well as arterial, portal, and total perfusion and hepatic perfusion index were determined for the liver. Values for 6-mm slices appeared similar to those for 3-mm slices. The liver had significantly greater median perfusion and peak enhancement index, compared with the pancreas.
CONCLUSIONS AND CLINICAL RELEVANCE
Measurement of pancreatic perfusion with contrast-enhanced CT was feasible in this group of dogs. Hepatic arterial and pancreatic perfusion values were similar to previously published findings for dogs, but hepatic portal and hepatic total perfusion measurements were not. These discrepancies might have been attributable to physiologic differences between dogs and people and related limitations of the CT software intended for evaluation of human patients. Further research is warranted to assess reliability of perfusion variables and applicability of the method for assessment of canine patients with pancreatic abnormalities.
To compare the volume of saline (0.9% NaCl) solution required to reach a maximum intraluminal peristaltic pressure of 25 mm Hg in dogs of various sizes.
25 grossly normal jejunal segments from 6 canine cadavers < 20 kg (small dogs) and 25 segments from 5 cadavers ≥ 20 kg (large dogs).
Jejunal specimens were obtained within 1.5 hours after euthanasia. Harvested tissue was transected into 12-cm-long segments, mesentery was trimmed, and each segment was measured from the antimesenteric to mesenteric serosal edges. A 10-cm segment was isolated with Doyen forceps, securing a pressure sleeve within the lumen. Intraluminal saline was infused, and the volume was recorded when a pressure of > 25 mm Hg was achieved. Data were analyzed only from specimens in which the pressure remained between 24 and 26 mm Hg for > 5 seconds.
Mean ± SD intestinal measurement for large dogs (17.82 ± 1.44 mm) was greater than that for small dogs (12.38 ± 1.38 mm) as was the volume of saline solution infused (17.56 ± 7.17 mL vs 3.28 ± 1.41 mL, respectively). The volume infused increased by 1.31 mL (95% CI, 1.08 to 1.18) for every 1-mm increase in intestinal measurement and by 1.06 mL (95% CI, 1.052 to 1.068) for every 1-kg increase in body weight.
CONCLUSIONS AND CLINICAL RELEVANCE
The volume of saline solution used for intestinal leak testing should be determined on the basis of patient intestinal measurement or body weight. In vivo studies are necessary to establish the optimal volume for intestinal leak testing.
Objective—To investigate tissue diffusion of anesthetic agent following administration of low palmar nerve blocks (LPBs) in horses.
Design—Randomized clinical trial.
Animals—12 adult horses.
Procedures—In 9 horses, mepivacaine hydrochloride–iohexol (50:50 dilution) injections were administered bilaterally (2 or 4 mL/site) to affect the medial and lateral palmar and palmar metacarpal nerves (4 sites). Lateral radiographic views of both metacarpal regions were obtained before and at 5, 15, 30, 60, 90, and 120 minutes after block administration; proximal and distal extents of contrast medium (and presumably anesthetic agent) diffusion from palmar and palmar metacarpal injection sites were measured and summed to determine total diffusion. Methylene blue solution was injected in forelimbs of 3 other horses that were subsequently euthanized to determine the potential route of anesthetic agent diffusion to the proximal suspensory ligament region.
Results—Mean extents of proximal and total contrast medium diffusion were 4.0 and 6.6 cm, respectively, for the palmar metacarpal nerves and 4.3 and 7.1 cm, respectively, for the palmar nerves. Subtle proximal diffusion secondary to lymphatic drainage was evident in 17 of the 18 limbs. Contrast medium was detected in the metacarpophalangeal joint or within the digital flexor tendon sheath in 8 and 7 limbs, respectively. In the cadaver limbs, methylene blue solution did not extend to the proximal suspensory ligament region.
Conclusions and Clinical Relevance—In horses, LPBs resulted in minimal proximal diffusion of anesthetic agent from the injection sites. Limbs should be aseptically prepared prior to LPB administration because inadvertent intrasynovial injection may occur.
Objective—To evaluate the relationship between width and depth of surgical margins, amount of edema within and around the tumor, and degree of demarcation between the tumor and surrounding tissues with the clinical outcome following surgical removal of cutaneous mast cell tumors (cMCTs) in dogs.
Design—Retrospective cohort study.
Animals—100 dogs with 115 resectable cMCTs.
