Infectious diseases random quiz — Veterinaria Madrid

Question 1/10

14 days ago you prescribed amoxicillin-clavulanate for a dog with a skin infection. The owner did not buy it at the time and now wants to use that prescription at the pharmacy because the dog has lesions again.

Which statement is correct according to European and Spanish regulations?

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A. The prescription is still valid because veterinary prescriptions last three months

Antimicrobial prescriptions have a specific validity period that is much shorter than for other medicines.

B. It can be used if the pharmacist considers the condition to be the same

The pharmacist cannot extend the validity or reassess the clinical case; the indication and duration of treatment are the prescribing veterinarian's responsibility.

C. It has expired: antimicrobial prescriptions are valid for 5 days; the dog must be reassessed and, if appropriate, a new prescription issued and reported to PRESVET

Correct. Regulation (EU) 2019/6 limits the validity of antimicrobial prescriptions to 5 days, and in Spain antibiotic prescriptions, including for companion animals, are reported to PRESVET. A recurrence calls for re-examination and probably culture.

D. It has expired, but you can prescribe the same antibiotic for human use for a month, which is cheaper

When an authorised veterinary medicine exists for the species and indication, a human medicine cannot be used for reasons of price. The quantity prescribed must also match the treatment duration.

lightbulb Key takeaway

Prescribe only the quantity needed for the planned treatment and never prescribe antimicrobials without examining the animal. Exceptional prescribing (the cascade) with human medicines is only justified when no authorised veterinary alternative exists.

References: Reglamento (UE) 2019/6 sobre medicamentos veterinarios · Real Decreto 666/2023

Question 2/10

Litter of six 10-day-old Cocker Spaniel puppies. Two have died within 24 hours after stopping suckling, crying constantly and showing abdominal pain and soft yellow-green faeces. Necropsy reveals petechial haemorrhages in the kidneys, lungs and liver. The dam is healthy.

What is the most important measure for the surviving puppies?

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A. Keep them in a warm environment and prevent hypothermia, with hydration and feeding support

Correct. Canine herpesvirus replicates best at temperatures slightly below adult body temperature; neonates thermoregulate poorly and cannot mount an effective fever. Keeping them warm limits viral replication, although the prognosis for those already ill is poor.

B. Amoxicillin-clavulanate for the whole litter, because it is neonatal bacterial septicaemia

Bacterial septicaemia is a differential, but multiorgan petechiae (especially renal) in puppies under 3 weeks old with a healthy dam are typical of herpesvirus. Antibiotics do not act on the virus.

C. Vaccinate the puppies against herpesvirus immediately

The canine herpesvirus vaccine is authorised for the pregnant bitch so that she passes antibodies in colostrum; it is not used in neonates and does not protect a litter that is already infected.

D. Separate the puppies from the dam and hand-rear them to stop her infecting them

The dam has already been in contact with the litter, and her colostrum and milk provide antibodies. Separating them adds stress and the risk of hypothermia and hypoglycaemia with no clear benefit.

lightbulb Key takeaway

Canine herpesvirus is severe in puppies under 2–3 weeks of age: afterwards, with better thermoregulation, infection is usually mild or inapparent. Survivors may have neurological, cardiac or renal sequelae. Later litters from that bitch are usually protected by the antibodies she has developed.

Question 3/10

The owner of a country dog in Extremadura has been diagnosed with Mediterranean spotted fever (fever, rash and a black eschar, the 'tache noire'). The dog is healthy but often has ticks.

What do you explain to her?

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A. The dog infected her directly through saliva or licking

Rickettsia conorii is not transmitted directly from dogs to people; it is transmitted by a tick bite.

B. The dog must be euthanased or rehomed to prevent further cases

It is disproportionate and does not remove the risk: the ticks are in the environment. What works is tick control.

C. It is transmitted by the bite of Rhipicephalus sanguineus; the dog does not pass it on directly, but brings ticks home: continuous acaricide and remove ticks with gloves, without crushing them

Correct. The dog acts as a host for the tick and as a sentinel (it is usually seropositive and asymptomatic). Crushing ticks with the fingers can inoculate the organism through the skin or conjunctiva.

D. The dog should be treated with doxycycline, even though healthy, so the owner is not reinfected

Treating the dog does not remove the organism from the ticks, which pass it on to their offspring. Risk depends on tick exposure, not on the dog's status.

lightbulb Key takeaway

Mediterranean spotted fever is common in the Mediterranean summer, and Rhipicephalus sanguineus can complete its life cycle indoors. In dogs infection is usually subclinical, although cases with fever and thrombocytopenia have been described. A long-acting acaricide protects both the dog and the family.

Question 4/10

5-year-old Labrador with a fever of 39.9–40.4 °C for 10 days, lethargy and reduced appetite. It has received amoxicillin-clavulanate for 7 days without improvement. Physical examination shows no clear focus and the haemogram only reveals mild neutrophilia.

What is the most appropriate approach?

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A. Switch to a fluoroquinolone and add meloxicam to control the fever

Chaining antibiotics without a diagnosis delays finding the real cause and renders cultures negative, and the antipyretic erases the temperature curve you need to assess response. The NSAID also prevents safe use of steroids later if they become necessary.

