Urinary Fractional Clearance of Sodium in 8 Healthy Beagle Dogs Fed Normal, Low, or Ultralow Sodium Diets.

The purpose of this study was to investigate in healthy adult dogs if there was a daily fluctuation in the FCNa, the role that dietary sodium intake played on the FCNa, and the role that feeding played on the obtained value for FCNa. Three different diets were used in a group of 8 healthy beagle dogs in a crossover design. The sodium content of the diets was normal (0.26%), low (0.18%), and ultralow (0.06%). Spot urine and blood samples were collected from which the urine and serum sodium and creatinine concentration were determined, and the FCNa was calculated. The median FCNa for the normal, low, and ultralow sodium diets was 0.5, 0.77, and 0.15, respectively. Individual dogs showed a daily variation in FCNa, and samples which were collected shortly after eating showed the greatest variation. This study showed that in a group of healthy beagle dogs without obvious renal disease, the FCNa could exceed 1 and that there was both an individual and daily variation in the FCNa. The greatest variation was seen whilst the dogs were fed the low and ultralow sodium diets and when the samples were collected shortly after eating. This study concluded that an FCNa > 1% may not be indicative of acute tubular dysfunction in young dogs, and use of the FCNa for assessing renal function in clinical cases should take into account the animal's diet, as well as the time the samples were taken in relation to feeding.

Hypercalcaemia in a dog with primary hypothyroidism.

A 7-year-old female beagle was evaluated for symptomatic hypercalcaemia and primary hypothyroidism. Clinical findings were typical for hypothyroidism. Plasma parathyroid hormone was low and obvious causes for the hypercalcaemia were ruled out by means of abdominal ultrasonography, ultrasonography of the parathyroid glands, survey thoracic radiographs, and fine needle aspirate cytology of the spleen, liver, and peripheral lymph nodes. Treatment with thyroxine resulted in resolution of the hypercalcaemia after approximately 9 weeks of therapy. This is the 1st report of primary adult-onset hypothyroidism associated with symptomatic hypercalcaemia in a dog.

Lymphoma in 3 related Rottweilers from a single household.

Over a period of approximately 1 year, 2 sibling Rottweilers and their dam in the same household developed stage IV and stage III lymphoma, respectively. All 3 initially responded to doxorubicin chemotherapy but relapsed after approximately 3 months and were subsequently euthanased. As no obvious environmental trigger could be identified in these dogs, it is speculated that an underlying genetic predisposition could have played a role in the development of lymphoma in these related dogs.

Myotonia congenita in a Jack Russell terrier.

A 4-month-old male Jack Russell terrier was evaluated for non-painful muscle spasms and collapse associated with exercise and activity. Clinical examination revealed well-defined, non-painful hypertrophic muscles of the fore and hind limbs and exercise and excitement induced hindquarter bunny-hopping gait, which improved with activity but worsened with resting and with any sudden changes in direction of movement. Neurological examination and routine laboratory testing showed no abnormalities. DNA analysis for myotonia congenita showed the dog to have a gene mutation in the chloride ion channel, diagnostic for myotonia congenita, which has not been reported in the Jack Russell terrier breed.

A retrospective study of chronic nasal disease in 75 dogs.

Chronic nasal disease is a common problem in dogs. To determine the aetiology, a retrospective study in 75 dogs with persistent and chronic nasal disease was done. All dogs were evaluated by means of survey nasal radiographs, antegrade and retrograde rhinoscopy, bacterial and fungal cultures, and histopathology. A definitive diagnosis was made in 74/75 cases (98.6%). Nasal neoplasia was the most common diagnosis (46.7%), median age 108 months, followed by lympho-plasmacytic rhinitis (20%), median age 112 months, and fungal rhinitis (10.7%), median age 53.5 months. Other diagnoses included nasal foreign body (5.3%), median age 51 months, and primary bacterial rhinitis (6.7%), median age 116.5 months. Rare aetiologies identified were nasal polyps, granulomatous rhinitis, oro-nasal fistula and naso-pharyngeal stenosis. This study showed that by using a structured combination of survey radiography, rhinoscopy, cultures and histopathology, a diagnosis could be made in dogs with chronic nasal disease.

