26 Feb 2025
Alex Gough
Job Title
Image: jagodka / Adobe Stock
Heart disease is common in older dogs. Generally, small breed dogs are more prone to mitral valve disease and large breed dogs are prone to cardiomyopathies. However, Wilson and Wesselowski1 report a retrospective study of the characteristics of myxomatous mitral valve disease (MMVD) in Labrador and golden retrievers.
Fifty-two Labrador retrievers and 20 golden retrievers that had been diagnosed with MMVD were included and dogs were staged according to consensus guidelines. The mean age was around 10 years, with males being slightly more predisposed than females – 89% of the Labradors were graded as stage B1, 6% as B2 and 6% as grade C; 70% of golden retrievers were B1, 10% B2 and 20% C.
However, half of the dogs that were B2 or C also had systolic dysfunction. Atrial fibrillation was uncommon in Labradors, but ventricular arrhythmias were a little more common. Atrial fibrillation ultimately occurred in five out of six of the golden retrievers with stage B2 or C MMVD. Mitral valve prolapse was found to be more common in Labradors than golden retrievers. The authors note that MMVD has a relatively late onset in both breeds, and that both breeds showed mitral valve thickening. A worse MMVD stage was associated with increased prevalence of systolic dysfunction.
Haemoperitoneum caused by splenic lesions is often associated with malignancy. It is therefore recommended to perform imaging to assess for signs of metastasis, in order to inform decision-making, for example, whether to proceed to surgery. Ramirez et al2 performed a post-hoc analysis on a prospective study that had initially been designed to investigate a novel treatment for haemangiosarcoma.
The objective of the new analysis was to assess the reliability of preoperative abdominal ultrasonography in staging dogs with haemoperitoneum due to splenic tumour rupture. A total of 99 dogs with non-traumatic haemoperitoneum secondary to splenic tumour rupture presenting to 20 hospitals in the US were included in the study. Ultrasonographic findings were compared to surgical and histological findings – 20% of cases had liver lesions identified on preoperative ultrasonography.
However, 22% of liver lesions that were observed intra-operatively had not been detected by prior ultrasonography. The finding of preoperative liver lesions was associated with a higher likelihood that the lesions were benign. Ultrasonography had a similarly low sensitivity in detecting intra-abdominal lesions besides splenic and hepatic lesions. The authors suggest the findings warrant a reassessment of practice regarding staging of tumours prior to surgery for haemoperitoneum secondary to splenic tumour rupture, for example, using whole-body CT for imaging instead.
Immune-mediated haemolytic anaemia (IMHA) is a relatively common cause of weakness and collapse in dogs. It carries a guarded prognosis, and even after successful treatment, relapses can occur. Bannister et al3 performed a retrospective study to attempt to identify risk factors for relapse. IMHA was defined as a packed cell volume (PCV) of less than 30% at initial presentation and the presence of at least two of spherocytosis, positive Coombs testing, hyperbilirubinaemia, haemoglobinaemia and positive slide agglutination.
A total of 163 dogs with IMHA were included in the study – 13 relapses occurred with a probability of a relapse by 3 months of 5% and by 12 months of 11%. The necessity for two or more blood transfusions was a positive risk factor for relapse by 12 months. Higher total bilirubin was also associated with an increased probability of relapse, but lower PCV at diagnosis was not. The authors recommend closer monitoring of dogs with high bilirubin and/or those that have required multiple blood transfusions.
General anaesthesia is known to reduce body temperature if measures are not taken to counteract this. Wenham and Santos4 performed a retrospective study to compare the effect of general anaesthesia on the body temperature of dogs undergoing neutering by veterinary students. Included in the study were 75 dogs that underwent ovariohysterectomy and 35 that underwent orchidectomy.
Female dogs exhibited a marked drop in body temperature, and this was larger than that seen in male dogs. Premedication dose, age, weight and anaesthesia duration did not have a significant effect. However, on recovery, female body temperature was higher than male temperature. The authors note that the results should be treated with caution given the retrospective nature of the study and the relatively small sample size.
As with many brachycephalic dog breeds, shih tzus are prone to ocular disease. Rajaei et al5 performed a retrospective analysis of 500 client-owned shih tzu dogs, representing 1,000 eyes, to assess the frequency of ophthalmic disorders in the breed – 96.4% of eyes had at least one abnormality with only 36 eyes found to be normal. In total, 59 different diagnoses were made, but at least one of three conditions (medial canthal entropion, caruncular trichiasis and reduced tear film break-up time) were found in nearly half of the eyes. Other disorders noted commonly included keratoconjunctivitis sicca, pigmentary keratitis and mature cataract.
The weekend effect refers to a difference in medical outcomes for patients admitted at weekends compared to during the week, which may be related to availability of staff at weekends, although the extent and causes of the effect remain controversial. Low and Rutherford6 performed a retrospective cohort study to assess whether surgery at weekends for acute thoracolaumbar intervertebral disc extrusion (IVDE) was associated with a poorer outcome than weekday surgery.
Included were 460 consecutive cases, with 401 undergoing surgery during the week and 59 at weekends – 79% of dogs operated on a weekends recovered ambulation compared to 92% of dogs operated on during the week, with an adjusted odds ratio of 3.01. Dogs operated on at weekends also had a higher risk of postoperative morbidity.
The authors conclude that dogs operated on at weekends seem to have poorer patient outcomes than those operated on during the week. They suggest that this should be considered when making decisions regarding treatment of acute thoracolumbar IVDE.
Fireworks are commonly released at major events and festivals throughout the year, and it is common for pet owners to seek veterinary advice at these times, since dogs and cats frequently demonstrate firework aversion.
Signs of firework aversion include behaviours such as inappetence, freezing, hiding and inappropriate elimination. Van Herwijnen et al7 performed a study aimed to collect reports from Dutch owners of dogs and cats on firework exposure, behaviours related to fireworks, and owner attitudes to fireworks.
Responses on 3,009 dogs and 622 cats were received. Suboptimal early life experience (for example, lack of noise habituation as a young animal) was associated with an increased risk of firework aversion in dogs, but not cats. Owners of dogs and cats that had less firework aversion were more likely to agree with the statement that owner behaviour effects an animal’s future reactions to fireworks.
It was also noted that fireworks were heard in multiple months of the year in the Netherlands. Less than 30% of interventions aimed at reducing firework aversion were reported to have a long-term effect.
The authors note that this study does not include direct observations, but may be useful to direct future research into firework aversion.
