Parasites of the genus babesia is a type of blood protozoans that can infect red blood cells of vertebrate hosts. Two species of babesia have been reported to infect dogs: Babesia Canis and Canine Babesia gibsoni.Traditionally, these creatures have been distinguished by their appearance on blood-stained smears.The firstly creatures are larger, appearing as two-leafed piriform creatures, often in pairs, about 4-5 um in length. The organisms of Canine Babesia gibsoni are smaller (1-2.5 um in diameter) and are round, oval, or ring-shaped in red blood cells, usually as a single plant. Babesia Canis is endemic in Europe, southern Africa, Asia and the Americas. There are 3 subtypes of Babes:B. canis canis, B. canis vogeli, and B. canis rossi. These strains differ in virulence, geographic location, and tick vectors, but are identical in appearance. In the United States, the most common strain is Lactobacillus Canis, which is the least pathogenic. Although severe hemolytic anemia, thrombocytopenia and life-threatening diseases have been reported in young dogs, severe parasitism in dogs, and transfusions of infected blood in dogs.In the United States, most dogs infected with B. Canis are subclinical carriers. Although not highly pathogenic, the canine B. canis vogeli organism appears to be endemic in the southeastern United States, particularly among greyhounds. A recent study distinguished three subspecies of Babesia Canis by polymerase chain reaction and restriction enzyme analysis, suggesting that they may in fact be closely related, but distinct and independent species. The most pathogenic dog type B is endemic to South Africa. Babesians are found in parts of Europe and Asia and are considered intermediate pathogenic.So it is a big challenge to diagnose of this disease.The purpose of this article was to introduce the current diagnostic evidence and the relating to the treatment of Canine Babesiosis in dogs.
Key words : Canine Babesiosis, diagnosis, treatment
Age：4 years old
History：outdoor activities,complete vaccination,no deworming,gastroenteritits one year ago
Owner took her to countryside half month ago, playing in the outdoors during that time.Two days ago,the dog started to appear lethargic and weak.Owner found it walk in a incoordinate post when walking dog.So decide to took her to the hospital.Vaccinate history is completed.No deworming in this year.
Body weight 25.5kg，temperature 39.7℃，respiratory rate was 80/min, heart rate：110 beats/min.No obvious murmurs in breathing .Mouth mucosa was pale，capillary refill time（CRT）<2s, body condition score（BCS）was 6/9 which can no touch the ribs in palpation.The patient was presented with depression dry coat and nose. Abdominal palpation was no obvious abnormal findin in abdomen.There were mild dental calculus and gingivitis in oral examination.Multiple areas of skin were soft. Obvious dehydration was not found.
Complete Blood Count (CBC) examination for Day 1
Interpretation: No obvious abnormality was observed in the leukocyte line. Severe low red blood cell count and HCT indicate positive cell hypochromic anemia and low blood volume, which may indicate iron deficiency anemia or anemia caused by chronic diseases Low platelet count
Idexx Catalyst biochemistry CHEM15
Interpretation:There was a slight increase in globulin, no obvious abnormalities in other biochemical indicators, no obvious specificity and sensitivity, suggesting the existence of inflammatory diseases in the body
The result of the CRP testing
Interpretation: The increased of CRP significantly, indicating the existence of serious acute inflammation or tissue cell damage.
Blood agglutination test
Microscope of the blood smear
Interpretation:Multiple nucleated red cells were seen at high field.Red blood cells of different sizes, a large number of spherical red blood cells, a small number of oral red blood cells. The presence of “ring” like contents in multiple red blood cells was observed.
The PCR result of infectious examination
Canine Babesia gibsoni
The diagnosis methods in Canine Babesia gibsoni usually used in clinical are consist of the physical examination findings history, laboratory examination such as complete blood count, cytology. Biochemistryprofile,urinalysis,polymerase chain reaction(PCR)assays.And we will also take serology and radiography examinations to have a full understanding of the patients.In general speaking,the evidence of anemian, the”ring-like”performance in the red blood cell,the highly elevate of the CRP and hyperglobulinemia are indicated to the babesia infection .
Although it is relatively easy to diagnose babesia under the microscope performance with “ring” like which can be directly seen from blood smear, for different species and strains, the pathogen may not be detected in the first time. Therefore, more clinical auxiliary examinations, such as urine detection and abdominal ultrasound examination, are required. On the one hand, more detailed of the pathogen conditions can be screened to prevent missed diagnosis happening. Further more, it could be found to make us suspect babesiosis early.
1.Blood transfusions 2mL/kg ivgtt
Relieve tissue hypoxia through blood transfusion: Blood type detection and cross-matching test were conducted actively in donor dogs. The red blood cell volume of 2ml/kg·BW was increased by 1%, and the dose of whole blood needed to be input was calculated.The elevation of HCT is limited because the affected dog is too heavy to get more whole blood for infusion
2.Gastroprotectants of omeprazole:1mg/k’g s.c q24hrs
3.Diminazene aceturate :3.5mg/kg i.m
4.LRS + 0.9% NaCl solution(1:1) 60mL/kg ivgtt
5.Clopidogrel 2mg/kg p.o q24hrs
The principle therapy is to manage to eliminate the pathogen as possible and maintain body function.