Anaerobic bacterial pericardial effusion in a cat.

A 9-year-old male cat was presented for evaluation of chronic weight loss and was subsequently diagnosed with pericardial effusion. The effusion was quantified as a septic exudate caused by the anaerobic bacterium Peptostreptococcus. Antibiotic therapy resulted in complete resolution of the pericardial effusion. As Peptostreptococcus is a common oral bacterium and the cat had a previous dental procedure, it is speculated that the pericardial effusion was secondary to bacteraemia from the dental procedure.

Ipsilateral vascularised ulnar transposition autograft for limb-sparing surgery of the distal radius in 2 dogs with osteosarcoma.

Canine osteosarcoma is the most commonly diagnosed primary bone tumour in the dog, affecting mainly large and giant breed dogs with the predilection site being the metaphysis of long bones, specifically the distal radius, proximal humerus, distal femur and proximal tibia and fibula. Treatment options are either palliative or curative intent therapy, the latter limb amputation or limb-sparing surgery together with chemotherapy. This article describes the use of an ipsilateral vascularised ulnar transposition autograft as well as chemotherapy in 2 dogs with osteosarcoma of the distal radius. Both dogs showed minimal complications with the technique and both survived over 381 days following the surgery. Complications seen were loosening of the screws and osteomyelitis. The procedure was well tolerated with excellent limb use. This technique is indicated for use in cases with small tumour size that have not broken through the bone cortex.

Nephro-cutaneous fistula in a dog.

Nephro-cutaneous fistula, although reported in humans, has not been reported in the dog. In humans the majority of cases develop in patients with a history of previous renal surgery, renal trauma, renal tumours, or chronic urinary tract infection with abscess formation. The dog in this report developed a nephro-cutaneous fistula secondary to a traumatic induced renal abscess with formation of a draining sinus tract to the exterior of the body. The animal underwent simple nephrectomy, which resulted in complete resolution of the fistula.

The elevated serum urea:creatinine ratio in canine babesiosis in South Africa is not of renal origin.

Pigmented serum, usually due to free haemoglobin and/or bilirubin, is a common finding in dogs with babesiosis, resulting in interference with all biochemical tests that rely on photochemistry. This is particularly true of urea and creatinine determinations, complicating the diagnosis of acute renal failure, which is a serious complication of babesiosis. A disproportionately raised serum urea concentration of unknown origin occurs in severely anaemic canine babesiosis patients and gives rise to an increased serum urea:creatinine ratio. The assay for cystatin-C, an excellent measure of glomerular filtration rate, is unaffected by free serum haemoglobin, and due to its different intrinsic origins, is free of influence by the metabolic derangements and organ pathology, other than renal disease, encountered in canine babesiosis. Serum cystatin-C was used to compare the concentrations of serum urea and serum creatinine in dogs with the severely anaemic form of canine babesiosis as well as a canine babesiosis-free reference group. Mean serum urea and mean serum urea:creatinine ratio were significantly elevated in the babesia-infected group relative to the reference population in this study. Mean serum creatinine and mean serum cystatin-C were within the reference ranges. Therefore an elevated urea:creatinine ratio in canine babesiosis in the presence of a normal serum creatinine concentration is considered to be caused by an elevated serum urea concentration and is most likely of non-renal origin. Serum creatinine was therefore as specific a measure of renal function as serum cystatin-C in canine babesiosis in this study. The sensitivity of serum creatinine as a measure of renal function was not established by this study. Serum urea, however, proved to be of little use compared to serum cystatin-C and serum creatinine. Serum urea should therefore not be used to diagnose renal failure in canine babesiosis.

The pharmacokinetics of diminazene aceturate after intramuscular administration in healthy dogs.

