Without a doubt, the viral infections that afflict dogs are one of the types of pathology that cause the most concern to canine guardians. Many of these pathologies are well known, although this does not mean that the less popular ones are less dangerous. All viral pathologies that are not treated in time threaten the life of the animal. The symptoms of viral infections are quite similar depending on the system they affect. Since most are digestive, they are often confused and require the expertise of a veterinarian to be diagnosed and treated correctly.
In this article on our site we will discuss the viruses in dogs, the most common viral diseases that affect these animals, their symptoms and its diagnosis. It is important for the dog's guardian to be able to acquire the skills to be suspicious in case a serious illness is taking hold in her best friend
Canine coronavirus
It is a highly contagious disease with an acute course caused by the canine coronavirus (CCoV), which is recognized as the agent aetiology of small intestine infections causing gastroenteritis (not to be confused with COVID-19, which causes respiratory disease in humans). Its incubation period ranges between 24 and 36 hours. This virus in dogs manages to damage the villi of the intestine, which ends up causing an alteration in the absorption of nutrients.
Symptoms
The symptoms are nonspecific and it is very difficult to differentiate it from other causes of infectious enteritis. However, the symptoms of this virus in dogs are usually the following:
- Foul-smelling diarrhoea, although rarely bloody
- Vomiting
- Abdominal pain
- Anorexy
- Fever
In severe cases, diarrhea can be watery and lead to dehydration and electrolyte imbalances.
Diagnostico: the diagnosis of this condition, like most viruses, is based on the patient's symptoms. Laboratory tests such as hematology and blood chemistry are mandatory, which allow us to know if the clinical signs are associated with a virus or another cause.
Canine parvovirus
It is one of the most frequent and popular infectious diseases in dogs and one of the main causes of death in puppies (the most affected are usually puppies from weaning to 12 weeks). The cause of canine parvovirus is parvovirus type 2 (CPV-2), discovered in the late 1970s. The form of transmission is through ingestion of feces or contaminated material, and little by little it replicates until it causes digestive signs. It is one of the most aggressive diseases that affect dogs, so it is important to learn to identify it as soon as possible and go to the veterinary clinic.
Symptoms
Parvovirus is highly variable, resulting in anything from an inapparent infection to a fatal disease depending on the puppy's immune status and vaccination. Likewise, the parvo virus has two forms of presentation: enteritis and myocarditis
enteritis is characterized by:
- Profuse diarrhea with presence of mucus and blood
- Fever
- Lethargy
- Anorexy
- Vomiting
- Dehydration and electrolyte imbalances
- Shock and sepsis
Severely affected dogs die in less than 3 days and those that survive the disease develop long-lasting immunity.
myocarditis is rare and has a mortality rate of over 50%. It is characterized by signs of congestive heart failure such as dyspnea, pulmonary edema, and arrhythmias. Puppies are usually found dead.
Diagnosis
It is based on the patient's clinical history in conjunction with typical laboratory tests that do not diagnose the disease, but provide data about the hemodynamic status. The ELISA test is an effective and rapid method of detecting antibodies and the PCR is highly sensitive.
Canine distemper
It is considered the most serious viral disease in dogs. Its etiological agent is the canine distemper virus (CDV) It has been studied in the canidae family (dog, wild dog, Australian dog, fox, coyote, wolf and jackal, among others) and in the mustelidae (weasel, ferret, mink, skunk, badger, stoat, marten and otter, among others). It is a disease of high morbidity and medium mortality, highly contagious and affects puppies under 1 year of age, with a greater presentation in dolichocephalic breeds such as the Greyhound, Siberian Husky, Weimaraner, Samoyed and Alaskan Malamuten, and in mestizo animals.
Transmission is by direct contact with sick animals and inhalation of droplets (droplets expelled through the mouth). A peculiarity of this disease is that the symptoms it produces can be both digestive and neurological.