Procedures—Information about the dogs' clinical outcomes following cMCT removal was obtained from primary care veterinarians. Histologic sections of excised tumors were assessed retrospectively for tumor grade and measurement of the narrowest lateral and deep margins of nonneoplastic tissue excised with the tumors; edema within the tumor and surrounding tissues was assessed as minimal, moderate, or severe. Tumors were classified as poorly, moderately, or well demarcated on the basis of the degree of mast cell infiltration into the adjoining connective tissue.
Results—Following tumor excision (with no additional postsurgery treatment), 96 dogs had no local recurrence or metastatic disease for 27 to 31 months; 4 metastatic disease–related deaths (dogs with grade II or III tumors) occurred within 3 to 9 months. Histologically, mean lateral and deep surgical margins around the tumors were 8.9 and 5.3 mm, respectively. No recurrence of tumor or metastatic disease developed following excision with lateral margins ≥ 10 mm and deep margins ≥ 4 mm. Edema and degree of demarcation were not correlated with outcome.
Conclusions and Clinical Relevance—Results suggested that most grade I and II cMCTs in dogs can be successfully treated by complete surgical removal with margins smaller than those currently recommended.
To assess the effect of oral cannabidiol (CBD) administration in addition to conventional antiepileptic treatment on seizure frequency in dogs with idiopathic epilepsy.
Randomized blinded controlled clinical trial.
26 client-owned dogs with intractable idiopathic epilepsy.
Dogs were randomly assigned to a CBD (n = 12) or placebo (14) group. The CBD group received CBD-infused oil (2.5 mg/kg [1.1 mg/lb], PO) twice daily for 12 weeks in addition to existing antiepileptic treatments, and the placebo group received noninfused oil under the same conditions. Seizure activity, adverse effects, and plasma CBD concentrations were compared between groups.
2 dogs in the CBD group developed ataxia and were withdrawn from the study. After other exclusions, 9 dogs in the CBD group and 7 in the placebo group were included in the analysis. Dogs in the CBD group had a significant (median change, 33%) reduction in seizure frequency, compared with the placebo group. However, the proportion of dogs considered responders to treatment (≥ 50% decrease in seizure activity) was similar between groups. Plasma CBD concentrations were correlated with reduction in seizure frequency. Dogs in the CBD group had a significant increase in serum alkaline phosphatase activity. No adverse behavioral effects were reported by owners.
CONCLUSIONS AND CLINICAL RELEVANCE
Although a significant reduction in seizure frequency was achieved for dogs in the CBD group, the proportion of responders was similar between groups. Given the correlation between plasma CBD concentration and seizure frequency, additional research is warranted to determine whether a higher dosage of CBD would be effective in reducing seizure activity by ≥ 50%.
Objective—To evaluate whether an equine-derived canine H3N8 influenza A virus was capable of infecting and transmitting disease to ponies.
Animals—20 influenza virus-seronegative 12- to 24-month-old ponies.
Procedures—5 ponies were inoculated via aerosol exposure with 107 TCID50 of A/Canine/Wyoming/86033/07 virus (Ca/WY)/pony. A second group of 5 ponies (positive control group) was inoculated via aerosol exposure with a contemporary A/Eq/Colorado/10/07 virus (Eq/CO), and 4 sham-inoculated ponies served as a negative control group. To evaluate the potential for virus transmission, ponies (3/inoculation group) were introduced 2 days after aerosol exposure and housed with Ca/WY- and Eq/CO-inoculated ponies to serve as sentinel animals. Clinical signs, nasal virus shedding, and serologic responses to inoculation were monitored in all ponies for up to 21 days after viral inoculation. Growth and infection characteristics of viruses were examined by use of Madin-Darby canine kidney cells and primary equine and canine respiratory epithelial cells.
Results—Ponies inoculated with Ca/WY had mild changes in clinical appearance, compared with results for Eq/CO-inoculated ponies. Additionally, Ca/WY inoculation induced significantly lower numbers for copies of the matrix gene in nasal secretions and lower systemic antibody responses in ponies than did Eq/CO inoculation. The Ca/WY isolate was not transmitted to sentinel ponies.
Conclusions and Clinical Relevance—Inoculation of ponies with the canine H3N8 isolate resulted in mild clinical disease, minimal nasal virus shedding, and weak systemic antibody responses, compared with responses after inoculation with the equine H3N8 influenza isolate. These results suggested that Ca/WY has not maintained infectivity for ponies.