The pharmacokinetics of diminazene aceturate following intramuscular (i.m.) administration at 4.2 mg/kg was evaluated in 8 healthy German Shepherd dogs. Blood samples were collected at 19 intervals over a period of 21 days. Diminazene plasma concentrations were measured using a validated HPLC method with UV detection and a sensitivity of 25 ng/ml. The in vitro and in vivo binding of diminazene to blood elements was additionally determined. Diminazene pharmacokinetics showed a large inter-individual variation after i.m. administration. It had a short absorption half-life (K01-HL of 0.11 +/- 0.18 h), resulting in a C(max) of 1849 +/- 268.7 ng/ml at T(max) of 0.37 h and a mean overall elimination half-life (T1/2beta) of 5.31 +/- 3.89 h. A terminal half-life of 27.5 +/- 25.0 h was measured. At 1 h after i.m. injection, 75% of the diminazene in whole blood was in the plasma fraction. The results of this study indicate that diminazene is rapidly distributed and sequestered into the liver, followed by a slower terminal phase during which diminazene is both redistributed to the peripheral tissues and/or renally excreted. It is recommended that diminazene administered i.m. at 4.2 mg/kg should not be repeated within a 21-day period.

Cardiac involvement in canine babesiosis.

Cardiac dysfunction in canine babesiosis has traditionally been regarded as a rare complication, with the majority of lesions reported as incidental findings at post-mortem examination. Recent studies have, however, demonstrated cardiac lesions in canine babesiosis. Cardiac troponins, especially troponin I, are sensitive markers of myocardial injury in canine babesiosis, and the magnitude of elevation of plasma troponin I concentrations appears to be proportional to the severity of the disease. ECG changes in babesiosis are similar to the pattern described for myocarditis and myocardial ischaemia and together with histopathological findings indicate that the heart suffers from the same pathological processes described in other organs in canine babesiosis, namely inflammation and hypoxia. The clinical application of the ECG appears to be limited and thus cardiovascular assessment should be based on functional monitoring rather than an ECG tracing. On cardiac histopathology from dogs that succumbed to babesiosis, haemorrhage, necrosis, inflammation and fibrin microthrombi in the myocardium were documented, all of which would have resulted in ECG changes and elevations in cardiac troponin. Myocardial damage causes left ventricular failure, which will result in hypotension and an expansion of the plasma volume due to homeostatic mechanisms.

Diagnosis of feline haemoplasma infection using a real-time PCR assay.

Haemobartonella felis has been reclassified within the genus Mycoplasma as Mycoplasma haemofelis and 'Candidatus Mycoplasma haemominutum', collectively referred to as the feline haemoplasmas. A total of 78 cats from the Johannesburg area that had blood samples submitted to a private veterinary laboratory were tested using a real-time polymerase chain reaction (PCR) assay able to detect and distinguish the two feline haemoplasma (basonym Haemobartonella) species. All samples had been diagnosed with haemoplasma infection by cytological examination of blood smears. Statistical analysis was performed to evaluate associations between haemoplasma status, age, and haematological and biochemical parameters. On PCR assay 43 cats (55%) were haemoplasma negative, 25 (32.1%) positive for 'Candidatus Mycoplasma haemominutum', 5 (6.4%) positive for Mycoplasma haemofelis and 5 (6.4%) positive for both species. Significant inverse correlation was found between the amount of M. haemofelis DNA present in the blood and the haematocrit value. Cats that were positive for M. haemofelis showed macrocytic regenerative anaemia, monocytosis and thrombocytopaenia. This report documents the existence of both haemoplasma species in cats in South Africa.

Retrospective study of snake envenomation in 155 dogs from the Onderstepoort area of South Africa.