Symptoms
It is very variable in terms of severity and duration of the disease. Approximately 50% of infected dogs develop subclinical or very mild disease, but can shed virus. The rest develop severe clinical signs with or without nervous involvement:
- Continuous or biphasic fever.
- Respiratory manifestations: serous or mucopurulent rhinitis, interstitial pneumonia and necrotizing bronchiolitis.
- Intestinal manifestations: catarrhal enteritis.
- Skin manifestations: pustular dermatitis located on the thighs, ventral abdomen and on the internal surfaces of the auricle, as well as hardening of the pads.
- Bone manifestations: dental hypoplasia, osteoporosis.
- Manifestations in the central nervous system: due to involvement of the gray matter myoclonus with hyperesthesia and depression predominate; Due to white matter involvement, the signs and symptoms are progressive, such as myoclonus, nystagmus, ataxia, postural deficit and paralysis. In both cases there may be signs of meningitis.
Diagnosis
Being a multisystemic disease, it is necessary to carry out complementary tests such as complete hematology, blood chemistry and analysis of cerebrospinal fluid and confirmatory tests such as direct immunofluorescence, ELISA, PCR or viral isolation.
Canine Rabies
Another of the most common viruses in dogs is the cause of canine rabies. It is an almost always fatal neurological disease of mammals, caused by the rabies virus There is a classification by type: urban, whose predominant reservoir is the dog, and the wild, if the reservoir is other mammals such as the bat, which ends up infecting any mammal it feeds on.
Symptoms
Canine rabies is divided into 3 phases:
- Prodromic: can last from 2 days to weeks and the characteristic symptom is a change in behavior; the animal hides or does not obey and fever and irritability may appear.
- Furiosa: Duration from hours to days. In this phase, the canine exhibits excited behavior, stares, tends to bite moving objects, and exhibits intense drooling.
- Paralytic: Progressive difficulty swallowing, immobility of limbs and general paralysis. Within 1 to 10 days, the dog dies.
Diagnosis
Premortem diagnosis is difficult, especially in early stages and in localities where rabies is not frequent, but the test of choice is immunofluorescence of fresh brain tissue.
Canine infectious tracheobronchitis
Very contagious disease of the upper respiratory tract commonly known as kennel cough, it affects all ages and is very common in dogs that live together. It is caused by a wide variety of pathogens, and one or more may be involved, such as:
- Parainfluenza Virus (PIC)
- Adenovirus type 2 (AVC-2)
- Canine reovirus
- Canine Herpesvirus
- Mycoplasma cynus
- Bordetella bronchiseptica
The parainfluenza virus and the bacteria Bordetella bronchiseptica can act together. The virus infects the epithelium of the respiratory system, so the main sign of this pathology is cough.
Symptoms
This virus in dogs, or group of pathogens, can show the following signs:
- Dry cough and paroxysmal cough that can be emetic
- Conjunctivitis
- Serous nasal discharge
Diagnosis
It is clinical, the problem lies in determining the type of pathogen and in complicated cases or cases of chronic cough it is resorted to performing secretion culturesand antibiograms.
Canine Infectious Hepatitis
Caused by the canine adenovirus type 1, an agent that is highly resistant to environmental conditions and the action of various disinfectants, is another of the most common viral diseases in dogs. It is an extremely contagious pathology that can be fatal, it mainly affects unvaccinated puppies, especially in overcrowded conditions, its mode of transmission being oronasal contact, either with contaminated feces, saliva or urine. Its incubation period is 4 to 7 days and when the signs appear it becomes a veterinary emergency.
Symptoms
The clinical signs that this virus shows in dogs are the following:
- High fever
- Adynamia
- Abdominal pain
- Diarrhea
- Vomiting
- Jaundice
- Cervical and mandibular lymphadenopathy
- Pharyngitis or tonsillitis
In very severe cases, bleeding diathesis, petechiae, ecchymosis and/or coagulopathy are observed.
Canine papillomatosis
Papillomatosis is an infectious disease caused by the canine papillomavirus and is characterized by its affinity for skin cells and of some mucous membranes causing wart-like lesions, which are usually benign. It is transmitted through direct contact with a dog that has lesions or indirectly, through blood or saliva.
