Pseća je herpesviroza globalno prisutna virusna zarazna bolest prouzročena psećim herpesvirusom 1 (Canid alphaherpesvirus-1; CHV). Infekcija ovim virusom ima dvije faze: litičku i latentnu. Sam ishod infekcije uvelike ovisi o dobi i razvijenosti imunološkog sustava psa. Najznačajnija patološka posljedica pseće herpesviroze je liza endotelnih stanica i epitelnih stanica više organskih sustava koja se pojavljuje u imunodeficijentnih štenaca. Zbog pantropizma CHV-a, posljedica infekcije je nekrohemoragična upala mnogobrojnih organa zbog koje štenci nerijetko i ugibaju. U imunokompetentnih starijih pasa, iako često asimptomatska, litička infekcija može biti i smrtonosna. Klinički simptomi uključuju infekcije dišnog i spolnog sustava i očiju. Najčešće prisutna lezija očiju je konjunktivitis, ali mogu se pojaviti i ulceracije, petehijalna krvarenja i eksudativni blefaritis s krustama i alopecijom. Utjecaj CHV-a na respiratorni sustav rezultira blagim rinitisom, faringitisom i traheobronhitisom, iznimno pneumonijom. CHV se često povezuje i sa zaraznim traheobronhitisom u pasa, tzv. ‘’kašaljem štenare’’. Infekcija spolnog sustava ograničena je na hiperemiju vagine ili prepucija s hiperplastičnim limfoidnim folikulima te papulovezikularnim lezijama, ali se smatra najvažnijim izvorom infekcije za štenad pri porođaju. Prestankom kliničkih simptoma CHV prelazi u fazu latencije u živčanim ganglijima te se na taj način trajno zadržava u domaćinu. Prilikom stresa i imunosupresije latentni se CHV virus može reaktivirati i uspostaviti litičku fazu. Time se virus ponovno počinje replicirati i izlučivati, a oboljeli pas se mora isključiti iz uzgoja jer predstavlja izvor daljnjeg širenja virusa. Ipak, primjenom cjepiva u gravidnih kuja moguće je zaštititi novorođenu štenad te spriječiti teške posljedice herpesviroze u pasa.
Canine alphaherpesvirus-1 (CHV) is a globally present virus causing infectious disease in dogs. The outcome of CHV infection depends significantly on the age and immune system development of the dog and occurs in two phases: lytic and latent. Due to the pantropism of CHV, lysis occurs in the endothelium and epithelium of various organ systems, causing necrohaemorrhagic inflammation and frequently death in immunodeficient puppies. Lytic infection produces reduced or silent symptoms in older, immunocompetent dogs, although it can occasionally be fatal. Clinical signs of infection appear in the ocular, reproductive, and respiratory systems. The most typical eye lesion is conjunctivitis, though other conditions such as ulcers, petechial haemorrhages, exudative blepharitis with crusts, and alopecia can also occur. When CHV affects the respiratory system, it can cause mild rhinitis, pharyngitis, and tracheobronchitis, as well as severe pneumonia. The virus is also frequently linked to infectious tracheobronchitis in dogs, or “kennel cough.” Although infection of the reproductive system is restricted to hyperaemia of the vagina or prepuce with hyperplastic lymphoid follicles and papulovesicular lesions, it is thought to be the most significant source of infection for puppies after birth. After the onset of clinical symptoms, CHV enters the latency phase in the nerve ganglia, where it remains in the host indefinitely. During times of stress and immunosuppression in dogs, the latent CHV virus can occasionally reactivate and establisha lytic phase, at which point it resumes replication and shedding. These CHV latency effects are a significant problem since the affected dog is permanently infected, cannot be bred, and is always a source of possible virus outbreak. Although death ensuing from CHV infection is the worst conceivable consequence, immunisation of pregnant females can protect newborn puppies and breeders from this outcome.