A retrospective study was undertaken to evaluate the incidence, signalment, haematological and biochemical changes, therapy, and outcome of dogs presented to the Outpatients section of the Onderstepoort Veterinary Academic Hospital for confirmed snake envenomation. Three hundred and seventy-six records of dogs presented for snake envenomation from 1998 to 2002 were reviewed and 155 were selected on the basis of there being a positively identified snake. The 2 most commonly encountered snake envenomations in dogs were puff-adders (Bitis arietans) and snouted cobras (Naja annulifera annulifera). The majority of cases (56%) occurred in the autumn (March to May), with most being bitten by puff-adders. Dogs were 3 to 168 months old with a median of 36 months. No sex predilection was identified. Ten per cent of cases died because of the snake envenomation. Fifty-seven per cent and 43% of snakebites were puff-adders and cobras, respectively. There was no difference in mortality between the 2 groups of snakes. Of the cobras 60% were the snouted cobra, 14% Mozambique spitting cobra, and 24% rhinkals. Swelling in the area of the bite, usually the face and forequarters, was the primary clinical abnormality. Significant haematological findings were leukocytosis (median 17.3 x 10(9)/l; range 0.4-44), neutrophilia (median 13.6 x 10(9)/l; range 0.3-39.9), band neutrophilia (median 0.4 x 10(9)/l; range 0-5.32), and thrombocytopaenia (median 124 x 10(9)/l; range 3-555). Dogs envenomated by a puff-adder and Mozambique spitting cobra had a greater degree of thrombocytopaenia: median of 68 and 66, respectively, versus 243 for the cobra group. The most commonly used treatments were intravenous fluids, antibiotics and glucocorticoids. Thirty-eight dogs were treated with polyvalent antiserum: 9 for puff-adder envenomation and 29 for cobra envenomation. Only 2 of the dogs that received antisera died, both of them of cobra envenomation. The study concluded that snake envenomation in dogs is associated with high morbidity but moderate mortality rate and that the most significant haematological abnormality is thrombocytopaenia.

Are urea and creatinine values reliable indicators of azotaemia in canine babesiosis?

Serum urea and creatinine are extensively used as parameters to screen for azotaemia. Their reciprocal plots roughly correlate with glomerular filtration rate (GFR). They are, however, subject to influence by non-renal factors and to increase their specificity they are often tested concurrently. In renal disease they are expected to behave similarly, with both parameters increasing as GFR decreases. Haemolysis, as it occurs in canine babesiosis, may cause non-renal elevations in serum urea, possibly due to ammonia loading. Furthermore, haemolysis with its related elevations in serum bilirubin and serum haemoglobin, may negatively bias the measurement of serum creatinine due to interference of these substances with the chemical analysis of serum creatinine. This negative bias occurs when the alkaline picrate method, or when direct enzymatic methods based on the measurement of hydrogen peroxide, are used. In order to investigate the significance of these perturbations in canine babesiosis, paired values of serum urea and serum creatinine from Babesia canis-negative, non-haemolysis dogs (Group 1), were used to establish a relationship between urea and creatinine over a range of azotaemia by linear regression analysis. This relationship was then used to predict serum creatinine values from actual serum urea values in B. canis-positive dogs (Group 2). The mean of the predicted serum creatinine values for Group 2 (237.03 micromol/l) was then compared with the mean of the actual serum creatinine values for Group 2 (131.31 micromol/l). For Group 2, the mean actual serum creatinine demonstrated a significant negative bias relative to the mean predicted creatinine value. There was also a higher correlation between serum urea and serum creatinine in Group 1 than in Group 2. These findings may have been caused by either nonrenal elevations of serum urea values or by interference with the measurement of serum creatinine. Therefore, although it is possible that some Group 2 dogs with B. canis with high serum urea and normal, low, or zero values for serum creatinine were not azotaemic, it is also possible that other Group 2 dogs with these biochemical findings did in fact have azotaemia. This study concluded that urea and creatinine do not behave in a similar and predictable manner over a range of azotaemia in canine babesiosis and are therefore not ideally suited for the detection of renal disease in this clinical setting.

Primary ciliary dyskinesia in a Staffordshire bull terrier.

Primary ciliary dyskinesia (PCD) is a diverse group of inherited structural and functional abnormalities of the respiratory and other cilia, which results in recurrent respiratory tract infections. Primary ciliary dyskinesia was diagnosed in a 14-week old Staffordshire bull terrier that had a history of respiratory disease from 7 weeks of age. Pneumonia was diagnosed on thoracic radiographs and transtracheal aspirate. Transmission electron microscopy of the bronchi and trachea indicated the presence of both primary and secondary ciliary dyskinesia. The most prominent primary defects consisted of absent inner dyneim arms, absent radial spokes and absence of the central microtubules. These defects accounted for 62% of the total number of cross-sections screened. Non-specific ciliary abnormalities encountered most often were compound cilia, swollen cilia, addition/deletion of peripheral doublets and disorganised axonemes (26%). To the authors' knowledge, this is the first case of PCD described in the Staffordshire bull terrier and the first report of PCD in South Africa.