Its incubation period is from 4 weeks to 6 months and its appearance depends on the immune status of the patient, so in immunosuppressed dogs (young, old or chronically ill dogs) lesions are quite frequent and they tend to relapse despite treatment, while in immunocompetent patients they may be infected but not present symptoms, behaving as carriers.
The typical lesion is raised, irregular, and may be single or multiple lesions. These lesions tend to coalesce giving a cauliflower-like appearance and can measure from 5 mm to 3 cm. They generally remit in 6 to 12 weeks if treatment and immune status allow, however, they rarely persist and progress to carcinoma.
Symptoms
According to its clinical characteristics, it is divided into: oral and mucocutaneous papillomatosis Oral papillomatosis is the most common form of presentation and warts can appear at any level: gums, hard or soft palate, throat, lips, tongue. The symptoms are:
- Difficulty to swallow
- Bad breath
- Resistance to eating due to difficulty swallowing
- Bleeding, usually due to handling
In mucocutaneous papillomatosis, the lesions appear on the surface of the skin, mainly on the head, eyelids and extremities. These lesions can be firm or soft, pedunculated, some are well defined and others are inverted.
Diagnosis
In addition to the anamnesis, diagnosis is simple through clinical inspection and identification of typical lesions, but it is important to complement it with histopathological diagnosis (biopsy) and thus determine benignity or malignancy.
Treatment
There is no specific treatment, It is symptomatic and will depend on the location of the lesion, the number, its growth, the immune status of the patient and symptomatology. In the case of few lesions and that by clinical evaluation show a course towards regression, treatment is not usually applied, since they are self-limited.
It is difficult to know for sure when to intervene because, as we have explained, the lesions can reappear in the same place or in other places and in greater numbers, and in those cases, there are several treatment options such as excision surgery, cryosurgery or electrosurgery, which should be evaluated only by a veterinarian.
Tick-borne viruses in dogs
There are many viruses that ticks transmit to dogs, however, in this article we will focus on the flavivirus, which are members of the Flaviviridae family and that cause encephalitis.
Tick-Borne Encephalitis Virus (TBEV)
This disease is transmitted directly through the bite of the Ixodes genus, affecting humans and different species of animals such as cattle and canines, and indirectly through the ingestion of contaminated dairy products from sick cattle. The symptoms of this type of virus in dogs occur in two phases:
- First phase: the canine is taken to consultation with a very non-specific flu-like clinical picture, in which symptoms such as fever are observed, myalgias, atralgias and sometimes conjunctivitis.
- Second phase: appears after 4 or 7 days due to central nervous system involvement, causing meningoencephalitis accompanied by headache, uncontrollable vomiting, seizures, neck stiffness, ataxia, sensitivity to light, confusion, and as it progresses, memory loss and paralysis.
Diagnosis
The clinical history of the patient and its systematic evaluation are extremely important. As there is compromise of the central nervous system, additional tests should be performed such as complete hematology, blood chemistryand lumbar puncture indicating hemodynamic compromise and type of causative agent. Likewise, it is necessary to carry out more specific tests such as PCR or ELISA of the cerebrospinal fluid, as well as imaging diagnosis, either by CT or magnetic resonance imaging, of the head, where the degree of brain involvement is evident.
Treatment
Currently, there is no effective antiviral treatment and only supportive measures are carried out. In some cases, immunoglobulins can be used with 60% effectiveness, but the preventive treatment is to avoid tick infestation through hygiene measures.
How to cure viruses in dogs? - Treatment
Treatment in this type of pathology is aimed at improving symptoms, for which rest is recommended, fluid and electrolyte replacement, nonsteroidal anti-inflammatory drugs, antiemetics, probiotics, and antipyretics. There are no specific drugs that directly combat these viral diseases in dogs. Prevention is very effective, since they all have their respective vaccine. Therefore, the best treatment in all cases is prevention.