B. Anti-inflammatory prednisolone as a therapeutic trial, in case it is immune-mediated

Steroids given before infection is ruled out can worsen an infection (leishmaniosis, discospondylitis, abscesses) and mask lymphoma. They are only used once an immune-mediated cause has been confirmed or reasonably demonstrated.

C. Withdraw drugs where possible and follow a stepwise protocol: history, repeated examination, bloods with urinalysis and urine culture, vector-borne serology or PCR and imaging; then arthrocentesis, blood cultures or aspirates as indicated

Correct. Fever of unknown origin is solved with a systematic approach: ask about travel and ticks, palpate joints, spine, lymph nodes and prostate, examine the fundus, and progress from general to specific tests. Multi-joint arthrocentesis is key even without lameness.

D. Echocardiography first, because endocarditis is the most common cause of fever of unknown origin

Endocarditis is a possible cause, but not the most common. In dogs, immune-mediated diseases (polyarthritis, steroid-responsive meningitis-arteritis), infections and neoplasia predominate; echocardiography is indicated if there is a new murmur or positive blood cultures.

lightbulb Key takeaway

Immune-mediated causes are among the most common causes of fever of unknown origin in dogs, and in Spain leishmaniosis and tick-borne diseases must always be included. Moderate fever is a defence and a useful marker: do not suppress it routinely; reserve antipyretics for very high temperatures or very sick animals.

Question 5/10

6-year-old male cat, rescued from the street 4 years ago and neutered, clinically healthy. A check-up confirms FIV infection. The owner asks how long he has left.

Which statement is correct?

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A. Many healthy FIV-positive cats live as long as negative cats; they need six-monthly check-ups and prompt attention to any sign, and the diagnosis alone does not justify euthanasia

Correct. The asymptomatic phase usually lasts years. Studies show that FIV infection, in well-cared-for cats, often does not substantially shorten life.

B. He will almost certainly develop the immunodeficiency syndrome within 1–2 years

Progression is highly variable and slow; many cats never reach the terminal phase and die of causes unrelated to FIV.

C. He needs continuous prophylactic antibiotics to prevent infections

It is not indicated: it promotes resistance and adverse effects. Infections are treated promptly and fully when they occur.

D. He must never be vaccinated, because any vaccine will accelerate the disease

He is vaccinated according to his actual exposure risk. The effect of immune stimulation on viral load is largely theoretical; an outdoor cat should be protected.

lightbulb Key takeaway

In FIV-positive cats, watch especially for gingivostomatitis, weight loss, recurrent infections and lymphoma. Weigh at every visit, examine the mouth and lymph nodes carefully, and keep the cat neutered and preferably indoors so it does not infect other cats.

Question 6/10

In a cattery, a healthy queen gave birth 10 days ago. The breeder and an assistant, who attended the birth without gloves or mask and cleaned up the placental remains, now have high fever, severe headache and atypical pneumonia.

Which zoonosis is most likely?

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A. Bartonellosis transmitted through the placenta

Bartonella henselae reaches people through scratches or bites contaminated with flea faeces, not through birth fluids, and it does not usually cause pneumonia.

B. Toxoplasmosis from contact with birth fluids

People are infected mainly by sporulated oocysts from faeces or by undercooked meat, not by birth fluids. Moreover, the picture does not fit atypical pneumonia in two people at once.

C. Q fever due to Coxiella burnetii, which is shed in large numbers with the placenta and birth fluids and is transmitted by inhalation

Correct. Cats are usually infected without signs, but at parturition they shed many organisms that are highly resistant in the environment. Human outbreaks have been described after attending queens' births.

D. Leptospirosis from contact with the queen's urine

Clinical leptospirosis in cats is rare and is not linked to parturition. The timing after handling the placenta points to Coxiella.

lightbulb Key takeaway

Ruminants are the main source of Q fever, but dogs and cats can also transmit it at parturition. Attend births wearing gloves and, if there is a lot of material, a mask; dispose of placentas safely. Pregnant women and immunocompromised people should avoid attending births.

Question 7/10

6-year-old cat that hunts birds, with 3 days of diarrhoea after eating a goldfinch in midwinter. It is alert, eating, has a temperature of 38.6 °C and no relevant dehydration. Faecal culture isolates Salmonella spp.

What is the most appropriate management?

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A. Enrofloxacin for 10 days to eliminate Salmonella

In uncomplicated enteritis antibiotics do not shorten the illness and may prolong shedding and select for resistance. In addition, high-dose enrofloxacin can cause blindness in cats.

B. Hospitalise in strict isolation with intravenous antibiotics

An alert, eating, afebrile cat needs neither hospitalisation nor intravenous antibiotics. They are reserved for systemic signs or sepsis.

C. Repeat faecal cultures until negative before allowing contact with the family

Shedding is intermittent and can last for weeks, so negative cultures guarantee nothing. Hygiene is the practical approach.