Congenital narrowing of the intrapharyngeal opening in a dog with concurrent oesophageal hiatal hernia.

A one-year-old, male, smooth-haired standard dachshund was presented with a history of chronic hypersalivation, dysphagia, puffing of the cheeks on expiration, and inspiratory stridor. Oral examination revealed a moderately thickened tongue radix and that the normal intrapharyngeal opening was obliterated. A 7 mm long, midline palatal slit was the only communication between the naso- and oropharynx. The soft palate was fused to the caudal pharyngeal wall. A concurrent hiatal hernia was diagnosed on thoracic radiographs. The soft palate abnormality was surgically corrected and the hiatal hernia was managed medically. On follow-up evaluations, the clinical signs had markedly improved, and the hiatal hernia was no longer visible on survey thoracic radiographs.

Phylogenetic analysis of hemoplasma species: an international study.

Nearly complete 16S rRNA gene sequences for feline and canine hemoplasma isolates from Europe, Australia, Africa, and Asia showed almost 100% identity to those previously reported for United States isolates. Partial sequences of the RNA subunit of the RNase P gene were also determined, and RNase P-based phylogenetic analysis showed that the hemoplasmas are most closely related to the members of the Mycoplasma pneumoniae group.

The effects of diminazene aceturate on systemic blood pressure in clinically healthy adult dogs.

Diminazene aceturate is a commonly used antibabesial agent. It has been postulated that diminazine may induce a decrease in blood pressure and exacerbate the hypotension presented in dogs with babesiosis. This study was undertaken to assess the effect of diminazine aceturate on the blood pressure of healthy dogs. Six healthy German shepherd dogs between 18 and 24 months of age with a mean weight of 30.4 +/- 2.75 kg were used. Blood pressure was directly measured at the following time intervals: -5, 0, 5, 10, 15, 20, 25, 30, 35, 40, 50, 60, 90 and 120 minutes after treatment with diminazine aceturate (4.2 mg/kg) intramuscularly. No statistical difference (P > 0.05) was found in blood pressure between any of the time intervals. An increase in heart rate was seen 5 minutes after the administration of diminazine aceturate but no change in blood pressure was evident. This study concluded that diminazene aceturate in its current formulation with antipyrine does not alter blood pressure in healthy adult dogs.

The prevalence of subclinical gastroduodenal ulceration in Dachshunds with intervertebral disc prolapse.

Endoscopy was used to determine the prevalence of subclinical gastroduodenal ulceration in 30 Dachshunds undergoing decompressive surgery for acute intervertebral disc prolapse. The endoscopy was performed on the day of admission and on the 3rd or 4th day after surgery. Three regions of the stomach (cardia, corpus and pylorus) and the proximal duodenum were visually inspected and biopsy samples were taken for histopathology. The combination of visual and microscopic changes were then used to determine the prevalence of subclinical gastroduodenal ulceration in this population. An overall prevalence of 76% was calculated from these findings. Ulcerogenic medication administered prior to admission did not appear to influence the prevalence. This result identifies a need for veterinarians to be aware of this potentially severe complication and warrants the use of prophylactic anti-ulcer medication in spinal surgery patients.

Renal T-cell lymphoma with cerebral metastasis in a dog with chronic canine ehrlichiosis.

A renal T-cell lymphoma with exclusive cerebral metastasis was diagnosed in a 5-year-old Staffordshire bull terrier bitch euthanased for aggression. This is the first recorded case of primary renal lymphoma in a dog. Immune suppression, due to chronic canine monocytic ehrlichiosis, may account for the unusual primary site and metastatic pattern of the tumour.