For the later stage of treatment and the period of acute infection, it is still recommended to carry out regular CBC and PCR examination, because any treatment can not completely eliminate the insect body, and regular deworming is needed to prevent secondary infection.Although the mechanism of action of drugs on babesiosis is largely unknown or not studied in detail, atovaquone and azithromycin are more recommended for babesiosis in dogs with relatively less side effects, but it has been suggested by veterinarians that the recurrence rate of treatment with this regimen is higher than treatment with triazmidine alone. If triazamidine is used alone for treatment, caution should be exercised with repeated administration because triazamidine has a narrow safety range, many side effects, and increased neurological and parasympathetic toxicity at cumulative doses of more than 7mg/kg, and repeated administration within 6 weeks is not recommended.For the treatment of babesia gibsoni, a new drug regimen has been proposed in recent years: Clindamycin combined with triazamidine and midoca. The specific mechanism of action is not completely clear, and there are few clinical trials, which need further study and research.Severe hemolytic anemia may require blood transfusion. The use of glucocorticoids is controversial because it may aggravate parasitic diseases. Assess and correct dehydration and acidosis. Start special treatment for any co-morbid disease (e.g., Eliktic disease, leishmaniasis, hepatic zoonosis). And we should not ignore the treatment of serious complications such as acute renal failure,pancreatitis,DIC.
The prognosis of this case is good,and recovery on day 7.In the report,the prognosis depends on the strain of infection and the immune capacity of the patient. Individuals with splenectomy usually have a poor prognosis.
The examination during the therapy
Complete Blood Count (CBC) examination after therapy
Definition and Etiology
Babesiosis is caused by hematoprotozoa which is inside the red blood cells. One to five species of babesia can be divided into large and small. Both dogs and cats can be infected with both viruses, although cats are rarer than dogs. Babesia is the second most common mammalian blood parasite in the world.Transmission can be mainly through tick bites, blood contamination (e.g. from a blood donor, fighting), or transplacenta. Once the host is infected, the incubation period is 7-21 days. The tick species associated with transmission are ridgehead, ixodes, dermis, haemaphysalis and hyaluronoma ticks. The most common vector in the United States is the haemaphysalis.
The babesia inside the erythrocyte is ingested by a vector, usually ticks of the ixodidae family, from the blood of an infected host. Infected red blood cells are usually digested and destroyed in the tick’s midgut. A few surviving cells turn into gametes, followed by zygotic fusion. Then they invade the midgut epithelium. The fertilized egg undergoes meiosis, transforms into a motile oocyte, and passes through the carrier’s blood sac. Babesia reproduce asexually, which causes sporospores to spread to all organ systems within the carrier, where they remain for life. Interestingly, ticks infected with babesia tend to mature less, although some ticks are developing a tolerance to the protozoa. After spreading to different organ systems, macrobabesia can be transprogenically transmitted to infect future carrier offspring. The salivary glands are the most critical of the organs into which the sporospores enter, as they become the source of future infections. Within the salivary glands Babesia undergoes a final stage of replication to produce spores. These spores enter the host through saliva during the vector’s bloodsucking on the host. The infection process may require vector feeding for 2-3 days. Sporozoites enter the red blood cells of the host and multiply by binary fusion. The reproduction and reproduction of babesia in the blood leads to the clinical symptoms of the disease. These signs are mainly associated with hemolytic anemia and thrombocytopenia. Pathogenicity varies from strain to strain. Infection may be more severe and may occur clinically in patients with prior splenectomy or splenectomy.
Some infections are subclinical. When clinical disorders occur, there are usually two forms, whose name is hemolytic anemia (most common) and multiple organ dysfunction (rare). The most severe clinical form is usually caused by Echinococcus Canis. Occasionally, disseminated intravascular coagulation (DIC) may occur with hemolytic and vascular damage, followed by platelet destruction and clotting factor depletion.
For many cases，the most important thing is to prevent the disease such as deworming on time especially for the situation that walking dogs outdoors,instead of treating.Topical and environmental acaricide prophylactics can be used to minimize exposure to tick vectors. Examples include: 1) Afozoolana (Nexguard) was shown in a small study to prevent transmission and clinical development of canine babesiosis for 28 days after a single treatment. 2) In two small studies, lotillaner (Credilio) provided 100% protection against B. Canis infection during experimental tick infection. 3) In another small study, Babesia Canis infection is prevented when Simparica was administered 21 or 28 days prior to tick exposure. 4) Oral and oral fluramide (Bravecto) can also prevent transmission of B. Canis from infected ticks.) Combination products containing fipronil and permethrin (Frontline) are also valid.
Carefully assess pets after exposure and remove ticks promptly. Testing blood donors is necessary before using them. Vaccines using soluble parasite antigen (SPA) of different species of babesia have been used in the past, but with varying efficacy, probably due to the genetic diversity of the parasite. A new form of this vaccine is being studied, which utilizes SPA’svaccine-challenged supernatant. This approach was moderately successful in a small study of dogs.