D. Supportive care without antibiotics, strict litter tray hygiene and handwashing, with antibiotics guided by susceptibility testing only if systemic signs develop

Correct. Most uncomplicated gastrointestinal salmonellosis resolves with supportive care. Antibiotics are reserved for fever, sepsis, young kittens or immunocompromised patients.

lightbulb Key takeaway

In winter, salmonellosis outbreaks occur in garden feeder birds, and cats that hunt them can become ill ('songbird fever'). Recommend keeping the cat indoors while it recovers, using gloves to clean the litter tray and taking extra care if vulnerable people live in the home.

Question 8/10

At a breeder with no vaccination programme, a young, never-vaccinated bitch has a litter of 7 puppies. At 6 weeks, three die suddenly after a brief episode of dyspnoea, with no vomiting or diarrhoea. Necropsy shows cardiac dilation with pale streaks in the myocardium.

Which statement about this condition is correct?

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A. It is the typical form of parvovirus in vaccinated puppies over 4 months of age

The cardiac form only appears when infection occurs in utero or in the first weeks of life without maternal antibodies. In older puppies the typical form is enteric.

B. The most likely cause is canine herpesvirus, which causes myocardial necrosis

Canine herpesvirus mainly kills puppies under 3 weeks of age, with multiorgan petechial haemorrhages (kidney, lung, liver), not myocarditis at 6 weeks.

C. It is parvoviral myocarditis: the virus replicates in cardiomyocytes, which are still dividing in the first weeks of life

Correct. Parvovirus needs dividing cells. In puppies infected before ~8 weeks without maternal antibodies, it replicates in the myocardium and causes sudden death or heart failure weeks or months later.

D. The surviving littermates will be protected for life and do not need vaccinating

You cannot know which puppies were infected; some survivors may develop heart failure later and uninfected ones remain susceptible. They must be vaccinated and monitored.

lightbulb Key takeaway

Parvoviral myocarditis is rare today because almost all bitches have antibodies (from vaccination or infection) that protect the litter in its first weeks. If it reappears, suspect unvaccinated dams in breeding or group settings: vaccinating the bitch before mating is the prevention.

Question 9/10

1-year-old domestic shorthair female, taken in from the street 2 weeks ago, healthy on examination. The in-house rapid test is FeLV antigen positive and FIV antibody negative. Another healthy adult cat, vaccinated against FeLV, lives in the home.

What is the most appropriate approach?

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A. Separate her from the other cat, confirm the result with another method and repeat the antigen test about 6 weeks later; only if still positive at 16 weeks is it considered progressive infection

Correct. After recent exposure, antigenaemia may be transient: many cats contain the viraemia and become regressively infected. In the meantime, separation protects the other cat, as vaccination does not give complete protection.

B. Recommend euthanasia to protect the resident cat

A single positive result in a healthy cat does not establish the prognosis, and even with progressive infection the cat may live for years with a good quality of life.

C. Regard her as progressively infected without further tests, and let them mix freely because the other cat is vaccinated

A single test cannot distinguish transient antigenaemia from progressive infection, and false positives can occur in low-prevalence populations. Moreover, vaccination does not guarantee protection for the in-contact cat.

D. Vaccinate her against FeLV to help her clear the virus

The vaccine has no therapeutic effect in an already infected cat and does not change the course of antigenaemia.

lightbulb Key takeaway

With a positive FeLV antigen in a healthy cat, confirm and retest before giving a prognosis: provirus PCR helps classify the infection. Test every cat before introducing it into a multi-cat home and keep it separate until results are available.

Question 10/10

Distemper is confirmed in a rescue shelter in a puppy that arrived 10 days ago with oculonasal discharge. It shares a building with 15 other dogs of variable vaccination status. The manager asks what to do.

Which statement is correct?

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A. The virus survives for months in the environment like parvovirus, so the priority is disinfecting with bleach for weeks

Distemper virus is enveloped and labile outside the host: it survives hours at room temperature (somewhat longer in the cold) and common disinfectants inactivate it. Cleaning is needed, but it is not the priority.

B. It is spread mainly by aerosols and direct contact; sick dogs must be isolated and contacts vaccinated as soon as possible with a modified-live vaccine

Correct. Spread is via respiratory secretions and close contact. Dogs shed virus from a few days before signs appear and for weeks or months afterwards. Modified-live vaccine induces very rapid protection in dogs without maternal antibodies.

C. Dogs are only contagious while febrile; once respiratory signs resolve they can return to the shared building

Shedding starts before signs and may continue for weeks or months after apparent recovery (up to around 3 months has been described), so improvement alone is not enough.

D. Transmission is faecal-oral, so removing faeces and separating food bowls is enough

Although the virus is shed in several secretions, the main route is respiratory (droplets and aerosols). Focusing only on faeces leaves the most important route uncontrolled.

lightbulb Key takeaway

In distemper, control relies on isolating sick dogs, vaccinating every dog on intake (with modified-live vaccine from 4–6 weeks of age in shelters) and not mixing animals of unknown status. Remember the wildlife reservoirs (foxes, wolves, mustelids): the virus still circulates in Spain and unvaccinated dogs remain at risk.