20 Apr 2021
Image © arcyto / Fotolia
Local anaesthesia is becoming increasingly utilised in canine dental treatment to improve analgesia during painful procedures.
Chohan and Pascoe1 performed a crossover study in six healthy dogs to compare the efficacy and duration of oral analgesia with a mix of lidocaine and bupivacaine, administered using a lateral percutaneous or modified infraorbital approach. Dogs were randomised for which side (left or right) and which approach would be used, with a two-week washout period between procedures. The dogs were given general anaesthetic, and then the allocated method of local anaesthesia was performed.
At various positions within the buccal cavity and over several time points up to around six hours after injection, reflex-evoked motor potentials were measured, using the contralateral maxillary canine tooth as a control. The proportion of dogs that had desensitisation achieved was recorded, and the time of onset and duration of desensitisation was compared between the two approaches.
No significant difference existed between the proportion of dogs successfully desensitised, or the time to onset of desensitisation, using the two different approaches, but the duration of desensitisation was longer with the infraorbital approach.
The authors concluded that the modified infraorbital approach had similar efficacy to the lateral percutaneous approach, but had a longer duration of action. However, neither approach was 100% effective at desensitising all the oral structures tested.
The nematode worm Physaloptera species is a parasite that can affect carnivorous animals, including the dog. Presence of the worm in the stomach of the dog can cause chronic vomiting. Infection occurs by ingestion of insect intermediate hosts, or paratenic hosts such as amphibians, reptiles and mammals. The worm is prevalent in the midwest US.
Diagnosis can be challenging since there is often a low worm burden, a single-sex infection and/or a failure to produce ova, and furthermore the ova do not float well in standard egg flotation solutions.
Soderman and Harkin2 performed a retrospective study of 27 dogs in which gastric Physaloptera species had been diagnosed endoscopically. In 23 of the 27 dogs the main clinical sign was vomiting, and, in 3 dogs, the worms were found incidentally when performing investigations for gastric or oesophageal foreign bodies.
In most of the dogs only 1 to 3 worms were discovered, but two dogs had more than 50 worms each. Eight dogs had previously received routine anthelmintic therapy, which had been ineffective against this parasite.
The authors recommended higher dose fenbendazole with pyrantel pamoate for treatment. They also noted that reinfection is common, and not necessarily a sign of treatment failure.
Tracheal collapse is a distressing respiratory condition, more common in small-breed dogs, that can lead to a characteristic honking cough and respiratory distress. These cases can be managed surgically or medically.
Congiusta et al3 performed a retrospective study to compare the results of medical and surgical management (tracheal endoluminal stent placement) in 159 dogs with tracheal collapse. Dogs managed medically typically showed good short-term improvement, but deteriorated over time.
The median survival time from diagnosis was 3.7 years for dogs medically managed and 5.2 years for dogs surgically managed. In dogs with severe disease, the median survival time was 1,338 days for surgically managed dogs, but only 12 days for medically managed dogs.
The authors concluded that while multimodal medical management improved clinical signs for months to years in dogs with mild to moderate tracheal collapse, surgical intervention should be considered for those dogs with the more severe form of the disease.
Exocrine pancreatic insufficiency (EPI) causes maldigestion, and certain nutrients such as B12 (cobalamin) and folate can be particularly affected due to the role of pancreatic duct cells in the secretion of intrinsic factor and bicarbonate.
Torreson et al4 performed a pilot study to explore the effects of oral cobalamin supplementation on dogs with EPI. Eighteen dogs with EPI diagnosed by low trypsin-like immunoreactivity levels and with concurrent low cobalamin levels were included in the study. All the dogs were treated with oral cobalamin, and cobalamin levels were measured before and after supplementation.
A marked and significant increase in serum cobalamin levels was found after supplementation, and the authors concluded that oral cobalamin supplementation may be a useful alternative to parenteral supplementation in dogs with EPI. They speculated that an alternative pathway for cobalamin absorption may be present in dogs.
Nutrient deficiencies are also commonplace in cats with chronic enteropathies due to maldigestion, malabsorption, and loss of protein and blood through damaged mucosa.
Hunt and Jugan5 performed a prospective cross-sectional study in 20 cats with primary gastrointestinal disease to examine the levels of iron deficiency and how this relates to cobalamin levels, anaemia and severity of disease. Complete blood count, iron metabolism markers, methylmalonic acid, cobalamin, folate, pancreatic lipase and trypsin-like reactivity were measured, and disease severity was evaluated.
Four cats were defined as anaemic (haematocrit less than 30%), seven had iron deficiency and eight had cobalamin deficiency. Body condition score and haematocrit were found to correlate negatively with methylmalonic acid levels.
The authors concluded that iron deficiency is common in cats with chronic enteropathies, and the impact of iron deficiency on cats with chronic enteropathies should be investigated further.
Systemic hypertension is a common effect of hyperadrenocorticism, and sometimes the high blood pressure persists despite treatment of the underlying cause.
Garcia San José et al6 performed a prospective case series study to assess changes in blood pressure in dogs in the first year of treatment with trilostane. In total, 51 dogs with pituitary-dependent hyperadrenocorticism were included, and blood pressure was measured at diagnosis and at 1, 3, 6 and 12 months. Dogs with hypertension were treated with benazepril, with amlodipine added if necessary.
A total of 36 dogs had hypertension at baseline, while at 12 months, 17 dogs were still hypertensive; 31 dogs required antihypertensive treatment, and 13 of these required the addition of amlodipine. Roughly one-third of the dogs that were not hypertensive at diagnosis subsequently required antihypertensive treatment.
The authors concluded that blood pressure should be measured at each assessment during treatment of hyperadrenocorticism, regardless of how well the disease is controlled or initial blood pressure readings. They also noted that more than one drug may be required to control the hypertension.
Idiopathic epilepsy is the most common cause of seizures in young adult dogs, and is characterised by a lack of underlying causes found on diagnostic testing such as clinical pathology and imaging. CSF analysis is a frequently used test in the investigation of neurological disease and is recommended in the International Veterinary Epilepsy Task Force consensus guidelines for Tier II level confidence of diagnosis, despite the procedure having some associated risks.
Gilbert et al7 performed a retrospective study to identify the frequency of CSF abnormalities in dogs with suspected idiopathic epilepsy. A total of 82 dogs between six months and six years of age that had experienced two or more seizures more than 24 hours apart, normal interictal neurological examinations, with no evidence of toxic or metabolic causes for the seizures and a normal MRI scan were included in the study.
Eleven per cent of the dogs had some abnormalities on CSF analysis; five had albuminocytological dissociation, three had mild increases in nucleated cell count, and one had a mild increase in both total protein and cell count. The dogs with elevated cell counts had a mononuclear pleocytosis.
The authors concluded that while CSF analysis can be important in the investigation of epilepsy, in dogs with normal interictal neurological examinations and MRI findings, it is uncommon to find significant abnormalities, and the risk of the procedure probably outweighs the benefits.
