Studies into commonly occurring conditions in canines and felines

Kluth et al¹ performed a study to report the frequency of the genetic mutation for the disease in Tibetan terriers registered with the German Tibetan Terrier Club, and to assess response to selection after DNA testing was introduced in 2010. A total of 1,120 out of 1,240 dogs registered with the club had DNA tests performed and 405 out of 420 registered breeding dogs were included.

Before the introduction of testing, the frequency of the mutant allele was found to be 0.20 and 0.28 in the registered and breeding populations, respectively. After the introduction of testing, this had fallen to 0.09 and 0.15, respectively. DNA testing in this case seems to have led to a reduction in the frequency of the mutation for canine ceroid lipofuscinosis in Tibetan terriers.

Oral and retroviral relationship

Retroviruses in cats – feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV) – can lead to a range of clinical signs and diseases. Kornya et al² performed a cross-sectional survey to assess the association between the oral health of cats and their FIV and FeLV status. More than 5,000 cats were included in the study, and these were scored for oral health status and tested by ELISA for retroviral status.

It found 4.6 per cent of the cats to be seropositive for FIV and 3.6 per cent for FeLV; 0.2 per cent were seropositive for both. A total of 21 per cent of the cats had gingivitis and 11 per cent had periodontitis; four per cent had stomatitis and five per cent had other oral disease. Inflammatory oral disease was associated with a significantly increased risk for a positive test result for FIV, when compared to the risk of FIV for other oral disease or no oral disease.

Also, cats with oral inflammatory disease were more likely to have a positive result for FeLV than cats without oral disease. Cats that were negative for the retroviruses had a higher prevalence of oral disease as they got older. The authors concluded cats with inflammatory oral disease should be tested for retroviral disease and managed appropriately.

Syringomyelia characteristics

Chiari-like malformation (CM) and syringomyelia (SM) are commonly found in cavalier King Charles spaniels, causing signs of neck pain and persistent scratching. The Brussels griffon breed is also thought to be prone to the same condition. Freeman et al³ performed a prospective study to determine the clinical and MRI characteristics of CM and SM in the American Brussels griffon.

A total of 84 dogs of this breed were recruited into the study. Medical histories were taken, neurological examinations were performed and MRIs were then obtained. CM was present in 65 per cent of the dogs, and SM in 52 per cent. A total of 28 per cent of dogs had neurological deficits and 20 per cent had neck pain. Larger syrinx size tended to be associated with neurological deficits, as well as with increased age. The authors note 52 per cent of dogs with SM were clinically normal.

Mitral valve disease

Myxomatous mitral valve disease is a common degenerative condition – particularly in small breed dogs. Mitral regurgitation leads to enlarged left atrial size and, occasionally, this can lead to left atrial rupture. Nakamura et al⁴ performed a retrospective study to assess the outcome of dogs with left atrial rupture secondary to mitral valve disease. Eleven dogs were included in the study.

Ten survived the initial 24 hours; the median survival time was 203 days. Dogs with no previous history of congestive heart failure at the time of diagnosis of the rupture had a longer median survival time of 345 days. The authors note the prognosis for left atrial rupture is better than previously reported – especially in dogs without congestive heart failure before or at the time of rupture.

Closed suction drainage

Septic peritonitis is a serious condition with a high morbidity and mortality rate. Closed suction drainage has been used to attempt to improve the outcome in these cases. Adams et al⁵ published a retrospective case series to determine the survival rate in dogs with septic peritonitis originating from the gastrointestinal tract. Twenty dogs were included in the study.

Dehiscence of a previous anastamosis was the cause of the peritonitis in 80 per cent of cases. The drains were left in place for between two and 11 days. Most dogs received nutritional support and 14 were given plasma transfusions; 85 per cent of dogs survived to discharge. The authors concluded closed suction drainage in combination with correction of the underlying cause of the peritonitis and other adjunctive treatment is effective for managing septic peritonitis of gastrointestinal origin in dogs.

Splenectomy

The spleen is a common site of neoplasia in dogs, leading to sequelae such as abdominal haemorrhage or metastasis, as well as ventricular arrhythmias. Splenectomy is therefore frequently carried out in these cases. Wendelburg et al⁶ published a retrospective case series of 539 dogs to determine risk factors and mortality rate for dogs that had undergone splenectomy because of the presence of splenic masses.

Eight per cent of the dogs died perioperatively. The most common causes of death were thrombosis, coagulopathy and haemorrhage from metastatic lesions. Preoperative platelet count, preoperative PCV and the occurrence of ventricular arrhythmias intraoperatively were all significantly associated with the outcome, and each decrease in platelet count of 10,000/ul was associated with a six per cent increase in risk of death.

Dogs with PCV less than 30 per cent had a mortality rate twice as high as dogs with a PCV greater than 30 per cent, and dogs with ventricular arrhythmias noted during surgery were twice as likely to die as those without. The authors conclude aiming to reduce thrombosis, coagulopathies and haemorrhage may decrease the risk of death from splenectomy.

• Please note some of the medications in this article are not licensed for veterinary use.

References

• 1. Kluth S, Eckardt J and Distl O (2014). Selection response to DNA testing for canine ceroid lipofuscinosis in Tibetan terriers, Vet J 201(3): 433-434.
• 2. Kornya M R, Little S E, Scherk M A et al (2014). Association between oral health status and retrovirus test results in cats, J Am Vet Med Assoc 245(8): 916-922.
• 3. Freeman A C, Platt S R, Kent M et al (2014). Chiari-like malformation and syringomyelia in American Brussels griffon dogs, J Vet Intern Med 28(5): 1,551–1,559.
• 4. Nakamura R D, Tompkins E, Russell N J et al (2014). Left atrial rupture secondary to myxomatous mitral valve disease in 11 dogs, J Am Anim Hosp Assoc 50(6): 405-408.
• 5. Adams R J, Doyle R S, Bray J P and Burton C A (2014). Closed suction drainage for treatment of septic peritonitis of confirmed gastrointestinal origin in 20 dogs, Vet Surg 43(7): 843–851.
• 6. Wendelburg K M, O’Toole T E, McCobb E et al (2014). Risk factors for perioperative death in dogs undergoing splenectomy for splenic masses: 539 cases (2001 to 2012), J Am Vet Med Assoc 245(12): 1,382-1,390.